Sample records for jet thrust vector

  1. Characteristics of a confined jet thrust vector control nozzle

    NASA Astrophysics Data System (ADS)

    Porzio, A. J.

    1984-12-01

    A study of confined jet thrust vector control (CJTVC) is presented. By isolating an area of flow separation within the body of a nozzle, CJTVC has the advantage over other thrust vector controls using secondary injection (SI) in that it can operate independent of altitude. This makes it ideal for applications in small missiles and spacecraft attitude control. In this study, axial thrust, side force, and pressure distribution across the nozzle were measured. The parameters were SI pressure, primary short supply pressure, and SI port area. Results indicate that there is a lower limit to the supply pressure ratio (SI pressure to primary pressure) and SI mass flow below which, the nozzle will not produce side force. Also, above a primary pressure of 200 psig, the undeflected jet exhibits instabilities. Without SI, a 4 Hz oscillation occurs in the nozzle and switching jet attachment occurs near the throat.

  2. Two-dimensional confined jet thrust vector control: Operating mechanisms and performance

    NASA Astrophysics Data System (ADS)

    Caton, Jeffrey L.

    1989-03-01

    An experimental investigation of two-dimensional confined jet thrust vector control nozzles was performed. Thrust vector control was accomplished by using secondary flow injection in the diverging section of the nozzle. Schlieren photographs and video tapes were used to study flow separation and internal shock structures. Nozzle performance parameters were determined for nozzle flow with and without secondary flows. These parameters included nozzles forces, vector angles, thrust efficiencies, and flow switching response times. Vector angles as great as 18 degrees with thrust efficiencies of 0.79 were measured. Several confined jet nozzles with variations in secondary flow port design were tested and results were compared to each other. Converging-diverging nozzles of similar design to the confined jet nozzles were also tested and results were compared to the confined jet nozzle results. Existing prediction models for nozzle side to axial force ratio were evaluated. A model for nozzle total forces based on shock losses that predicted values very close to actual results was developed.

  3. Thrust-Vector Deflectors For Spacecraft

    NASA Technical Reports Server (NTRS)

    Soong, William C.

    1990-01-01

    Rotating shield steers thrust in desired direction. Report discusses use of thrust-vector deflectors (TVD's) to enhance controllability and reduce number of small rocket engines (thrustors) needed to control attitudes of artificial satellites. Developed in aircraft industry for use in jet engines. Principal advantages gained, lower cost and greater simplicity.

  4. Design and evaluation of thrust vectored nozzles using a multicomponent thrust stand

    NASA Technical Reports Server (NTRS)

    Carpenter, Thomas W.; Blattner, Ernest W.; Stagner, Robert E.; Contreras, Juanita; Lencioni, Dennis; Mcintosh, Greg

    1990-01-01

    Future aircraft with the capability of short takeoff and landing, and improved maneuverability especially in the post-stall flight regime will incorporate exhaust nozzles which can be thrust vectored. In order to conduct thrust vector research in the Mechanical Engineering Department at Cal Poly, a program was planned with two objectives; design and construct a multicomponent thrust stand for the specific purpose of measuring nozzle thrust vectors; and to provide quality low moisture air to the thrust stand for cold flow nozzle tests. The design and fabrication of the six-component thrust stand was completed. Detailed evaluation tests of the thrust stand will continue upon the receipt of one signal conditioning option (-702) for the Fluke Data Acquisition System. Preliminary design of thrust nozzles with air supply plenums were completed. The air supply was analyzed with regard to head loss. Initial flow visualization tests were conducted using dual water jets.

  5. Thrust Vectoring Flow Control Using Plasma Actuators

    NASA Astrophysics Data System (ADS)

    Jacob, Jamey; Bolitho, Michael

    2007-11-01

    Thrust vectoring flow control is demonstrated using plasma synthetic jet actuators (PSJA). The PSJA is a geometric variant of a plasma actuator, consisting of a symmetric electrode array that results in a circular region of dielectric barrier discharge plasma. Quiescent flow PIV measurements of the PSJA reveal that the flowfield on actuation resembles that of a zero-mass flux or synthetic jet that is useful for flow control, particularly separation reduction. Like synthetic jets, unsteady pulsed actuator operation results in formation of multiple vortex rings. The output jet momentum is found to be affected by the power input, actuator dimension and pulsing frequency. While increasing the input power increases the maximum jet velocity, an optimum range of pulsing frequencies and actuator dimensions are observed to exist in order to maximize jet momentum. By asymmetrically varying the plasma input parameters, such as frequency, amplitude and duty cycle, it is possible to control the jet angle. Vectoring using high frequency pusling akin to synthetic jets is more effective than vectoring by modifying steady control inputs and differences in control effectiveness are due primarily to the time scales associated with the vortex formation.

  6. Aerodynamics of thrust vectoring by Navier-Stokes solutions

    NASA Technical Reports Server (NTRS)

    Tseng, Jing-Biau; Lan, C. Edward

    1991-01-01

    Induced aerodynamics from thrust vectoring are investigated by a computational fluid dynamic method. A thin-layer Reynolds-averaged Navier-Stokes code with multiblock capability is used. Jet properties are specified on the nozzle exit plane to simulate the jet momentum. Results for a rectangular jet in a cross flow are compared with data to verify the code. Further verification of the calculation is made by comparing the numerical results with transonic data for a wing-body combination. Additional calculations were performed to elucidate the following thrust vectoring effects: the thrust vectoring effect on shock and expansion waves, induced effects on nearby surfaces, and the thrust vectoring effect on the leading edge vortex.

  7. Analysis of stratified and closely spaced jets exhausting into a crossflow. [aerodynamic characteristics of lift-jet, vectored thrust, and lift fan V/STOL aircraft

    NASA Technical Reports Server (NTRS)

    Ziegler, H.; Woller, P. T.

    1973-01-01

    Procedures have been developed for determining the flow field about jets with velocity stratification exhausting into a crossflow. Jets with three different types of exit velocity stratification have been considered: (1) jets with a relatively high velocity core; (2) jets with a relatively low velocity core; and (3) jets originating from a vaned nozzle. The procedure developed for a jet originating from a high velocity core nozzle is to construct an equivalent nozzle having the same mass flow and thrust but having a uniform exit velocity profile. Calculations of the jet centerline and induced surface static pressures have been shown to be in good agreement with test data for a high velocity core nozzle. The equivalent ideal nozzle has also been shown to be a good representation for jets with a relatively low velocity core and for jets originating from a vaned nozzle in evaluating jet-induced flow fields. For the singular case of a low velocity core nozzle, namely a nozzle with a dead air core, and for the vaned nozzle, an alternative procedure has been developed. The internal mixing which takes place in the jet core has been properly accounted for in the equations of motion governing the jet development. Calculations of jet centerlines and induced surface static pressures show good agreement with test data these nozzles.

  8. A flight evaluation of a vectored thrust jet V/STOL airplane during simulated instrument approaches using the Kestrel (XV-6A) airplane

    NASA Technical Reports Server (NTRS)

    Morello, S. A.; Person, L. H., Jr.; Shanks, R. E.; Culpepper, R. G.

    1972-01-01

    An in-flight investigation was made to determine the terminal-area operating problems of a vectored-thrust-jet vertical and short take-off landing (V/STOL) airplane under simulated instrument conditions. Handling-qualities data pertinent to the terminal-area approach and landing task are presented in the text, and additional documentation is included in the appendixes. Problems dealing with the cruise letdown to localizer capture, conversion to powered-lift flight, precise control of the glide slope, approach velocity or deceleration schedule, hover, and landing are discussed.

  9. Thrust vector control using electric actuation

    Microsoft Academic Search

    Robert T. Bechtel; David K. Hall

    1995-01-01

    Presently, gimbaling of launch vehicle engines for thrust vector control is generally accomplished using a hydraulic system. In the case of the space shuttle solid rocket boosters and main engines, these systems are powered by hydrazine auxiliary power units. Use of electromechanical actuators would provide significant advantages in cost and maintenance. However, present energy source technologies such as batteries are

  10. Electromechanical actuation for thrust vector control applications

    Microsoft Academic Search

    Mary Ellen Roth

    1990-01-01

    At present, actuation systems for the Thrust Vector Control (TVC) for launch vehicles are hydraulic systems. The Advanced Launch System (ALS), a joint initiative between NASA and the Air Force, is a launch vehicle that is designed to be cost effective, highly reliable and operationally efficient with a goal of reducing the cost per pound to orbit. As part of

  11. Jet-Engine Exhaust Nozzle With Thrust-Directing Flaps

    NASA Technical Reports Server (NTRS)

    Wing, David J.

    1996-01-01

    Convergent/divergent jet-engine exhaust nozzle has cruciform divergent passage containing flaps that move to deflect flow of exhaust in either or both planes perpendicular to main fore-and-aft axis of undeflected flow. Prototype of thrust-vector-control nozzles installed in advanced, high-performance airplanes to provide large pitching (usually, vertical) and yawing (usually, horizontal) attitude-control forces independent of attitude-control forces produced by usual aerodynamic control surfaces.

  12. Test apparatus for measuring jet engine thrust

    Microsoft Academic Search

    Laskody

    1988-01-01

    This patent describes an apparatus for simultaneously measuring variables to calculate total thrust generated from a turbofan jet engine having a lengthwise axis and which is characterized by (1) a section for generating drive gases, (2) a fan section which rotates about the lengthwise axis in response to the drive gases and which includes (i) exterior blades which rotate with

  13. Computational Study of Fluidic Thrust Vectoring using Separation Control in a Nozzle

    NASA Technical Reports Server (NTRS)

    Deere, Karen; Berrier, Bobby L.; Flamm, Jeffrey D.; Johnson, Stuart K.

    2003-01-01

    A computational investigation of a two- dimensional nozzle was completed to assess the use of fluidic injection to manipulate flow separation and cause thrust vectoring of the primary jet thrust. The nozzle was designed with a recessed cavity to enhance the throat shifting method of fluidic thrust vectoring. The structured-grid, computational fluid dynamics code PAB3D was used to guide the design and analyze over 60 configurations. Nozzle design variables included cavity convergence angle, cavity length, fluidic injection angle, upstream minimum height, aft deck angle, and aft deck shape. All simulations were computed with a static freestream Mach number of 0.05. a nozzle pressure ratio of 3.858, and a fluidic injection flow rate equal to 6 percent of the primary flow rate. Results indicate that the recessed cavity enhances the throat shifting method of fluidic thrust vectoring and allows for greater thrust-vector angles without compromising thrust efficiency.

  14. Electromechanical actuator for thrust vector control

    NASA Astrophysics Data System (ADS)

    Zubkow, Zygmunt

    Attention is given to the development and testing of electromechanical actuator (EMA) systems for use in first- and second-stage thrust vector control of rocket engines. An overview of the test program is also presented. Designs for both first- and second-stage actuators employ redundant dc brushless, three-phase rare-earth permanent magnet motors. The first-stage actuator is about 28 hp per motor and uses a roller screw. Second-stage thrust vector control is implemented with a much smaller actuator of about 1 hp per motor. This actuator uses a gear drive with a recycling ball screw mechanism. An operational EMA is presented. This 6.5-in. actuator is capable of a stall force of 1350 pounds per motor and a frequency response of about 5 HZ.

  15. A review of thrust-vectoring schemes for fighter applications

    NASA Technical Reports Server (NTRS)

    Berrier, B. L.; Re, R. J.

    1978-01-01

    This paper presents a review of thrust vectoring schemes for advanced fighter applications. Results are presented from wind tunnel and system integration studies on thrust vectoring nozzle concepts. Vectoring data are presented from wind tunnel tests of axisymmetric C-D (convergent-divergent) and nonaxisymmetric wedge, C-D, single ramp and USB (upper-surface blowing) nozzle concepts. Results from recent airframe/nozzle integration studies on the impact of thrust vectoring on weight, cooling and performance characteristics are discussed. This review indicates that the aircraft designer has, at his disposal, a wide range of thrust vectoring schemes which offer potential for added or improved aircraft capability.

  16. Hot gas thrust vector control motor

    NASA Astrophysics Data System (ADS)

    Berdoyes, Michel; Ellis, Russell A.

    1992-07-01

    A hot gas thrust vector control (HGTVC) motor developed in the framework of a Foreign Weapon Evaluation program is discussed. Two HGTVC versions were evaluated on the two nozzles of the program, normal injection with a blunt pintle and 10 deg upstream injection with a tapered pintle. The HGTVC system was tested on a modified ORBUS-1 motor which is based on two technologies, namely, a composite chamber polar boss (CPB) and a two-piece C-C nozzle which threads to the CPB and receives two HGVs embedded into its exit cone, 180 deg apart. It is concluded that the composite polar bosses and C-C nozzles performed successfully in both firings.

  17. A Computational Study of a New Dual Throat Fluidic Thrust Vectoring Nozzle Concept

    NASA Technical Reports Server (NTRS)

    Deere, Karen A.; Berrier, Bobby L.; Flamm, Jeffrey D.; Johnson, Stuart K.

    2005-01-01

    A computational investigation of a two-dimensional nozzle was completed to assess the use of fluidic injection to manipulate flow separation and cause thrust vectoring of the primary jet thrust. The nozzle was designed with a recessed cavity to enhance the throat shifting method of fluidic thrust vectoring. Several design cycles with the structured-grid, computational fluid dynamics code PAB3D and with experiments in the NASA Langley Research Center Jet Exit Test Facility have been completed to guide the nozzle design and analyze performance. This paper presents computational results on potential design improvements for best experimental configuration tested to date. Nozzle design variables included cavity divergence angle, cavity convergence angle and upstream throat height. Pulsed fluidic injection was also investigated for its ability to decrease mass flow requirements. Internal nozzle performance (wind-off conditions) and thrust vector angles were computed for several configurations over a range of nozzle pressure ratios from 2 to 7, with the fluidic injection flow rate equal to 3 percent of the primary flow rate. Computational results indicate that increasing cavity divergence angle beyond 10 is detrimental to thrust vectoring efficiency, while increasing cavity convergence angle from 20 to 30 improves thrust vectoring efficiency at nozzle pressure ratios greater than 2, albeit at the expense of discharge coefficient. Pulsed injection was no more efficient than steady injection for the Dual Throat Nozzle concept.

  18. Reduced-length scarfed-nozzles for thrust vector adjustment

    Microsoft Academic Search

    Jay S. Lilley

    1993-01-01

    The results of an investigation into the utilization of scarfed, truncated perfect-nozzles for thrust vector adjustment in tactical strap-on boosters is presented. The use of truncated perfect-nozzle expansion contours was evaluated as a means of achieving significant nozzle length reductions over conical nozzle designs without degrading axial thrust or thrust vector adjustment capability. Previously developed perfect-nozzle and scarfed-nozzle performance analysis

  19. Static performance investigation of a skewed-throat multiaxis thrust-vectoring nozzle concept

    NASA Technical Reports Server (NTRS)

    Wing, David J.

    1994-01-01

    The static performance of a jet exhaust nozzle which achieves multiaxis thrust vectoring by physically skewing the geometric throat has been characterized in the static test facility of the 16-Foot Transonic Tunnel at NASA Langley Research Center. The nozzle has an asymmetric internal geometry defined by four surfaces: a convergent-divergent upper surface with its ridge perpendicular to the nozzle centerline, a convergent-divergent lower surface with its ridge skewed relative to the nozzle centerline, an outwardly deflected sidewall, and a straight sidewall. The primary goal of the concept is to provide efficient yaw thrust vectoring by forcing the sonic plane (nozzle throat) to form at a yaw angle defined by the skewed ridge of the lower surface contour. A secondary goal is to provide multiaxis thrust vectoring by combining the skewed-throat yaw-vectoring concept with upper and lower pitch flap deflections. The geometric parameters varied in this investigation included lower surface ridge skew angle, nozzle expansion ratio (divergence angle), aspect ratio, pitch flap deflection angle, and sidewall deflection angle. Nozzle pressure ratio was varied from 2 to a high of 11.5 for some configurations. The results of the investigation indicate that efficient, substantial multiaxis thrust vectoring was achieved by the skewed-throat nozzle concept. However, certain control surface deflections destabilized the internal flow field, which resulted in substantial shifts in the position and orientation of the sonic plane and had an adverse effect on thrust-vectoring and weight flow characteristics. By increasing the expansion ratio, the location of the sonic plane was stabilized. The asymmetric design resulted in interdependent pitch and yaw thrust vectoring as well as nonzero thrust-vector angles with undeflected control surfaces. By skewing the ridges of both the upper and lower surface contours, the interdependency between pitch and yaw thrust vectoring may be eliminated and the location of the sonic plane may be further stabilized.

  20. Forebody vortex control as a complement to thrust vectoring

    NASA Technical Reports Server (NTRS)

    Malcolm, G. N.; Ng, T. T.

    1990-01-01

    The desire to enhance the controllability of fighter aircraft at high angles of attack, particularly yaw control, has fostered an interest in both vectored thrust and active control of forebody vortices. This paper reviews several methods of forebody vortex control that have been investigated with water and wind tunnel tests of both generic and actual fighter configurations. The methods investigated include pneumatic or blowing techniques using surface-mounted jets and slots, surface suction, variable-height deployable strakes, and rotatable tip strakes. Flow visualization, and force and moment measurements have shown that all of the methods are effective in manipulating the forebody vortices over a wide range of angles of attack and sideslip, primarily through control over flow separation on the surface of the forebody. All are most effective when applied near the forebody tip. The advantages and limitations of the various methods are reviewed.

  1. Static performance of a cruciform nozzle with multiaxis thrust-vectoring and reverse-thrust capabilities

    NASA Technical Reports Server (NTRS)

    Wing, David J.; Asbury, Scott C.

    1992-01-01

    A multiaxis thrust vectoring nozzle designed to have equal flow turning capability in pitch and yaw was conceived and experimentally tested for internal, static performance. The cruciform-shaped convergent-divergent nozzle turned the flow for thrust vectoring by deflecting the divergent surfaces of the nozzle, called flaps. Methods for eliminating physical interference between pitch and yaw flaps at the larger multiaxis deflection angles was studied. These methods included restricting the pitch flaps from the path of the yaw flaps and shifting the flow path at the throat off the nozzle centerline to permit larger pitch-flap deflections without interfering with the operation of the yaw flaps. Two flap widths were tested at both dry and afterburning settings. Vertical and reverse thrust configurations at dry power were also tested. Comparison with two dimensional convergent-divergent nozzles showed lower but still competitive thrust performance and thrust vectoring capability.

  2. Design Enhancements of the Two-Dimensional, Dual Throat Fluidic Thrust Vectoring Nozzle Concept

    NASA Technical Reports Server (NTRS)

    Flamm, Jeffrey D.; Deere, Karen A.; Mason, Mary L.; Berrier, Bobby L.; Johnson, Stuart K.

    2006-01-01

    A Dual Throat Nozzle fluidic thrust vectoring technique that achieves higher thrust-vectoring efficiencies than other fluidic techniques, without sacrificing thrust efficiency has been developed at NASA Langley Research Center. The nozzle concept was designed with the aid of the structured-grid, Reynolds-averaged Navier-Stokes computational fluidic dynamics code PAB3D. This new concept combines the thrust efficiency of sonic-plane skewing with increased thrust-vectoring efficiencies obtained by maximizing pressure differentials in a separated cavity located downstream of the nozzle throat. By injecting secondary flow asymmetrically at the upstream minimum area, a new aerodynamic minimum area is formed downstream of the geometric minimum and the sonic line is skewed, thus vectoring the exhaust flow. The nozzle was tested in the NASA Langley Research Center Jet Exit Test Facility. Internal nozzle performance characteristics were defined for nozzle pressure ratios up to 10, with a range of secondary injection flow rates up to 10 percent of the primary flow rate. Most of the data included in this paper shows the effect of secondary injection rate at a nozzle pressure ratio of 4. The effects of modifying cavity divergence angle, convergence angle and cavity shape on internal nozzle performance were investigated, as were effects of injection geometry, hole or slot. In agreement with computationally predicted data, experimental data verified that decreasing cavity divergence angle had a negative impact and increasing cavity convergence angle had a positive impact on thrust vector angle and thrust efficiency. A curved cavity apex provided improved thrust ratios at some injection rates. However, overall nozzle performance suffered with no secondary injection. Injection holes were more efficient than the injection slot over the range of injection rates, but the slot generated larger thrust vector angles for injection rates less than 4 percent of the primary flow rate.

  3. Aircraft ground test and subscale model results of axial thrust loss caused by thrust vectoring using turning vanes

    NASA Technical Reports Server (NTRS)

    Johnson, Steven A.

    1992-01-01

    The NASA-Dryden F/A-18 high alpha research vehicle was modified to incorporate three independently controlled turning vanes located aft of the primary nozzle of each engine to vector thrust for pitch and yaw control. Ground measured axial thrust losses were compared with the results from a 14.25 pct. cold jet model for single and dual vanes inserted up to 25 degs into the engine exhaust. Data are presented for nozzle pressure ratios of 2.0 and 3.0 and nozzle exit areas of 253 and 348 sq in. The results indicate that subscale nozzle test results properly predict trends but underpredict the full scale results by approx. 1 to 4.5 pct. in thrust loss.

  4. Electromechanical actuation for thrust vector control applications

    NASA Astrophysics Data System (ADS)

    Roth, Mary Ellen

    At present, actuation systems for the Thrust Vector Control (TVC) for launch vehicles are hydraulic systems. The Advanced Launch System (ALS), a joint initiative between NASA and the Air Force, is a launch vehicle that is designed to be cost effective, highly reliable and operationally efficient with a goal of reducing the cost per pound to orbit. As part of this initiative, an electromechanical actuation system is being developed as an attractive alternative to the hydraulic systems used today. NASA-Lewis is developing and demonstrating an Induction Motor Controller Actuation System with a 40 hp peak rating. The controller will integrate 20 kHz resonant link Power Management and Distribution (PMAD) technology and Pulse Population Modulation (PPM) techniques to implement Field Oriented Vector Control (FOVC) of a new advanced induction motor. Through PPM, multiphase variable frequency, variable voltage waveforms can be synthesized from the 20 kHz source. FOVC shows that varying both the voltage and frequency and their ratio (V/F), permits independent control of both torque and speed while operating at maximum efficiency at any point on the torque-speed curve. The driver and the FOVC will be microprocessor controlled. For increased system reliability, a Built-in Test (BITE) capability will be included. This involves introducing testability into the design of a system such that testing is calibrated and exercised during the design, manufacturing, maintenance and prelaunch activities. An actuator will be integrated with the motor controller for performance testing of the EMA TVC system. The design and fabrication of the motor controller is being done by General Dynamics Space Systems Division. The University of Wisconsin-Madison will assist in the design of the advanced induction motor and in the implementation of the FOVC theory. A 75 hp electronically controlled dynamometer will be used to test the motor controller in all four quadrants of operation using flight type control algorithms. Integrated testing of the controller and actuator will be conducted at a facility yet to be named. The EMA system described above is discussed in detail.

  5. Acoustically shielded exhaust system for high thrust jet engines

    NASA Technical Reports Server (NTRS)

    Carey, John P. (Inventor); Lee, Robert (Inventor); Majjigi, Rudramuni K. (Inventor)

    1995-01-01

    A flade exhaust nozzle for a high thrust jet engine is configured to form an acoustic shield around the core engine exhaust flowstream while supplementing engine thrust during all flight conditions, particularly during takeoff. The flade airflow is converted from an annular 360.degree. flowstream to an arcuate flowstream extending around the lower half of the core engine exhaust flowstream so as to suppress exhaust noise directed at the surrounding community.

  6. Thrust Characteristics of Multiple Lifting Jets in Ground Proximity

    NASA Technical Reports Server (NTRS)

    Davenport, Edwin E.; Spreeman, Kenneth P.

    1960-01-01

    An investigation has been made to determine the thrust characteristics within ground proximity of a series of models which might represent vertical take-off-and-landing (VTOL) aircraft with multiple exit jet engines exhausting vertically downward beneath a lifting surface. Variations in simulated engine configurations were provided by a series of nozzle insert plugs in which the number of jet exits, located symmetrically on a fixed circle, was varied, or the diameter of the circle was varied for a given number of jet exits. represent lifting surfaces, and high-pressure air was used to simulate jet-engine exhaust. Plywood plates were used to The results of the investigation showed that increasing the number of exits, such that an annular jet configuration was approached, provided more favorable thrust characteristics within ground proximity than any other variation in the geometry of these multiple jets. Tests of a configuration with two nozzles approximating a fan-in-wing VTOL aircraft with fans located at different spanwise locations indicated that the augmentation in thrust within ground proximity was greater for the arrangement with the more inboard location of the nozzles.

  7. Thrust Vectoring on the NASA F-18 High Alpha Research Vehicle

    NASA Technical Reports Server (NTRS)

    Bowers, Albion H.; Pahle, Joseph W.

    1996-01-01

    Investigations into a multiaxis thrust-vectoring system have been conducted on an F-18 configuration. These investigations include ground-based scale-model tests, ground-based full-scale testing, and flight testing. This thrust-vectoring system has been tested on the NASA F-18 High Alpha Research Vehicle (HARV). The system provides thrust vectoring in pitch and yaw axes. Ground-based subscale test data have been gathered as background to the flight phase of the program. Tests investigated aerodynamic interaction and vane control effectiveness. The ground-based full-scale data were gathered from static engine runs with image analysis to determine relative thrust-vectoring effectiveness. Flight tests have been conducted at the NASA Dryden Flight Research Center. Parameter identification input techniques have been developed. Individual vanes were not directly controlled because of a mixer-predictor function built into the flight control laws. Combined effects of the vanes have been measured in flight and compared to combined effects of the vanes as predicted by the cold-jet test data. Very good agreement has been found in the linearized effectiveness derivatives.

  8. Design of an ion thruster movable grid thrust vectoring system

    NASA Astrophysics Data System (ADS)

    Kural, Aleksander; Leveque, Nicolas; Welch, Chris; Wolanski, Piotr

    2004-08-01

    Several reasons justify the development of an ion propulsion system thrust vectoring system. Spacecraft launched to date have used ion thrusters mounted on gimbals to control the thrust vector within a range of about ±5°. Such devices have large mass and dimensions, hence the need exists for a more compact system, preferably mounted within the thruster itself. Since the 1970s several thrust vectoring systems have been developed, with the translatable accelerator grid electrode being considered the most promising. Laboratory models of this system have already been built and successfully tested, but there is still room for improvement in their mechanical design. This work aims to investigate possibilities of refining the design of such movable grid thrust vectoring systems. Two grid suspension designs and three types of actuators were evaluated. The actuators examined were a micro electromechanical system, a NanoMuscle shape memory alloy actuator and a piezoelectric driver. Criteria used for choosing the best system included mechanical simplicity (use of the fewest mechanical parts), accuracy, power consumption and behaviour in space conditions. Designs of systems using these actuators are proposed. In addition, a mission to Mercury using the system with piezoelectric drivers has been modelled and its performance presented.

  9. Computational Investigation of the Aerodynamic Effects on Fluidic Thrust Vectoring

    NASA Technical Reports Server (NTRS)

    Deere, K. A.

    2000-01-01

    A computational investigation of the aerodynamic effects on fluidic thrust vectoring has been conducted. Three-dimensional simulations of a two-dimensional, convergent-divergent (2DCD) nozzle with fluidic injection for pitch vector control were run with the computational fluid dynamics code PAB using turbulence closure and linear Reynolds stress modeling. Simulations were computed with static freestream conditions (M=0.05) and at Mach numbers from M=0.3 to 1.2, with scheduled nozzle pressure ratios (from 3.6 to 7.2) and secondary to primary total pressure ratios of p(sub t,s)/p(sub t,p)=0.6 and 1.0. Results indicate that the freestream flow decreases vectoring performance and thrust efficiency compared with static (wind-off) conditions. The aerodynamic penalty to thrust vector angle ranged from 1.5 degrees at a nozzle pressure ratio of 6 with M=0.9 freestream conditions to 2.9 degrees at a nozzle pressure ratio of 5.2 with M=0.7 freestream conditions, compared to the same nozzle pressure ratios with static freestream conditions. The aerodynamic penalty to thrust ratio decreased from 4 percent to 0.8 percent as nozzle pressure ratio increased from 3.6 to 7.2. As expected, the freestream flow had little influence on discharge coefficient.

  10. Design and test of electromechanical actuators for thrust vector control

    Microsoft Academic Search

    J. R. Cowan; Rae Ann Weir

    1993-01-01

    New control mechanisms technologies are currently being explored to provide alternatives to hydraulic thrust vector control (TVC) actuation systems. For many years engineers have been encouraging the investigation of electromechanical actuators (EMA) to take the place of hydraulics for spacecraft control\\/gimballing systems. The rationale is to deliver a lighter, cleaner, safer, more easily maintained, as well as energy efficient space

  11. Solid rocket booster thrust vector control subsystem description

    NASA Technical Reports Server (NTRS)

    Redmon, J., Jr. (compiler)

    1983-01-01

    Major Solid Rocket Booster-Thrust Vector Control (SRB-TVC) subsystem components and subcomponents used in the Space Transportation System (STS) are identified. Simplified schematics, detailed schematics, figures, photographs, and data are included to acquaint the reader with the operation, performance, and physical layout as well as the materials and instrumentation used.

  12. Experimental investigation of thrust-vector deviation in a plasma thruster

    NASA Astrophysics Data System (ADS)

    Bugrova, A. I.; Bugrov, G. E.; Bishaev, A. M.; Desyatskov, A. V.; Kozintseva, M. V.; Lipatov, A. S.; Kharchevnikov, V. K.; Smirnov, P. G.

    2014-02-01

    We have studied deviation of the thrust vector of a plasma thruster with the aid of a magnetic system arranged behind the thruster edge. The magnetic field generated by the system acted upon the directional motion of ions in the jet. The experiments were performed on a laboratory model of the ?-100 stationary plasma thruster (SPT) with an output channel diameter of 100 mm and overall dimensions L = 70 mm and D = 200 mm. The results of measurements showed that, in the range of parameters studied, the angle of rotation of the output plasma jet exhibited a nearly linear dependence on the current in coils of the deviating magnetic system.

  13. Static internal performance of a two-dimensional convergent nozzle with thrust-vectoring capability up to 60 deg

    NASA Technical Reports Server (NTRS)

    Leavitt, L. D.

    1985-01-01

    An investigation was conducted at wind-off conditions in the static-test facility of the Langley 16-Foot Transonic Tunnel to determine the internal performance characteristics of a two-dimensional convergent nozzle with a thrust-vectoring capability up to 60 deg. Vectoring was accomplished by a downward rotation of a hinged upper convergent flap and a corresponding rotation of a center-pivoted lower convergent flap. The effects of geometric thrust-vector angle and upper-rotating-flap geometry on internal nozzle performance characteristics were investigated. Nozzle pressure ratio was varied from 1.0 (jet off) to approximately 5.0.

  14. Static investigation of a two-dimensional convergent-divergent exhaust nozzle with multiaxis thrust-vectoring capability

    NASA Technical Reports Server (NTRS)

    Taylor, John G.

    1990-01-01

    An investigation was conducted in the Static Test Facility of the NASA Langley 16-Foot Transonic Tunnel to determine the internal performance of two-dimensional convergent-divergent nozzles designed to have simultaneous pitch and yaw thrust vectoring capability. This concept utilized divergent flap rotation of thrust vectoring in the pitch plane and deflection of flat yaw flaps hinged at the end of the sidewalls for yaw thrust vectoring. The hinge location of the yaw flaps was varied at four positions from the nozzle exit plane to the throat plane. The yaw flaps were designed to contain the flow laterally independent of power setting. In order to eliminate any physical interference between the yaw flap deflected into the exhaust stream and the divergent flaps, the downstream corners of both upper and lower divergent flaps were cut off to allow for up to 30 deg of yaw flap deflection. The impact of varying the nozzle pitch vector angle, throat area, yaw flap hinge location, yaw flap length, and yaw flap deflection angle on nozzle internal performance characteristics, was studied. High-pressure air was used to simulate jet exhaust at nozzle pressure ratios up to 7.0. Static results indicate that configurations with the yaw flap hinge located upstream of the exit plane provide relatively high levels of thrust vectoring efficiency without causing large losses in resultant thrust ratio. Therefore, these configurations represent a viable concept for providing simultaneous pitch and yaw thrust vectoring.

  15. Static internal performance of single-expansion-ramp nozzles with thrust-vectoring capability up to 60 deg

    NASA Technical Reports Server (NTRS)

    Berrier, B. L.; Leavitt, L. D.

    1984-01-01

    An investigation has been conducted at static conditions (wind off) in the static-test facility of the Langley 16-Foot Transonic Tunnel. The effects of geometric thrust-vector angle, sidewall containment, ramp curvature, lower-flap lip angle, and ramp length on the internal performance of nonaxisymmetric single-expansion-ramp nozzles were investigated. Geometric thrust-vector angle was varied from -20 deg. to 60 deg., and nozzle pressure ratio was varied from 1.0 (jet off) to approximately 10.0.

  16. Evaluation of dual flow thrust vector nozzles with exhaust stream impingement

    NASA Astrophysics Data System (ADS)

    Carpenter, Thomas W.; Dobbins, Sean; Vaccarezza, Steven

    To supplement previous work performed by NASA, a cold-jet facility was established at the California Polytechnic State University, San Luis Obispo campus. The purpose of this facility is to continue the studies of cold flow multiaxis thrust vectoring conducted at the NASA Langley Research Center. A single nozzle test apparatus was completed and is presently operational. Included are the results of the single flow test envelope that was requested by NASA personnel. Details about the test apparatus are included in the Cal Poly Semi-Annual Progress report.

  17. Multiaxis Thrust-Vectoring Characteristics of a Model Representative of the F-18 High-Alpha Research Vehicle at Angles of Attack From 0 deg to 70 deg

    NASA Technical Reports Server (NTRS)

    Asbury, Scott C.; Capone, Francis J.

    1995-01-01

    An investigation was conducted in the Langley 16-Foot Transonic Tunnel to determine the multiaxis thrust-vectoring characteristics of the F-18 High-Alpha Research Vehicle (HARV). A wingtip supported, partially metric, 0.10-scale jet-effects model of an F-18 prototype aircraft was modified with hardware to simulate the thrust-vectoring control system of the HARV. Testing was conducted at free-stream Mach numbers ranging from 0.30 to 0.70, at angles of attack from O' to 70', and at nozzle pressure ratios from 1.0 to approximately 5.0. Results indicate that the thrust-vectoring control system of the HARV can successfully generate multiaxis thrust-vectoring forces and moments. During vectoring, resultant thrust vector angles were always less than the corresponding geometric vane deflection angle and were accompanied by large thrust losses. Significant external flow effects that were dependent on Mach number and angle of attack were noted during vectoring operation. Comparisons of the aerodynamic and propulsive control capabilities of the HARV configuration indicate that substantial gains in controllability are provided by the multiaxis thrust-vectoring control system.

  18. Attitude control of a spinning rocket via thrust vectoring

    SciTech Connect

    White, J.E.

    1990-12-19

    Two controllers are developed to provide attitude control of a spinning rocket that has a thrust vectoring capability. The first controller has a single-input/single-output design that ignores the gyroscopic coupling between the control channels. The second controller has a multi-input/multi-output structure that is specifically intended to account for the gyroscopic coupling effects. A performance comparison between the two approached is conducted for a range of roll rates. Each controller is tested for the ability to track step commands, and for the amount of coupling impurity. Both controllers are developed via a linear-quadratic-regulator synthesis procedure, which is motivated by the multi-input/multi-output nature of second controller. Time responses and a singular value analysis are used to evaluate controller performance. This paper describes the development and comparison of two controllers that are designed to provide attitude control of a spinning rocket that is equipped with thrust vector control. 12 refs., 13 figs., 2 tabs.

  19. Space Transportation System solid rocket booster thrust vector control system

    NASA Technical Reports Server (NTRS)

    Verble, A. J., Jr.; Mccool, A. A.; Potter, J. H.

    1980-01-01

    The Solid Rocket Booster, Thrust Vector Control (TVC) system was designed in accordance with the following requirements: self-contained power supply, failsafe operation, 20 flight uses after exposure to seawater landings, optimized cost, and component interchangeability. Trade studies were performed which led to the selection of a recirculating hydraulic system powered by Auxiliary Power Units (APU) which drive the hydraulic actuators and gimbal the solid rocket motor nozzle. Other approaches for the system design were studied in arriving at the recirculating hydraulic system powered by an APU. These systems must withstand the imposed environment and be usable for a minimum of 20 Space Transportation System flights with a minimum of refurbishment. The TVC system completed the required qualification and verification tests and is certified for the intended application. Substantiation data include analytical and test data.

  20. Space transportation system solid rocket booster thrust vector control system

    NASA Technical Reports Server (NTRS)

    Verble, A. J., Jr.; Mccool, A. A.; Potter, J. H.

    1979-01-01

    The Solid Rocket Booster, Thrust Vector Control (TVC) system was designed in accordance with the following requirements: self-contained power supply, fail-safe operation, 20 flight uses after exposure to seawater landings, optimized cost, and component interchangeability. Trade studies were performed which led to the selection of a recirculating hydraulic system powered by Auxiliary Power Units (APU) which drive the hydraulic actuators and gimbal the solid rocket motor nozzle. Other approaches for the system design were studied in arriving at the recirculating hydraulic system powered by an APU. These systems must withstand the imposed environment and be usable for a minimum of 20 Space Transportation System flights with a minimum of refurbishment. The TVC system has completed the major portion of qualification and verification tests and is prepared to be cleared for the first Shuttle flight (STS-1). Substantiation data will include analytical and test data.

  1. Solid rocket booster thrust vector control subsystem test report (d-1)

    Microsoft Academic Search

    Pagan

    1978-01-01

    The results of the sequence of tests performed on the space shuttle solid rocket booster thrust vector control subsystem are presented. The operational characteristics of the thrust vector control subsystem components, as determined from the tests, are discussed. Special analyses of fuel consumption, basic steady state characteristics, GN2 spin, and actuator displacement were reviewed which will aid in understanding the

  2. Flow Visualization of Thrust-Vectoring Lightcraft Engines with ˜1?s Pulsed TEA CO2 Laser

    NASA Astrophysics Data System (ADS)

    Kenoyer, D. A.; Salvador, I. I.; Notaro, S. N.; Myrabo, L. N.

    2011-11-01

    The thrust-vectoring performance of four laser propulsion engine geometries were visualized using a twin Lumonics K922M pulsed TEA CO2 laser system, with a Cordin® high speed digital camera and Schlieren photography. Airbreathing mode engines were used to explore engine thrust-vectoring behavior, as a function of: a) laser beam lateral offset from the engine axis of symmetry; b) laser pulse duration (˜50 ns spike with selectable 1.5 or 2.5 ?s tail, depending upon laser gas mixture); and c) engine geometry (Lightcraft Type ?150, ?200, ?250, and parabolic bell). The resulting Schlieren images visually prove thrust vectoring if the exhaust plume is responsible for the beam-riding phenomenon. Parabolic bell engines demonstrate very little thrust vectoring ability, even at the large offsets nominal for beam-riding and thrust-vectoring in other geometries.

  3. Variable Flavor Number Scheme for Final State Jets in Thrust

    E-print Network

    Piotr Pietrulewicz; Simon Gritschacher; Andre H. Hoang; Ilaria Jemos; Vicent Mateu

    2014-12-02

    We present results for mass effects coming from secondary radiation of heavy quark pairs related to gluon splitting in the thrust distribution for e+e- collisions. The results are given in the dijet limit where the hard interaction scale and the scales related to collinear and soft radiation are widely separated. We account for the corresponding fixed-order corrections at O(alpha_s^2) and the summation of all logarithmic terms related to the hard, collinear and soft scales as well as the quark mass at N3LL order. We also remove the O(Lambda_QCD) renormalon in the partonic soft function leading to an infrared evolution equation with a matching condition related to the massive quark threshold. The quark mass can be arbitrary, ranging from the infinitely heavy case, where decoupling takes place, down to the massless limit where the results smoothly merge into the well known predictions for massless quarks. Our results are formulated in the framework of factorization theorems for e+e- dijet production and provide universal threshold corrections for the renormalization group evolution of the hard current, the jet and soft functions at the scale where the massive quarks are integrated out. The results represent a first explicit realization of a variable flavor number scheme for final state jets along the lines of the well known flavor number dependent evolution of the strong coupling alpha_s and the parton distribution functions.

  4. Summary of Fluidic Thrust Vectoring Research Conducted at NASA Langley Research Center

    NASA Technical Reports Server (NTRS)

    Deere, Karen A.

    2003-01-01

    Interest in low-observable aircraft and in lowering an aircraft's exhaust system weight sparked decades of research for fixed geometry exhaust nozzles. The desire for such integrated exhaust nozzles was the catalyst for new fluidic control techniques; including throat area control, expansion control, and thrust-vector angle control. This paper summarizes a variety of fluidic thrust vectoring concepts that have been tested both experimentally and computationally at NASA Langley Research Center. The nozzle concepts are divided into three categories according to the method used for fluidic thrust vectoring: the shock vector control method, the throat shifting method, and the counterflow method. This paper explains the thrust vectoring mechanism for each fluidic method, provides examples of configurations tested for each method, and discusses the advantages and disadvantages of each method.

  5. Static performance of an axisymmetric nozzle with post-exit vanes for multiaxis thrust vectoring

    NASA Technical Reports Server (NTRS)

    Berrier, Bobby L.; Mason, Mary L.

    1988-01-01

    An investigation was conducted in the static test facility of the Langley 16-Foot Transonic Tunnel to determine the flow-turning capability and the nozzle internal performance of an axisymmetric convergent-divergent nozzle with post-exit vanes installed for multiaxis thrust vectoring. The effects of vane curvature, vane location relative to the nozzle exit, number of vanes, and vane deflection angle were determined. A comparison of the post-exit-vane thrust-vectoring concept with other thrust-vectoring concepts is provided. All tests were conducted with no external flow, and nozzle pressure ratio was varied from 1.6 to 6.0.

  6. Implicit time-marching solution of the Navier-Stokes equations for thrust reversing and thrust vectoring nozzle flows

    NASA Astrophysics Data System (ADS)

    Imlay, S. T.

    1986-11-01

    An implicit finite volume method is investigated for the solution of the compressible Navier-Stokes equations for flows within thrust reversing and thrust vectoring nozzles. Thrust reversing nozzles typically have sharp corners, and the rapid expansion and large turning angles near these corners are shown to cause unacceptable time step restrictions when conventional approximate factorization methods are used. In this investigation these limitations are overcome by using second-order upwind differencing and line Gauss-Siedel relaxation. This method is implemented with a zonal mesh so that flows through complex nozzle geometries may be efficiently calculated. Results are presented for five nozzle configurations including two with time varying geometries. Three cases are compared with available experimental data and the results are generally acceptable.

  7. Static Investigation of a Multiaxis Thrust-Vectoring Nozzle With Variable Internal Contouring Ability

    NASA Technical Reports Server (NTRS)

    Wing, David J.; Mills, Charles T. L.; Mason, Mary L.

    1997-01-01

    The thrust efficiency and vectoring performance of a convergent-divergent nozzle were investigated at static conditions in the model preparation area of the Langley 16-Foot Transonic Tunnel. The diamond-shaped nozzle was capable of varying the internal contour of each quadrant individually by using cam mechanisms and retractable drawers to produce pitch and yaw thrust vectoring. Pitch thrust vectoring was achieved by either retracting the lower drawers to incline the throat or varying the internal flow-path contours to incline the throat. Yaw thrust vectoring was achieved by reducing flow area left of the nozzle centerline and increasing flow area right of the nozzle centerline; a skewed throat deflected the flow in the lateral direction.

  8. Internal performance of two nozzles utilizing gimbal concepts for thrust vectoring

    NASA Technical Reports Server (NTRS)

    Berrier, Bobby L.; Taylor, John G.

    1990-01-01

    The internal performance of an axisymmetric convergent-divergent nozzle and a nonaxisymmetric convergent-divergent nozzle, both of which utilized a gimbal type mechanism for thrust vectoring was evaluated in the Static Test Facility of the Langley 16-Foot Transonic Tunnel. The nonaxisymmetric nozzle used the gimbal concept for yaw thrust vectoring only; pitch thrust vectoring was accomplished by simultaneous deflection of the upper and lower divergent flaps. The model geometric parameters investigated were pitch vector angle for the axisymmetric nozzle and pitch vector angle, yaw vector angle, nozzle throat aspect ratio, and nozzle expansion ratio for the nonaxisymmetric nozzle. All tests were conducted with no external flow, and nozzle pressure ratio was varied from 2.0 to approximately 12.0.

  9. Static Thrust and Vectoring Performance of a Spherical Convergent Flap Nozzle with a Nonrectangular Divergent Duct

    NASA Technical Reports Server (NTRS)

    Wing, David J.

    1998-01-01

    The static internal performance of a multiaxis-thrust-vectoring, spherical convergent flap (SCF) nozzle with a non-rectangular divergent duct was obtained in the model preparation area of the Langley 16-Foot Transonic Tunnel. Duct cross sections of hexagonal and bowtie shapes were tested. Additional geometric parameters included throat area (power setting), pitch flap deflection angle, and yaw gimbal angle. Nozzle pressure ratio was varied from 2 to 12 for dry power configurations and from 2 to 6 for afterburning power configurations. Approximately a 1-percent loss in thrust efficiency from SCF nozzles with a rectangular divergent duct was incurred as a result of internal oblique shocks in the flow field. The internal oblique shocks were the result of cross flow generated by the vee-shaped geometric throat. The hexagonal and bowtie nozzles had mirror-imaged flow fields and therefore similar thrust performance. Thrust vectoring was not hampered by the three-dimensional internal geometry of the nozzles. Flow visualization indicates pitch thrust-vector angles larger than 10' may be achievable with minimal adverse effect on or a possible gain in resultant thrust efficiency as compared with the performance at a pitch thrust-vector angle of 10 deg.

  10. Traceable Calibration of the 3 axis Thrust Vector in the mN range

    NASA Astrophysics Data System (ADS)

    Hughes, B.; Oldfield, S.

    2004-10-01

    The possibility of measuring the three force components i.e. the main axial component and the two orthogonal radial components, generated by an electric propulsion system is important for two reasons. Firstly, to assess the impact of spacecraft/propulsion system integration issues, for example to verify the alignment of the thrust vector with the spacecraft centre-of-mass for spacecraft stability. Secondly, to operate the thruster properly during flight, for example to determine the thrust vector relative to the mechanical axis of the thruster. Furthermore, a three-axis measurement capability will be useful for the experimental performance verification of the next generation of vectored electric propulsion devices, especially regarding the many unresolved issues connected with indirect thrust measurement using electrostatic probes. The capability to monitor thrust vector drift in real time and with significant bandwidth is also important. Thus enabling vector drift during thruster warm-up, to be measured, and the response of vectored thrusters to change in vector demand can be assessed. In this paper we describe the design, construction and testing of an instrument proof of concept. The instrument was designed to accommodate a dummy thruster mass of 0.5 kg and operate in the 0 to 10 mN range. The directional resolution that has been demonstrated is better than 0.05 ° in both axes when operating at full thrust.

  11. Investigation of the Longitudinal Characteristics of a Large-Scale Jet Transport Model Equipped with Controllable Thrust Reversers

    NASA Technical Reports Server (NTRS)

    Hickey, David H.; Tolhurst, William H., Jr.; Aoyagi, Kiyoshi

    1961-01-01

    An investigation was conducted to determine the effect of thrust control by means of controllable thrust reversers on the longitudinal characteristics of a large-scale airplane model with a 35' sweptback wing of aspect ratio of 7 and four pylon-mounted jet engines equipped with target-type thrust reversers designed to provide thrust control ranging from full forward thrust to full reverse thrust. The thrust control in landing-approach configurations formed the major portion of the study. Results were obtained with both leading- and trailing-edge high-lift devices.

  12. The complete two-loop integrated jet thrust distribution in soft-collinear effective theory

    NASA Astrophysics Data System (ADS)

    von Manteuffel, Andreas; Schabinger, Robert M.; Zhu, Hua Xing

    2014-03-01

    In this work, we complete the calculation of the soft part of the two-loop integrated jet thrust distribution in e + e - annihilation. This jet mass observable is based on the thrust cone jet algorithm, which involves a veto scale for out-of-jet radiation. The previously uncomputed part of our result depends in a complicated way on the jet cone size, r, and at intermediate stages of the calculation we actually encounter a new class of multiple polylogarithms. We employ an extension of the coproduct calculus to systematically exploit functional relations and represent our results concisely. In contrast to the individual contributions, the sum of all global terms can be expressed in terms of classical polylogarithms. Our explicit two-loop calculation enables us to clarify the small r picture discussed in earlier work. In particular, we show that the resummation of the logarithms of r that appear in the previously uncomputed part of the two-loop integrated jet thrust distribution is inextricably linked to the resummation of the non-global logarithms. Furthermore, we find that the logarithms of r which cannot be absorbed into the non-global logarithms in the way advocated in earlier work have coefficients fixed by the two-loop cusp anomalous dimension. We also show that in many cases one can straightforwardly predict potentially large logarithmic contributions to the integrated jet thrust distribution at L loops by making use of analogous contributions to the simpler integrated hemisphere soft function.

  13. Multiaxis control power from thrust vectoring for a supersonic fighter aircraft model at Mach 0.20 to 2.47

    NASA Technical Reports Server (NTRS)

    Capone, Francis J.; Bare, E. Ann

    1987-01-01

    The aeropropulsive characteristics of an advanced twin-engine fighter aircraft designed for supersonic cruise have been studied in the Langley 16-Foot Tansonic Tunnel and the Lewis 10- by 10-Foot Supersonic Tunnel. The objective was to determine multiaxis control-power characteristics from thrust vectoring. A two-dimensional convergent-divergent nozzle was designed to provide yaw vector angles of 0, -10, and -20 deg combined with geometric pitch vector angles of 0 and 15 deg. Yaw thrust vectoring was provided by yaw flaps located in the nozzle sidewalls. Roll control was obtained from differential pitch vectoring. This investigation was conducted at Mach numbers from 0.20 to 2.47. Angle of attack was varied from 0 to about 19 deg, and nozzle pressure ratio was varied from about 1 (jet off) to 28, depending on Mach number. Increments in force or moment coefficient that result from pitch or yaw thrust vectoring remain essentially constant over the entire angle-of-attack range of all Mach numbers tested. There was no effect of pitch vectoring on the lateral aerodynamic forces and moments and only very small effects of yaw vectoring on the longitudinal aerodynamic forces and moments. This result indicates little cross-coupling of control forces and moments for combined pitch-yaw vectoring.

  14. Development and qualification of a STAR 48 rocket motor with thrust vector control

    NASA Astrophysics Data System (ADS)

    Hamke, R.; Rade, J.; Weldin, R.

    1992-07-01

    A thrust vector control (TVC) nozzle for use on the STAR 48 rocket motor (STAR 48V) has been developed for use on the COMET program aboard the Conestoga launch vehicle. The first stages of qualification testing have been completed. The first STAR 48V has been successfully static-tested. The flexseal TVC nozzle design is based upon the qualified and flight-proven fixed nozzle design used on spin-stabilized spacecraft. The flexseal design and fabrication approach benefit from flight-proven and man-rated Thiokol Corporation flexseal designs. The thrust vector control system provides vectoring capability to 4 deg for use on nonspinning spacecraft. Electromechanical actuators coupled with a closed-loop controller provide thrust vector positioning and spacecraft attitude control.

  15. Thrust Vectoring of a Continuous Rotating Detonation Engine by Changing the Local Injection Pressure

    NASA Astrophysics Data System (ADS)

    Liu, Shi-Jie; Lin, Zhi-Yong; Sun, Ming-Bo; Liu, Wei-Dong

    2011-09-01

    The thrust vectoring ability of a continuous rotating detonation engine is numerically investigated, which is realized via increasing local injection stagnation pressure of half of the simulation domain compared to the other half. Under the homogeneous injection condition, both the flow-field structure and the detonation wave propagation process are analyzed. Due to the same injection condition along the inlet boundary, the outlines of fresh gas zones at different moments are similar to each other. The main flow-field features under thrust vectoring cases are similar to that under the baseline condition. However, due to the heterogeneous injection system, both the height of the fresh gas zone and the pressure value of the fresh gas in the high injection pressure zone are larger than that in the low injection pressure zone. Thus the average pressure in half of the engine is larger than that in the other half and the thrust vectoring adjustment is realized.

  16. Static investigation of two STOL nozzle concepts with pitch thrust-vectoring capability

    NASA Technical Reports Server (NTRS)

    Mason, M. L.; Burley, J. R., II

    1986-01-01

    A static investigation of the internal performance of two short take-off and landing (STOL) nozzle concepts with pitch thrust-vectoring capability has been conducted. An axisymmetric nozzle concept and a nonaxisymmetric nozzle concept were tested at dry and afterburning power settings. The axisymmetric concept consisted of a circular approach duct with a convergent-divergent nozzle. Pitch thrust vectoring was accomplished by vectoring the approach duct without changing the nozzle geometry. The nonaxisymmetric concept consisted of a two dimensional convergent-divergent nozzle. Pitch thrust vectoring was implemented by blocking the nozzle exit and deflecting a door in the lower nozzle flap. The test nozzle pressure ratio was varied up to 10.0, depending on model geometry. Results indicate that both pitch vectoring concepts produced resultant pitch vector angles which were nearly equal to the geometric pitch deflection angles. The axisymmetric nozzle concept had only small thrust losses at the largest pitch deflection angle of 70 deg., but the two-dimensional convergent-divergent nozzle concept had large performance losses at both of the two pitch deflection angles tested, 60 deg. and 70 deg.

  17. Developmental Testing of Electric Thrust Vector Control Systems for Manned Launch Vehicle Applications

    NASA Technical Reports Server (NTRS)

    Bates, Lisa B.; Young, David T.

    2012-01-01

    This paper describes recent developmental testing to verify the integration of a developmental electromechanical actuator (EMA) with high rate lithium ion batteries and a cross platform extensible controller. Testing was performed at the Thrust Vector Control Research, Development and Qualification Laboratory at the NASA George C. Marshall Space Flight Center. Electric Thrust Vector Control (ETVC) systems like the EMA may significantly reduce recurring launch costs and complexity compared to heritage systems. Electric actuator mechanisms and control requirements across dissimilar platforms are also discussed with a focus on the similarities leveraged and differences overcome by the cross platform extensible common controller architecture.

  18. Control of Ducted Fan Flying Object Using Thrust Vectoring

    NASA Astrophysics Data System (ADS)

    Miwa, Masafumi; Shigematsu, Yuki; Yamashita, Takashi

    Recently, R/C helicopter is used in fields of aerial photography and aerial investigation. But helicopter rotor blades are not covered, and the thrust is generated by high rotational speed. Thus R/C helicopter has a high risk of damage. In this study, we developed a new flying object using ducted fans instead of rotor blades. At first, PD control was employed for pitch and roll attitude control, but it caused steady state error. Moreover, PI-D control was used instead of PD control, and it reduced the steady state error. We succeeded to achieve stable hovering by 3-axes (roll, pitch and yaw axis) attitude control.

  19. Spreading characteristics and thrust of jets from asymmetric nozzles

    NASA Technical Reports Server (NTRS)

    Zaman, K. B. M. Q.

    1995-01-01

    The spreading characteristics of jets from several asymmetric nozzles are studied in comparison to those of an axisymmetric jet, over the Mach number (M(sub J)) range of 0.3 to 1.96. The effect of tabs in two cases, the axisymmetric nozzle fitted with four tabs and a rectangular nozzle fitted with two large tabs, is also included in the comparison. Compared to the axisymmetric jet, the asymmetric jets spread only slightly faster at subsonic conditions, while at supersonic conditions, when screech occurs, they spread much faster. Screech profoundly increases the spreading of all jets. The effect varies in the different stages of screech, and the corresponding unsteady flowfield characteristics are documented via phase-averaged measurement of the fluctuating total pressure. An organization and intensification of the azimuthal vortical structures under the screeching condition is believed to be responsible for the increased spreading. Curiously, the jet from a 'lobed mixer' nozzle spreads much less at supersonic conditions compared to all other cases. This is due to the absence of screech with this nozzle. Jet spreading for the two tab configurations, on the other hand, is significantly more than any of the no-tab cases. This is true in the subsonic regime, as well as in the supersonic regime in spite of the fact that screech is essentially eliminated by the tabs. The dynamics of the streamwise vortex pairs produced by the tabs cause the most efficient jet spreading thus far observed in the study.

  20. Sliding mode attitude controller design for nonlinear flexible geosynchronous satellite with thrust jets

    Microsoft Academic Search

    Erkan Abdulhamitbilal; Elbrous M. Jafarov

    2008-01-01

    In this paper, the attitude dynamics and effects of flexible solar arrays of a three axes stabilized geosynchronous communication satellite are studied. A spacecraft is assumed to be controlled externally with small attitude thrust jets. A new combined variable structure P+relay chattering-free controller with optimal sliding manifold is designed which successfully stabilizes the nonlinear attitude dynamics of the spacecraft with

  1. Solid rocket booster thrust vector control subsystem verification test (V-2) report

    NASA Technical Reports Server (NTRS)

    Pagan, B.

    1979-01-01

    The results of the verification testing sequence V-2 performed on the space shuttle solid rocket booster thrust vector control subsystem are presented. A detailed history of the hot firings plus additional discussion of the auxiliary power unit and the hydraulic component performance is presented. The test objectives, data, and conclusions are included.

  2. Pneumatic motor powered Thrust Vector Control (TVC) for liquid propelled launch vehicles

    Microsoft Academic Search

    Mark C. Malone; P. S. Evans

    1992-01-01

    Recent studies performed for the Titan 4 launch vehicle indicate significant potential advantages in replacing the current stage 1 and 2 recirculating hydraulic TVC (thrust vector control) system with a PMA (pneumatic mechanical actuation) system. Some of the advantages of a PMA system over the recirculating hydraulic system include reduced part count and weight, reduced maintenance and life-cycle cost, and

  3. Aeroservoelastic Modeling and Validation of a Thrust-Vectoring F/A-18 Aircraft

    NASA Technical Reports Server (NTRS)

    Brenner, Martin J.

    1996-01-01

    An F/A-18 aircraft was modified to perform flight research at high angles of attack (AOA) using thrust vectoring and advanced control law concepts for agility and performance enhancement and to provide a testbed for the computational fluid dynamics community. Aeroservoelastic (ASE) characteristics had changed considerably from the baseline F/A-18 aircraft because of structural and flight control system amendments, so analyses and flight tests were performed to verify structural stability at high AOA. Detailed actuator models that consider the physical, electrical, and mechanical elements of actuation and its installation on the airframe were employed in the analysis to accurately model the coupled dynamics of the airframe, actuators, and control surfaces. This report describes the ASE modeling procedure, ground test validation, flight test clearance, and test data analysis for the reconfigured F/A-18 aircraft. Multivariable ASE stability margins are calculated from flight data and compared to analytical margins. Because this thrust-vectoring configuration uses exhaust vanes to vector the thrust, the modeling issues are nearly identical for modem multi-axis nozzle configurations. This report correlates analysis results with flight test data and makes observations concerning the application of the linear predictions to thrust-vectoring and high-AOA flight.

  4. Robust vibration suppression of an adaptive circular composite plate for satellite thrust vector control

    Microsoft Academic Search

    Su Yan; Kougen Ma; Mehrdad N. Ghasemi-Nejhad

    2008-01-01

    In this paper, a novel application of adaptive composite structures, a University of Hawaii at Manoa (UHM) smart composite platform, is developed for the Thrust Vector Control (TVC) of satellites. The device top plate of the UHM platform is an adaptive circular composite plate (ACCP) that utilizes integrated sensors\\/actuators and controllers to suppress low frequency vibrations during the thruster firing

  5. Thrust Vectoring of a Continuous Rotating Detonation Engine by Changing the Local Injection Pressure

    Microsoft Academic Search

    Shi-Jie Liu; Zhi-Yong Lin; Ming-Bo Sun; Wei-Dong Liu

    2011-01-01

    The thrust vectoring ability of a continuous rotating detonation engine is numerically investigated, which is realized via increasing local injection stagnation pressure of half of the simulation domain compared to the other half. Under the homogeneous injection condition, both the flow-field structure and the detonation wave propagation process are analyzed. Due to the same injection condition along the inlet boundary,

  6. Robust synthesized control of electromechanical actuator for thrust vector system in spacecraft

    Microsoft Academic Search

    Hao Lu; Yunhua Li; Chenglin Zhu

    A kind of robust control of electromechanical actuator (EMA) system for thrust vector control in a spacecraft was investigated. In the flight of a spacecraft, the EMA system must overcome the influence of load disturbance and working point alteration to improve the robust control performances. Addressing this problem and considering the large inertia and low stiffness load of the EMA

  7. Further consideration of an electromechanical thrust vector control actuator experiencing large magnitude collinear transient forces

    Microsoft Academic Search

    Virginia T. Byrd; Joey K. Parker

    1997-01-01

    Thrust vector control (TVC) for the Space Shuttle Main Engines (SSMEs) is accomplished by hydraulic servo actuators. Marshall Space Flight Center (MSFC) is developing electromechanical actuator technology to be physically and functionally interchangeable with the existing hydraulic actuator. One of the major concerns for this design task is the large transient loads experienced by the TVC during start-up and shut-down.

  8. Mixing and Noise Benefit Versus Thrust Penalty in Supersonic Jets Using Impingement Tones

    NASA Technical Reports Server (NTRS)

    Raman, Ganesh; Rice, Edward J.

    1994-01-01

    This paper reports the results of an experimental investigation on the effect of impingement tones generated by obstacles of various geometries on the spreading of a supersonic jet flow. A rectangular supersonic jet was produced using a convergent-divergent nozzle that was operated near its design point (with shocks minimized). The immersion of obstacles in the flow produced an intense impingement tone which then propagated upstream (as feedback) to the jet lip and excited the antisymmetric hydrodynamic mode in the jet, thus setting up a resonant self-sustaining loop. The violent flapping motion of the jet due to excitation of the antisymmetric mode, combined with the unsteady wakes of the obstacles, produced large changes in jet mixing. It was possible to control the frequency and amplitude of the impingement tone excitation by varying the nozzle-to-obstacle distance and the obstacle immersion. By proper shaping of the obstacles it was possible to reduce the thrust penalty significantly.

  9. NLO Vector Boson Production With Light Jets

    SciTech Connect

    Bern, Z.; Diana, G.; Dixon, L.J.; Febres Cordero, F.; Forde, D.; Gleisberg, T.; Hoeche, S.; Ita, H.; Kosower, D.A.; Maitre, D.; Ozeren, K.

    2012-02-15

    In this contribution we present recent progress in the computation of next-to-leading order (NLO) QCD corrections for the production of an electroweak vector boson in association with jets at hadron colliders. We focus on results obtained using the virtual matrix element library BlackHat in conjunction with SHERPA, focusing on results relevant to understanding the background to top production. The production of a vector boson in association with several jets at the Large Hadron Collider (LHC) is an important background for other Standard Model processes as well as new physics signals. In particular, the production of a W boson in association with many jets is an important background for processes involving one or more top quarks. Precise predictions for the backgrounds are crucial to measurement of top-quark processes. Vector boson production in association with multiple jets is also a very important background for many SUSY searches, as it mimics the signatures of many typical decay chains. Here we will discuss how polarization information can be used as an additional handle to differentiate top pair production from 'prompt' W-boson production. More generally, ratios of observables, for example for events containing a W boson versus those containing a Z boson, are expected to be better-behaved as many uncertainties cancel in such ratios. Precise calculation of ratios, along with measurement of one of the two processes in the ratio, can be used in data-driven techniques for estimating backgrounds.

  10. Estimating off-nominal performance of a solid rocket motor for thrust vector control guidance

    NASA Astrophysics Data System (ADS)

    Schmidt, Garfield C.

    1992-08-01

    There are two main parameters relating the off-nominal performance of a solid rocket motor to its nominal performance. One parameter is associated with specific impulse and the other with burn rate. The way in which these parameters can be used to predict off-nominal acceleration from the nominal is reviewed, and a filter for estimating these parameters using accelerometer output and stored tables of nominal performance is derived. A closed-form solution is then derived for the thrust angle required of a thrust-vector-controlled rocket in order to intercept a constant velocity target.

  11. Static internal performance of a single expansion ramp nozzle with multiaxis thrust vectoring capability

    NASA Technical Reports Server (NTRS)

    Capone, Francis J.; Schirmer, Alberto W.

    1993-01-01

    An investigation was conducted at static conditions in order to determine the internal performance characteristics of a multiaxis thrust vectoring single expansion ramp nozzle. Yaw vectoring was achieved by deflecting yaw flaps in the nozzle sidewall into the nozzle exhaust flow. In order to eliminate any physical interference between the variable angle yaw flap deflected into the exhaust flow and the nozzle upper ramp and lower flap which were deflected for pitch vectoring, the downstream corners of both the nozzle ramp and lower flap were cut off to allow for up to 30 deg of yaw vectoring. The effects of nozzle upper ramp and lower flap cutout, yaw flap hinge line location and hinge inclination angle, sidewall containment, geometric pitch vector angle, and geometric yaw vector angle were studied. This investigation was conducted in the static-test facility of the Langley 16-Foot Transonic Tunnel at nozzle pressure ratios up to 8.0.

  12. Thrust vectoring for single-stage-to-orbit, horizontal takeoff, horizontal landing, space vehicles

    NASA Astrophysics Data System (ADS)

    Cunningham, M. J.; Freeman, D. C., Jr.; Wilhite, A. W.; Powell, R. W.

    1986-06-01

    The preliminary design of a horizontal takeoff, horizontal landing, single-stage-to-orbit, rocket-powered space vehicle was performed. The purpose was to examine technology requirements for future small payload launch vehicles. The distinguishing aspect of the design was the utilization of thrust vectoring to provide half of the lift at takeoff. The inclusion of a canard was necessary to provide additional lift at takeoff and to balance the moments produced with thrust vectoring. A weights estimation, an aerodynamic assessment, a trajectory analysis, and a gear weight analysis were performed. The takeoff weight of the resulting vehicle was approximately 1.26 million pounds, based on advanced technology structures and subsystems. The vehicle was designed to deliver a 5000-pound payload to a polar orbit.

  13. Optimal Pitch Thrust-Vector Angle and Benefits for all Flight Regimes

    NASA Technical Reports Server (NTRS)

    Gilyard, Glenn B.; Bolonkin, Alexander

    2000-01-01

    The NASA Dryden Flight Research Center is exploring the optimum thrust-vector angle on aircraft. Simple aerodynamic performance models for various phases of aircraft flight are developed and optimization equations and algorithms are presented in this report. Results of optimal angles of thrust vectors and associated benefits for various flight regimes of aircraft (takeoff, climb, cruise, descent, final approach, and landing) are given. Results for a typical wide-body transport aircraft are also given. The benefits accruable for this class of aircraft are small, but the technique can be applied to other conventionally configured aircraft. The lower L/D aerodynamic characteristics of fighters generally would produce larger benefits than those produced for transport aircraft.

  14. Design and test of a high power electromechanical actuator for thrust vector control

    NASA Astrophysics Data System (ADS)

    Cowan, J. R.; Myers, W. N.

    1992-07-01

    NASA-Marshall is involved in the development of electromechanical actuators (EMA) for thrust-vector control (TVC) system testing and implementation in spacecraft control/gimballing systems, with a view to the replacement of hydraulic hardware. TVC system control is furnished by solid state controllers and power supplies; a pair of resolvers supply position feedback to the controller for precise positioning. Performance comparisons between EMA and hydraulic TVC systems are performed.

  15. The development of H-II rocket solid rocket booster thrust vector control system

    Microsoft Academic Search

    Hirokazu Nagai; Yukio Fukushima; Hiroo Kazama; Tatsuro Asai; Shunichi Okaya; Yasushi Watanabe; Shoji Muramatsu

    1990-01-01

    The development of the thrust-vector-control (TVC) system for the two solid rocket boosters (SRBs) of the H-II rocket, which was started in 1984 and completed in 1989, is described. Special attention is given to the system's design, the trade-off studies, and the evaluation of the SRB-TVC system performance, as well as to problems that occurred in the course of the

  16. Development and qualification of a STAR 48 rocket motor with thrust vector control

    Microsoft Academic Search

    R. Hamke; J. Rade; R. Weldin

    1992-01-01

    A thrust vector control (TVC) nozzle for use on the STAR 48 rocket motor (STAR 48V) has been developed for use on the COMET program aboard the Conestoga launch vehicle. The first stages of qualification testing have been completed. The first STAR 48V has been successfully static-tested. The flexseal TVC nozzle design is based upon the qualified and flight-proven fixed

  17. Static Investigation of Paddle Vane Oscillating in Jet of 1,300-Pound-Thrust Rocket Motor

    NASA Technical Reports Server (NTRS)

    Lanford, Wade E.

    1958-01-01

    The results of a static investigation conducted to measure the normal forces on the entire jet-vane assembly and the hinge moments on the jet vane produced by a paddle vane oscillating in the jet of a 1,500-pound-thrust rocket motor are presented for vane-deflection angles from -5 deg to 25 deg. A maximum average normal force of 71 pounds with a corresponding value for maximum average hinge moment of 228 inch-pounds was obtained with the maximum area of jet vane immersed at a jet-vane angle of 25 deg decrease in thrust caused by immersion of the jet vane varied from a maximum loss of about 58 pounds, or approximately 5 percent at maximum jet-vane angle of 25 deg, to zero loss at jet-vane angles less than approximately 10 deg.

  18. Dryden/Edwards 1994 Thrust-Vectoring Aircraft Fleet - F-18 HARV, X-31, F-16 MATV

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The three thrust-vectoring aircraft at Edwards, California, each capable of flying at extreme angles of attack, cruise over the California desert in formation during flight in March 1994. They are, from left, NASA's F-18 High Alpha Research Vehicle (HARV), flown by the NASA Dryden Flight Research Center; the X-31, flown by the X-31 International Test Organization (ITO) at Dryden; and the Air Force F-16 Multi-Axis Thrust Vectoring (MATV) aircraft. All three aircraft were flown in different programs and were developed independently. The NASA F-18 HARV was a testbed to produce aerodynamic data at high angles of attack to validate computer codes and wind tunnel research. The X-31 was used to study thrust vectoring to enhance close-in air combat maneuvering, while the F-16 MATV was a demonstration of how thrust vectoring could be applied to operational aircraft.

  19. Linear Test Bed. Volume 2: Test Bed No. 2. [linear aerospike test bed for thrust vector control

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Test bed No. 2 consists of 10 combustors welded in banks of 5 to 2 symmetrical tubular nozzle assemblies, an upper stationary thrust frame, a lower thrust frame which can be hinged, a power package, a triaxial combustion wave ignition system, a pneumatic control system, pneumatically actuated propellant valves, a purge and drain system, and an electrical control system. The power package consists of the Mark 29-F fuel turbopump, the Mark 29-0 oxidizer turbopump, a gas generator assembly, and propellant ducting. The system, designated as a linear aerospike system, was designed to demonstrate the feasibility of the concept and to explore technology related to thrust vector control, thrust vector optimization, improved sequencing and control, and advanced ignition systems. The propellants are liquid oxygen/liquid hydrogen. The system was designed to operate at 1200-psia chamber pressure at an engine mixture ratio of 5.5. With 10 combustors, the sea level thrust is 95,000 pounds.

  20. A static investigation of the thrust vectoring system of the F/A-18 high-alpha research vehicle

    NASA Technical Reports Server (NTRS)

    Mason, Mary L.; Capone, Francis J.; Asbury, Scott C.

    1992-01-01

    A static (wind-off) test was conducted in the static test facility of the Langley 16-foot Transonic Tunnel to evaluate the vectoring capability and isolated nozzle performance of the proposed thrust vectoring system of the F/A-18 high alpha research vehicle (HARV). The thrust vectoring system consisted of three asymmetrically spaced vanes installed externally on a single test nozzle. Two nozzle configurations were tested: A maximum afterburner-power nozzle and a military-power nozzle. Vane size and vane actuation geometry were investigated, and an extensive matrix of vane deflection angles was tested. The nozzle pressure ratios ranged from two to six. The results indicate that the three vane system can successfully generate multiaxis (pitch and yaw) thrust vectoring. However, large resultant vector angles incurred large thrust losses. Resultant vector angles were always lower than the vane deflection angles. The maximum thrust vectoring angles achieved for the military-power nozzle were larger than the angles achieved for the maximum afterburner-power nozzle.

  1. Measurements of vector boson plus jets at the Tevatron

    SciTech Connect

    Cerrito, Lucio; /Queen Mary, U. of London

    2010-08-01

    We present preliminary measurements of Z/{gamma}* + jets, W + c and Z + b + X at the Tevatron, and review recent measurements of vector boson plus inclusive and heavy-flavor jets production. All measurements are in agreement with next-to-leading-order QCD calculations within the experimental and theoretical uncertainties. We also point to comparisons of the production rate and kinematics of the data with several Monte Carlo simulation programs of vector boson + jets processes.

  2. Robust Linear-Parameter Varying Autopilot Design for a Tail\\/Thrust Vector Controlled Missile

    Microsoft Academic Search

    Berno J. E. Misgeld; Marco Darcis; Thomas Kuhn

    \\u000a A robust autopilot design methodology using linear parameter varying transformations is presented and applied to a high-agile\\u000a surface launched air defence missile, which is currently developed by Diehl-BGT-Defence. The lateral dynamics of the tail\\/thrust\\u000a vector controlled missile are modelled as a second-order quasi-linear parameter varying (LPV) system. The incidence angle\\u000a is used as exogenous variable, which is assumed to be

  3. The development of H-II rocket solid rocket booster thrust vector control system

    NASA Astrophysics Data System (ADS)

    Nagai, Hirokazu; Fukushima, Yukio; Kazama, Hiroo; Asai, Tatsuro; Okaya, Shunichi; Watanabe, Yasushi; Muramatsu, Shoji

    The development of the thrust-vector-control (TVC) system for the two solid rocket boosters (SRBs) of the H-II rocket, which was started in 1984 and completed in 1989, is described. Special attention is given to the system's design, the trade-off studies, and the evaluation of the SRB-TVC system performance, as well as to problems that occurred in the course of the system's development and to the countermeasures that were taken. Schematic diagrams are presented for the H-II rocket, the SRB, and the SRB-TVC system configurations.

  4. Static internal performance of a two-dimensional convergent-divergent nozzle with thrust vectoring

    NASA Technical Reports Server (NTRS)

    Bare, E. Ann; Reubush, David E.

    1987-01-01

    A parametric investigation of the static internal performance of multifunction two-dimensional convergent-divergent nozzles has been made in the static test facility of the Langley 16-Foot Transonic Tunnel. All nozzles had a constant throat area and aspect ratio. The effects of upper and lower flap angles, divergent flap length, throat approach angle, sidewall containment, and throat geometry were determined. All nozzles were tested at a thrust vector angle that varied from 5.60 tp 23.00 deg. The nozzle pressure ratio was varied up to 10 for all configurations.

  5. Design of a mixer for the thrust-vectoring system on the high-alpha research vehicle

    NASA Technical Reports Server (NTRS)

    Pahle, Joseph W.; Bundick, W. Thomas; Yeager, Jessie C.; Beissner, Fred L., Jr.

    1996-01-01

    One of the advanced control concepts being investigated on the High-Alpha Research Vehicle (HARV) is multi-axis thrust vectoring using an experimental thrust-vectoring (TV) system consisting of three hydraulically actuated vanes per engine. A mixer is used to translate the pitch-, roll-, and yaw-TV commands into the appropriate TV-vane commands for distribution to the vane actuators. A computer-aided optimization process was developed to perform the inversion of the thrust-vectoring effectiveness data for use by the mixer in performing this command translation. Using this process a new mixer was designed for the HARV and evaluated in simulation and flight. An important element of the Mixer is the priority logic, which determines priority among the pitch-, roll-, and yaw-TV commands.

  6. A numerical and experimental investigation of the thrust vector control by secondary gas injection

    NASA Astrophysics Data System (ADS)

    Waidmann, Winfried

    1991-07-01

    A numerical and experimental analysis of the cross injection of secondary gas stream into a supersonic flow is presented. The two dimensional compressible Navier-Stokes equations were solved by the explicit Runge-Kutta finite volume method. The equations describing the turbulent flow are closed by an algebraic turbulence model. The results of the numerical calculations are compared with experimental results performed in a rectangular expansion nozzle with a two dimensional injector. Shadow graphs, wall pressure, and side thrust measurements were used as diagnostic tools. A parametric study concerning the influence of different injection conditions and gas media delivers the best injection conditions for a maximal side thust. The effect of the different jet injection conditions is discussed in connection with the corresponding flow structure.

  7. Pneumatic motor powered Thrust Vector Control (TVC) for liquid propelled launch vehicles

    NASA Astrophysics Data System (ADS)

    Malone, Mark C.; Evans, P. S.

    1992-02-01

    Recent studies performed for the Titan 4 launch vehicle indicate significant potential advantages in replacing the current stage 1 and 2 recirculating hydraulic TVC (thrust vector control) system with a PMA (pneumatic mechanical actuation) system. Some of the advantages of a PMA system over the recirculating hydraulic system include reduced part count and weight, reduced maintenance and life-cycle cost, and improved mission reliability. PMA technology, used in aircraft applications since the 1960s, is well suited in launch vehicle TVC applications where an existing pneumatic pressure source is available. A typical pneumatic motor TVC consists of a pneumatic power source, a dual rotor pneumatic motor, a gear box, a ball screw actuator, and the associated closed-loop servo-control elements. One key issue with implementing this mechanical approach is designing a TVC system to withstand large load transient disturbances during liquid engine starting. Hydraulic actuator transient loads have exceeded 60,000 lb(sub f) for a 30,000 lb(sub f) stall design actuator during ground starts of the Titan 3B, Stage 1 engine. A PMA TVC system must also withstand these start transients without imparting excessive reaction loads to the engine nozzle and thrust structure. Work completed to date with Martin Marietta to examine pneumatic motor powered TVC options and technology benefits is presented. The load transient issue is discussed along with potential solutions and the associated trades. General background on PMA technology and experience base is also presented.

  8. A conceptual design of vectored water-jet propulsion system

    Microsoft Academic Search

    Shuxiang Guo; Xichuan Lin; S. Hata

    2009-01-01

    This paper presents a novel vectored water-jet propulsion system which is supposed to be used on a spherical underwater vehicle. This system uses water-jet as its propulsion method and by using servo motors, the direction of output force can be regulated for different propulsion tasks. This paper mainly focuses on the conceptual design of the system. To testify the availability

  9. The effects on propulsion-induced aerodynamic forces of vectoring a partial-span rectangular jet at Mach numbers from 0.40 to 1.20

    NASA Technical Reports Server (NTRS)

    Capone, F. J.

    1975-01-01

    An investigation was conducted in the Langley 16-foot transonic tunnel to determine the induced lift characteristics of a vectored thrust concept in which a rectangular jet exhaust nozzle was located in the fuselage at the wing trailing edge. The effects of nozzle deflection angles of 0 deg to 45 deg were studied at Mach numbers from 0.4 to 1.2, at angles of attack up to 14 deg, and with thrust coefficients up to 0.35. Separate force balances were used to determine total aerodynamic and thrust forces as well as thrust forces which allowed a direct measurement of jet turning angle at forward speeds. Wing pressure loading and flow characteristics using oil flow techniques were also studied.

  10. Design and evaluation of single and dual flow thrust vector nozzles with post exit vanes

    NASA Astrophysics Data System (ADS)

    Carpenter, Thomas W.; Vaccarezza, Stephen E.; Dobbins, Sean

    1992-12-01

    This Thrust Vectored Research project required that a 1/24 scale model of the F/A-18 High Alpha Research Vehicle, (HARV), propulsion system be constructed on the university campus. This propulsion system was designed for cold flow testing on a multicomponent test rig. Forces and moments were measured to study nozzle performance parameters. The flow visualization technique of color Schlieren photography was performed to investigate the flow phenomena at the nozzle exit. The flow interactions that were identified consisted of vane nozzleing between the outer and lower vanes and vane tip interference. The thrust vectoring system consisted of three asymmetrically spaced vanes installed circumferentially on a maximum afterburner nozzle. The performance of the nozzle was investigated with the outer and lower vanes equally deflected, (-10 deg is less than delta(sub v) is less than 25 deg), and with the upper vane fully retracted, (delta(sub v) equals -10 deg). The nozzle pressure ratio ranged from 4 to 6. The results indicated that a vane nozzleing effect developed at nozzle pressure ratios of 4 and 6 when the outer and lower vanes were deflected far enough into the flow field such that the increase in vane area accelerated the flow past the vanes causing distorted shock waves. This accelerated flow was a result of a pressure differential existing between the inside surface of the vane and the ambient pressure. The stagnation pressure that developed along the inside surface of the vane accelerated the flow past the vanes causing it to equalize with ambient pressure, thus providing distorted shock waves. A tip interference was present at the trailing edge of the upper vane as a result of low nozzle pressure, NPR 4, with high vane deflection, delta(sub v) equals 25 degrees, and also with a high nozzle pressure, NPR 6, and low vane deflections, delta(sub v) equals 15 degrees.

  11. Design and development of the quad redundant servoactuator for the space shuttle solid rocket booster thrust vector control

    NASA Technical Reports Server (NTRS)

    Lominick, J. M.

    1980-01-01

    The design and theory of operation of the servoactuator used for thrust vector control of the space shuttle solid rocket booster is described accompanied by highlights from the development and qualification test programs. Specific details are presented concerning major anomalies that occurred during the test programs and the corrective courses of action pursued.

  12. Variable-flavor-number scheme for final state jets in thrust

    NASA Astrophysics Data System (ADS)

    Pietrulewicz, Piotr; Gritschacher, Simon; Hoang, Andre H.; Jemos, Ilaria; Mateu, Vicent

    2014-12-01

    We present results for mass effects coming from secondary radiation of heavy quark pairs related to gluon splitting in the thrust distribution for e+e- collisions. The results are given in the dijet limit where the hard interaction scale and the scales related to collinear and soft radiation are widely separated. We account for the corresponding fixed-order corrections at O (?s2) and the summation of all logarithmic terms related to the hard, collinear, and soft scales as well as the quark mass at N3LL order. We also remove the O (?QCD) renormalon in the partonic soft function, leading to an infrared evolution equation with a matching condition related to the massive quark threshold. The quark mass can be arbitrary, ranging from the infinitely heavy case, where decoupling takes place, down to the massless limit, where the results smoothly merge into the well-known predictions for massless quarks. Our results are formulated in the framework of factorization theorems for e+e- dijet production and provide universal threshold corrections for the renormalization group evolution of the hard current, the jet, and the soft functions at the scale where the massive quarks are integrated out. The results represent a first explicit realization of a variable-flavor-number scheme for final-state jets along the lines of the well-known flavor-number-dependent evolution of the strong coupling ?s and the parton distribution functions.

  13. A simple dynamic engine model for use in a real-time aircraft simulation with thrust vectoring

    NASA Technical Reports Server (NTRS)

    Johnson, Steven A.

    1990-01-01

    A simple dynamic engine model was developed at the NASA Ames Research Center, Dryden Flight Research Facility, for use in thrust vectoring control law development and real-time aircraft simulation. The simple dynamic engine model of the F404-GE-400 engine (General Electric, Lynn, Massachusetts) operates within the aircraft simulator. It was developed using tabular data generated from a complete nonlinear dynamic engine model supplied by the manufacturer. Engine dynamics were simulated using a throttle rate limiter and low-pass filter. Included is a description of a method to account for axial thrust loss resulting from thrust vectoring. In addition, the development of the simple dynamic engine model and its incorporation into the F-18 high alpha research vehicle (HARV) thrust vectoring simulation. The simple dynamic engine model was evaluated at Mach 0.2, 35,000 ft altitude and at Mach 0.7, 35,000 ft altitude. The simple dynamic engine model is within 3 percent of the steady state response, and within 25 percent of the transient response of the complete nonlinear dynamic engine model.

  14. Preliminary Investigation on Battery Sizing Investigation for Thrust Vector Control on Ares I and Ares V Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Miller, Thomas B.

    2011-01-01

    An investigation into the merits of battery powered Electro Hydrostatic Actuation (EHA) for Thrust Vector Control (TVC) of the Ares I and Ares V launch vehicles is described. A top level trade study was conducted to ascertain the technical merits of lithium-ion (Li-ion) and thermal battery performance to determine the preferred choice of an energy storage system chemistry that provides high power discharge capability for a relatively short duration.

  15. Vector Boson + Heavy Flavor Jets Production at the Tevatron

    E-print Network

    Kenichi Hatakeyama

    2008-10-16

    Recent measurements on the vector boson plus heavy-flavor jets production by the CDF and D0 experiments are presented in comparisons with recent theoretical predictions. Good understanding of such processes is important to improve our understanding of QCD and also to enhance the potential to search for yet-to-be-discovered new physics phenomena which lead to similar final states.

  16. Measurements of vector boson plus jets from ATLAS

    NASA Astrophysics Data System (ADS)

    Ninomiya, Yoichi

    2015-05-01

    Measurements of single W, Z boson production in association with jets probe QCD in multi-scale environment. Measurements of W + jet and Z + jet production and their ratio, extending to high jet multiplicities, and a large set of kinematic distributions are presented for 7 TeV data. The results are compared to the predictions of modern Monte Carlo generators. The production of vector bosons plus heavy flavors is sensitive to the c and b quark parton distribution functions (PDFs) and gluon splitting effects. Measurements of W + c and Z + b(b) are reported and compared to predictions based on various PDFs in 4 and 5 flavour schemes. An overview of the results is given.

  17. Thrust vectoring effects of a transverse gas injection into a supersonic cross flow of an axisymmetric convergent-divergent nozzle

    NASA Astrophysics Data System (ADS)

    Zmijanovic, V.; Lago, V.; Leger, L.; Depussay, E.; Sellam, M.; Chpoun, A.

    2013-03-01

    The transverse gas injection into the main supersonic flow of an axisymmetric convergent-divergent (C-D) propulsive nozzle is investigated for the fluidic thrust vectoring (FTV) possibilities as the segment part of the CNES "Perseus" project. Truncated ideal contour and conical C-D nozzles with different position and angle of the secondary circular injection port are selected as test models in the current numerical and experimental study. Analytical approach revealed parameters which affect the FTV efficiency, these criterions are further numerically explored and results data of the conical nozzle test cases are compared and coupled with the ones from experiments. It is found that upstream inclined injection has positive effect on vectoring capabilities and that with moderate secondary to primary mass-flow ratios, ranging around 5%, pertinent vector side force is possible to be achieved.

  18. Vector boson plus one jet production in POWHEG

    E-print Network

    Simone Alioli; Paolo Nason; Carlo Oleari; Emanuele Re

    2010-09-28

    We present an implementation of the next-to-leading order vector boson plus one jet production process in hadronic collision in the framework of POWHEG, which is a method to implement NLO calculations within a Shower Monte Carlo context. All spin correlations in the vector boson decay products have been taken into account. The process has been implemented in the framework of the POWHEG-BOX, an automated computer code for turning a NLO calculation into a shower Monte Carlo program. We present phenomenological results for the case of the Z/gamma plus one jet production process, obtained by matching the POWHEG calculation with the shower performed by PYTHIA, for the LHC, and we compare our results with available Tevatron data.

  19. Classifier based on support vector machine for JET plasma configurations

    SciTech Connect

    Dormido-Canto, S.; Farias, G.; Dormido, R.; Sanchez, J.; Duro, N.; Vargas, H. [Departamento de Informatica y Automatica, UNED, C/Juan del Rosal 16, 5a. 28040 Madrid (Spain); Vega, J. [Asociacion EURATOM/CIEMAT para FUSION, Avda. Complutense 22. 28040 Madrid (Spain); Murari, A. [Consorzio RFX-Associazione EURATOM ENEA per la Fusione. I-35127 Padua (Italy)

    2008-10-15

    The last flux surface can be used to identify the plasma configuration of discharges. For automated recognition of JET configurations, a learning system based on support vector machines has been developed. Each configuration is described by 12 geometrical parameters. A multiclass system has been developed by means of the one-versus-the-rest approach. Results with eight simultaneous classes (plasma configurations) show a success rate close to 100%.

  20. Large-Scale Wind-Tunnel Tests of Exhaust Ingestion Due to Thrust Reversal on a Four-Engine Jet Transport during Ground Roll

    NASA Technical Reports Server (NTRS)

    Tolhurst, William H., Jr.; Hickey, David H.; Aoyagi, Kiyoshi

    1961-01-01

    Wind-tunnel tests have been conducted on a large-scale model of a swept-wing jet transport type airplane to study the factors affecting exhaust gas ingestion into the engine inlets when thrust reversal is used during ground roll. The model was equipped with four small jet engines mounted in nacelles beneath the wing. The tests included studies of both cascade and target type reversers. The data obtained included the free-stream velocity at the occurrence of exhaust gas ingestion in the outboard engine and the increment of drag due to thrust reversal for various modifications of thrust reverser configuration. Motion picture films of smoke flow studies were also obtained to supplement the data. The results show that the free-stream velocity at which ingestion occurred in the outboard engines could be reduced considerably, by simple modifications to the reversers, without reducing the effective drag due to reversed thrust.

  1. Preliminary Characterization of the Altair Lunar Lander Slosh Dynamics and Some Implications for the Thrust Vector Control Design

    NASA Technical Reports Server (NTRS)

    Lee, Allan Y.; Strahan, Alan; Tanimoto, Rebekah; Casillas, Arturo

    2010-01-01

    This paper describes a conceptual design of the Thrust Vector Control (TVC) system and preliminary modeling of propellant slosh, for the Altair Lunar Lander. Altair is a vehicle element of the NASA Constellation Program aimed at returning humans to the moon. Guidance, Navigation, and Control (GN&C) is the measurement and control of spacecraft position, velocity, and attitude in support of mission objectives. One key GN&C function is the commanding of effectors that control attitude and impart delta V on the vehicle, utilizing both reaction control system (RCS) thrusters and throttling and TVC gimbaling of the vehicle main engine. Both the Altair descent and ascent modules carry fuel tanks. During thrusting maneuvers, the sloshing of liquid fuels in partially filled tanks can interact with the controlled system in such a way as to cause the overall system to be unstable. These fuel tanks must be properly placed, relative to the spacecraft's c.m., to avoid any unstable interactions. Following this will be a discussion of propellant slosh modeling work performed for the present vehicle configuration, including slosh frequency and participatory fluid mass predictions. Knowing the range of slosh mode frequencies over mission phases, the TVC bandwidth must be carefully selected so as not to excite the slosh modes at those frequencies. The likely need to increase the damping factor of slosh modes via baffles will also be discussed. To conclude, a discussion of operations procedures aimed at minimizing TVC-slosh interactions will be given.

  2. Noise generated by a flight weight, air flow control valve in a vertical takeoff and landing aircraft thrust vectoring system

    NASA Astrophysics Data System (ADS)

    Huff, Ronald G.

    1989-02-01

    Tests were conducted in the NASA Lewis Research Center's Powered Lift Facility to experimentally evaluate the noise generated by a flight weight, 12 in. butterfly valve installed in a proposed vertical takeoff and landing thrust vectoring system. Fluctuating pressure measurements were made in the circular duct upstream and downstream of the valve. This data report presents the results of these tests. The maximum overall sound pressure level is generated in the duct downstream of the valve and reached a value of 180 dB at a valve pressure ratio of 2.8. At the higher valve pressure ratios the spectra downstream of the valve is broad banded with its maximum at 1000 Hz.

  3. Preliminary study of the use of Laplace and momentum vectors in the determination of interplanetary low thrust trajectories

    NASA Astrophysics Data System (ADS)

    Bartholomew-Biggs, M. C.; Dixon, L. C. W.; Hersom, S. E.

    1985-07-01

    The feedback and Pontryagin approaches to the optimization of low thrust trajectories using the momentum and Laplace vectors are considered. The feedback algorithm runs into numerical difficulties at the final point and at intermediary points where the efficiencies are low. These difficulties can be avoided by using the switching function, but impractical trajectories can still occur and hence cause trouble if this happens inside an optimization routine. The algorithm readily produces final orbits which are correct except for the argument of perihelion, but is of no practical use to proceed beyond this point. In the Pontryagin approach, the use of the first order approximation, in which the adjoint variables are assumed constant, is justified. This enables optimization to be undertaken with a much shorter computer time per iteration and with little degradation in performance.

  4. Noise generated by a flight weight, air flow control valve in a vertical takeoff and landing aircraft thrust vectoring system

    NASA Technical Reports Server (NTRS)

    Huff, Ronald G.

    1989-01-01

    Tests were conducted in the NASA Lewis Research Center's Powered Lift Facility to experimentally evaluate the noise generated by a flight weight, 12 in. butterfly valve installed in a proposed vertical takeoff and landing thrust vectoring system. Fluctuating pressure measurements were made in the circular duct upstream and downstream of the valve. This data report presents the results of these tests. The maximum overall sound pressure level is generated in the duct downstream of the valve and reached a value of 180 dB at a valve pressure ratio of 2.8. At the higher valve pressure ratios the spectra downstream of the valve is broad banded with its maximum at 1000 Hz.

  5. Vector boson+jets as background to top-quark physics at Tevatron and LHC

    E-print Network

    Frédéric Déliot; for the ATLAS; CDF; CMS; D0 Collaborations

    2013-02-14

    I review here the latest measurements related to vector boson production in association with light or heavy flavor jets at the Tevatron and at the LHC. The methods to estimate the W+jets and Z+jets background in top-quark analyses are also presented.

  6. Optimal dimensionless design and analysis of jet ejectors as compressors and thrust augmenters 

    E-print Network

    Mohan, Ganesh

    2006-08-16

    , the results showed a completely new parameter (christenedGM- Gauge Mach) that when kept constant will result in non-dimensionalization. Non-dimensionalization of a jet ejector for watercraft propulsion was conducted using 2D axis symmetric, steady-state flow...

  7. Configuration management and automatic control of an augmentor wing aircraft with vectored thrust

    NASA Technical Reports Server (NTRS)

    Cicolani, L. S.; Sridhar, B.; Meyer, G.

    1979-01-01

    An advanced structure for automatic flight control logic for powered-lift aircraft operating in terminal areas is under investigation at Ames Research Center. This structure is based on acceleration control; acceleration commands are constructed as the sum of acceleration on the reference trajectory and a corrective feedback acceleration to regulate path tracking errors. The central element of the structure, termed a Trimmap, uses a model of the aircraft aerodynamic and engine forces to calculate the control settings required to generate the acceleration commands. This report describes the design criteria for the Trimmap and derives a Trimmap for Ames experimental augmentor wing jet STOL research aircraft.

  8. A Method for Integrating Thrust-Vectoring and Actuated Forebody Strakes with Conventional Aerodynamic Controls on a High-Performance Fighter Airplane

    NASA Technical Reports Server (NTRS)

    Lallman, Frederick J.; Davidson, John B.; Murphy, Patrick C.

    1998-01-01

    A method, called pseudo controls, of integrating several airplane controls to achieve cooperative operation is presented. The method eliminates conflicting control motions, minimizes the number of feedback control gains, and reduces the complication of feedback gain schedules. The method is applied to the lateral/directional controls of a modified high-performance airplane. The airplane has a conventional set of aerodynamic controls, an experimental set of thrust-vectoring controls, and an experimental set of actuated forebody strakes. The experimental controls give the airplane additional control power for enhanced stability and maneuvering capabilities while flying over an expanded envelope, especially at high angles of attack. The flight controls are scheduled to generate independent body-axis control moments. These control moments are coordinated to produce stability-axis angular accelerations. Inertial coupling moments are compensated. Thrust-vectoring controls are engaged according to their effectiveness relative to that of the aerodynamic controls. Vane-relief logic removes steady and slowly varying commands from the thrust-vectoring controls to alleviate heating of the thrust turning devices. The actuated forebody strakes are engaged at high angles of attack. This report presents the forward-loop elements of a flight control system that positions the flight controls according to the desired stability-axis accelerations. This report does not include the generation of the required angular acceleration commands by means of pilot controls or the feedback of sensed airplane motions.

  9. Static thrust-vectoring performance of nonaxisymmetric convergent-divergent nozzles with post-exit yaw vanes. M.S. Thesis - George Washington Univ., Aug. 1988

    NASA Technical Reports Server (NTRS)

    Foley, Robert J.; Pendergraft, Odis C., Jr.

    1991-01-01

    A static (wind-off) test was conducted in the Static Test Facility of the 16-ft transonic tunnel to determine the performance and turning effectiveness of post-exit yaw vanes installed on two-dimensional convergent-divergent nozzles. One nozzle design that was previously tested was used as a baseline, simulating dry power and afterburning power nozzles at both 0 and 20 degree pitch vectoring conditions. Vanes were installed on these four nozzle configurations to study the effects of vane deflection angle, longitudinal and lateral location, size, and camber. All vanes were hinged at the nozzle sidewall exit, and in addition, some were also hinged at the vane quarter chord (double-hinged). The vane concepts tested generally produced yaw thrust vectoring angles much less than the geometric vane angles, for (up to 8 percent) resultant thrust losses. When the nozzles were pitch vectored, yawing effectiveness decreased as the vanes were moved downstream. Thrust penalties and yawing effectiveness both decreased rapidly as the vanes were moved outboard (laterally). Vane length and height changes increased yawing effectiveness and thrust ratio losses, while using vane camber, and double-hinged vanes increased resultant yaw angles by 50 to 100 percent.

  10. Design Specification for a Thrust-Vectoring, Actuated-Nose-Strake Flight Control Law for the High-Alpha Research Vehicle

    NASA Technical Reports Server (NTRS)

    Bacon, Barton J.; Carzoo, Susan W.; Davidson, John B.; Hoffler, Keith D.; Lallman, Frederick J.; Messina, Michael D.; Murphy, Patrick C.; Ostroff, Aaron J.; Proffitt, Melissa S.; Yeager, Jessie C.; Foster, John V.; Bundick, W. Thomas; Connelly, Patrick J.; Kelly, John W.; Pahle, Joseph W.; Thomas, Michael; Wichman, Keith D.; Wilson, R. Joseph

    1996-01-01

    Specifications for a flight control law are delineated in sufficient detail to support coding the control law in flight software. This control law was designed for implementation and flight test on the High-Alpha Research Vehicle (HARV), which is an F/A-18 aircraft modified to include an experimental multi-axis thrust-vectoring system and actuated nose strakes for enhanced rolling (ANSER). The control law, known as the HARV ANSER Control Law, was designed to utilize a blend of conventional aerodynamic control effectors, thrust vectoring, and actuated nose strakes to provide increased agility and good handling qualities throughout the HARV flight envelope, including angles of attack up to 70 degrees.

  11. Preliminary performance of a vertical-attitude takeoff and landing, supersonic cruise aircraft concept having thrust vectoring integrated into the flight control system

    NASA Technical Reports Server (NTRS)

    Robins, A. W.; Beissner, F. L., Jr.; Domack, C. S.; Swanson, E. E.

    1985-01-01

    A performance study was made of a vertical attitude takeoff and landing (VATOL), supersonic cruise aircraft concept having thrust vectoring integrated into the flight control system. Those characteristics considered were aerodynamics, weight, balance, and performance. Preliminary results indicate that high levels of supersonic aerodynamic performance can be achieved. Further, with the assumption of an advanced (1985 technology readiness) low bypass ratio turbofan engine and advanced structures, excellent mission performance capability is indicated.

  12. Effects of upper-surface blowing and thrust vectoring on low-speed aerodynamic characteristics of a large-scale supersonic transport model

    NASA Technical Reports Server (NTRS)

    Coe, P. L., Jr.; Mclemore, H. C.; Shivers, J. P.

    1975-01-01

    Tests were conducted in the Langley full-scale tunnel to determine the low-speed aerodynamic characteristics of a large-scale arrow-wing supersonic transport configured with engines mounted above the wing for upper surface blowing, and conventional lower surface engines with provisions for thrust vectoring. A limited number of tests were conducted for the upper surface engine configuration in the high lift condition for beta = 10 in order to evaluate lateral directional characteristics, and with the right engine inoperative to evaluate the engine out condition.

  13. Vector Boson Jets with BlackHat and Sherpa

    SciTech Connect

    Berger, C.F.; /MIT, LNS; Bern, Z.; /UCLA; Dixon, Lance J.; /SLAC; Cordero, F.Febres; /Simon Bolivar U.; Forde, D.; /CERN /NIKHEF, Amsterdam; Gleisberg, T.; /SLAC; Ita, H.; /UCLA; Kosower, D.A.; /Saclay, SPhT; Maitre, D.; /Durham U.

    2010-08-25

    We review recent NLO QCD results for W, Z + 3-jet production at hadron colliders, computing using BlackHat and SHERPA, and including also some new results for Z + 3-jet production for the LHC at 7 TeV. We report new progress towards the NLO cross section for W + 4-jet production. In particular, we show that the virtual matrix elements produced by BlackHat are numerically stable. We also show that with an improved integrator and tree-level matrix elements from BlackHat, SHERPA produces well-behaved real-emission contributions. As an illustration, we present the real-emission contributions - including dipole-subtraction terms - to the p{sub T} distribution of the fourth jet, for a single subprocess with the maximum number of gluons.

  14. Measurements of the jet and vector boson in association with jets production, extraction of ?s and PDF constraints at CMS

    NASA Astrophysics Data System (ADS)

    D'Imperio, Giulia

    2015-05-01

    We present CMS results about measurements of cross sections for jet production, which allow basic tests of perturbative QCD predictions. Results include recent jet, dijet, and multijet differential cross sections, and hadronic event shape measurements in pp collisions at a centre-of-mass energy of 7 and 8 TeV, using data collected in the CMS experiment. Total and differential cross section measurements of vector bosons production in association with jets and heavy flavour quarks are also presented. The experimental results are compared to leading and next-to-leading order calculations, both at parton level and in event generators where matrix element calculations are interfaced with parton showers. Recent CMS results related to the extraction of the strong coupling constant and extraction of ?S and PDF are discussed.

  15. Vectoring: Steering a Plane

    NSDL National Science Digital Library

    2011-08-20

    In this two part activity, learners work in pairs or individually to discover how vectoring the thrust from a jet engine affects movement of an airplane. In part one, learners construct an F-15 ACTIVE model with a balloon engine. In part two, learners conduct a series of experiments by changing the angle of the straw to control the direction of the thrust. This activity emphasizes the scientific method including prediction, observation, data collection, and analysis. This lesson plan includes background information, an extension and a sample worksheet.

  16. Effects of upper-surface blowing and thrust vectoring on low speed aerodynamic characteristics of a large-scale supersonic transport model

    NASA Technical Reports Server (NTRS)

    Coe, P. L., Jr.; Mclemore, H. C.; Shivers, J. P.

    1976-01-01

    Tests were conducted in a full scale tunnel to determine the low speed aerodynamic characteristics of a large scale arrow wing supersonic transport configured with engines mounted above the wing for upper surface blowing and conventional lower surface engines having provisions for thrust vectoring. Tests were conducted over an angle of attack range of -10 deg to 34 deg and for Reynolds numbers (based on the mean aerodynamic chord) of 5.17 x 1 million and 3.89 x 1 million. A limited number of tests were also conducted for the upper surface engine configuration in the high lift condition at an angle of sideslip of 10 deg in order to evaluate lateral directional characteristics and with the right engine inoperative in order to evaluate the engine out condition.

  17. Pulsed Ejector Thrust Amplification Tested and Modeled

    NASA Technical Reports Server (NTRS)

    Wilson, Jack

    2004-01-01

    There is currently much interest in pulsed detonation engines for aeronautical propulsion. This, in turn, has sparked renewed interest in pulsed ejectors to increase the thrust of such engines, since previous, though limited, research had indicated that pulsed ejectors could double the thrust in a short device. An experiment has been run at the NASA Glenn Research Center, using a shrouded Hartmann-Sprenger tube as a source of pulsed flow, to measure the thrust augmentation of a statistically designed set of ejectors. A Hartmann- Sprenger tube directs the flow from a supersonic nozzle (Mach 2 in the present experiment) into a closed tube. Under appropriate conditions, an oscillation is set up in which the jet flow alternately fills the tube and then spills around flow emerging from the tube. The tube length determines the frequency of oscillation. By shrouding the tube, the flow was directed out of the shroud as an axial stream. The set of ejectors comprised three different ejector lengths, three ejector diameters, and three nose radii. The thrust of the jet alone, and then of the jet plus ejector, was measured using a thrust plate. The arrangement is shown in this photograph. Thrust augmentation is defined as the thrust of the jet with an ejector divided by the thrust of the jet alone. The experiments exhibited an optimum ejector diameter and length for maximizing the thrust augmentation, but little dependence on nose radius. Different frequencies were produced by changing the length of the Hartmann-Sprenger tube, and the experiment was run at a total of four frequencies. Additional measurements showed that the major feature of the pulsed jet was a starting vortex ring. The size of the vortex ring depended on the frequency, as did the optimum ejector diameter.

  18. Experimental investigation of a thrust augmenting ejector

    NASA Astrophysics Data System (ADS)

    Hidayat, W.

    1985-12-01

    An ejector is basically a jet pump in which the kinetic energy of the jet is made to impart motion to the fluid surrounding it. During this process,in a well designed system,the ejector as a whole experiences a thrust much higher than that of the jet alone. In principle, an ejector is nothing but a jet surrounded by a shroud. This investigation concerns the performance of a two-dimensional ejector with its primary jet excited by a novel method. A constant area duct was used in this experiment. The velocity of the jet at the exit was subsonic. Maximum thrust was obtained when the ejector to jet exit area ratio was about 35. Under this condition a thrust augmentation ratio of 1.65 was achieved, with the jet excited at 20 Hz, whereas without excitation it was only 1.40. The mixing characteristics of the jet under excitation was examined using flow visualization techniques. Smoke filaments illuminated by a sheet of powerful light and schlieren optics with the jet heated were used. Excitation of the jet was found to generate large vortex-like flow structures which might be responsible for enhanced mixing. These vortices extended to considerable distances on both sides of the jet.

  19. Underwater test qualification of the Tomahawk booster and jet tab TVC system

    Microsoft Academic Search

    O. Brevig; K. I. Sleigh; R. W. Casebolt; J. R. Ellison

    1979-01-01

    The test results from the underwater static test firings and the underwater missile launches for the qualification of the Tomahawk booster and jet tab thrust vector control (TVC) are presented. The booster motor is described, noting that it is required to launch the missile from a submerged submarine, travel underwater until broach, and to propel the missile to booster burnout

  20. Statistical error model for a solar electric propulsion thrust subsystem

    NASA Technical Reports Server (NTRS)

    Bantell, M. H.

    1973-01-01

    The solar electric propulsion thrust subsystem statistical error model was developed as a tool for investigating the effects of thrust subsystem parameter uncertainties on navigation accuracy. The model is currently being used to evaluate the impact of electric engine parameter uncertainties on navigation system performance for a baseline mission to Encke's Comet in the 1980s. The data given represent the next generation in statistical error modeling for low-thrust applications. Principal improvements include the representation of thrust uncertainties and random process modeling in terms of random parametric variations in the thrust vector process for a multi-engine configuration.

  1. Deciphering cumulative fault slip vectors from fold scarps: relationships between long-term and co-seismic deformation at the piedmont of the Taiwan fold-and-thrust belt

    NASA Astrophysics Data System (ADS)

    Le Beon, Maryline; Suppe, John; Jaiswal, Manoj; Chen, Yue-Gau; Ustaszewski, Michaela

    2014-05-01

    We document the 30-ka cumulative slip history and long-term slip vector azimuth on the Northern Chelungpu fault based on a series of fault-bend folded alluvial terraces and draw quantitative relationships between geological structure, deformation observed from the geomorphology, and coseismic displacements during the 1999 Mw=7.6 Chi-Chi earthquake. In our study area, three main terrace levels show progressive folding by kink-band migration in relation to the underlying fault geometry, forming a main N-S fold scarp up to ~193 m high and secondary E-W scarps. Detailed analysis using 5-m resolution DEM allows us to characterize the scarp morphology and quantify the deformation parameters, namely terrace heights, fold scarp relief, and fold limb width and slope angle. The 3D deformation of the highest terrace, OSL-dated at 30.2 ± 4.0 ka, enables to simultaneously determine amplitude and azimuth of the long-term slip vector based on scarp relief. The long-term slip vector, oriented N338° ± 6°, is found to parallel the Chi-Chi coseismic displacements in this area. Cumulative slip and dating results yield a constant slip rate of 17.7 ± 2.2 mm/a in the direction N338° ± 6°, which represents ~16% of total shortening across the mountain belt. Late Quaternary shortening rates observed at four sites vary along-strike in similar proportion to Chi-Chi coseismic displacements. Together with the colinearity of long-term and coseismic slip vectors at our study site, this suggests that Chi-Chi earthquake is a characteristic earthquake for the Chelungpu thrust with recurrence interval ~440 years. We also discuss implications for the regional and long-term distribution of shortening in the central Western Foothills.

  2. Vectors

    NSDL National Science Digital Library

    Stern, David P. (David Peter), 1931-

    This web page, authored and curated by David P. Stern, introduces vectors as an extension of numbers having both magnitude and direction. The initial motivation is to describe velocity but the material includes a general discussion of vector algebra and an application to forces for the inclined plane. The page contains links to a related lesson plan and further opportunities to explore vectors. This is part of the extensive web site "From Stargazers to Starships", that uses space exploration and space science to introduce topics in physics and astronomy. Translations in Spanish and French are available.

  3. Precision tests of QCD with jets and vector bosons at HERA and TevaTron

    E-print Network

    C. Glasman

    2008-10-20

    Recent results from HERA and TevaTron on precision tests of QCD with jets, W and Z bosons and photons associated with jets and heavy flavours are presented. The measurements were used to probe QCD at the highest energies, to provide experimental constraints on SM processes that constitute background to new physics, to extract values of the coupling of the strong interaction and to constrain the proton parton distribution functions. The implications of the results on LHC physics are discussed.

  4. Thrust and propulsive efficiency from an instructive viewpoint

    NASA Astrophysics Data System (ADS)

    Kaufman, Richard D.

    2010-09-01

    In a typical engineering or physics curriculum, the momentum equation is used for the determination of jet engine thrust. Even a simple thrust analysis requires a heavy emphasis on mathematics that can cause students and engineers to lose a physical perspective on thrust. This article provides for this physical understanding using only static pressures that act on engine surfaces. Such an alternative, but equivalent, method can offer insights into some special examples of jet engine thrust that contradict commonly held beliefs. One such example is provided by the engine bellmouth that is used for testing jet engines on the ground. The static pressure distribution clearly shows that the engine bellmouth actually experiences forward thrust. Another example is provided by the conic exhaust nozzle that is used at the end of some jet engines. The static pressure distribution shows that the conic nozzle does not experience any forward thrust (although the nozzle increases the overall thrust of an engine through higher pressures upstream of the nozzle). Following these examples, a basis for conceptualizing propulsive efficiency is discussed. This illustrates that it is more efficient to have a smaller acceleration of a large amount of air than a larger acceleration of a smaller amount of air.

  5. Thrust Augmentation with Mixer/Ejector Systems

    NASA Technical Reports Server (NTRS)

    Presz, Walter M., Jr.; Reynolds, Gary; Hunter, Craig

    2002-01-01

    Older commercial aircraft often exceed FAA (Federal Aviation Administration) sideline noise regulations. The major problem is the jet noise associated with the high exhaust velocities of the low bypass ratio engines on such aircraft. Mixer/ejector exhaust systems can provide a simple means of reducing the jet noise on these aircraft by mixing cool ambient air with the high velocity engine gases before they are exhausted to ambient. This paper presents new information on thrust performance predictions, and thrust augmentation capabilities of mixer/ejectors. Results are presented from the recent development program of the patented Alternating Lobe Mixer Ejector Concept (ALMEC) suppressor system for the Gulfstream GII, GIIB and GIII aircraft. Mixer/ejector performance procedures are presented which include classical control volume analyses, compound compressible flow theory, lobed nozzle loss correlations and state of the art computational fluid dynamic predictions. The mixer/ejector thrust predictions are compared to subscale wind tunnel test model data and actual aircraft flight test measurements. The results demonstrate that a properly designed mixer/ejector noise suppressor can increase effective engine bypass ratio and generate large thrust gains at takeoff conditions with little or no thrust loss at cruise conditions. The cruise performance obtained for such noise suppressor systems is shown to be a strong function of installation effects on the aircraft.

  6. Spectroscopy-based thrust sensor for high-speed gaseous flows

    NASA Technical Reports Server (NTRS)

    Hanson, Ronald K. (Inventor)

    1993-01-01

    A system and method for non-intrusively obtaining the thrust value of combustion by-products of a jet engine is disclosed herein. The system includes laser elements for inducing absorption for use in determining the axial velocity and density of the jet flow stream and elements for calculating the thrust value therefrom.

  7. Measuring axial pump thrust

    DOEpatents

    Suchoza, B.P.; Becse, I.

    1988-11-08

    An apparatus for measuring the hydraulic axial thrust of a pump under operation conditions is disclosed. The axial thrust is determined by forcing the rotating impeller off of an associated thrust bearing by use of an elongate rod extending coaxially with the pump shaft. The elongate rod contacts an impeller retainer bolt where a bearing is provided. Suitable measuring devices measure when the rod moves to force the impeller off of the associated thrust bearing and the axial force exerted on the rod at that time. The elongate rod is preferably provided in a housing with a heat dissipation mechanism whereby the hot fluid does not affect the measuring devices. 1 fig.

  8. Measuring axial pump thrust

    DOEpatents

    Suchoza, Bernard P. (McMurray, PA); Becse, Imre (Washington, PA)

    1988-01-01

    An apparatus for measuring the hydraulic axial thrust of a pump under operation conditions is disclosed. The axial thrust is determined by forcing the rotating impeller off of an associated thrust bearing by use of an elongate rod extending coaxially with the pump shaft. The elongate rod contacts an impeller retainer bolt where a bearing is provided. Suitable measuring devices measure when the rod moves to force the impeller off of the associated thrust bearing and the axial force exerted on the rod at that time. The elongate rod is preferably provided in a housing with a heat dissipation mechanism whereby the hot fluid does not affect the measuring devices.

  9. Flight-Determined, Subsonic, Lateral-Directional Stability and Control Derivatives of the Thrust-Vectoring F-18 High Angle of Attack Research Vehicle (HARV), and Comparisons to the Basic F-18 and Predicted Derivatives

    NASA Technical Reports Server (NTRS)

    Iliff, Kenneth W.; Wang, Kon-Sheng Charles

    1999-01-01

    The subsonic, lateral-directional, stability and control derivatives of the thrust-vectoring F-1 8 High Angle of Attack Research Vehicle (HARV) are extracted from flight data using a maximum likelihood parameter identification technique. State noise is accounted for in the identification formulation and is used to model the uncommanded forcing functions caused by unsteady aerodynamics. Preprogrammed maneuvers provided independent control surface inputs, eliminating problems of identifiability related to correlations between the aircraft controls and states. The HARV derivatives are plotted as functions of angles of attack between 10deg and 70deg and compared to flight estimates from the basic F-18 aircraft and to predictions from ground and wind tunnel tests. Unlike maneuvers of the basic F-18 aircraft, the HARV maneuvers were very precise and repeatable, resulting in tightly clustered estimates with small uncertainty levels. Significant differences were found between flight and prediction; however, some of these differences may be attributed to differences in the range of sideslip or input amplitude over which a given derivative was evaluated, and to differences between the HARV external configuration and that of the basic F-18 aircraft, upon which most of the prediction was based. Some HARV derivative fairings have been adjusted using basic F-18 derivatives (with low uncertainties) to help account for differences in variable ranges and the lack of HARV maneuvers at certain angles of attack.

  10. A Jet-diffuser ejector for a V/STOL fighter

    NASA Technical Reports Server (NTRS)

    Alperin, M.; Wu, J. J.

    1981-01-01

    A single ejector equipped with only one vector control jet and a diffuser flap was installed close to the leading edge of the strake of a one-fifth scale, semi-span model of the aircraft, without wing, canard, or tail surface. Tests of the system at a nozzle pressure ratio of 1.24 indicated a thrust augmentation of 1.92 and a thrust in the flight direction of about 12% of the total thrust under static conditions. An ejector stall occured at a ratio of tunnel dynamic pressure to nozzle gage pressure of about 0.008. Ejector stall speed can be delayed by using a boundary layer control jet at the front inlet lip of the ejector.

  11. Static Performance of Six Innovative Thrust Reverser Concepts for Subsonic Transport Applications: Summary of the NASA Langley Innovative Thrust Reverser Test Program

    NASA Technical Reports Server (NTRS)

    Asbury, Scott C.; Yetter, Jeffrey A.

    2000-01-01

    The NASA Langley Configuration Aerodynamics Branch has conducted an experimental investigation to study the static performance of innovative thrust reverser concepts applicable to high-bypass-ratio turbofan engines. Testing was conducted on a conventional separate-flow exhaust system configuration, a conventional cascade thrust reverser configuration, and six innovative thrust reverser configurations. The innovative thrust reverser configurations consisted of a cascade thrust reverser with porous fan-duct blocker, a blockerless thrust reverser, two core-mounted target thrust reversers, a multi-door crocodile thrust reverser, and a wing-mounted thrust reverser. Each of the innovative thrust reverser concepts offer potential weight savings and/or design simplifications over a conventional cascade thrust reverser design. Testing was conducted in the Jet-Exit Test Facility at NASA Langley Research Center using a 7.9%-scale exhaust system model with a fan-to-core bypass ratio of approximately 9.0. All tests were conducted with no external flow and cold, high-pressure air was used to simulate core and fan exhaust flows. Results show that the innovative thrust reverser concepts achieved thrust reverser performance levels which, when taking into account the potential for system simplification and reduced weight, may make them competitive with, or potentially more cost effective than current state-of-the-art thrust reverser systems.

  12. Variable thrust cartridge

    DOEpatents

    Taleyarkhan, Rusi P. (Knoxville, TN)

    2000-11-07

    The present invention is a variable thrust cartridge comprising a water-molten aluminum reaction chamber from which a slug is propelled. The cartridge comprises a firing system that initiates a controlled explosion from the reaction chamber. The explosive force provides a thrust to a slug, preferably contained within the cartridge.

  13. PPT Thrust Stand

    NASA Technical Reports Server (NTRS)

    Haag, Thomas W.

    1995-01-01

    A torsional-type thrust stand has been designed and built to test Pulsed Plasma Thrusters (PPT's) in both single shot and repetitive operating modes. Using this stand, momentum per pulse was determined strictly as a function of thrust stand deflection, spring constant, and natural frequency. No empirical corrections were required. The accuracy of the method was verified using a swinging impact pendulum. Momentum transfer data between the thrust stand and the pendulum were consistent to within 1%. Following initial calibrations, the stand was used to test a Lincoln Experimental Satellite (LES-8/9) thruster. The LES-8/9 system had a mass of approximately 7.5 kg, with a nominal thrust to weight ratio of 1.3 x 10(exp -5). A total of 34 single shot thruster pulses were individually measured. The average impulse bit per pulse was 266 microN-s, which was slightly less than the value of 300 microN-s published in previous reports on this device. Repetitive pulse measurements were performed similar to ordinary steady-state thrust measurements. The thruster was operated for 30 minutes at a repetition rate of 132 pulses per minute and yielded an average thrust of 573 microN. Using average thrust, the average impulse bit per pulse was estimated to be 260 microN-s, which was in agreement with the single shot data. Zero drift during the repetitive pulse test was found to be approximately 1% of the measured thrust.

  14. Strawkets and Thrust

    NSDL National Science Digital Library

    2014-09-18

    In this activity, students investigate the effect that thrust has on rocket flight. Students will make two paper rockets that they can launch themselves by blowing through a straw. These "strawkets" will differ in diameter, such that students will understand that a rocket with a smaller exit nozzle will provide a larger thrust. Students have the opportunity to compare the distances traveled by their two strawkets after predicting where they will land. Since each student will have a slightly different rocket and launching technique, they will observe which factors contribute to a strawket's thrust and performance.

  15. Thrust stand for low-thrust liquid pulsed rocket engines.

    PubMed

    Xing, Qin; Zhang, Jun; Qian, Min; Jia, Zhen-yuan; Sun, Bao-yuan

    2010-09-01

    A thrust stand is developed for measuring the pulsed thrust generated by low-thrust liquid pulsed rocket engines. It mainly consists of a thrust dynamometer, a base frame, a connecting frame, and a data acquisition and processing system. The thrust dynamometer assembled with shear mode piezoelectric quartz sensors is developed as the core component of the thrust stand. It adopts integral shell structure. The sensors are inserted into unique double-elastic-half-ring grooves with an interference fit. The thrust is transferred to the sensors by means of static friction forces of fitting surfaces. The sensors could produce an amount of charges which are proportional to the thrust to be measured. The thrust stand is calibrated both statically and dynamically. The in situ static calibration is performed using a standard force sensor. The dynamic calibration is carried out using pendulum-typed steel ball impact technique. Typical thrust pulse is simulated by a trapezoidal impulse force. The results show that the thrust stand has a sensitivity of 25.832 mV/N, a linearity error of 0.24% FSO, and a repeatability error of 0.23% FSO. The first natural frequency of the thrust stand is 1245 Hz. The thrust stand can accurately measure thrust waveform of each firing, which is used for fine control of on-orbit vehicles in the thrust range of 5-20 N with pulse frequency of 50 Hz. PMID:20887003

  16. Robust nonlinear control of vectored thrust aircraft

    NASA Technical Reports Server (NTRS)

    Doyle, John C.; Murray, Richard; Morris, John

    1993-01-01

    An interdisciplinary program in robust control for nonlinear systems with applications to a variety of engineering problems is outlined. Major emphasis will be placed on flight control, with both experimental and analytical studies. This program builds on recent new results in control theory for stability, stabilization, robust stability, robust performance, synthesis, and model reduction in a unified framework using Linear Fractional Transformations (LFT's), Linear Matrix Inequalities (LMI's), and the structured singular value micron. Most of these new advances have been accomplished by the Caltech controls group independently or in collaboration with researchers in other institutions. These recent results offer a new and remarkably unified framework for all aspects of robust control, but what is particularly important for this program is that they also have important implications for system identification and control of nonlinear systems. This combines well with Caltech's expertise in nonlinear control theory, both in geometric methods and methods for systems with constraints and saturations.

  17. Static test of a large scale swivel nozzle thrust deflector

    NASA Technical Reports Server (NTRS)

    Federspiel, J. F.

    1979-01-01

    Experimental results from a swivel nozzle thrust deflector test program are presented. The deflector was installed behind a 36-inch fan with a tip turbine hot gas drive. The maximum nozzle pressure ratio was 1.2. Nozzle thrust and flow coefficients are presented for a range of vectoring angles. The results are also compared to small scale cold flow test results. The comparison suggests a need for accurate simulation of nozzle entry pressure and temperature profiles on model tests.

  18. Flow induction by rotary jets

    NASA Astrophysics Data System (ADS)

    Garris, Charles A.; Foa, Joseph V.

    Theoretical analyses of generalized flow induction were carried out which showed that the least dissipative mode of flow induction is the cryptosteady mode. Studies were carried out on the energetics of vortex formation showing that in pulsatile thrust augmentors, considerable energy is carried away as kinetic energy of rotation. Parametric studies were conducted on rotary-jet thrust augmentation yielding a best thrust augmentation of 1.97. Theoretical and experimental studies on the utilization of propagating stall were conducted. The promise of eliminating moving parts for the rotary-jet thrust augmentor was explored and parametric testing was conducted to establish conditions for obtaining stall. Experiments showed, however, that stall is relatively difficult to obtain in configurations compatible with the rotary jet thrust augmentor.

  19. Classification of jet fuel properties by near-infrared spectroscopy using fuzzy rule-building expert systems and support vector machines.

    PubMed

    Xu, Zhanfeng; Bunker, Christopher E; Harrington, Peter de B

    2010-11-01

    Monitoring the changes of jet fuel physical properties is important because fuel used in high-performance aircraft must meet rigorous specifications. Near-infrared (NIR) spectroscopy is a fast method to characterize fuels. Because of the complexity of NIR spectral data, chemometric techniques are used to extract relevant information from spectral data to accurately classify physical properties of complex fuel samples. In this work, discrimination of fuel types and classification of flash point, freezing point, boiling point (10%, v/v), boiling point (50%, v/v), and boiling point (90%, v/v) of jet fuels (JP-5, JP-8, Jet A, and Jet A1) were investigated. Each physical property was divided into three classes, low, medium, and high ranges, using two evaluations with different class boundary definitions. The class boundaries function as the threshold to alarm when the fuel properties change. Optimal partial least squares discriminant analysis (oPLS-DA), fuzzy rule-building expert system (FuRES), and support vector machines (SVM) were used to build the calibration models between the NIR spectra and classes of physical property of jet fuels. OPLS-DA, FuRES, and SVM were compared with respect to prediction accuracy. The validation of the calibration model was conducted by applying bootstrap Latin partition (BLP), which gives a measure of precision. Prediction accuracy of 97 ± 2% of the flash point, 94 ± 2% of freezing point, 99 ± 1% of the boiling point (10%, v/v), 98 ± 2% of the boiling point (50%, v/v), and 96 ± 1% of the boiling point (90%, v/v) were obtained by FuRES in one boundaries definition. Both FuRES and SVM obtained statistically better prediction accuracy over those obtained by oPLS-DA. The results indicate that combined with chemometric classifiers NIR spectroscopy could be a fast method to monitor the changes of jet fuel physical properties. PMID:21073794

  20. Low thrust monopropellant engine

    NASA Technical Reports Server (NTRS)

    Kuenzly, J. D. (inventor)

    1981-01-01

    The engine has a conventional body and nozzle configuration. The monopropellant fuel is fed into the thruster with dual injection tubes via an injector shell with dual spray jets. The spray jets are positioned generally opposed to each other. A heater screen pack combination thermally decomposes the fuel after injection into the combustion chamber of the thruster.

  1. Solar electric propulsion thrust subsystem development

    NASA Technical Reports Server (NTRS)

    Masek, T. D.

    1973-01-01

    The Solar Electric Propulsion System developed under this program was designed to demonstrate all the thrust subsystem functions needed on an unmanned planetary vehicle. The demonstration included operation of the basic elements, power matching input and output voltage regulation, three-axis thrust vector control, subsystem automatic control including failure detection and correction capability (using a PDP-11 computer), operation of critical elements in thermal-vacuum-, zero-gravity-type propellant storage, and data outputs from all subsystem elements. The subsystem elements, functions, unique features, and test setup are described. General features and capabilities of the test-support data system are also presented. The test program culminated in a 1500-h computer-controlled, system-functional demonstration. This included simultaneous operation of two thruster/power conditioner sets. The results of this testing phase satisfied all the program goals.

  2. Axisymmetric and non-axisymmetric exhaust jet induced effects on a V/STOL vehicle design. Part 3: Experimental technique

    NASA Technical Reports Server (NTRS)

    Schnell, W. C.

    1982-01-01

    The jet induced effects of several exhaust nozzle configurations (axisymmetric, and vectoring/modulating varients) on the aeropropulsive performance of a twin engine V/STOL fighter design was determined. A 1/8 scale model was tested in an 11 ft transonic tunnel at static conditions and over a range of Mach Numbers from 0.4 to 1.4. The experimental aspects of the static and wind-on programs are discussed. Jet effects test techniques in general, fow through balance calibrations and tare force corrections, ASME nozzle thrust and mass flow calibrations, test problems and solutions are emphasized.

  3. Calibration for Thrust and Airflow Measurements in the CE-22 Advanced Nozzle Test Facility

    NASA Technical Reports Server (NTRS)

    Werner, Roger A.; Wolter, John D.

    2010-01-01

    CE-22 facility procedures and measurements for thrust and airflow calibration obtained with choked-flow ASME nozzles are presented. Six calibration nozzles are used at an inlet total pressure from 20 to 48 psia. Throat areas are from 9.9986 to 39.986 sq. in.. Throat Reynolds number varies from 1.8 to 7.9 million. Nozzle gross thrust coefficient (CFG) uncertainty is 0.25 to 0.75 percent, with smaller uncertainly generally for larger nozzles and higher inlet total pressure. Nozzle discharge coefficient (CDN) uncertainty is 0.15 percent or less for all the data. ASME nozzle calibrations need to be done before and after research model testing to achieve these uncertainties. In addition, facility capability in terms of nozzle pressure ratio (NPR) and nozzle airflow are determined. Nozzle pressure ratio of 50 or more is obtainable at 40 psia for throat areas between 20 and 30 sq. in.. Also presented are results for two of the ASME nozzles vectored at 10deg, a dead-weight check of the vertical (perpendicular to the jet axis) force measurement, a calibration of load cell forces for the effects of facility tank deflection with tank pressure, and the calibration of the metric-break labyrinth seal.

  4. Recommended Practices in Thrust Measurements

    NASA Technical Reports Server (NTRS)

    Polk, James E.; Pancotti, Anthony; Haag, Thomas; King, Scott; Walker, Mitchell; Blakely, Joseph; Ziemer, John

    2013-01-01

    Accurate, direct measurement of thrust or impulse is one of the most critical elements of electric thruster characterization, and one of the most difficult measurements to make. The American Institute of Aeronautics and Astronautics has started an initiative to develop standards for many important measurement processes in electric propulsion, including thrust measurements. This paper summarizes recommended practices for the design, calibration, and operation of pendulum thrust stands, which are widely recognized as the best approach for measuring micro N- to mN-level thrust and micro Ns-level impulse bits. The fundamentals of pendulum thrust stand operation are reviewed, along with its implementation in hanging pendulum, inverted pendulum, and torsional balance configurations. Methods of calibration and recommendations for calibration processes are presented. Sources of error are identified and methods for data processing and uncertainty analysis are discussed. This review is intended to be the first step toward a recommended practices document to help the community produce high quality thrust measurements.

  5. Low thrust vehicle concept study

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Low thrust chemical (hydrogen-oxygen) propulsion systems configured specifically for low acceleration orbit transfer of large space systems were defined. Results indicate that it is cost effective and least risk to combine the OTV and stowed spacecraft in a single 65 K Shuttle. The study shows that the engine for an optimized low thrust stage (1) does not require very low thrust; (2) 1-3 K thrust range appears optimum; (3) thrust transient is not a concern; (4) throttling probably not worthwhile; and (5) multiple thrusters complicate OTV/LSS design and aggravate LSS loads. Regarding the optimum vehicle for low acceleration missions, the single shuttle launch (LSS and expendable OTV) is most cost effective and least risky. Multiple shuttles increase diameter 20%. The space based radar structure short OTV (which maximizes space available for packaged LSS) favors use of torus tank. Propellant tank pressures/vapor residuals are little affected by engine thrust level or number of burns.

  6. 12.2 Vectors in 2D and 3D 1. Vector and Magnitude

    E-print Network

    Anderson, Douglas R.

    12.2 Vectors in 2D and 3D 1. Vector and Magnitude: 2. Examples: 3. Equivalent Vectors: 4. Vector a vector with magnitude 6 in the direction of 2, 2, -1 . 19. The thrust of an airplane's engine produces, in other words in the direction of -i? 21. Two forces F1 and F2 with magnitudes 10 lbs and 12 lbs

  7. Thrust modeling for hypersonic engines

    NASA Technical Reports Server (NTRS)

    Riggins, D. W.; Mcclinton, C. R.

    1995-01-01

    Expressions for the thrust losses of a scramjet engine are developed in terms of irreversible entropy increases and the degree of incomplete combustion. A method is developed which allows the calculation of the lost vehicle thrust due to different loss mechanisms within a given flow-field. This analysis demonstrates clearly the trade-off between mixing enhancement and resultant increased flow losses in scramjet combustors. An engine effectiveness parameter is defined in terms of thrust loss. Exergy and the thrust-potential method are related and compared.

  8. 14 CFR 33.97 - Thrust reversers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...flight-idle forward thrust to maximum reverse thrust and 25 reversals must be made from rated takeoff thrust to maximum reverse thrust. After each reversal the reverser must be operated at full reverse thrust for a period of one minute,...

  9. 14 CFR 33.97 - Thrust reversers.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...flight-idle forward thrust to maximum reverse thrust and 25 reversals must be made from rated takeoff thrust to maximum reverse thrust. After each reversal the reverser must be operated at full reverse thrust for a period of one minute,...

  10. An experimental study of voice-coil driven synthetic jet propulsion for underwater vehicles

    Microsoft Academic Search

    A. M. Polsenberg-Thomas; Joel Burdick; Kamran Mohseni

    2005-01-01

    This paper investigates the thrust and flow structures produced by submerged synthetic jet actuators. Inspired by the propulsion methods of many sea creatures, such as jellyfish, squids, and salps; synthetic jets use vortex rings to create a net thrust. To assess the potential usability of these thrusters for propulsion and maneuvering of small underwater vehicles, a range of synthetic jet

  11. Study of Vector Boson Scattering and Search for New Physics in Events with Two Same-Sign Leptons and Two Jets

    NASA Astrophysics Data System (ADS)

    Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Bergauer, T.; Dragicevic, M.; Erö, J.; Friedl, M.; Frühwirth, R.; Ghete, V. M.; Hartl, C.; Hörmann, N.; Hrubec, J.; Jeitler, M.; Kiesenhofer, W.; Knünz, V.; Krammer, M.; Krätschmer, I.; Liko, D.; Mikulec, I.; Rabady, D.; Rahbaran, B.; Rohringer, H.; Schöfbeck, R.; Strauss, J.; Treberer-Treberspurg, W.; Waltenberger, W.; Wulz, C.-E.; Mossolov, V.; Shumeiko, N.; Suarez Gonzalez, J.; Alderweireldt, S.; Bansal, M.; Bansal, S.; Cornelis, T.; De Wolf, E. A.; Janssen, X.; Knutsson, A.; Lauwers, J.; Luyckx, S.; Ochesanu, S.; Rougny, R.; Van De Klundert, M.; Van Haevermaet, H.; Van Mechelen, P.; Van Remortel, N.; Van Spilbeeck, A.; Blekman, F.; Blyweert, S.; D'Hondt, J.; Daci, N.; Heracleous, N.; Keaveney, J.; Lowette, S.; Maes, M.; Olbrechts, A.; Python, Q.; Strom, D.; Tavernier, S.; Van Doninck, W.; Van Mulders, P.; Van Onsem, G. P.; Villella, I.; Caillol, C.; Clerbaux, B.; De Lentdecker, G.; Dobur, D.; Favart, L.; Gay, A. P. R.; Grebenyuk, A.; Léonard, A.; Mohammadi, A.; Perniè, L.; Reis, T.; Seva, T.; Thomas, L.; Vander Velde, C.; Vanlaer, P.; Wang, J.; Zenoni, F.; Adler, V.; Beernaert, K.; Benucci, L.; Cimmino, A.; Costantini, S.; Crucy, S.; Dildick, S.; Fagot, A.; Garcia, G.; Mccartin, J.; Ocampo Rios, A. A.; Ryckbosch, D.; Salva Diblen, S.; Sigamani, M.; Strobbe, N.; Thyssen, F.; Tytgat, M.; Yazgan, E.; Zaganidis, N.; Basegmez, S.; Beluffi, C.; Bruno, G.; Castello, R.; Caudron, A.; Ceard, L.; Da Silveira, G. G.; Delaere, C.; du Pree, T.; Favart, D.; Forthomme, L.; Giammanco, A.; Hollar, J.; Jafari, A.; Jez, P.; Komm, M.; Lemaitre, V.; Nuttens, C.; Pagano, D.; Perrini, L.; Pin, A.; Piotrzkowski, K.; Popov, A.; Quertenmont, L.; Selvaggi, M.; Vidal Marono, M.; Vizan Garcia, J. M.; Beliy, N.; Caebergs, T.; Daubie, E.; Hammad, G. H.; Aldá Júnior, W. L.; Alves, G. A.; Brito, L.; Correa Martins Junior, M.; Dos Reis Martins, T.; Mora Herrera, C.; Pol, M. E.; Carvalho, W.; Chinellato, J.; Custódio, A.; Da Costa, E. M.; De Jesus Damiao, D.; De Oliveira Martins, C.; Fonseca De Souza, S.; Malbouisson, H.; Matos Figueiredo, D.; Mundim, L.; Nogima, H.; Prado Da Silva, W. L.; Santaolalla, J.; Santoro, A.; Sznajder, A.; Tonelli Manganote, E. J.; Vilela Pereira, A.; Bernardes, C. A.; Dogra, S.; Fernandez Perez Tomei, T. R.; Gregores, E. M.; Mercadante, P. G.; Novaes, S. F.; Padula, Sandra S.; Aleksandrov, A.; Genchev, V.; Iaydjiev, P.; Marinov, A.; Piperov, S.; Rodozov, M.; Sultanov, G.; Vutova, M.; Dimitrov, A.; Glushkov, I.; Hadjiiska, R.; Litov, L.; Pavlov, B.; Petkov, P.; Bian, J. G.; Chen, G. M.; Chen, H. S.; Chen, M.; Cheng, T.; Du, R.; Jiang, C. H.; Plestina, R.; Romeo, F.; Tao, J.; Wang, Z.; Asawatangtrakuldee, C.; Ban, Y.; Li, Q.; Liu, S.; Mao, Y.; Qian, S. J.; Wang, D.; Zou, W.; Avila, C.; Cabrera, A.; Chaparro Sierra, L. F.; Florez, C.; Gomez, J. P.; Gomez Moreno, B.; Sanabria, J. C.; Godinovic, N.; Lelas, D.; Polic, D.; Puljak, I.; Antunovic, Z.; Kovac, M.; Brigljevic, V.; Kadija, K.; Luetic, J.; Mekterovic, D.; Sudic, L.; Attikis, A.; Mavromanolakis, G.; Mousa, J.; Nicolaou, C.; Ptochos, F.; Razis, P. A.; Bodlak, M.; Finger, M.; Finger, M.; Assran, Y.; Ellithi Kamel, A.; Mahmoud, M. A.; Radi, A.; Kadastik, M.; Murumaa, M.; Raidal, M.; Tiko, A.; Eerola, P.; Fedi, G.; Voutilainen, M.; Härkönen, J.; Karimäki, V.; Kinnunen, R.; Kortelainen, M. J.; Lampén, T.; Lassila-Perini, K.; Lehti, S.; Lindén, T.; Luukka, P.; Mäenpää, T.; Peltola, T.; Tuominen, E.; Tuominiemi, J.; Tuovinen, E.; Wendland, L.; Talvitie, J.; Tuuva, T.; Besancon, M.; Couderc, F.; Dejardin, M.; Denegri, D.; Fabbro, B.; Faure, J. L.; Favaro, C.; Ferri, F.; Ganjour, S.; Givernaud, A.; Gras, P.; Hamel de Monchenault, G.; Jarry, P.; Locci, E.; Malcles, J.; Rander, J.; Rosowsky, A.; Titov, M.; Baffioni, S.; Beaudette, F.; Busson, P.; Charlot, C.; Dahms, T.; Dalchenko, M.; Dobrzynski, L.; Filipovic, N.; Florent, A.; Granier de Cassagnac, R.; Mastrolorenzo, L.; Miné, P.; Mironov, C.; Naranjo, I. N.; Nguyen, M.; Ochando, C.; Paganini, P.; Regnard, S.; Salerno, R.; Sauvan, J. B.; Sirois, Y.; Veelken, C.; Yilmaz, Y.; Zabi, A.; Agram, J.-L.; Andrea, J.; Aubin, A.; Bloch, D.; Brom, J.-M.; Chabert, E. C.; Collard, C.; Conte, E.; Fontaine, J.-C.; Gelé, D.; Goerlach, U.; Goetzmann, C.; Le Bihan, A.-C.; Van Hove, P.; Gadrat, S.; Beauceron, S.; Beaupere, N.; Boudoul, G.; Bouvier, E.; Brochet, S.; Carrillo Montoya, C. A.; Chasserat, J.; Chierici, R.; Contardo, D.; Depasse, P.; El Mamouni, H.; Fan, J.; Fay, J.; Gascon, S.; Gouzevitch, M.; Ille, B.; Kurca, T.; Lethuillier, M.; Mirabito, L.; Perries, S.; Ruiz Alvarez, J. D.; Sabes, D.; Sgandurra, L.; Sordini, V.; Vander Donckt, M.; Verdier, P.; Viret, S.; Xiao, H.; Tsamalaidze, Z.; Autermann, C.; Beranek, S.

    2015-02-01

    A study of vector boson scattering in p p collisions at a center-of-mass energy of 8 TeV is presented. The data sample corresponds to an integrated luminosity of 19.4 fb-1 collected with the CMS detector. Candidate events are selected with exactly two leptons of the same charge, two jets with large rapidity separation and high dijet mass, and moderate missing transverse energy. The signal region is expected to be dominated by electroweak same-sign W -boson pair production. The observation agrees with the standard model prediction. The observed significance is 2.0 standard deviations, where a significance of 3.1 standard deviations is expected based on the standard model. Cross section measurements for W±W± and W Z processes in the fiducial region are reported. Bounds on the structure of quartic vector-boson interactions are given in the framework of dimension-eight effective field theory operators, as well as limits on the production of doubly charged Higgs bosons.

  12. A Simple Model of Pulsed Ejector Thrust Augmentation

    NASA Technical Reports Server (NTRS)

    Wilson, Jack; Deloof, Richard L. (Technical Monitor)

    2003-01-01

    A simple model of thrust augmentation from a pulsed source is described. In the model it is assumed that the flow into the ejector is quasi-steady, and can be calculated using potential flow techniques. The velocity of the flow is related to the speed of the starting vortex ring formed by the jet. The vortex ring properties are obtained from the slug model, knowing the jet diameter, speed and slug length. The model, when combined with experimental results, predicts an optimum ejector radius for thrust augmentation. Data on pulsed ejector performance for comparison with the model was obtained using a shrouded Hartmann-Sprenger tube as the pulsed jet source. A statistical experiment, in which ejector length, diameter, and nose radius were independent parameters, was performed at four different frequencies. These frequencies corresponded to four different slug length to diameter ratios, two below cut-off, and two above. Comparison of the model with the experimental data showed reasonable agreement. Maximum pulsed thrust augmentation is shown to occur for a pulsed source with slug length to diameter ratio equal to the cut-off value.

  13. Rapidity correlations between high p{sub T} intermediate vector bosons and jets in {bar p}p collisions at {radical}s = 1.8 TeV

    SciTech Connect

    Abachi, S.

    1995-07-01

    D{O} has used W {yields} e{nu} and Z {yields} e{sup +}e{sup -} events produced in association with a high p{sub T}, jet to examine the effects of strong radiative corrections. We have compared the primary jet pseudorapidity distribution, as a function of reconstructed W or Z boson rapidity to leading order (LO) and Next-to-Leading order (NLO) QCD Monte Carlo generators, as well as a model based on extended color dipoles. We find that the primary jet is more central than either LO or NLO expectations. None of the Monte Carlo programs does a good job of predicting the shape of the jet distributions as a function of intermediate vector bosons rapidity.

  14. Deep space communications technology thrusts

    NASA Technical Reports Server (NTRS)

    Yuen, Joseph H.

    1992-01-01

    The paper discusses the technology thrusts that are currently being developed for deep space missions as well as the expected dividends of these thrusts during the 1990's and beyond. Particular attention is given to Ka-band (32 GHz) development, channel coding, source coding, and optical communications. The ongoing development described here attempts to meet the telecommunications demands of future missions by stressing cooperative developments between ground networks and flight projects in order to optimize NASA's overall investment in solar system investment.

  15. In-flight thrust determination

    NASA Technical Reports Server (NTRS)

    Abernethy, Robert B.; Adams, Gary R.; Ascough, John C.; Baer-Riedhart, Jennifer L.; Balkcom, George H.; Biesiadny, Thomas

    1986-01-01

    The major aspects of processes that may be used for the determination of in-flight thrust are reviewed. Basic definitions are presented as well as analytical and ground-test methods for gathering data and calculating the thrust of the propulsion system during the flight development program of the aircraft. Test analysis examples include a single-exhaust turbofan, an intermediate-cowl turbofan, and a mixed-flow afterburning turbofan.

  16. Micro thrust and heat generator

    SciTech Connect

    Garcia, E.J.

    1995-12-31

    The present invention relates generally to micromachines such as microengines or micromotors. More specifically, the invention is directed to a micro rocket which functions as a source of heat and thrust, and utilizes chemical energy to drive or power micromechanical apparatuses. The invention is adaptable to applications involving defense, bio-medical, manufacturing, consumer product, aviation, automotive, computer, inspection, and safety systems. A micro thrust and heat generator has a means for providing a combustion fuel source to an ignition chamber of the micro thrust and heat generator. The fuel is ignited by a ignition means within the micro thrust and heat generator`s ignition chamber where it burns and creates a pressure. A nozzle formed from the combustion chamber extends outward from the combustion chamber and tappers down to a narrow diameter and then opens into a wider diameter where the nozzle then terminates outside of said combustion chamber. The pressure created within the combustion chamber accelerates as it leaves the chamber through the nozzle resulting in pressure and heat escaping from the nozzle to the atmosphere outside the micro thrust and heat generator. The micro thrust and heat generator can be microfabricated from a variety of materials, e.g., of polysilicon, on one wafer using surface micromachining batch fabrication techniques or high aspect ratio micromachine techniques (LIGA).

  17. Uncertainty of in-flight thrust determination

    NASA Technical Reports Server (NTRS)

    Abernethy, Robert B.; Adams, Gary R.; Steurer, John W.; Ascough, John C.; Baer-Riedhart, Jennifer L.; Balkcom, George H.; Biesiadny, Thomas

    1986-01-01

    Methods for estimating the measurement error or uncertainty of in-flight thrust determination in aircraft employing conventional turbofan/turbojet engines are reviewed. While the term 'in-flight thrust determination' is used synonymously with 'in-flight thrust measurement', in-flight thrust is not directly measured but is determined or calculated using mathematical modeling relationships between in-flight thrust and various direct measurements of physical quantities. The in-flight thrust determination process incorporates both ground testing and flight testing. The present text is divided into the following categories: measurement uncertainty methodoogy and in-flight thrust measurent processes.

  18. Search for vector-like $B$ quarks in events with one isolated lepton, missing transverse momentum and jets at $\\sqrt{s}=$ 8 TeV with the ATLAS detector

    E-print Network

    ATLAS Collaboration

    2015-03-18

    A search has been performed for pair production of heavy vector-like down-type ($B$) quarks. The analysis explores the lepton-plus-jets final state, characterized by events with one isolated charged lepton (electron or muon), significant missing transverse momentum and multiple jets. One or more jets are required to be tagged as arising from $b$-quarks, and at least one pair of jets must be tagged as arising from the hadronic decay of an electroweak boson. The analysis uses the full data sample of $pp$ collisions recorded in 2012 by the ATLAS detector at the LHC, operating at a center-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 20.3 fb$^{-1}$. No significant excess of events is observed above the expected background. Limits are set on vector-like $B$ production, as a function of the $B$ branching ratios, assuming the allowable decay modes are $B \\rightarrow Wt/Zb/Hb$. In the chiral limit with a branching ratio of 100% for the decay $B \\rightarrow Wt$, the observed (expected) 95% CL lower limit on the vector-like $B$ mass is 810 GeV (760 GeV). In the case where the vector-like $B$ quark has branching ratio values corresponding to those of an $SU(2)$ singlet state, the observed (expected) 95% CL lower limit on the vector-like $B$ mass is 640 GeV (505 GeV). The same analysis, when used to investigate pair production of a colored, charge 5/3 exotic fermion $T_{5/3}$, with subsequent decay $T_{5/3} \\rightarrow Wt$, sets an observed (expected) 95% CL lower limit on the $T_{5/3}$ mass of 840 GeV (780 GeV).

  19. Army (MANTECH) Thrust Area Concept: Optics Thrust Area

    NASA Technical Reports Server (NTRS)

    Kopacz, Stanley P.

    1992-01-01

    With the shrinking of the U.S. Army's material needs and the compression of defense requirements, the Army Manufacturing Technology (MANTECH) Program has the opportunity to advance the manufacturing state-of-the-art and solve near term production problems of the U.S. industrial base. To exploit this opportunity, the Army restructured its MANTECH efforts in FY 90 based on a thrust area concept. Each of the ten current thrusts, directed by a thrust area manager, has a broad technical objective selected to improve specific manufacturing processes. The manager is charged with setting objectives, selecting tasks, monitoring execution, leveraging external resources, and establishing microfactories to promote technology transfer. The Optics Manufacturing Thrust is an example of the concept. It is currently directed at revitalizing the domestic precision optics manufacturing base, now characterized by high labor costs and 1940's technology, through introduction of revolutionary machines, new processes, and Computer Integrated Manufacturing (CIM) principles. Leveraging of MANTECH dollars with those of industry, academia, and state governments led to the establishment of the center for Optics Manufacturing and plans for regional centers. Recognition of the U.S. as a world leader in precision optics manufacturing and a dramatic reduction of both manufacturing time and cost should accrue from thrust area efforts.

  20. Predicted flight characteristics of the augmentor wing jet STOL research aircraft

    NASA Technical Reports Server (NTRS)

    Spitzer, R. E.

    1972-01-01

    An existing deHavilland C-8A airplane has been modified into an augmentor wing flight test vehicle. Research objectives are to verify the augmentor flap concept and to produce data for STOL airworthiness criteria. The Modified C-8A provides the means for jet-STOL flight research down to a 60 knot approach speed. The airplane has a high thrust-to-weight ratio, high-lift flap system, vectored thrust, powerful flight controls, and lateral-directional stability augmentation system. Normal performance and handling qualities are expected to be satisfactory. Analysis and piloted simulator results indicate that stability and control characteristics in conventional flight are rated satisfactory. Handling qualities in the STOL regime are also generally satisfactory, although pilot workload is high about the longitudinal axis.

  1. Finite-thrust optimization of interplanetary transfers of space vehicle with bimodal nuclear thermal propulsion

    NASA Astrophysics Data System (ADS)

    Kharytonov, Oleksii M.; Kiforenko, Boris M.

    2011-08-01

    The nuclear thermal rocket (NTR) propulsion is one of the leading promising technologies for primary space propulsion for manned exploration of the solar system due to its high specific impulse capability and sufficiently high thrust-to-weight ratio. Another benefit of NTR is its possible bimodal design, when nuclear reactor is used for generation of a jet thrust in a high-thrust mode and (with an appropriate power conversion system) as a source of electric power to supply the payload and the electric engines in a low-thrust mode. The model of the NTR thrust control was developed considering high-thrust NTR as a propulsion system of limited power and exhaust velocity. For the proposed model the control of the thrust value is accomplished by the regulation of reactor thermal power and propellant mass flow rate. The problem of joint optimization of the combination of high- and low-thrust arcs and the parameters of bimodal NTR (BNTR) propulsion system is considered for the interplanetary transfers. The interplanetary trajectory of the space vehicle is formed by the high-thrust NTR burns, which define planet-centric maneuvers and by the low-thrust heliocentric arcs where the nuclear electric propulsion (NEP) is used. The high-thrust arcs are analyzed using finite-thrust approach. The motion of the corresponding dynamical system is realized in three phase spaces concerning the departure planet-centric maneuver by means of high-thrust NTR propulsion, the low-thrust NEP heliocentric maneuver and the approach high-thrust NTR planet-centric maneuver. The phase coordinates are related at the time instants of the change of the phase spaces due to the relations between the space vehicle masses. The optimal control analysis is performed using Pontryagin's maximum principle. The numerical results are analyzed for Earth-Mars "sprint" transfer. The optimal values of the parameters that define the masses of NTR and NEP subsystems have been evaluated. It is shown that the low-thrust NEP subsystem with Brayton cycle power conversion system is preferable in comparison with NEP subsystem with thermoemission power conversion system.

  2. Low thrust propulsion literature survey

    NASA Technical Reports Server (NTRS)

    Monroe, Darrel

    1989-01-01

    A literature search was performed to investigate the area of low thrust propulsion. In an effort to evaluate this technology, a number of articles, obtained through the use of the NASA-RECON database, were collected and categorized. The study indicates that although much was done, particularly in the 1960's and 1970's, more can be done in the area of practical navigation and guidance. It is suggested that the older studies be reinvestigated to see what potential there exists for future low thrust applications.

  3. Study of Slanted Perforated Jets

    NASA Astrophysics Data System (ADS)

    Ahmed, R. Asad; Thanigaiarasu, S.; Santhosh, J.; Elangovan, S.; Rathakrishnan, E.

    2013-12-01

    This paper presents the numerical simulation of the subsonic jets controlled by slanted perforated tabs and its performance of mixing efficiency is compared with the jet controlled by solid tab and free jet. The objective of this paper is to study the performance of slanted perforation geometry tabs in controlling high speed jets to enhance the mixing of jet with the ambient air, to suppress the noise level and to minimize the thrust loss. In this paper the simulations have been carried out using the commercial meshing and analysis software. Due to the effect of tabs the potential core decay occurs and velocity reduces drastically because of enhanced mixing produced by the tabs. From the results it is found that in slanted perforated tab the main jet interacts with the slanted perforated jet which causes in effective mixing, instability in jets and lower thrust loss when compared with the free jet. The decay of the potential core and velocity reduction is computed by simulation for 0.4 Mach number. Velocity plots are obtained at both near field and far field downstream locations to study the jet distortion with slanted perforated tabs and solid tabs. The results obtained for perforated tabs for 0.4 Mach number are also compared with various other Mach numbers. They have also been validated with experimental results which show good agreement with the computational results.

  4. Pulsed Electric Propulsion Thrust Stand Calibration Method

    NASA Technical Reports Server (NTRS)

    Wong, Andrea R.; Polzin, Kurt A.; Pearson, J. Boise

    2011-01-01

    The evaluation of the performance of any propulsion device requires the accurate measurement of thrust. While chemical rocket thrust is typically measured using a load cell, the low thrust levels associated with electric propulsion (EP) systems necessitate the use of much more sensitive measurement techniques. The design and development of electric propulsion thrust stands that employ a conventional hanging pendulum arm connected to a balance mechanism consisting of a secondary arm and variable linkage have been reported in recent publications by Polzin et al. These works focused on performing steady-state thrust measurements and employed a static analysis of the thrust stand response. In the present work, we present a calibration method and data that will permit pulsed thrust measurements using the Variable Amplitude Hanging Pendulum with Extended Range (VAHPER) thrust stand. Pulsed thrust measurements are challenging in general because the pulsed thrust (impulse bit) occurs over a short timescale (typically 1 micros to 1 millisecond) and cannot be resolved directly. Consequently, the imparted impulse bit must be inferred through observation of the change in thrust stand motion effected by the pulse. Pulsed thrust measurements have typically only consisted of single-shot operation. In the present work, we discuss repetition-rate pulsed thruster operation and describe a method to perform these measurements. The thrust stand response can be modeled as a spring-mass-damper system with a repetitive delta forcing function to represent the impulsive action of the thruster.

  5. Aeroacoustics of hot jets

    NASA Astrophysics Data System (ADS)

    Viswanathan, K.

    2004-10-01

    A systematic study has been undertaken to quantify the effect of jet temperature on the noise radiated by subsonic jets. Nozzles of different diameters were tested to uncover the effects of Reynolds number. All the tests were carried out at Boeing's Low Speed Aeroacoustic Facility, with simultaneous measurement of thrust and noise. It is concluded that the change in spectral shape at high jet temperatures, normally attributed to the contribution from dipoles, is due to Reynolds number effects and not dipoles. This effect has not been identified before. A critical value of the Reynolds number that would need to be maintained to avoid the effects associated with low Reynolds number has been estimated to be {˜}400 000. It is well-known that large-scale structures are the dominant generators of noise in the peak radiation direction for high-speed jets. Experimental evidence is presented that shows the spectral shape at angles close to the jet axis from unheated low subsonic jets to be the same as from heated supersonic jets. A possible mechanism for the observed trend is proposed. When a subsonic jet is heated with the Mach number held constant, there is a broadening of the angular sector in which peak radiation occurs. Furthermore, there is a broadening of the spectral peak. Similar trends have been observed at supersonic Mach numbers. The spectral shapes in the forward quadrant and in the near-normal angles from unheated and heated subsonic jets also conform to the universal shape obtained from supersonic jet data. Just as for unheated jets, the peak frequency at angles close to the jet axis is independent of jet velocity as long as the acoustic Mach number is less than unity. The extensive database generated in the current test programme is intended to provide test cases with high-quality data that could be used for the evaluation of theoretical/semi-theoretical jet noise prediction methodologies.

  6. Thrust reverser with variable nozzle

    NASA Technical Reports Server (NTRS)

    Butler, Lawrence (Inventor)

    1997-01-01

    A thrust reverser is provided for both modulating and reversing bypass flow discharged from a fan through a bypass duct of a turbofan gas turbine engine. The reverser includes an aft cowl joined to a forward cowl and having an aft end surrounding a core engine to define a discharge fan nozzle of minimum flow throat area. The aft cowl is axially translatable relative to the forward cowl from a first position fully retracted against the forward cowl, to a second position partially extended from the forward cowl, and to a third position fully extended from the forward cowl. A plurality of cascade turning vanes are disposed between the forward and aft cowls, and a plurality of thrust reversing deflector doors are pivotally mounted to the aft cowl and bound the bypass duct. The deflector doors are selectively deployed from a stowed position corresponding with the first and second positions of the aft cowl for allowing unrestricted flow of the bypass flow through the fan nozzle. The doors also have a deployed position corresponding with the third position of the aft cowl for substantially deflecting the bypass flow from discharging through the fan nozzle to discharging through the cascade vanes for effecting thrust reverse. Axial translation of the aft cowl between the first and second positions varies flow area of the fan nozzle to vary thrust effected by the discharged bypass flow.

  7. CFES RESEARCH THRUSTS: Energy Storage

    E-print Network

    Lü, James Jian-Qiang

    CFES RESEARCH THRUSTS: Energy Storage Wind Energy Solar Energy Smart Grids Smart Buildings For our industrial partners, the Energy Scholars program is an opportunity to connect with the talent of Rensselaer Energy Systems (CFES) actively partners with industry, government, and educational institutions

  8. Experimental performance of cascade thrust reversers at forward velocity

    NASA Technical Reports Server (NTRS)

    Dietrich, D. A.; Luidens, R. W.

    1973-01-01

    A series of static and wind tunnel tests were performed on four cowl cascade thrust reverser configurations which had various reversed jet emission patterns applicable to an externally blown flap STOL aircraft. The work was performed using a model fan which was 14.0 cm in diameter and passed a fan mass flow of 2.49 kg/sec at an approximate fan pressure ratio of 1.22 and fan corrected rotational speed of 35,800 rpm. The tests demonstrated that the reingestion of fan flow significantly reduced the reverser efficiency and that the thrust reverser efficiency was improved by reducing the reversed jet azimuthal emmission angle. The reverser efficiency at STOL landing speeds was as high as 0.95; however, configurations with lateral emission were adversely affected by yawing the nacelle at forward velocity. Measurements of the internal static pressure at the stator exit showed significant increases in the local static pressure for configurations with reduced jet emission angles.

  9. Formation of a synthetic jet based on a dielectric barrier discharge

    NASA Astrophysics Data System (ADS)

    Bocharnikov, V. M.; Semin, N. V.; Savel'ev, A. S.; Krivokorytov, M. S.; Golub, V. V.

    2014-07-01

    Specific thrust of a synthetic jet based on a dielectric barrier discharge generated by a symmetric actuator has been measured. The dependence of the specific thrust on the distance between exposed electrodes at various applied voltages has been studied. The role of convection at various distances between exposed electrodes has been qualitatively assessed by schlieren imaging of synthetic jets.

  10. Analytical guidance for spacecraft relative motion under constant thrust using relative orbit elements

    NASA Astrophysics Data System (ADS)

    Bevilacqua, Riccardo; Lovell, Thomas Alan

    2014-09-01

    Proximity control of modern nano-spacecraft often relies on low and discrete thrust engines that are characterized by low consumption, and generate on-off force profiles. New guidance solutions must take into account the nature of this type of orbital engines. This paper introduces novel analytical guidance solutions for spacecraft relative motion considering continuous, on-off thrust, and using relative orbit elements as a geometrical representation of the dynamics. The solutions provide the relative state vector at any given time, accommodating any thrust magnitude along the three directions of the relative frame, as well as generic activation times and durations. Relative orbit elements geometrically interpret key aspects of the relative motion, including for example, the relative ellipse size, and the evolution of its center in time. The new solutions provide the guidance designer with a direct visualization of the thrust effects on the relative motion geometry, offering new possibilities for analytical guidance in the presence of continuous thrust engines, such as low thrust engines on nano-spacecraft. The paper presents the analytical solutions, and tests their effectiveness using a sample thrust profile based on input-shaping, previously developed by one of the authors using classical Cartesian coordinates. The use of relative orbit elements shows substantial benefits and added simplicity with respect to Cartesian-based approaches, holding the promise for straightforward onboard spacecraft implementation. The software developed for this research will be available open source1

  11. The application of parameter estimation to flight measurements to obtain lateral-directional stability derivatives of an augmented jet-flap STOL airplane

    NASA Technical Reports Server (NTRS)

    Stephenson, J. D.

    1983-01-01

    Flight experiments with an augmented jet flap STOL aircraft provided data from which the lateral directional stability and control derivatives were calculated by applying a linear regression parameter estimation procedure. The tests, which were conducted with the jet flaps set at a 65 deg deflection, covered a large range of angles of attack and engine power settings. The effect of changing the angle of the jet thrust vector was also investigated. Test results are compared with stability derivatives that had been predicted. The roll damping derived from the tests was significantly larger than had been predicted, whereas the other derivatives were generally in agreement with the predictions. Results obtained using a maximum likelihood estimation procedure are compared with those from the linear regression solutions.

  12. Pneumatically actuated micromachined synthetic jet modulators

    Microsoft Academic Search

    David J. Coe; Mark G. Allen; Christopher S. Rinehart; Ari Glezer

    2006-01-01

    Results presented in the synthetic jet literature have focused on the demonstration of and application of one or more single-orifice synthetic jet actuators in jet vectoring and other aerodynamic applications. For these applications, amplitude and phase modulation techniques are often used in conjunction with the oscillatory nature of the synthetic jet flow to achieve the desired results. In this work

  13. Modular multi-engine thrust control assembly

    SciTech Connect

    Sakurai, S.

    1986-02-04

    This patent describes a modular thrust control lever assembly for controling forward/reverse thrust generated by an aircraft engine. It includes an electric/electronic engine thrust control system, an inhibit mechanism for preventing inadverent or premature establishment of at least one of forward and reverse engine thrust. It consists of a (a) housing; (b) a control lever assembly pivotally mounted within the housing for fore and aft pivotal movement in a single vertical plane; (c) movable inhibit mechanism normally mounted in the path of movement of the laterally projecting roller on the control lever assembly between at least one of the maximum thrust limit positions of the assembly and the adjacent intermediate idle thrust position; (d) a electric/electronic engine thrust control system including an mechanism for reconfiguring the thrust controls of the engine upon movement of the thrust control lever assembly to the adjacent intermediate idle thrust position; (e) a mechanism responsive to the output signal for shifting the inhibit mechanism out of the path of movement of the control lever assembly.

  14. Jet-propulsion in anisopteran dragonfly larvae

    Microsoft Academic Search

    P. J. Mill; R. S. Pickard

    1975-01-01

    Jet-propulsion in dragonfly larvae is achieved by the rapid ejection of water from a specialised rectal chamber via the anus, at a frequency of up to 2.2 cycles\\/s. Movement, forward thrust and muscular activity have been recorded in restrained and free-swimming larvae. Forward thrusts of up to 1.5 g wt result from the expiratory phases of cycles lasting 0.1 to

  15. Development and test of electromechanical actuators for thrust vector control

    Microsoft Academic Search

    Rae A. Weir; John R. Cowan

    1993-01-01

    A road map of milestones toward the goal of a full scale Redesigned Solid Rocket Motor\\/Flight Support Motor (RSRM\\/FSM) hot fire test is discussed. These milestones include: component feasibility, full power system demonstration, SSME hot fire tests, and RSRM hot fire tests. The participation of the Marshall Space Flight Center is emphasized.

  16. Thrust chamber material technology program

    NASA Technical Reports Server (NTRS)

    Andrus, J. S.; Bordeau, R. G.

    1989-01-01

    This report covers work performed at Pratt & Whitney on development of copper-based materials for long-life, reusable, regeneratively cooled rocket engine thrust chambers. The program approached the goal of enhanced cyclic life through the application of rapid solidification to alloy development, to introduce fine dispersions to strengthen and stabilize the alloys at elevated temperatures. After screening of alloy systems, copper-based alloys containing Cr, Co, Hf, Ag, Ti, and Zr were processed by rapid-solidification atomization in bulk quantities. Those bulk alloys showing the most promise were characterized by tensile testing, thermal conductivity testing, and elevated-temperature, low-cycle fatigue (LFC) testing. Characterization indicated that Cu- 1.1 percent Hf exhibited the greatest potential as an improved-life thrust chamber material, exhibiting LCF life about four times that of NASA-Z. Other alloys (Cu- 0.6 percent Zr, and Cu- 0.6 percent Zr- 1.0 percent Cr) exhibited promise for use in this application, but needed more development work to balance properties.

  17. Structure of the eastern Red Rocks and Wind Ridge thrust faults, Wyoming: how a thrust fault gains displacement along strike

    E-print Network

    Huntsman, Brent Stanley

    1983-01-01

    displacement on th1s fault could not be documented. Along the str1ke of the Red Rocks Fault the hor1zontal shortening in the direction of tecton1c transport decreases by 225 m in a distance of 1340 m as it terminates towards the southeast. Much... thrust fault can gain displacement along strike is proposed. The Red Rocks Fault gains displacement along strike towards the northwest via oblique faults (the transverse faults). Net displacement vectors point in the direction of tectonic transport...

  18. Dielectric Barrier Discharge (DBD) Plasma Actuators Thrust-Measurement Methodology Incorporating New Anti-Thrust Hypothesis

    NASA Technical Reports Server (NTRS)

    Ashpis, David E.; Laun, Matthew C.

    2014-01-01

    We discuss thrust measurements of Dielectric Barrier Discharge (DBD) plasma actuators devices used for aerodynamic active flow control. After a review of our experience with conventional thrust measurement and significant non-repeatability of the results, we devised a suspended actuator test setup, and now present a methodology of thrust measurements with decreased uncertainty. The methodology consists of frequency scans at constant voltages. The procedure consists of increasing the frequency in a step-wise fashion from several Hz to the maximum frequency of several kHz, followed by frequency decrease back down to the start frequency of several Hz. This sequence is performed first at the highest voltage of interest, then repeated at lower voltages. The data in the descending frequency direction is more consistent and selected for reporting. Sample results show strong dependence of thrust on humidity which also affects the consistency and fluctuations of the measurements. We also observed negative values of thrust or "anti-thrust", at low frequencies between 4 Hz and up to 64 Hz. The anti-thrust is proportional to the mean-squared voltage and is frequency independent. Departures from the parabolic anti-thrust curve are correlated with appearance of visible plasma discharges. We propose the anti-thrust hypothesis. It states that the measured thrust is a sum of plasma thrust and anti-thrust, and assumes that the anti-thrust exists at all frequencies and voltages. The anti-thrust depends on actuator geometry and materials and on the test installation. It enables the separation of the plasma thrust from the measured total thrust. This approach enables more meaningful comparisons between actuators at different installations and laboratories. The dependence on test installation was validated by surrounding the actuator with a large diameter, grounded, metal sleeve.

  19. Vector boson plus multijet production

    E-print Network

    Marek Schonherr

    2013-02-15

    In this contribution the developments in the description of vector boson plus jets signatures at hadron colliders in recent years are summarised. Particular focus is put on its relevance as background to top physics.

  20. Search for production of vector-like quark pairs and of four top quarks in the lepton-plus-jets final state in $pp$ collisions at $\\sqrt{s}=8$ TeV with the ATLAS detector

    E-print Network

    Aad, Georges; ATLAS Collaboration; Abdallah, Jalal; Abdinov, Ovsat; Aben, Rosemarie; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Abreu, Ricardo; Abulaiti, Yiming; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Adelman, Jahred; Adomeit, Stefanie; Adye, Tim; Affolder, Tony; Agatonovic-Jovin, Tatjana; Aguilar-Saavedra, Juan Antonio; Ahlen, Steven; Ahmadov, Faig; Aielli, Giulio; Akerstedt, Henrik; Åkesson, Torsten Paul Ake; Akimoto, Ginga; Akimov, Andrei; Alberghi, Gian Luigi; Albert, Justin; Albrand, Solveig; Alconada Verzini, Maria Josefina; Aleksa, Martin; Aleksandrov, Igor; Alexa, Calin; Alexander, Gideon; Alexopoulos, Theodoros; Alhroob, Muhammad; Alimonti, Gianluca; Alio, Lion; Alison, John; Alkire, Steven Patrick; Allbrooke, Benedict; Allport, Phillip; Aloisio, Alberto; Alonso, Alejandro; Alonso, Francisco; Alpigiani, Cristiano; Altheimer, Andrew David; Alvarez Gonzalez, Barbara; ?lvarez Piqueras, Damián; Alviggi, Mariagrazia; Amadio, Brian Thomas; Amako, Katsuya; Amaral Coutinho, Yara; Amelung, Christoph; Amidei, Dante; Amor Dos Santos, Susana Patricia; Amorim, Antonio; Amoroso, Simone; Amram, Nir; Amundsen, Glenn; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anders, John Kenneth; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Angelidakis, Stylianos; Angelozzi, Ivan; Anger, Philipp; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoki, Masato; Aperio Bella, Ludovica; Arabidze, Giorgi; Arai, Yasuo; Araque, Juan Pedro; Arce, Ayana; Arduh, Francisco Anuar; Arguin, Jean-Francois; Argyropoulos, Spyridon; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnal, Vanessa; Arnold, Hannah; Arratia, Miguel; Arslan, Ozan; Artamonov, Andrei; Artoni, Giacomo; Asai, Shoji; Asbah, Nedaa; Ashkenazi, Adi; Åsman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astalos, Robert; Atkinson, Markus; Atlay, Naim Bora; Auerbach, Benjamin; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Axen, Bradley; Ayoub, Mohamad Kassem; Azuelos, Georges; Baak, Max; Baas, Alessandra; Bacci, Cesare; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Bagiacchi, Paolo; Bagnaia, Paolo; Bai, Yu; Bain, Travis; Baines, John; Baker, Oliver Keith; Balek, Petr; Balestri, Thomas; Balli, Fabrice; Banas, Elzbieta; Banerjee, Swagato; Bannoura, Arwa A E; Bansil, Hardeep Singh; Barak, Liron; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnes, Sarah Louise; Barnett, Bruce; Barnett, Michael; Barnovska, Zuzana; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Bartoldus, Rainer; Barton, Adam Edward; Bartos, Pavol; Basalaev, Artem; Bassalat, Ahmed; Basye, Austin; Bates, Richard; Batista, Santiago Juan; Batley, Richard; Battaglia, Marco; Bauce, Matteo; Bauer, Florian; Bawa, Harinder Singh; Beacham, James Baker; Beattie, Michael David; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Anne Kathrin; Becker, Maurice; Becker, Sebastian; Beckingham, Matthew; Becot, Cyril; Beddall, Andrew; Beddall, Ayda; Bednyakov, Vadim; Bee, Christopher; Beemster, Lars; Beermann, Thomas; Begel, Michael; Behr, Janna Katharina; Belanger-Champagne, Camille; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellerive, Alain; Bellomo, Massimiliano; Belotskiy, Konstantin; Beltramello, Olga; Benary, Odette; Benchekroun, Driss; Bender, Michael; Bendtz, Katarina; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Bensinger, James; Bentvelsen, Stan; Beresford, Lydia; Beretta, Matteo; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Beringer, Jürg; Bernard, Clare; Bernard, Nathan Rogers; Bernius, Catrin; Bernlochner, Florian Urs; Berry, Tracey; Berta, Peter; Bertella, Claudia; Bertoli, Gabriele; Bertolucci, Federico; Bertsche, Carolyn; Bertsche, David; Besana, Maria Ilaria; Besjes, Geert-Jan; Bessidskaia Bylund, Olga; Bessner, Martin Florian; Besson, Nathalie; Betancourt, Christopher; Bethke, Siegfried; Bevan, Adrian John; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianchini, Louis; Bianco, Michele; Biebel, Otmar; Bieniek, Stephen Paul; Biglietti, Michela; Bilbao De Mendizabal, Javier; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet

    2015-01-01

    A search for pair production of vector-like quarks, both up-type ($T$) and down-type ($B$), as well as for four-top-quark production, is presented. The search is based on $pp$ collisions at $\\sqrt{s}=8$ TeV recorded in 2012 with the ATLAS detector at the CERN Large Hadron Collider and corresponding to an integrated luminosity of 20.3 fb$^{-1}$. Data are analysed in the lepton-plus-jets final state, characterised by an isolated electron or muon with high transverse momentum, large missing transverse momentum and multiple jets. Dedicated analyses are performed targeting three cases: a $T$ quark with significant branching ratio to a $W$ boson and a $b$-quark ($T\\bar{T} \\to Wb$+X), and both a $T$ quark and a $B$ quark with significant branching ratio to a Higgs boson and a third-generation quark ($T\\bar{T} \\to Ht$+X and $B\\bar{B} \\to Hb$+X respectively). No significant excess of events above the Standard Model expectation is observed, and 95% CL lower limits are derived on the masses of the vector-like $T$ and ...

  1. Thrust bolting: roof bolt support apparatus

    DOEpatents

    Tadolini, Stephen C. (Lakewood, CO); Dolinar, Dennis R. (Golden, CO)

    1992-01-01

    A method of installing a tensioned roof bolt in a borehole of a rock formation without the aid of a mechanical anchoring device or threaded tensioning threads by applying thrust to the bolt (19) as the bonding material (7') is curing to compress the strata (3) surrounding the borehole (1), and then relieving the thrust when the bonding material (7') has cured.

  2. Lightweight Chambers for Thrust Assemblies

    NASA Technical Reports Server (NTRS)

    Elam, Sandra K.; Lee, Jonathan; Holmes, Richard; Zimmerman, Frank; Effinger, Mike; Turner, James E. (Technical Monitor)

    2001-01-01

    The Marshall Space Flight Center (MSFC) of the National Aeronautics and Space Administration (NASA) has successfully applied new materials and fabrication techniques to create actively cooled thrust chambers that operate 200-400 degrees hotter and weigh 50% lighter than conventional designs. In some vehicles, thrust assemblies account for as much as 20% of the engine weight. So, reducing the weight of these components and increasing their operating range will benefit many engines and vehicle designs, including Reusable Launch Vehicle (RLV) concepts. Obviously, copper and steel alloys have been used successfully for many years in the chamber components of thrust assemblies. Yet, by replacing the steel alloys with Polymer Matrix Composite (PMC) and/or Metal Matrix Composite (MMC) materials, design weights can be drastically reduced. In addition, replacing the traditional copper alloys with a Ceramic Matrix Composite (CMC) or an advanced copper alloy (Cu-8Cr-4Nb, also known as GRCop-84) significantly increases allowable operating temperatures. Several small MMC and PMC demonstration chambers have recently been fabricated with promising results. Each of these designs included GRCop-84 for the cooled chamber liner. These units successfully verified that designs over 50% lighter are feasible. New fabrication processes, including advanced casting technology and a low cost vacuum plasma spray (VPS) process, were also demonstrated with these units. Hot-fire testing at MSFC is currently being conducted on the chambers to verify increased operating temperatures available with the GRCop-84 liner. Unique CMC chamber liners were also successfully fabricated and prepared for hot-fire testing. Yet, early results indicate these CMC liners need significantly more development in order to use them in required chamber designs. Based on the successful efforts with the MMC and PMC concepts, two full size "lightweight" chambers are currently being designed and fabricated for hot-fire testing at MSFC in 2001. These "full size" chambers will be similar in size to those used on the X33 engine (RS2200). One will be fabricated with a MMC structural jacket, while the other uses a PMC jacket. Each will be designed for thrust levels of 15,000 pounds in an oxygen/hydrogen environment with liquid hydrogen coolant. Both chambers will use GRCop-84 for its channel wall liner. Each unit is expected to be at least 60% lighter than a conventional design with traditional materials. Hot-fire testing on the full size units in late 2001 will directly compare performance results between a conventional chamber design and these "lightweight" alternatives. The technology developed and demonstrated by this effort will not only benefit next generation RLV programs, but it can be applied to other existing and future engine programs, as well. Efforts were sponsored by the Advanced Space Transportation Program for RLV Focused Technologies. The task team was led by MSFC with additional members from NASA-Glenn Research Center and the Rocketdyne Division of The Boeing Company. Specific materials development and fabrication processes were provided by Aerojet, Lockheed Martin Astronautics, Composite Optics, Inc., Hyper-Therm, Ceramic Composites, Inc., MSE Technology Applications, and Plasma Processes, Inc.

  3. Measurements of scramjet thrust in shock tunnels

    NASA Technical Reports Server (NTRS)

    Stalker, R. J.; Simmons, J. M.; Paull, A.; Mee, D. J.

    1995-01-01

    By using results obtained in tests on supersonic combustion of hydrogen in air, the conditions governing model size and operating pressure levels for shock tunnel experiments on models of flight vehicles with scramjet propulsion are established. It is seen that large models are required. The development of the stress wave force balance is then described, and its use as a method of measuring thrust/drag on such models is discussed. Test results on a simple, fully integrated scramjet model, with intakes, combustion chambers, thrust surfaces and exterior surfaces, using a 13 percent silane 87 percent hydrogen fuel mixture, showed that a steady state with thrust generation could be achieved within the shock tunnel test time, and the thrust could be measured. Results are presented for a range of stagnation enthalpies, and show that the scramjet model produces net positive thrust at velocities up to 2.4 km/sec.

  4. Spectral-tomographic methods and means of studying propellant flows of ion and plasma low-thrust engines

    NASA Astrophysics Data System (ADS)

    Filonin, O. V.

    2015-01-01

    Methods of spectral-tomographic diagnostics of ion and plasma jets in ion-plasma low-thrust engines are described. Methods that I have developed of 2D and 3D reconstruction of local values of temperature, concentration and absolute intensity in the ion-plasma jet are analyzed. Experimental setups of laboratory type for studying parameters of propellants of ion and plasma propulsion engines are described.

  5. Friction losses in a lubricated thrust-loaded cageless angular-contract bearing

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.; Allen, C. W.; Zaretsky, E. V.

    1973-01-01

    The NASA spinning torque apparatus was modified to measure the spinning torque on a cageless ball thrust bearing. Friction torque was measured for thrust loads varying from 44.5 to 403 newtons (10 to 90 lb) at speeds of 1000, 2000, and 3000 rpm. Tests were conducted with di-2-ethylhexyl sebacate and a synthetic paraffinic oil. These tests were run with either oil jet lubrication or with a thin surface film of lubricant only. An analytical model which included rolling resistance was developed and extended from previous models for spinning torque and lubricant rheology. The model was extended by the inclusion of rolling resistance. The computed values were in fair agreement with the experimental results and confirmed previous hypotheses that a thin lubricant film gives minimum bearing torque and an oil jet flow of a viscous lubricant will result in considerable rolling torque in addition to the torque due to ball spin.

  6. An experimental study of a three-dimensional thrust augmenting ejector using laser Doppler velocimetry

    NASA Technical Reports Server (NTRS)

    Storms, Bruce Lowell

    1989-01-01

    Flow field measurements were obtained in a three-dimensional thrust augmenting ejector using laser Doppler velocimetry and hot wire anemometry. The primary nozzle, segmented into twelve slots of aspect ratio 3.0, was tested at a pressure ratio of 1.15. Results are presented on the mean velocity, turbulence intensity, and Reynolds stress progressions in the mixing chamber of the constant area ejector. The segmented nozzle was found to produce streamwise vortices that may increase the mixing efficiency of the ejector flow field. Compared to free jet results, the jet development is reduced by the presence of the ejector walls. The resulting thrust augmentation ratio of this ejector was also calculated to be 1.34.

  7. The Aeroacoustics of Supersonic Coaxial Jets

    NASA Technical Reports Server (NTRS)

    Dahl, Milo D.

    1994-01-01

    Instability waves have been established as the dominant source of mixing noise radiating into the downstream arc of a supersonic jet when the waves have phase velocities that are supersonic relative to ambient conditions. Recent theories for supersonic jet noise have used the concepts of growing and decaying linear instability waves for predicting radiated noise. This analysis is extended to the prediction of noise radiation from supersonic coaxial jets. Since the analysis requires a known mean flow and the coaxial jet mean flow is not described easily in terms of analytic functions, a numerical prediction is made for its development. The Reynolds averaged, compressible, boundary layer equations are solved using a mixing length turbulence model. Empirical correlations are developed for the effects of velocity and temperature ratios and Mach number. Both normal and inverted velocity profile coaxial jets are considered. Comparisons with measurements for both single and coaxial jets show good agreement. The results from mean flow and stability calculations are used to predict the noise radiation from coaxial jets with different operating conditions. Comparisons are made between different coaxial jets and a single equivalent jet with the same total thrust, mass flow, and exit area. Results indicate that normal velocity profile jets can have noise reductions compared to the single equivalent jet. No noise reductions are found for inverted velocity profile jets operated at the minimum noise condition compared to the single equivalent jet. However, it is inferred that changes in area ratio may provide noise reduction benefits for inverted velocity profile jets.

  8. A computational model for three-dimensional incompressible wall jets with large cross flow

    NASA Technical Reports Server (NTRS)

    Murphy, W. D.; Shankar, V.; Malmuth, N. D.

    1979-01-01

    A computational model for the flow field of three dimensional incompressible wall jets prototypic of thrust augmenting ejectors with large cross flow is presented. The formulation employs boundary layer equations in an orthogonal curvilinear coordinate system. Simulation of laminar as well as turbulen wall jets is reported. Quantification of jet spreading, jet growth, nominal separation, and jet shrink effects due to corss flow are discussed.

  9. Toward Active Control of Noise from Hot Supersonic Jets

    E-print Network

    Dabiri, John O.

    supersonic isothermal and heated Mach 1.5 jets from ideal expansion nozzles. A spinning valve device is used Design requirements for tactical aircraft include low drag and weight and high specific thrust, which problems for aircraft carrier launch/recovery crews. Currently, passive methods to increase jet mixing

  10. Low thrust chemical rocket technology

    NASA Technical Reports Server (NTRS)

    Schneider, Steven J.

    1992-01-01

    An on-going technology program to improve the performance of low thrust chemical rockets for spacecraft on-board propulsion applications is reviewed. Improved performance and lifetime is sought by the development of new predictive tools to understand the combustion and flow physics, introduction of high temperature materials and improved component designs to optimize performance, and use of higher performance propellants. Improved predictive technology is sought through the comparison of both local and global predictions with experimental data. Predictions are based on both the RPLUS Navier-Stokes code with finite rate kinetics and the JANNAF methodology. Data were obtained with laser-based diagnostics along with global performance measurements. Results indicate that the modeling of the injector and the combustion process needs improvement in these codes and flow visualization with a technique such as 2-D laser induced fluorescence (LIF) would aid in resolving issues of flow symmetry and shear layer combustion processes. High temperature material fabrication processes are under development and small rockets are being designed, fabricated, and tested using these new materials. Rhenium coated with iridium for oxidation protection was produced by the Chemical Vapor Deposition (CVD) process and enabled an 800 K increase in rocket operating temperature. Performance gains with this material in rockets using Earth storable propellants (nitrogen tetroxide and monomethylhydrazine or hydrazine) were obtained through component redesign to eliminate fuel film cooling and its associated combustion inefficiency while managing head end thermal soakback. Material interdiffusion and oxidation characteristics indicated that the requisite lifetimes of tens of hours were available for thruster applications. Rockets were designed, fabricated, and tested with thrusts of 22, 62, 440 and 550 N. Performance improvements of 10 to 20 seconds specific impulse were demonstrated. Higher performance propellants were evaluated: Space storable propellants, including liquid oxygen (LOX) as the oxidizer with nitrogen hydrides or hydrocarbon as fuels. Specifically, a LOX/hydrazine engine was designed, fabricated, and shown to have a 95 pct theoretical c-star which translates into a projected vacuum specific impulse of 345 seconds at an area ratio of 204:1. Further performance improvment can be obtained by the use of LOX/hydrogen propellants, especially for manned spacecraft applications, and specific designs must be developed and advanced through flight qualification.

  11. Orbital motion under continuous tangential thrust

    NASA Technical Reports Server (NTRS)

    Boltz, Frederick W.

    1992-01-01

    The effect of continuous tangential thrust on the orbital motion and mass loss of a vehicle initially in a circular orbit is investigated analytically. It is shown that, for a thrust-to-weight ratio of greater than 0.16175, escape speed will eventually be reached along an unwinding spiral trajectory. For lower thrust-to-weight ratios, escape speed is never attained, and the flight path oscillates around a logarithmic spiral trajectory. Formulas are obtained for the approximate orbital motion and time of flight along each type of trajectory and for mass loss due to expenditure of rocket propellant.

  12. Scramjet thrust measurement in a shock tunnel

    NASA Technical Reports Server (NTRS)

    Paull, A.; Stalker, R. J.; Mee, D. J.

    1995-01-01

    This note reports tests in a shock tunnel in which a fully integrated scamjet configuration produced net thrust. The experiments not only showed that impluse facilities can be used for assessing thrust performance, but also were a demonstration of the application of a new technique to the measurement of thrust on scramjet configurations in shock tunnels. These two developments are of significance because scramjets are expected to operate at speeds well in excess of 2 km/s, and shock tunnels offer a means of generating high Mach number flows at such speeds.

  13. Scramjet thrust measurement in a shock tunnel

    NASA Technical Reports Server (NTRS)

    Paull, A.; Stalker, R. J.; Mee, D. J.

    1995-01-01

    This note reports tests in a shock tunnel in which a fully integrated scramjet configuration produced net thrust. The experiments not only showed that impulse facilities can be used for assessing thrust performance, but also were a demonstration of the application of a new technique to the measurement of thrust on scramjet configurations in shock tunnels. These two developments are of significance because scramjets are expected to operate at speeds well in excess of 2 km/sec, and shock tunnels offer a means of generating high Mach number flows at such speeds.

  14. Vortex Rings in Bio-inspired and Biological Jet Propulsion Paul S. Krueger1, a

    E-print Network

    Hynes, Wayne L.

    Vortex Rings in Bio-inspired and Biological Jet Propulsion Paul S. Krueger1, a , Ali A. Moslemi1,b@odu.edu, e wstewart@uci.edu Keywords: Vortex rings, pulsed jets, propulsion, thrust, propulsive efficiency. Abstract. Pulsed-jets are commonly used for aquatic propulsion, such as squid and jellyfish locomotion

  15. Collar nut and thrust ring

    DOEpatents

    Lowery, Guy B. (Aiken, SC)

    1991-01-01

    A collar nut comprises a hollow cylinder having fine interior threads at one end for threadably engaging a pump mechanical seal assembly and an inwardly depending flange at the other end. The flange has an enlarged portion with a groove for receiving an O-ring for sealing against the intrusion of pumpage from the exterior. The enlarged portion engages a thrust ring about the pump shaft for crushing a hard O-ring, such as a graphite O-ring. The hard O-ring seals the interior of the mechanical seal assembly and pump housing against the loss of lubricants or leakage of pumpage. The fine threads of the hollow cylinder provide the mechanical advantage for crushing the hard O-ring evenly and easily with a hand tool from the side of the collar nut rather than by tightening a plurality of bolts from the end and streamlines the exterior surface of the mechanical seal. The collar nut avoids the spatial requirements of bolt heads at the end of a seal and associated bolt head turbulence.

  16. Mixing, Noise and Thrust Benefits Using Corrugated Designs

    NASA Technical Reports Server (NTRS)

    White, Samuel G.; Gilinsky, Mikhail M.

    1998-01-01

    This project was conducted as a support for effective research, training and teaching of Hampton University students in Fluid Mechanics and Acoustics. Basically, this work is organized and implemented by the new Fluid Mechanics and Acoustics Laboratory (FM & AL) which was established at Hampton University in the School of Engineering and Technology (E & T) in 1996. In addition, FM & AL in cooperation with NASA LaRC jointly conducts research with the Central AeroHydrodynamics Institute (TSAGI, Moscow) in Russia under a 2 year Civilian Research and Development Foundation (CRDF). This project is also conducted under control of NASA HQ. For fulfillment of the current project, several researchers were involved as was shown in the proposal to NASA in 1996. This work is the development and support for projects solve problems with the goal of reducing jet noise and increasing nozzle thrust.

  17. Coupled Structural Behavior-Flow Characteristics of a Synthetic Jet

    NASA Astrophysics Data System (ADS)

    Strassburg, M.; Mohseni, K.

    2006-11-01

    Synthetic jet actuators are zero net mass flux jets, which consist of a cavity with an oscillating wall opposite an orifice through which fluid is ingested and expelled in a periodic fashion. In this study, a piezoelectric bender and an aluminum cavity are employed in order to characterize thrust generation in synthetic jets. Simultaneous measurements of the jet velocity and diaphragm movements are carried out. These measurements are taken using hot wire anemometry and laser nano-sensing, respectively. Many actuators with various cavity and orifice dimensions are fabricated and tested. Data presented contains oscillating frequencies ranging from 500 to 2000 Hz, and a range of different voltages, which allows for different expelled fluid volumes. For different orifice diameters, the exit fluid volume is correlated to center stream velocity. Thrust generation at various formation numbers is investigated. It is found that the rate of thrust enhancement is decreased after a formation number around 3.

  18. Jet Streams

    NSDL National Science Digital Library

    COMET

    2012-11-13

    This module describes the general characteristics of upper-level jet streams (Polar Jet, Subtropical Jet, and Tropical Easterly Jet) and two major tropical low-level wind maxima (Somali Jet, African Easterly Jet). Included are discussions of their formation, maintenance, influence on synoptic weather, and role in the general circulation.

  19. Low-thrust chemical rocket engine study

    NASA Technical Reports Server (NTRS)

    Shoji, J. M.

    1981-01-01

    An analytical study evaluating thrust chamber cooling engine cycles and preliminary engine design for low thrust chemical rocket engines for orbit transfer vehicles is described. Oxygen/hydrogen, oxygen/methane, and oxygen/RP-1 engines with thrust levels from 444.8 N to 13345 N, and chamber pressures from 13.8 N/sq cm to 689.5 N/sq cm were evaluated. The physical and thermodynamic properties of the propellant theoretical performance data, and transport properties are documented. The thrust chamber cooling limits for regenerative/radiation and film/radiation cooling are defined and parametric heat transfer data presented. A conceptual evaluation of a number of engine cycles was performed and a 2224.1 N oxygen/hydrogen engine cycle configuration and a 2224.1 N oxygen/methane configuration chosen for preliminary engine design. Updated parametric engine data, engine design drawings, and an assessment of technology required are presented.

  20. Three dimensional thrust chamber life prediction

    NASA Technical Reports Server (NTRS)

    Armstrong, W. H.; Brogren, E. W.

    1976-01-01

    A study was performed to analytically determine the cyclic thermomechanical behavior and fatigue life of three configurations of a Plug Nozzle Thrust Chamber. This thrust chamber is a test model which represents the current trend in nozzle design calling for high performance coupled with weight and volume limitations as well as extended life for reusability. The study involved the use of different materials and material combinations to evaluate their application to the problem of low-cycle fatigue in the thrust chamber. The thermal and structural analyses were carried out on a three-dimensional basis. Results are presented which show plots of continuous temperature histories and temperature distributions at selected times during the operating cycle of the thrust chamber. Computed structural data show critical regions for low-cycle fatigue and the histories of strain within the regions for each operation cycle.

  1. Combination radial and thrust magnetic bearing

    NASA Technical Reports Server (NTRS)

    Blumenstock, Kenneth A. (Inventor)

    2002-01-01

    A combination radial and thrust magnetic bearing is disclosed that allows for both radial and thrust axes control of an associated shaft. The combination radial and thrust magnetic bearing comprises a rotor and a stator. The rotor comprises a shaft, and first and second rotor pairs each having respective rotor elements. The stator comprises first and second stator elements and a magnet-sensor disk. In one embodiment, each stator element has a plurality of split-poles and a corresponding plurality of radial force coils and, in another embodiment, each stator element does not require thrust force coils, and radial force coils are replaced by double the plurality of coils serving as an outer member of each split-pole half.

  2. Shedding light on hydroelectric thrust bearing problems

    SciTech Connect

    Baudry, R.A.; Rielly, D.H. (ElectroMechanical Engineering Associates, Pittsburgh, PA (United States))

    1991-07-01

    Why did thrust bearing failures, so rare in hydro plants built in the first decades of this century, increase greatly during and after World War II Engineers have found that modern manufacturing techniques created problems as well as solutions. Two primary reasons for failure are a too smooth surface finish, and an oil film force that causes the split runner in the thrust bearings to slip, which results in fretting.

  3. GSFC Technology Thrusts and Partnership Opportunities

    NASA Technical Reports Server (NTRS)

    Le Moigne, Jacqueline

    2010-01-01

    This slide presentation reviews the technology thrusts and the opportunities to partner in developing software in support of the technological advances at the Goddard Space Flight Center (GSFC). There are thrusts in development of end-to-end software systems for mission data systems in areas of flight software, ground data systems, flight dynamic systems and science data systems. The required technical expertise is reviewed, and the supported missions are shown for the various areas given.

  4. Multiphysics Nuclear Thermal Rocket Thrust Chamber Analysis

    NASA Technical Reports Server (NTRS)

    Wang, Ten-See

    2005-01-01

    The objective of this effort is t o develop an efficient and accurate thermo-fluid computational methodology to predict environments for hypothetical thrust chamber design and analysis. The current task scope is to perform multidimensional, multiphysics analysis of thrust performance and heat transfer analysis for a hypothetical solid-core, nuclear thermal engine including thrust chamber and nozzle. The multiphysics aspects of the model include: real fluid dynamics, chemical reactivity, turbulent flow, and conjugate heat transfer. The model will be designed to identify thermal, fluid, and hydrogen environments in all flow paths and materials. This model would then be used to perform non- nuclear reproduction of the flow element failures demonstrated in the Rover/NERVA testing, investigate performance of specific configurations and assess potential issues and enhancements. A two-pronged approach will be employed in this effort: a detailed analysis of a multi-channel, flow-element, and global modeling of the entire thrust chamber assembly with a porosity modeling technique. It is expected that the detailed analysis of a single flow element would provide detailed fluid, thermal, and hydrogen environments for stress analysis, while the global thrust chamber assembly analysis would promote understanding of the effects of hydrogen dissociation and heat transfer on thrust performance. These modeling activities will be validated as much as possible by testing performed by other related efforts.

  5. Search for Heavy Down-Type Vector-Like Quarks in the Lepton-Plus-Jets Final State in 8 TeV pp Collisions Using the ATLAS Detector at the LHC

    NASA Astrophysics Data System (ADS)

    Hu, Diedi

    This dissertation presents a search for pair production of heavy down-type vector-like quarks (VLQ B) using the full 2012 data set of proton-proton collisions at the center of mass 8 TeV recorded by the ATLAS detector at the CERN Large Hadron Collider, corresponding to an integrated luminosity of 20.3 1/fb. Events with a single charged lepton, which can be either an electron or muon, missing transverse energy, at least six jets, at least one tagged as a b-jet, and at least one reconstructed hadronically-decaying W/Z boson candidate are analyzed. No significant deviation from the Standard Model background prediction is observed. Under the assumption that only the B?Wt/Zb/Hb decay modes are allowed, 95% CL upper limits are derived in the two dimensional plane of the B?Wt branching ratio versus B?Hb branching ratio. In the specific case where the branching ratios are consistent with a SU(2) singlet scenario, the observed (expected) 95% CL lower limit on the VLQ B mass is 640 GeV (505 GeV). In the chiral B scenario with a 100% branching ratio of the decay B?Wt, the observed (expected) 95% CL lower limit on the B mass is 814 GeV (756 GeV).

  6. Jet noise from ultrahigh bypass turbofan engines

    Microsoft Academic Search

    Joe W. Posey; Thomas D. Norum; Martha C. Brown; Thonse R. S. Bhat

    2002-01-01

    Modern commercial jet transport aircraft are powered by turbofan engines. Thrust from a turbofan engine is derived in part from the exhaust of a ducted fan, which may or may not be mixed with the core exhaust before exiting the nacelle. The historical trend has been toward ever higher bypass ratios (BPRs). The BPR is the ratio of air mass

  7. Study of Vector Boson Scattering and Search for New Physics in Events with Two Same-Sign Leptons and Two Jets

    E-print Network

    Apyan, Aram

    A study of vector boson scattering in pp collisions at a center-of-mass energy of 8 TeV is presented. The data sample corresponds to an integrated luminosity of 19.4??fb[superscript ?1] collected with the CMS detector. ...

  8. A thrust balance for low power hollow cathode thrusters

    NASA Astrophysics Data System (ADS)

    Frollani, D.; Coletti, M.; Gabriel, S. B.

    2014-06-01

    A hanging thrust balance has been designed, manufactured and tested at the University of Southampton. The current design allows for direct steady thrust measurements ranging from 0.1 to 3 mN but this can be easily extended to measure thrust in a different range. Moreover the chosen balance design and the thrust measurement procedure allow for the cancellation of thermal drifts. The thrust balance was tested with a T6 hollow cathode thruster providing measurements with an uncertainty of about 9.7%. The thrust data were compared to those obtained with another direct thrust balance and they are in quantitative agreement—the maximum difference being only 6%.

  9. Aeropropulsive characteristics of twin nonaxisymmetric vectoring nozzles installed with forward-swept and aft-swept wings. [in the Langley 16 Foot Transonic Tunnel

    NASA Technical Reports Server (NTRS)

    Capone, F. J.

    1981-01-01

    An investigation was conducted in the Langley 16 Foot Transonic Tunnel to determine the aeropropulsive characteristics of a single expansion ramp nozzle (SERN) and a two dimensional convergent divergent nozzle (2-D C-D) installed with both an aft swept and a forward swept wing. The SERN was tested in both an upright and an inverted position. The effects of thrust vectoring at nozzle vector angles from -5 deg to 20 deg were studied. This investigation was conducted at Mach numbers from 0.40 to 1.20 and angles of attack from -2.0 deg to 16 deg. Nozzle pressure ratio was varied from 1.0 (jet off) to about 9.0. Reynolds number based on the wing mean geometric chord varied from about 3 million to 4.8 million, depending upon free stream number.

  10. Twin Jet

    NASA Technical Reports Server (NTRS)

    Henderson, Brenda; Bozak, Rick

    2010-01-01

    Many subsonic and supersonic vehicles in the current fleet have multiple engines mounted near one another. Some future vehicle concepts may use innovative propulsion systems such as distributed propulsion which will result in multiple jets mounted in close proximity. Engine configurations with multiple jets have the ability to exploit jet-by-jet shielding which may significantly reduce noise. Jet-by-jet shielding is the ability of one jet to shield noise that is emitted by another jet. The sensitivity of jet-by-jet shielding to jet spacing and simulated flight stream Mach number are not well understood. The current experiment investigates the impact of jet spacing, jet operating condition, and flight stream Mach number on the noise radiated from subsonic and supersonic twin jets.

  11. Toward multi-differential cross sections: measuring two angularities on a single jet

    E-print Network

    Larkoski, Andrew James

    The analytic study of differential cross sections in QCD has typically focused on individual observables, such as mass or thrust, to great success. Here, we present a first study of double differential jet cross sections ...

  12. Aerodynamics in ground effect and predicted landing ground roll of a fighter configuration with a secondary-nozzle thrust reverser

    NASA Technical Reports Server (NTRS)

    Banks, Daniel W.

    1988-01-01

    An experimental investigation of the in-ground effect aerodynamic characteristics and predicted landing-ground-roll performance of wing-canard fighter configuration with a secondary nozzle thrust reverser was completed. These tests were conducted in the Langley 14 by 22 foot Subsonic Wind Tunnel using a model equipped with a pneumatic jet for thrust simulation of nozzle pressure ratios up to 4.0. The model was tested in the landing rollout configuration at approx. wheel touchdown height for a range of decreasing dynamic pressure from 50 psf down to 10 psf. Landing-ground-roll predictions of the configuration were calculated using the wind tunnel results.

  13. Static internal performance of a single-engine onaxisymmetric-nozzle vaned-thrust-reverser design with thrust modulation capabilities

    NASA Technical Reports Server (NTRS)

    Leavitt, L. D.; Burley, J. R., II

    1985-01-01

    An investigation has been conducted at wind-off conditions in the stati-test facility of the Langley 16-Foot Transonic Tunnel. The tests were conducted on a single-engine reverser configuration with partial and full reverse-thrust modulation capabilities. The reverser design had four ports with equal areas. These ports were angled outboard 30 deg from the vertical impart of a splay angle to the reverse exhaust flow. This splaying of reverser flow was intended to prevent impingement of exhaust flow on empennage surfaces and to help avoid inlet reingestion of exhaust gas when the reverser is integrated into an actual airplane configuration. External vane boxes were located directly over each of the four ports to provide variation of reverser efflux angle from 140 deg to 26 deg (measured forward from the horizontal reference axis). The reverser model was tested with both a butterfly-type inner door and an internal slider door to provide area control for each individual port. In addition, main nozzle throat area and vector angle were varied to examine various methods of modulating thrust levels. Other model variables included vane box configuration (four or six vanes per box), orientation of external vane boxes with respect to internal port walls (splay angle shims), and vane box sideplates. Nozzle pressure ratio was varied from 2.0 approximately 7.0.

  14. W/Z+Jets and W/Z+Heavy Flavor Jets at the Tevatron

    E-print Network

    Nilsen, Henrik

    2009-01-01

    The associated production of jets and vector bosons is an important process at hadron colliders. An overview over recent Tevatron vector boson+jets measurements is given with an emphasis on comparisons between data and the predictions of various theory models.

  15. Evaluation and modeling of autonomous attitude thrust control for the Geostation Operational Environmental Satellite (GOES)-8 orbit determination

    Microsoft Academic Search

    W. Forcey; C. R. Minnie; R. L. Defazio

    1995-01-01

    The Geostationary Operational Environmental Satellite (GOES)-8 experienced a series of orbital perturbations from autonomous attitude control thrusting before perigee raising maneuvers. These perturbations influenced differential correction orbital state solutions determined by the Goddard Space Flight Center (GSFC) Goddard Trajectory Determination System (GTDS). The maneuvers induced significant variations in the converged state vector for solutions using increasingly longer tracking data spans.

  16. Jet Substructure

    NASA Astrophysics Data System (ADS)

    Shelton, J.

    2013-08-01

    Jet physics is a rich and rapidly evolving field, with many applications to physics in and beyond the Standard Model. These notes, based on lectures delivered at the June 2012 Theoretical Advanced Study Institute, provide an introduction to jets at the Large Hadron Collider. Topics covered include sequential jet algorithms, jet shapes, jet grooming, and boosted Higgs and top tagging.

  17. Thrust Stand for Electric Propulsion Performance Evaluation

    NASA Technical Reports Server (NTRS)

    Markusic, T. E.; Jones, J. E.; Cox, M. D.

    2004-01-01

    An electric propulsion thrust stand capable of supporting thrusters with total mass of up to 125 kg and 1 mN to 1 N thrust levels has been developed and tested. The mechanical design features a conventional hanging pendulum arm attached to a balance mechanism that transforms horizontal motion into amplified vertical motion, with accommodation for variable displacement sensitivity. Unlike conventional hanging pendulum thrust stands, the deflection is independent of the length of the pendulum arm, and no reference structure is required at the end of the pendulum. Displacement is measured using a non-contact, optical linear gap displacement transducer. Mechanical oscillations are attenuated using a passive, eddy current damper. An on-board microprocessor-based level control system, which includes a two axis accelerometer and two linear-displacement stepper motors, continuously maintains the level of the balance mechanism - counteracting mechanical %era drift during thruster testing. A thermal control system, which includes heat exchange panels, thermocouples, and a programmable recirculating water chiller, continuously adjusts to varying thermal loads to maintain the balance mechanism temperature, to counteract thermal drifts. An in-situ calibration rig allows for steady state calibration both prior to and during thruster testing. Thrust measurements were carried out on a well-characterized 1 kW Hall thruster; the thrust stand was shown to produce repeatable results consistent with previously published performance data.

  18. Scaled Lunar Module Jet Erosion Experiments

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Scaled Lunar Module Jet Erosion Experiments. An experimental research program was conducted on the erosion of particulate surfaces by a jet exhaust. These experiments were scaled to represent the lunar module (LM) during landing. A conical cold-gas nozzle simulating the lunar module nozzle was utilized. The investigation was conducted within a large vacuum chamber by using gravel or glass beads as a simulated soil. The effects of thrust, descent speed, nozzle terminal height, particle size on crater size, and visibility during jet erosion were determined. [Entire movie available on DVD from CASI as Doc ID 20070031010. Contact help@sti.nasa.gov

  19. Pulsed thrust measurements using electromagnetic calibration techniques

    SciTech Connect

    Tang Haibin; Shi Chenbo; Zhang Xin'ai; Zhang Zun; Cheng Jiao [School of Astronautics, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China)

    2011-03-15

    A thrust stand for accurately measuring impulse bits, which ranged from 10-1000 {mu}N s using a noncontact electromagnetic calibration technique is described. In particular, a permanent magnet structure was designed to produce a uniform magnetic field, and a multiturn coil was made to produce a calibration force less than 10 mN. The electromagnetic calibration force for pulsed thrust measurements was linear to the coil current and changed less than 2.5% when the distance between the coil and magnet changed 6 mm. A pulsed plasma thruster was first tested on the thrust stand, and afterward five single impulse bits were measured to give a 310 {mu}N s average impulse bit. Uncertainty of the measured impulse bit was analyzed to evaluate the quality of the measurement and was found to be 10 {mu}N s with 95% credibility.

  20. Test plan pressure fed thrust chamber technology

    NASA Technical Reports Server (NTRS)

    Dunn, Glenn

    1990-01-01

    Aerojet is developing the technology for the design of a reliable, low cost, efficient, and lightweight LOX/RP-1 pressure fed engine. This technology program is a direct result of Aerojet's liquid rocket booster (LRB) study and previous NASA studies that identified liquid engines using high bulk density hydrocarbon fuels as very attractive for a space transportation system (STS). Previous large thrust LOX/RP-1 engine development programs were characterized by costly development problems due to combustion instability damage. The combustion stability solution was typically obtained through trial and error methods of minimizing instability damage by degrading engine performance. The approach to this program was to utilize existing and newly developed combustion analysis models and design methodology to create a thrust chamber design with features having the potential of producing reliable and efficient operation. This process resulted in an engine design with a unique high thrust-per-element OFO triplet injector utilizing a low cost modular approach. Cost efficient ablative materials are baselined for the injector face and chamber. Technology demonstration will be accomplished through a hot fire test program using appropriately sized subscale hardware. This subscale testing will provide a data base to supplement the current industry data bank and to anchor and validate the applied analysis models and design methodology. Once anchored and validated, these analysis models and design methodology can be applied with greatly increased confidence to design and characterize a large scale pressure fed LOX/RP-1 thrust chamber. The objective of this test program is to generate a data base that can be used to anchor and validate existing analysis models and design methodologies and to provide early concept demonstration of a low cost, efficient LOX/RP-1 thrust chamber. Test conditions and hardware instrumentation were defined to provide data sufficient to characterize combustion stability, performance, and thermal operation over a wide thrust chamber throttling range.

  1. The induced thrust effect - A propulsion method

    NASA Astrophysics Data System (ADS)

    Pais, Salvatore C.

    1991-09-01

    The 'induced thrust' (IT) method whose theoretical fundamentals and basic implementation are presented is applicable to both nuclear and chemical rocket-propulsion systems. IT principles are illustrated in the framework of the back-to-back 'joined ship' model, in which the combustion chamber pressure within one vehicle is caused to act as the back pressure of the other vehicle to which it is joined (and vice versa). The IT impulse generated by mutual plume impingement as the vehicles move away from each other constitutes an additional propulsive force which exceeds the individual thrust capacity of the separate powerplants. A unique mathematical algorithm is used to analyze the concept.

  2. Thrust chamber thermal barrier coating techniques

    NASA Technical Reports Server (NTRS)

    Quentmeyer, Richard J.

    1989-01-01

    Methods for applying thermal barrier coatings to the hot-gas side wall of rocket thrust chambers in order to significantly reduce the heat transfer in high heat flux regions has been the focus of technology efforts for many years. A successful technique developed by NASA-Lewis that starts with the coating on a mandrel and then builds the thrust chamber around it by electroforming appropriate materials is described. This results in a smooth coating with exceptional adherence, as was demonstrated in hot fire rig tests. The low cycle fatigue life of chambers with coatings applied in this manner was increased dramatically compared to uncoated chambers.

  3. A microNewton thrust stand for average thrust measurement of pulsed microthruster

    NASA Astrophysics Data System (ADS)

    Zhou, Wei-Jing; Hong, Yan-Ji; Chang, Hao

    2013-12-01

    A torsional thrust stand has been developed for the study of the average thrust for microNewton pulsed thrusters. The main body of the thrust stand mainly consists of a torsional balance, a pair of flexural pivots, a capacitive displacement sensor, a calibration assembly, and an eddy current damper. The behavior of the stand was thoroughly studied. The principle of thrust measurement was analyzed. The average thrust is determined as a function of the average equilibrium angle displacement of the balance and the spring stiffness. The thrust stand has a load capacity up to 10 kg, and it can theoretically measure the force up to 609.6 ?N with a resolution of 24.4 nN. The static calibrations were performed based on the calibration assembly composed of the multiturn coil and the permanent magnet. The calibration results demonstrated good repeatability (less than 0.68% FSO) and good linearity (less than 0.88% FSO). The assembly of the multiturn coil and the permanent magnet was also used as an exciter to simulate the microthruster to further research the performance of the thrust stand. Three sets of force pulses at 17, 33.5, and 55 Hz with the same amplitude and pulse width were tested. The repeatability error at each frequency was 7.04%, 1.78%, and 5.08%, respectively.

  4. Early Cenozoic thrust in Qiangtang block, Northern Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Wu, Z.; Ye, P.; Hu, D.; Lu, L.; Zhang, Y.

    2011-12-01

    Huge thrust systems, North Qiangtang Thrust (NQT) and South Qiangtang Thrust (SQT), were discovered in Qiangtang block, northern Tibetan Plateau. North Qiangtang thrust (NQT), including Dogai Coren thrust (DCT) and Longwei Co Thrust (LCT) formed in northern Qiangtang block. Triassic shale, sandstone and slate were thrusted southward over Late Cretaceous-Early Cenozoic conglomerate and sandstone (simplified as red-beds) along thrust faults of DCT, and Jurassic limestone and sandstone were thrusted over Late Cretaceous-Paleogene red-beds and Paleozoic metamorphic rocks along thrust faults of LCT in north of Central Qiangtang Uplift (CQU). South Qiangtang Thrust (SQT), including Xiaocaka-Shuanghu thrust (XST), Doma-Qixiang Co thrust (DQT) and Saibu Co-Zagya thrust (SZT), formed in southern Qiangtang block, accompanied by Nima-Silin thrust (NST) in northern Lhasa block. Permian marbleized limestone and dolomite, Triassic sandstone and shale, Jurassic limestone and ophiolite were thrusted southward over Paleogene red-beds along thrust faults of XST, DQT and SZT. Early Cenozoic thrust along NQT and SQT formed variety of tectonic slices, outliers and nappes of Permian-Jurassic rocks overlying Late Cretaceous-Paleogene red-beds in northern, central and southern Qiangtang block. Minimal estimation on southward offsets of DCT and LCT is 25km and 50km respectively, corresponding to 43% shortening in northern Qiangtang block, and minimal estimation on southward thrust offsets of XST, DQT and SZT yields ~90km southward thrust displacement of SQT, corresponding to ~47% shortening in southern Qiangtang block. Major thrust faults of NQT and SQT formed in upper crust according to seismic reflection profile, and such thrust and shortening were geodynamically related to northward subduction of India continental plate. Intensive thrust of NQT and SQT stopped before Early Miocene, followed by regional peneplanation, widespread lacustrine deposits in Early Miocene and crust extension as Shuanghu graben in Mid Miocene. Tectonic transition from Early Cenozoic contraction to Mid-Late Miocene extension of crust indicates Late Oligocene-Early Miocene uplift of Qiangtang block, northern Tibetan Plateau.

  5. Industrial jet noise: Coanda nozzles

    NASA Astrophysics Data System (ADS)

    Li, P.; Halliwell, N. A.

    1985-04-01

    Within the U.K. manufacturing industries noise from industrial jets ranks third as a major contributor to industrial deafness. Noise control is hindered because use is made of the air once it has exuded from the nozzle exit. Important tasks include swarf removal, paint spreading, cooling, etc. Nozzles which employ the Coanda effect appear to offer the possibility of significant noise reduction whilst maintaining high thrust efficiency when compared with the commonly used simple open pipe or ordinary convergent nozzle. In this paper the performance of Coanda-type nozzles is examined in detail and an index rating for nozzle performance is introduced. Results show that far field stagnation pressure distributions are Gaussian and similar in all cases with a dispersion coefficient ? = 0·64. Noise reduction and thrust efficiency are shown to be closely related to the design geometry of the central body of the nozzle. Performance is based on four fundamental characteristics, these being the noise level at 1 m from the exit and at a 90° station to the nozzle axis, and the thrust on a chosen profile, the noise reduction and the thrust efficiency. Physically, performance is attributed to flow near field effects where, although all nozzles are choked, shock cell associated noise is absent.

  6. In-flight thrust determination on a real-time basis

    NASA Technical Reports Server (NTRS)

    Ray, R. J.; Carpenter, T.; Sandlin, T.

    1984-01-01

    A real time computer program was implemented on a F-15 jet fighter to monitor in-flight engine performance of a Digital Electronic Engine Controlled (DEES) F-100 engine. The application of two gas generator methods to calculate in-flight thrust real time is described. A comparison was made between the actual results and those predicted by an engine model simulation. The percent difference between the two methods was compared to the predicted uncertainty based on instrumentation and model uncertainty and agreed closely with the results found during altitude facility testing. Data was obtained from acceleration runs of various altitudes at maximum power settings with and without afterburner. Real time in-flight thrust measurement was a major advancement to flight test productivity and was accomplished with no loss in accuracy over previous post flight methods.

  7. Thrust Area 2 Monopropellant-Powered Actuation

    E-print Network

    Barth, Eric J.

    Thrust Area 2 Monopropellant-Powered Actuation Dr. Michael Goldfarb Dr. Eric Barth p pDr. Kevin minutes · No external work · Max walk 1.6 mph Honda P3 humanoid robot ·Approach is to utilize liquid monopropellants as gas generants for hot gas actuators. ·Requires compact mechanisms for converting gas generation

  8. Control Method of Heavy Hydrostatic Thrust Bearing

    Microsoft Academic Search

    Guihua Han; Jianying Li; Yuhong Dong; Junpeng Shao

    2009-01-01

    A hybrid fuzzy control scheme was applied to improve the rigidity of hydrostatic thrust bearing. The bearing oil film control was realized by coupling oil film thickness of four controllable chambers. The chamber flow can be regulated by electro hydraulic servo valve-control variable pump according to the surface roughness, load, cutting force, and thermal effects of worktable. The nonlinear hybrid

  9. Thrust Stand for Electric Propulsion Performance Evaluation

    NASA Technical Reports Server (NTRS)

    Polzin, Kurt A.; Markusic, Thomas E.; Stanojev, Boris J.; Dehoyos, Amado; Spaun, Benjamin

    2006-01-01

    An electric propulsion thrust stand capable of supporting testing of thrusters having a total mass of up to 125 kg and producing thrust levels between 100 microN to 1 N has been developed and tested. The design features a conventional hanging pendulum arm attached to a balance mechanism that converts horizontal deflections produced by the operating thruster into amplified vertical motion of a secondary arm. The level of amplification is changed through adjustment of the location of one of the pivot points linking the system. Response of the system depends on the relative magnitudes of the restoring moments applied by the displaced thruster mass and the twisting torsional pivots connecting the members of the balance mechanism. Displacement is measured using a non-contact, optical linear gap displacement transducer and balance oscillatory motion is attenuated using a passive, eddy-current damper. The thrust stand employs an automated leveling and thermal control system. Pools of liquid gallium are used to deliver power to the thruster without using solid wire connections, which can exert undesirable time-varying forces on the balance. These systems serve to eliminate sources of zero-drift that can occur as the stand thermally or mechanically shifts during the course of an experiment. An in-situ calibration rig allows for steady-state calibration before, during and after thruster operation. Thrust measurements were carried out on a cylindrical Hall thruster that produces mN-level thrust. The measurements were very repeatable, producing results that compare favorably with previously published performance data, but with considerably smaller uncertainty.

  10. Fuel-optimal, low-thrust transfers between libration point orbits

    NASA Astrophysics Data System (ADS)

    Stuart, Jeffrey R.

    Mission design requires the efficient management of spacecraft fuel to reduce mission cost, increase payload mass, and extend mission life. High efficiency, low-thrust propulsion devices potentially offer significant propellant reductions. Periodic orbits that exist in a multi-body regime and low-thrust transfers between these orbits can be applied in many potential mission scenarios, including scientific observation and communications missions as well as cargo transport. In light of the recent discovery of water ice in lunar craters, libration point orbits that support human missions within the Earth-Moon region are of particular interest. This investigation considers orbit transfer trajectories generated by a variable specific impulse, low-thrust engine with a primer-vector-based, fuel-optimizing transfer strategy. A multiple shooting procedure with analytical gradients yields rapid solutions and serves as the basis for an investigation into the trade space between flight time and consumption of fuel mass. Path and performance constraints can be included at node points along any thrust arc. Integration of invariant manifolds into the design strategy may also yield improved performance and greater fuel savings. The resultant transfers offer insight into the performance of the variable specific impulse engine and suggest novel implementations of conventional impulsive thrusters. Transfers incorporating invariant manifolds demonstrate the fuel savings and expand the mission design capabilities that are gained by exploiting system symmetry. A number of design applications are generated.

  11. A six degree-of-freedom thrust sensor for a labscale hybrid rocket

    NASA Astrophysics Data System (ADS)

    Wright, Ann M.; Wright, Andrew B.; Born, Traig; Strickland, Ryan

    2013-12-01

    A six degree-of-freedom thrust sensor was designed, constructed, calibrated, and tested using the labscale hybrid rocket at the University of Arkansas at Little Rock. The system consisted of six independent legs: one parallel to the axis of symmetry of the rocket for main thrust measurement, two vertical legs near the nozzle end of the rocket, one vertical leg near the oxygen input end of the rocket, and two separated horizontal legs near the nozzle end. Each leg was composed of a rotational bearing, a load cell, and a universal joint above and below the load cell. The leg was designed to create point contact along only one direction and minimize the non-axial forces applied to the load cell. With this system, force in each direction and moments for roll, pitch, and yaw can be measured. The system was calibrated and tested using a labscale hybrid rocket using gaseous oxygen and hydroxyl-terminated polybutadiene solid fuel. The thrust stand proved to be stable during calibration tests. Thrust force vector components and roll, pitch, and yaw moments were calculated for test firings with an oxygen mass flow rate range of 0.0174-0.0348 kg s-1.

  12. Thrust dip and thrust refraction in fault-bend folds: analogue models and theoretical predictions

    NASA Astrophysics Data System (ADS)

    Maillot, Bertrand; Koyi, Hemin

    2006-01-01

    Analogue models made of two layers of loose sand separated by a thin layer of micro glass beads were shortened by a rigid emerging ramp dipping at either 30° or 45° and possessing a high, intermediate, or null surface friction. Shortening resulted in formation of closely spaced back thrusts in the sand layers. The dips of the back thrusts vary within a range of 30° depending on the ramp friction, and 7° depending on its dip. An increase in ramp friction, or, to a lesser extent, in ramp dip, decreases the thrust dips in the model. The second important observation is that, when friction is greater along the ramp than along the layer of glass beads, then the glass beads layer acts as a separate upper ramp above which the back thrusts steepen. The theory proposed to explain these observations predicts the thrust dips through a two-step procedure: first, global equilibrium of forces in the two layers is required to yield the mean forces at stake along the ramps and thrusts, second, the total dissipation is minimized with respect to the dips of the back thrusts. The relevant frictional properties of our analogue materials have been measured in stress conditions as close as possible to the experimental ones (below 1 kPa), and used with the theory to yield optimal back thrust dips that are all within 3° of the measured dips. This is a surprisingly good fit when considering that we did not take into account geometric changes, strain-softening, and dilatancy or compaction, due to slip on the thrusts. We conclude that this general two-step theoretical procedure is validated in the context of analogue frictional materials. We also propose a possible mechanism for thrust refraction and top-to-the-foreland sense of shear observed in the hanging walls of lower-flat to ramp transition in sedimentary piles that is based on the triggering of secondary upper ramps. Finally, this mechanical approach can also be seen as complementary to the kinematic models of fold-thrust structures which, by definition, cannot grasp the strong effects of friction on the kinematics.

  13. Vector Introduction Vector components and example machines

    E-print Network

    California at Berkeley, University of

    vector 1 Vector Introduction Lecture 10 2/21/96 vector 2 Outline Motivation Vector components and example machines Vector instructions & vector program Vector Execution Vector Load/Store Units Vector Length, Stride, Strip Mining Vector Optimizations: Chaining, Gather/Scatter, Conditional Vector Metrics

  14. Search for 3rd Generation Vector Leptoquarks in the Di-tau Di-jet Channel in Proton Antiproton Collisions at square root s = 1.96 TeV

    SciTech Connect

    Forrester, Stanley Scott; /UC, Davis

    2006-12-01

    We search for third generation vector leptoquarks (V LQ3) produced in colliding p{bar p} beams operating at {radical}s = 1.96 TeV at the CDF experiment in Run II of the Fermilab Tevatron. We use 322 pb{sup -1} of data to search for the V LQ3 signal in the di-tau plus di-jet channel. For the first time, the full matrix element is used in the Monte Carlo simulation of this signal. With no events observed in the signal region, we set a 95% C.L. upper limit on the V LQ3 pair production cross section of {sigma} < 344fb, assuming Yang-Mills couplings and Br(V LQ3 {yields} b{tau}) = 1, and a lower limit on the V LQ3 mass of m{sub V LQ3} > 317 GeV=c{sup 2}. If theoretical uncertainties on the cross section are applied in the least favorable manner the results are {sigma} < 360fb and m{sub V LQ3} > 294 GeV=c{sup 2}. The Minimal coupling V LQ3 result is an upper limit on the cross section of {sigma} < 493fb ({sigma} < 610fb) and the lower limit on the mass is m{sub V LQ3} > 251 GeV=c{sup 2} (m{sub V LQ3} > 223 GeV=c{sup 2}) for the nominal (1{sigma} varied) theoretical expectation.

  15. Thrust measurements of a hollow-cathode discharge

    NASA Technical Reports Server (NTRS)

    Snyder, A.; Banks, B. A.

    1972-01-01

    Thrust measurements of a hollow cathode mercury discharge were made with a synthetic mica target on a torsion pendulum. Thrust measurements were made for various target angles, tip temperatures, flow rates, keeper discharge powers, and accelerator electrode voltages. The experimental thrust data are compared with theoretical values for the case where no discharge power was employed.

  16. Thrust augmentation nozzle (TAN) concept for rocket engine booster applications

    Microsoft Academic Search

    Scott Forde; Mel Bulman; Todd Neill

    2006-01-01

    Aerojet used the patented thrust augmented nozzle (TAN) concept to validate a unique means of increasing sea-level thrust in a liquid rocket booster engine. We have used knowledge gained from hypersonic Scramjet research to inject propellants into the supersonic region of the rocket engine nozzle to significantly increase sea-level thrust without significantly impacting specific impulse. The TAN concept overcomes conventional

  17. Fluid Flow and Deformation Along the Glarus Thrust, Eastern Switzerland

    Microsoft Academic Search

    R. Abart; N. Badertscher; M. Burkhard

    2002-01-01

    The Glarus thrust is a prominent tectonic feature in the eastern Helvetic Alps. It accommodated an at least 40 kilometre northward displacement of the Helfvetic nappe system in the hangingwall of the thrust with respect to the Infrahelvetic units in the footwall. The Glarus thrust was active at sub-greenschist to greenschist facies conditions during Miozene times. Oxygen, carbon and strontium

  18. Structure of the eastern Red Rocks and Wind Ridge thrust faults, Wyoming: how a thrust fault gains displacement along strike 

    E-print Network

    Huntsman, Brent Stanley

    1983-01-01

    STRUCTURE OF THE EASTERN RED ROCKS AND WIND RIDGE THRUST FAULTS, WYOMING: HOW A THRUST FAULT GAINS DISPLACEMENT ALONG STRIKE A Thesis by BRENT STANLEY HUNTSMAN Submitted to the Graduate College of Texas A&M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE December 1983 Major Subject: Geology STRUCTURE OF THE EASTERN RED ROCKS AND WIND RIDGE THRUST FAULTS, WYOMING: HOW A THRUST FAULT GAINS DISPLACEMENT ALONG STRIKE A Thesis by BRENT STANLEY HUNTSMAN...

  19. [McWilliams, Possible Wind River Basin Thrust Fault]1 Evidence of a Possible 32-Mile-Wide Thrust Fault,

    E-print Network

    Lee Jr., Richard E.

    [McWilliams, Possible Wind River Basin Thrust Fault]1 Evidence of a Possible 32-Mile-Wide Thrust Fault, Wind River Basin, Fremont County Wyoming Robert G. McWilliams, Professor Emeritus, Department Indian Meadows and lower Wind River Formations. Love (1987) described in detail this fold-thrust fault

  20. Study of orientation of three-jet events in Z0 hadronic decays using the DELPHI detector

    Microsoft Academic Search

    P. Abreu; W. Adam; F. Adami; T. Adami; T. Adye; T. Akesson; G. D. Alekseev; P. Allen; S. Almehed; F. Alted; S. J. Alvsvaag; U. Amaldi; E. Anassontzis; P. Antilogus; W.-D. Apel; R. J. Apsimon; B. Åsman; P. Astier; J.-E. Augustin; A. Augustinus; P. Baillon; P. Bambade; F. Barao; G. Barbiellini; D. Y. Bardin; A. Baroncelli; O. Barring; W. Bartl; M. Battaglia; M Baubillier; K.-H. Becks; C. J. Beeston; M. Begalli; P. Beilliere; Yu. Belokopytov; K. Belous; P. Beltran; D. Benedic; J. M. Benlloch; M. Berggren; D. Bertrand; S. Biagi; F. Bianchi; J. H. Bibby; M. S. Bilenky; P. Billoir; J. Bjarne; D. Bloch; S. Blyth; P. N. Bogolubov; T. Bolognese; M. Bonapart; M. Bonesini; W. Bonivento; P. S. L. Booth; M. Bonatav; P. Borgeaud; H. Borner; C. Bosio; O. Botner; B. Bouquet; M. Bozzo; S. Braibant; P. Branchini; K. D. Brand; R. A. Brenner; C. Bricman; R. C. A. Brown; N. Brummer; J.-M. Brunet; L. Bugge; T. Buran; H. Burmeister; J. A. M. A. Buytaert; M. Caccia; M. Calvi; A. J. Camacho Rozas; J.-E. Campagne; A. Campion; T. Camporesi; V. Canale; F. Cao; L. Carroll; C. Caso; E. Castelli; M. V. Castillo Gimenez; A. Cattai; F. R. Cavallo; L. Cerrito; M. Chapkin; P. Charpentier; P. Checchia; G. A. Chelkov; L. Chevalier; P. Chliapnikov; V. Chorowicz; R. Cirio; M. P. Clara; P. Collins; J. L. Contreras; R. Contri; G. Cosme; F. Couchot; H. B. Crawley; D. Crennell; G. Crosetti; N. Crosland; M. Crozon; J. Cuevas Maestro; S. Czellar; S. Dagoret; E. Dahl-Jensen; B. Dalmagne; M. Dam; G. Damgaard; G. Darbo; E. Daubie; P. D. Dauncey; M. Davenport; P. David; A. de Angelis; M. de Beer; H. de Boeck; W. de Boer; C. de Clercq; M. D. M. de Fez Laso; N. de Groot; C. de La Vaissiere; B. de Lotto; C. Defoix; D. Delikaris; S. Delorme; P. Delpierre; N. Demaria; A. Demin; J. Derkaoui; L. di Ciaccio; H. Dijkstra; F. Djama; J. Dolbeau; M. Donszelmann; K. Doroba; M. Dracos; J. Drees; M. Dris; W. Dulinski; R. Dzhelyadin; L.-O. Eek; P. A.-M. Eerola; T. Ekelof; G. Ekspong; A. Elliot Peisert; J.-P. Engel; V. Falaleev; D. Fassouliotis; M. Fernandez Alonso; A Filippas-Tassos; T. A. Filippas; A. Firestone; H. Foeth; E. Fokitis; P. Folegati; F. Fontanelli; H. Forsbach; B. Franek; K. E. Fransson; P. Frenkiel; D. C. Fries; A. G. Frodesen; R. Fruhwirth; F. Fulda-Quenzer; K. Furnival; H. Furstenau; J. Fuster; J. M. Gago; G. Galeazzi; D. Gamba; C. Garcia; J. Garcia; U. Gasparini; P. Gavillet; E. N. Gazis; J.-P. Gerber; P. Giacomelli; K.-W. Glitza; R. Gokieli; V. M. Golovatyuk; J. J. Gomez Y Cadenas; A. Goobar; G. Gopal; M. Gorski; V. Gracco; A. Grant; F. Grard; E. Graziani; M.-H. Gros; G. Grosdidier; B. Grossetete; J. Guy; F. Hahn; M. Hahn; S. Haider; Z. Hajduk; A. Hakansson; A. Hallgren; K. Hamacher; G. Hamel de Monchenault; F. J. Harris; B. W. Heck; I. Herbst; J. J. Hernandez; P. Herquet; H. Herr; I. Hietanen; E. Higon; H. J. Hilke; S. D. Hodgson; T. Hofmokl; R. Holmes; S.-O. Holmgren; D. Holthuizen; P. F. Honore; J. E. Hooper; M. Houlden; J. Hrubec; P. O. Hulth; K. Hultqvist; D. Husson; B. D. Hyams; P. Ioannou; D. Isenhower; P.-S. Iversen; J. N. Jackson; P. Jalocha; G. Jarlskog; P. Jarry; B. Jean-Marie; E. K. Johansson; D. Johnson; M. Jonker; L. Jonsson; P. Juillot; G. Kalkanis; G Kantardjian; F. Kapusta; S. Katsanevas; E. C. Katsoufis; R. Keranen; J. Kesteman; B. A. Khomenko; N N Khovanskii; B J King; N. J. Kjaer; H. Klein; W. Klempt; G. Kliutchnikov; A. Klovning; P M Kluit; J. H. Koehne; B. Koene; P. Kokkinias; M. Kopf; M. Koratzinos; K. Korcyl; A. V. Korytov; B. Korzen; C. Kourkoumelis; T. Kreuzberger; J. Krolikowski; J. Krstic; U. Kruener-Marquis; W. Krupinski; W. Kucewicz; K. Kurvinen; C Lambropoulos; J. W. Lamsa; L. Lanceri; V. Lapin; J.-P. Laugier; R. Lauhakangas; G. Leder; F. Ledroit; J. Lemonne; G. Lenzen; V. Lepeltier; A. Letessier-Selvon; D. Liko; E Lillethun; J. Lindgren; A. Lipniacka; I. Lippi; R. Llosa; B. Loerstad; M. Lokajicek; J. G. Loken; M. A. Lopez Aguera; A. Lopez-Fernandez; M. Los; D. Loukas; A. Lounis; J. J. Lozano; R. Lucock; P. Lutz; L. Lyons; G. Maehlum; J. Maillard; A. Maltezos; S. Maltezos; F. Mandl; J. Marco; M. Margoni; J.-C. Marin; A. Markou; S. Marti; L. Mathis; F. Matorras; C. Matteuzzi; G. Matthiae; M L McCubbin; M. Mazzucato; M. Mc Cubbin; R. Mc Kay; R. Mc Nulty; E. Menichetti; C. Meroni; W. T. Meyer; M. Michelotto; W. A. Mitaroff; G. V. Mitselmakher; U. Mjoernmark; T. Moa; R. Moeller; K. Moenig; M. R. Monge; P. Morettini; H. Mueller; H. Muller; W. J. Murray; G. Myatt; F. Naraghi; U. Nau-Korzen; F. L. Navarria; P. Negri; B. S. Nielsen; B. Nijjhar; V. Nikolaenko; V. Obraztsov; A. G. Olshevski; R. Orava; A. Ostankov; A. Ouraou; R. Pain; H. Palka; T. Papadopoulou; L. Pape; A. Passeri; M. Pegoraro; V. Perevozchikov; M. Pernicka; A. Perrotta; F. Pierre; M. Pimenta; O. Pingot; A. Pinsent; M. E. Pol; G. Polok; P. Poropat; P. Privitera; A. Pullia; J. Pyyhtia; D. Radojicic

    1992-01-01

    The study of the orientation of three-jet events from e+e- --> Z0 --> multi-hadrons is presented, in particular the polar angle distributions of the thrust axis and of the normal to the three-jet plane, and the azimuthal correlations between the hadron plane and the one defined by the beam and thrust axes. The data are compared with results at lower

  1. Effect of Target-type Thrust Reverser on Transonic Aerodynamic Characteristics of a Single-engine Fighter Model

    NASA Technical Reports Server (NTRS)

    Swihert, John M

    1958-01-01

    A brief investigation of a target-type thrust reverser on a single-engine fighter model has been conducted in the Langley 16-foot transonic tunnel at Mach numbers from 0.20 to 1.05.At Mach numbers of 0.80, 0.92, and 1.05, a hydrogen peroxide turbojet-engine simulator was operated with the thrust reverser extended. The angle of attack was varied from 0 degrees to 5 degrees at these Mach numbers. The Reynolds number of the free stream, based on the mean aerodynamic chord, was about 5 x 10(6). It was estimated that reversed jet operations separated the model boundary-layer flow over the upper surface of the horizontal tail and upper part of the afterbody. This resulted in a positive pitch increment due to reversed jet operation. Jet-on operation also tended to stabilize the severe lateral oscillations which occurred with the reverser extended and the jet off. It appeared that these jet-off oscillations were the result of an alternating separation and reattachment of the flow on the rearmost portions of the fuselage afterbody.

  2. Jet energy scale setting with "photon+Jet" events at LHC energies. Selection of events with a clean "photon+Jet" topology and photon Pt - jet Pt disbalance

    E-print Network

    D. V. Bandourin; V. F. Konoplyanikov; N. B. Skachkov

    2001-04-27

    It is shown in the paper that Pt activity limitation (modulus of the vector sum) of all particle beyond "photon+Jet" system Pt^out leads to the noticeable photon Pt - jet Pt disbalance decreasing. On a simultaneous restriction of the cluster Pt and Pt^out from above it is possible to reach an acceptable balance between photon Pt - jet Pt with a sufficient number of the photon Pt - jet Pt events for the jet energy scale setting and hadron calorimeter calibratiom of the CMS detector at LHC.

  3. Thrust-induced effects on low-speed aerodynamics of fighter aircraft. [Langley 4- by 7-meter tunnel

    NASA Technical Reports Server (NTRS)

    Banks, D. W.; Quinto, P. F.; Paulson, J. W., Jr.

    1982-01-01

    Results of NASA Langley has conducted wind-tunnel investigations of several fighter configurations conducted to determine the effects of both thrust vectoring and spanwise blowing are reviewed. A recent joint NASA/Grumman Aerospace Corporation/U.S. Air Force Wright Aeronautical Laboratory wind-tunnel investigation was conducted to examine the effects of spanwise blowing on the trailing-edge flap system. This application contrasts with the more familiar method of spanwise blowing near the wing leading edge. Another joint program among NASA/McDonnell Aircraft Company/U.S. Air Force Wright Aeronautical Laboratory investigated the effects of reverse thrust on the low-speed aerodynamics of an F-15 configuration. The F-15 model was fitted with a rotating van thrust reverser concept which could simulate both in-flight reversing for approach and landing or full reversing for ground roll reduction. The significant results of these two joint programs are reported.

  4. LOX cooled thrust chamber technology developments

    NASA Technical Reports Server (NTRS)

    Spencer, R. G.; Rousar, D. C.; Price, H. G.

    1978-01-01

    An experimental LOX heat-transfer study and a LOX-cooled thrust-chamber demonstration program are summarized. Heat transfer to supercritical oxygen was investigated at 17 to 34.5 MPa (2460 to 5000 psia), and heat fluxes up to 90 MW/sq m (55 Btu/sq in.-sec). Experimental data obtained previously were correlated along with these recent data, and a design equation was derived which correlates 95% of the data within + or - 30%. Liquid-oxygen-cooled thrust chambers have been designed using this correlation and are currently being fabricated. A test program is planned for evaluating the LOX-cooled design concept using NASA test facilities. The purpose of these tests is to verify the LOX cooling correlation in a high-pressure liquid rocket engine and to determine the effects of a LOX coolant leak.

  5. Static Thrust Analysis of the Lifting Airscrew

    NASA Technical Reports Server (NTRS)

    Knight, Montgomery; Hefner, Ralph A

    1937-01-01

    This report presents the results of a combined theoretical and experimental investigation conducted at the Georgia School of Technology on the static thrust of the lifting air screw of the type used in modern autogiros and helicopters. The theoretical part of this study is based on Glauert's analysis but certain modifications are made that further clarify and simplify the problem. Of these changes the elimination of the solidity as an independent parameter is the most important. The experimental data were obtained from tests on four rotor models of two, four, and five blades and, in general, agree quite well with the theoretical calculations. The theory indicates a method of evaluating scale effects on lifting air screws, and these corrections have been applied to the model results to derive general full-scale static thrust, torque, and figure-of-merit curves for constant-chord, constant-incidence rotors. Convenient charts are included that enable hovering flight performance to be calculated rapidly.

  6. MATERIALS PERFORMANCE TARGETED THRUST FY 2004 PROJECTS

    SciTech Connect

    DOE

    2005-09-13

    The Yucca Mountain site was recommended by the President to be a geological repository for commercial spent nuclear fuel and high-level radioactive waste. The multi-barrier approach was adopted for assessing and predicting system behavior, including both natural barriers and engineered barriers. A major component of the long-term strategy for safe disposal of nuclear waste is first to completely isolate the radionuclides in waste packages for long times and then to greatly retard the egress and transport of radionuclides from penetrated packages. The goal of the Materials Performance Targeted Thrust program is to further enhance the understanding of the role of engineered barriers in waste isolation. In addition, the Thrust will explore technical enhancements and seek to offer improvements in materials costs and reliability.

  7. A guidance and navigation system for continuous low thrust vehicles. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Tse, C. J. C.

    1973-01-01

    A midcourse guidance and navigation system for continuous low thrust vehicles is described. A set of orbit elements, known as the equinoctial elements, are selected as the state variables. The uncertainties are modelled statistically by random vector and stochastic processes. The motion of the vehicle and the measurements are described by nonlinear stochastic differential and difference equations respectively. A minimum time nominal trajectory is defined and the equation of motion and the measurement equation are linearized about this nominal trajectory. An exponential cost criterion is constructed and a linear feedback guidance law is derived to control the thrusting direction of the engine. Using this guidance law, the vehicle will fly in a trajectory neighboring the nominal trajectory. The extended Kalman filter is used for state estimation. Finally a short mission using this system is simulated. The results indicate that this system is very efficient for short missions.

  8. Static performance of five twin-engine nonaxisymmetric nozzles with vectoring and reversing capability

    NASA Technical Reports Server (NTRS)

    Capone, F. J.

    1978-01-01

    Transonic tunnel test was performed to determine the static performance of five twin-engine nonaxisymmetric nozzles and a base-line axisymmetric nozzle at three nozzle power settings. Static thrust-vectoring and thrust-reversing performance were also determined. Nonaxisymmetric-nozzle concepts included two-dimensional convergent-divergent nozzles, wedge nozzles, and a nozzle with a single external-expansion ramp. All nonaxisymmetric nozzles had essentially the same statis performance as the axisymmetric nozzle. Effective thrust vectoring and reversing was also achieved.

  9. CFD Code Survey for Thrust Chamber Application

    NASA Technical Reports Server (NTRS)

    Gross, Klaus W.

    1990-01-01

    In the quest fo find analytical reference codes, responses from a questionnaire are presented which portray the current computational fluid dynamics (CFD) program status and capability at various organizations, characterizing liquid rocket thrust chamber flow fields. Sample cases are identified to examine the ability, operational condition, and accuracy of the codes. To select the best suited programs for accelerated improvements, evaluation criteria are being proposed.

  10. Thrust bolting: Roof-bolt-support apparatus

    SciTech Connect

    Tadolini, S.C.; Dolinar, D.R.

    1991-01-01

    The invention relates to a method for installing a roof bolt in a borehole of a rock formation and more specifically to tensioning the unit without the aid of a mechanical anchoring device or threaded tensioning threads. The bolt is capable of being placed into tension along the length and the levels of active support can be controlled by varying the length of the grouted portion and the level of thrust applied to the bolt during installation.

  11. Low thrust viscous nozzle flow fields prediction

    NASA Technical Reports Server (NTRS)

    Liaw, G. S.; Mo, J. D.

    1991-01-01

    A Navier-Stokes code was developed for low thrust viscous nozzle flow field prediction. An implicit finite volume in an arbitrary curvilinear coordinate system lower-upper (LU) scheme is used to solve the governing Navier-Stokes equations and species transportation equations. Sample calculations of carbon dioxide nozzle flow are presented to verify the validity and efficiency of this code. The computer results are in reasonable agreement with the experimental data.

  12. Low Carbon Propulsion Strategic Thrust Overview

    NASA Technical Reports Server (NTRS)

    Dryer, Jay

    2014-01-01

    NASA is taking a leadership role with regard to developing new options for low-carbon propulsion. Work related to the characterization of alternative fuels is coordinated with our partners in government and industry, and NASA is close to concluding a TC in this area. Research on alternate propulsion concepts continues to grow and is an important aspect of the ARMD portfolio. Strong partnerships have been a key enabling factor for research on this strategic thrust.

  13. Thrust and power measurements of Olympic swimmers

    NASA Astrophysics Data System (ADS)

    Wei, Timothy; Wu, Vicki; Hutchison, Sean; Mark, Russell

    2012-11-01

    Elite level swimming is an extremely precise and even choreographed activity. Swimmers not only know the exact number of strokes necessary to take them across the pool, they also plan to be a precise distance from the wall at the end of their last stroke. Too far away and they lose time by drifting into the wall. Too close and their competitor may slide in before their hand comes forward to touch the wall. In this context, it is important to know, in detail, where and how a swimmer propels her/himself through the water. Over the past decade, state-of-the-art flow and thrust measurement diagnostics have been brought to competitive swimming. But the ability to correlate stroke mechanics to thrust production without somehow constraining the swimmer has here-to-fore not been possible. Using high speed video, a simple approach to mapping the swimmer's speed, thrust and net power output in a time resolved manner has been developed. This methodology has been applied to Megan Jendrick, gold medalist in the 100 individual breast stroke and 4 × 100 medley relay events in 2000 and Ariana Kukors, 2009 world champion and continuing world record holder in the 200 individual medley. Implications for training future elite swimmers will be discussed.

  14. The Zagros hinterland fold-and-thrust belt in-sequence thrusting, Iran

    NASA Astrophysics Data System (ADS)

    Sarkarinejad, Khalil; Ghanbarian, Mohammad Ali

    2014-05-01

    The collision of the Iranian microcontinent with the Afro-Arabian continent resulted in the deformation of the Zagros orogenic belt. The foreland of this belt in the Persian Gulf and Arabian platform has been investigated for its petroleum and gas resource potentials, but the Zagros hinterland is poorly investigated and our knowledge about its deformation is much less than other parts of this orogen. Therefore, this work presents a new geological map, stratigraphic column and two detailed geological cross sections. This study indicates the presence of a hinterland fold-and-thrust belt on northeastern side of the Zagros orogenic core that consists of in-sequence thrusting and basement involvement in this important part of the Zagros hinterland. The in-sequence thrusting resulted in first- and second-order duplex systems, Mode I fault-bend folding, fault-propagation folding and asymmetric detachment folding which indicate close relationships between folding and thrusting. Study of fault-bend folds shows that layer-parallel simple shear has the same role in the southeastern and northwestern parts of the study area (?e = 23.4 ± 9.1°). A major lateral ramp in the basement beneath the Talaee plain with about one kilometer of vertical offset formed parallel to the SW movement direction and perpendicular to the major folding and thrusting.

  15. Evaluation and modeling of autonomous attitude thrust control for the Geostation Operational Environmental Satellite (GOES)-8 orbit determination

    NASA Technical Reports Server (NTRS)

    Forcey, W.; Minnie, C. R.; Defazio, R. L.

    1995-01-01

    The Geostationary Operational Environmental Satellite (GOES)-8 experienced a series of orbital perturbations from autonomous attitude control thrusting before perigee raising maneuvers. These perturbations influenced differential correction orbital state solutions determined by the Goddard Space Flight Center (GSFC) Goddard Trajectory Determination System (GTDS). The maneuvers induced significant variations in the converged state vector for solutions using increasingly longer tracking data spans. These solutions were used for planning perigee maneuvers as well as initial estimates for orbit solutions used to evaluate the effectiveness of the perigee raising maneuvers. This paper discusses models for the incorporation of attitude thrust effects into the orbit determination process. Results from definitive attitude solutions are modeled as impulsive thrusts in orbit determination solutions created for GOES-8 mission support. Due to the attitude orientation of GOES-8, analysis results are presented that attempt to absorb the effects of attitude thrusting by including a solution for the coefficient of reflectivity, C(R). Models to represent the attitude maneuvers are tested against orbit determination solutions generated during real-time support of the GOES-8 mission. The modeling techniques discussed in this investigation offer benefits to the remaining missions in the GOES NEXT series. Similar missions with large autonomous attitude control thrusting, such as the Solar and Heliospheric Observatory (SOHO) spacecraft and the INTELSAT series, may also benefit from these results.

  16. Evaluation and modeling of autonomous attitude thrust control for the Geostation Operational Environmental Satellite (GOES)-8 orbit determination

    NASA Astrophysics Data System (ADS)

    Forcey, W.; Minnie, C. R.; Defazio, R. L.

    1995-05-01

    The Geostationary Operational Environmental Satellite (GOES)-8 experienced a series of orbital perturbations from autonomous attitude control thrusting before perigee raising maneuvers. These perturbations influenced differential correction orbital state solutions determined by the Goddard Space Flight Center (GSFC) Goddard Trajectory Determination System (GTDS). The maneuvers induced significant variations in the converged state vector for solutions using increasingly longer tracking data spans. These solutions were used for planning perigee maneuvers as well as initial estimates for orbit solutions used to evaluate the effectiveness of the perigee raising maneuvers. This paper discusses models for the incorporation of attitude thrust effects into the orbit determination process. Results from definitive attitude solutions are modeled as impulsive thrusts in orbit determination solutions created for GOES-8 mission support. Due to the attitude orientation of GOES-8, analysis results are presented that attempt to absorb the effects of attitude thrusting by including a solution for the coefficient of reflectivity, C(R). Models to represent the attitude maneuvers are tested against orbit determination solutions generated during real-time support of the GOES-8 mission. The modeling techniques discussed in this investigation offer benefits to the remaining missions in the GOES NEXT series. Similar missions with large autonomous attitude control thrusting, such as the Solar and Heliospheric Observatory (SOHO) spacecraft and the INTELSAT series, may also benefit from these results.

  17. Extended performance solar electric propulsion thrust system study. Volume 2: Baseline thrust system

    NASA Technical Reports Server (NTRS)

    Poeschel, R. L.; Hawthorne, E. I.

    1977-01-01

    Several thrust system design concepts were evaluated and compared using the specifications of the most advanced 30- cm engineering model thruster as the technology base. Emphasis was placed on relatively high-power missions (60 to 100 kW) such as a Halley's comet rendezvous. The extensions in thruster performance required for the Halley's comet mission were defined and alternative thrust system concepts were designed in sufficient detail for comparing mass, efficiency, reliability, structure, and thermal characteristics. Confirmation testing and analysis of thruster and power-processing components were performed, and the feasibility of satisfying extended performance requirements was verified. A baseline design was selected from the alternatives considered, and the design analysis and documentation were refined. The baseline thrust system design features modular construction, conventional power processing, and a concentractor solar array concept and is designed to interface with the space shuttle.

  18. Thrust Performance of a Low Power Hall Thruster

    NASA Astrophysics Data System (ADS)

    Yamamoto, Naoji; Ezaki, Toru; Nakashima, Hideki

    For the application of Hall thrusters to small satellites, we have been developing a low power Hall thruster. As an initial test, we evaluated the thrust performance of a 50 W class miniature Hall thruster developed at Kyushu University. The outer diameter and the length of the acceleration channel are 18 mm and 7 mm, respectively. A torsional type thrust stand was developed, since the estimated thrust is 1-3 mN, which is too small to be measured by means of a conventional pendulum type thrust stand for Hall thrusts. The uncertainty of this thrust stand is less than 10% at 2 mN with calibration. The thrust, the discharge current, specific impulse and the thrust efficiency at xenon mass flow rate of 0.30 mg/s and discharge voltage of 125 V were 1.7 mN, 0.35 A, 600 sec and 11.4%, respectively. The thrust increased with an increase in discharge voltage and the thrust became 3.1 mN at discharge voltage of 250 V.

  19. High-power, null-type, inverted pendulum thrust stand.

    PubMed

    Xu, Kunning G; Walker, Mitchell L R

    2009-05-01

    This article presents the theory and operation of a null-type, inverted pendulum thrust stand. The thrust stand design supports thrusters having a total mass up to 250 kg and measures thrust over a range of 1 mN to 5 N. The design uses a conventional inverted pendulum to increase sensitivity, coupled with a null-type feature to eliminate thrust alignment error due to deflection of thrust. The thrust stand position serves as the input to the null-circuit feedback control system and the output is the current to an electromagnetic actuator. Mechanical oscillations are actively damped with an electromagnetic damper. A closed-loop inclination system levels the stand while an active cooling system minimizes thermal effects. The thrust stand incorporates an in situ calibration rig. The thrust of a 3.4 kW Hall thruster is measured for thrust levels up to 230 mN. The uncertainty of the thrust measurements in this experiment is +/-0.6%, determined by examination of the hysteresis, drift of the zero offset and calibration slope variation. PMID:19485530

  20. Interim prediction method for jet noise

    NASA Technical Reports Server (NTRS)

    Stone, J. R.

    1974-01-01

    A method is provided for predicting jet noise for a wide range of nozzle geometries and operating conditions of interest for aircraft engines. Jet noise theory, data and existing prediction methods was reviewed, and based on this information a interim method of jet noise prediction is proposed. Problem areas are idenified where further research is needed to improve the prediction method. This method predicts only the noise generated by the exhaust jets mixing with the surrounding air and does not include other noises emanating from the engine exhaust, such as combustion and machinery noise generated inside the engine (i.e., core noise). It does, however, include thrust reverser noise. Prediction relations are provided for conical nozzles, plug nozzles, coaxial nozzles and slot nozzles.

  1. Jet Spreading Increase by Passive Control and Associated Performance Penalty

    NASA Technical Reports Server (NTRS)

    Zaman, K. B. M. Q.

    1999-01-01

    This paper reviews the effects of 'screech', 'asymmetric nozzle shaping', 'tabs' and 'overexpansion' on the spreading of free jets. Corresponding thrust penalty for the tabs and overexpanded condition are also evaluated. The asymmetric shapes include rectangular ones with varying aspect ratio. Tabs investigated are triangular shaped 'delta-tabs' placed at the exit of a convergent circular nozzle. The effect of overexpansion is examined with circular convergent-divergent (C-D) nozzles. Tabs and overexpansion are found to yield the largest increase in jet spreading. Each, however, involves a performance penalty, i.e., a loss in thrust coefficient. Variation of the size of four delta-tabs show that there exists an optimum size for which the gain in jet spreading is the maximum per unit loss in thrust coefficient. With the C-D nozzles, the minimum in thrust coefficient is expected near the beginning of the overexpanded regime based on idealized flow calculations. The maximum increase in jet spreading, however, is found to occur at higher pressure ratios well into the overexpanded regime. The optimum benefit with the overexpanded flow, in terms of gain in spreading for unit penalty, is found to be comparable to the optimum tab case.

  2. Low thrust trajectory design for resonant flybys and captures using invariant manifolds

    NASA Astrophysics Data System (ADS)

    Anderson, Rodney L.

    The application of dynamical systems techniques to the problem of low thrust trajectory design in the three-body problem has revealed a close relationship between these trajectories and the invariant manifolds of unstable periodic orbits. In this study, this relationship was explored for low thrust trajectories in the Jovian system with the focus primarily on the Jupiter-Europa three-body problem. Research in this problem was motivated by the observation that previous low thrust trajectories developed for the Jupiter Icy Moons Orbiter appeared to generally follow the invariant manifolds of periodic orbits. Two of the primary components of low thrust trajectory design in the Jovian system are the construction of resonant flybys and the capture problem. Resonant flybys were analyzed by first examining a continuous trajectory traveling between two resonances via Europa flybys. This analysis was compared to a planar Europa orbiter trajectory traveling between the same resonances while including impulsive maneuvers. In each case, the trajectories appeared to closely follow the invariant manifolds of unstable resonant orbits during the resonance transitions. It was determined that the resonant flybys were performed at energy levels where the invariant manifolds of the two relevant resonant orbits were closely related. The approach and capture problem was first characterized using collision orbit metrics, which allowed the development of general mission design boundaries. Next, it was verified that spacecraft must target a libration orbit's stable manifold in order to perform the capture. It was determined that the libration orbit's stable manifold only enclosed the desired resonant orbit for some energies, indicating that both the energy level and the resonance prior to approach must be targeted together. Finally, these same techniques were extended to analyze a low thrust trajectory. It was determined that the optimization algorithm, implemented in the Jet Propulsion Laboratory's Mystic software, produced a trajectory that closely followed the invariant manifolds of resonant orbits across energy levels. The understanding of the relationship between invariant manifolds and trajectories enabled by this analysis provides a clear indication of how low thrust trajectories may be designed and establishes a basis for the development of algorithms to use this knowledge.

  3. Control of Jet Noise Through Mixing Enhancement

    NASA Technical Reports Server (NTRS)

    Bridges, James; Wernet, Mark; Brown, Cliff

    2003-01-01

    The idea of using mixing enhancement to reduce jet noise is not new. Lobed mixers have been around since shortly after jet noise became a problem. However, these designs were often a post-design fix that rarely was worth its weight and thrust loss from a system perspective. Recent advances in CFD and some inspired concepts involving chevrons have shown how mixing enhancement can be successfully employed in noise reduction by subtle manipulation of the nozzle geometry. At NASA Glenn Research Center, this recent success has provided an opportunity to explore our paradigms of jet noise understanding, prediction, and reduction. Recent advances in turbulence measurement technology for hot jets have also greatly aided our ability to explore the cause and effect relationships of nozzle geometry, plume turbulence, and acoustic far field. By studying the flow and sound fields of jets with various degrees of mixing enhancement and subsequent noise manipulation, we are able to explore our intuition regarding how jets make noise, test our prediction codes, and pursue advanced noise reduction concepts. The paper will cover some of the existing paradigms of jet noise as they relate to mixing enhancement for jet noise reduction, and present experimental and analytical observations that support these paradigms.

  4. Results of boron-aluminum thrust structure

    NASA Technical Reports Server (NTRS)

    Hyer, M. W.; Lightfoot, M. C.

    1976-01-01

    Results are presented of testing-to-failure a two member boron-aluminum thrust structure. The structure represented one section of a more complex planar truss and was designed to test the integrity of a diffusion bonded joint. The structure failed at 107 percent of the ultimate design load in the diffusion bond region. Strain gages and displacement transducers were used to measure loads and deflections of the truss. The experimentally derived axial loads, bending moments, and torsion in the various members are presented and compared with predicted values.

  5. Factorization and resummation for transverse thrust

    NASA Astrophysics Data System (ADS)

    Becher, Thomas; i Tormo, Xavier Garcia

    2015-06-01

    We analyze transverse thrust in the framework of Soft Collinear Effective Theory and obtain a factorized expression for the cross section that permits resummation of terms enhanced in the dijet limit to arbitrary accuracy. The factorization theorem for this hadron-collider event-shape variable involves collinear emissions at different virtualities and suffers from a collinear anomaly. We compute all its ingredients at the one-loop order, and show that the two-loop input for next-to-next-to-leading logarithmic accuracy can be extracted numerically, from existing fixed-order codes.

  6. Low-thrust chemical rocket engine study

    NASA Technical Reports Server (NTRS)

    Mellish, J. A.

    1981-01-01

    Engine data and information are presented to perform system studies on cargo orbit-transfer vehicles which would deliver large space structures to geosynchronous equatorial orbit. Low-thrust engine performance, weight, and envelope parametric data were established, preliminary design information was generated, and technologies for liquid rocket engines were identified. Two major engine design drivers were considered in the study: cooling and engine cycle options. Both film-cooled and regeneratively cooled engines were evaluated. The propellant combinations studied were hydrogen/oxygen, methane/oxygen, and kerosene/oxygen.

  7. Fluid storage and transport in thrust belts: the Gavarnie Thrust system revisited

    NASA Astrophysics Data System (ADS)

    McCaig, Andrew

    2015-04-01

    There has been renewed interest in the pressure and movement of fluids in thrust systems in recent years with the discovery and increasing importance of slow slip earthquakes. Unfortunately the overpressured regime thought to be the source region for both normal and slow-slip earthquakes is inaccessible to direct observation, so information about the actual water content, flow regimes and permeability structure at the time of thrusting can only be obtained in exhumed rocks. The Gavarnie Thrust System in the Pyrenees (including the immediate footwall of the thrust and overlying thrust sheets) is exceptionally well studied in terms of structural and microstructural work, fluid inclusions, and isotopic tracing of fluid flow. Southward thrusting by 12-15 km occurred during the Eocene, and the current geometry of the thrust is a broad dome, allowing sampling at many locations. There is abundant evidence for near-lithostatic fluid pressures at depths of 8-15 km in the crust and temperatures of 300-400 °C, and fluids at these levels are dominated by hypersaline brines with Cl/Br ratios indicating evaporation of seawater. They are inferred to be derived from widespread Triassic evaporates, and stored in underlying redbeds and fractured basement rocks. There is also evidence from fluid inclusions for periodic pressure cycling down to near-hydrostatic values. This is thought to be related to co-seismic fault valve behaviour with release of fluid both into the shallow thrust and into steeply dipping shear zones in the hangingwall. Isotopic studies of carbonate mylonites along the Gavarnie thrust indicate unidirectional southward (structurally upward) flow of fluid , again probably mainly during transient veining events. These relatively slow moving fluids appear to have fed into a hydrostatic regime with topographically driven flow at higher levels. If time averaged permeability was high, most of the fluid would have rapidly escaped, since there is little opportunity to replenish fluid by metamorphic dehydration in the Pyrenees. This does not appear to have occurred, suggesting that any enhanced permeability events were shortlived and perhaps form patches of limited size. Fluid can be stored at various scales: in fluid inclusions in vein minerals and on grain boundaries (eg. pressure shadows in cleaved rocks); in veins and pull-aparts in competent layers such as dolomite within calcite mylonites; and in structural culminations such as the Pic de Port Vieux, where development of fold-thrust structures allowed slow dilation with evidence from fluid inclusions for influx of fluid from both footwall and hangingwall. This latter can be considered a dynamic form of storage generated by deviatoric stress and strain at high fluid pressure (not "hydraulic fracture"), whereas fluid inclusions can be considered passive storage. Stored fluid in such sites can be expelled during seismic events (both slow and fast slip) where the pressure regime in large volumes of crust will change dramatically.

  8. Kinematic modeling of folding above listric propagating thrusts

    NASA Astrophysics Data System (ADS)

    Cardozo, Nestor; Brandenburg, J. P.

    2014-03-01

    We describe a kinematic approach to simulate folds above listric propagating thrusts. The model is based on a pre-defined circular thrust geometry with a maximum central angle beyond which the thrust is planar, inclined shear above the circular thrust, and trishear in front of the thrust. Provided the trajectory of thrust propagation is established, the model can be run forward and backwards. We use this last feature to implement a global simulated annealing, inverse modeling strategy. This inverse modeling strategy is applied to synthetic folds as well as two real examples in offshore Venezuela and the Niger Delta toe-thrust system. These three examples illustrate the benefits of the algorithm, particularly in predicting the possible range of models that can fit the structures. Thrust geometry, depth to detachment level, and backlimb geometry have high impact in model parameters such as backlimb shear angle and fault slip; while forelimb geometry is critical to constrain parameters such as fault propagation to fault slip ratio and trishear angle. Steep to overturned beds in forelimb areas are often not imaged by seismic, so in the absence of additional well data, considering all possible thrust-fold geometries is critical for the modeling and whatever prediction (e.g. hydrocarbon trap integrity) is made from it.

  9. Space shuttle orbit maneuvering engine reusable thrust chamber program

    NASA Technical Reports Server (NTRS)

    Senneff, J. M.

    1975-01-01

    The feasibility of potential reusable thrust chamber concepts is studied. Propellant condidates were examined and analytically combined with potential cooling schemes. A data base of engine data which would assist in a configuration selection was produced. The data base verification was performed by the demonstration of a thrust chamber of a selected coolant scheme design. A full scale insulated columbium thrust chamber was used for propellant coolant configurations. Combustion stability of the injectors and a reduced size thrust chamber were experimentally verified as proof of concept demonstrations of the design and study results.

  10. [Lifting-thrusting and rotating manipulations: a comparison on energy input].

    PubMed

    Wang, Xi-ming

    2011-01-01

    Through the energy input model of lifting-thrusting and rotating manipulations, using the theory of energy density, energy flux density and sound intensity level in physics, the average energy flux intensity and frequency distributions of average poynting's vector were calculated respectively within the range of infrasound. According to the distribution table, it was discovered that both of the energy flux density and sound intensity level during the process of acupuncture were high. And it was concluded that the essence of meridians was probably fascial tissues which were rich in elastic fibers and collagenous fibers. The heat-producing needling with reinforcing effect (setting the moutain on fire) which focused on forceful thrusting was held to be the result of the action of same position solitary wave. And the coolness-producing needling with reducing effect (thorough heavenly cool) emphasized on the manipulation of forceful lifting was considered as the action of opposite position solitary wave. The energy input of lifting-thrusting manipulation is comparatively larger than the rotating method, however without significant difference. The speed of manipulations applied is regarded to have greater impact on energy transmission. And the energy produced by rotating manipulation can be better transmitted through meridians. PMID:21355164

  11. Rocket thrust chamber thermal barrier coatings

    NASA Technical Reports Server (NTRS)

    Batakis, A. P.; Vogan, J. W.

    1985-01-01

    A research program was conducted to generate data and develop analytical techniques to predict the performance and reliability of ceramic thermal barrier coatings in high heat flux environments. A finite element model was used to analyze the thermomechanical behavior of coating systems in rocket thrust chambers. Candidate coating systems (using a copper substrate, NiCrAlY bond coat and ZrO2.8Y2O3 ceramic overcoat) were selected for detailed study based on photomicrographic evaluations of experimental test specimens. The effects of plasma spray application parameters on the material properties of these coatings were measured and the effects on coating performance evaluated using the finite element model. Coating design curves which define acceptable operating envelopes for seleted coating systems were constructed based on temperature and strain limitations. Spray gun power levels was found to have the most significant effect on coating structure. Three coating systems were selected for study using different power levels. Thermal conductivity, strain tolerance, density, and residual stress were measured for these coatings. Analyses indicated that extremely thin coatings ( 0.02 mm) are required to accommodate the high heat flux of a rocket thrust chamber and ensure structural integrity.

  12. Biomechanics of swimming in the pufferfish Diodon holocanthus: propulsive momentum enhancement is an adaptation for thrust production in an undulatory median and paired-fin swimmer.

    PubMed

    Blake, R W; Chan, K H S

    2011-12-01

    A form of large-amplitude elongated-body theory appropriate for the analysis of undulatory fins attached to a rigid body of elliptical section suggests a benefit due to momentum enhancement relative to the fins on their own. This theoretical prediction is experimentally confirmed for the first time. Theoretical momentum enhancement factors for Diodon holocanthus (2.2 and 2.7 for the median and pectoral fins, respectively) compared well to inferred thrust values determined from particle-image velocimetry (PIV) wake measurements (2.2-2.4 and 2.7-2.9). Caudal fin mean theoretical thrust was not significantly different from measured (PIV) values (n = 24, P > 0.05), implying no momentum enhancement. Pectoral-fin thrust was half that of the median and caudal fins due to high fin-jet angles, low circulation and momentum. Average total fin thrust and fish drag were not significantly different (n = 24, P > 0.05). Vortex rings generated by the fins were elliptical, with size dependent on fin chord and stroke amplitude. Hydrodynamic advantages (thrust enhancement at no cost to hydrodynamic efficiency, reduction of side forces minimizing energy wasting yawing motions and body drag) are probably common among rigid-bodied organisms propelled by undulatory fins. A trade-off between momentum enhancement and the rate of momentum generation (thrust force) sets a practical limit to the former. For small fins whilst momentum enhancement is high, absolute thrust is low. In addition, previously suggested limitations on thrust enhancement set by reductions in propulsive force associated with progressive reductions in fin wavelength are found to be biologically unrealistic. PMID:22141887

  13. Kinematics in Vector Boson Fusion

    E-print Network

    D. Green

    2006-03-02

    The vector boson fusion process leads to two forward/backward jets (tag jets) and the produced state, a Higgs boson in this case, moving slowly in the p-p C.M. frame at the LHC. For the case of Higgs decaying to W+W (W*) with Higgs mass below 180 GeV, the W bosons have low momentum in the Higgs C.M. For the case of W leptonic decays, this fact allows for an approximate reconstruction of the two final state neutrinos. In turn, those solutions then provide additional kinematic cuts against background.

  14. Fault interaction along the Central Andean thrust front: The Las Peñas thrust, Cerro Salinas thrust and the Montecito Anticline

    NASA Astrophysics Data System (ADS)

    Schoenbohm, L. M.; Costa, C. H.; Brooks, B. A.; Bohon, W.; Gardini, C.; Cisneros, H.

    2013-12-01

    The region in west-central Argentina between the thin-skinned Precordillera and the thick-skinned Sierras Pampeanas structural domain is among the most active zones of thrust tectonics in the world. We quantify the rates of deformation on the east-vergent Las Peñas thrust (LPT), and the west-vergent Cerro Salinas thrust (CST). The Montecito anticline (MA) is located at their intersection. We mapped three key locations, collected stratigraphic logs from the MA, dated three ashes using U-Pb in zircon and dated 10 terraces using cosmogenic Be-10 depth profiles. Five terrace levels are present where the Rio Las Peñas crosses the LPT, up to 45 m above the modern river. Cosmogenic dating of the uppermost terrace (T1) yields and age of 123.8 +26.5/-12.3 ka. A reconstruction of this surface using a blind thrust rupture scenario indicates 73 +/- 7 m horizontal shortening and 34 +/- 3 m vertical displacement. Shortening across the structure is therefore 0.59 +0.10/-0.13 mm/yr with a vertical uplift rate of 0.27 +0.05/-0.06 mm/a. Previous work indicates higher rates to the south on the order of 2 mm/yr (Schmidt et al., 2011). Lower terraces give ages of 38.0 +11/-6.2 ka (T2) and 1.5 +5.0/-0.6 ka (T4). Three terrace levels are preserved near the center of the CST. The middle surface (T2) is folded across the axis of the structure and yields an age of 112.5 +33/-14.4 ka. Given 22.9 m surface uplift, this indicates a vertical uplift rate of 0.20 +0.05/-0.06 mm/yr, similar to the rate on the LPT. The upper terrace (T1) yields a younger age (97.1 +29.8/-12.4 ka); the T1 and T2 ages overlap within uncertainty, indicating rapid river incision at the time of their formation. An intercalated ash within the Neogene strata gives an age of 16.2 +/- 0.2. Previous work indicates long-term shortening rates of 0.8 mm/yr (Verges et al., 2007) and that the CST initiated after 8.5 Ma. The lowermost unit exposed in the MA is the Los Pozos Fm., with no indication of syn-depositional deformation. An intercalated ash from the top of this formation yields an age of 5.76 +/- 0.09 Ma. Internal unconformities are present within the overlying transitional unit and the Mogotes Fm., indicating deformation post-dates 5.8 Ma in the MA. An ash within the Mogotes Fm. is 1.52 +/- 0.06 Ma. Slip is modeled as 3.5 km reverse slip across an east-dipping dislocation with a 45 degree dip. This suggests horizontal shortening and vertical uplift of 0.42 mm/yr since the onset of deformation. Uplifted terraces near the center of the MA are 4.7 +0.8/-0.3 ka (T2) and 1.9 +3.4/-1.9 ka (T3), 6 and 4.6 m above the modern river, respectively. This suggests recent vertical uplift or incision rates of 1.3-2.4 mm/yr. These data suggest that deformation in the MA is comparable to that at the LPT and CST. Deformation in the MA could be accelerating, but alternatively, river incision could be accelerating due to climate change.

  15. An Experimental Investigation of an Exhaust-gas-to-air Heat Exchanger for Use on Jet-stack-equipped Engines

    NASA Technical Reports Server (NTRS)

    Stalder, Jackson R; Spies, Ray J , Jr

    1948-01-01

    Tests were made to determine the loss in exhaust-jet thrust and engine power resulting from the insertion of an exhaust-gas-to-air heat exchanger in a jet-type exhaust stack of an aircraft engine. The thermal performance of the heat exchanger was also determined.

  16. Jet noise of an augmentor wing-advanced supersonic transport

    NASA Technical Reports Server (NTRS)

    Franciscus, L.

    1972-01-01

    A preliminary mission study was made of the range and jet noise of an advanced supersonic transport (AST) employing an augmentor wing and four duct burning turbofan engines. The airplane weight and aerodynamic characteristics of the Boeing 2707-300 airplane with a gross weight of 750,000 pounds and 234 passengers was used for the study. Engine thrust was fixed at 58,000 pounds per engine and engine size was increased to obtain the required thrust at reduced power settings for jet noise reduction. Turbofan engine core noise was reduced to FAR 36 noise levels and lower by proper selection of turbine inlet temperature, bypass ratio and fan pressure ratio. The study showed that an augmentor wing can reduce the bypass jet noise sufficiently so that total noise levels below FAR 36 can be attained without significant range penalties if the augmentor wing can be designed without severe weight and performance penalties.

  17. Computer study of a jet flap ASTVOL 'Harrier'

    NASA Technical Reports Server (NTRS)

    Wilson, S. B., III; Liperra, L. D.

    1984-01-01

    A study of the costs/benefits trade-off was conducted for an Advanced Supersonic Short Takeoff and Vertical Landing (ASTOVL) aircraft incorporating a jet flap. The data used were the theory of jet flaps and high aspect ratio nozzles, experience with a V/STOL aircraft study performed for NASA Ames Research Center in February 1982, and a high performance aircraft-synthesis program (ACSYNT). The methodology was to accurately model the supersonic Harrier V/STOL aircraft design on ACSYNT, and then modify the design by both adding high aspect-ratio nozzles in place of the rear (core-flow) nozzles on the Pegasus-type turbofan engine, and integrating these nozzles on each wing's trailing edge, thus creating a jet flap. The predicted performance advantages (increase in maximum lift coefficient with flap deflection and horizontal thrust recovery) were traded off against the disadvantages (additional weight and thrust loss due to ducting) on two representative missions.

  18. Water Jetting

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Hi-Tech Inc., a company which manufactures water jetting equipment, needed a high pressure rotating swivel, but found that available hardware for the system was unsatisfactory. They were assisted by Marshall, which had developed water jetting technology to clean the Space Shuttles. The result was a completely automatic water jetting system which cuts rock and granite and removes concrete. Labor costs have been reduced; dust is suppressed and production has been increased.

  19. A Target Indirect Thrust Measurement Method of Pulse Detonation Engine

    NASA Astrophysics Data System (ADS)

    Huang, Xiqiao; Xiong, Yuefei; Li, Chao; Zheng, Longxi; Li, Qing

    2015-05-01

    An indirect thrust measurement method based on impulse of a target plate was developed, and a new thrust measurement system (TMS) was successfully designed and constructed. A series of multi-cycle experiments on thrust measurement were conducted to investigate the feasibility of this method with the newly-built indirect TMS. The thrust measurement of PDE was made at different plate target axial positions and operating frequencies. All the experiments were conducted using gasoline as fuel and air as oxidant. The experimental results implied that the thrust of PDE by using the indirect impulse method was a function of the target plate axial position, and there existed an optimum measurement position for PDE with a diameter of 60 mm. The optimum target plate position located at 3.33. According to the experimental results, the thrusts obtained by using indirect TMS were less than the actual values, and so the observed value of thrust was modified in order to make the thrust more reliable. A relative accurate calibration formula depending on the operating frequency was found.

  20. Levitation and thrust control of a Maglev LCD glass conveyor

    Microsoft Academic Search

    Chang-Hyun Kim; Jong-Min Lee; Hyung-Suk Han; Bong-Seup Kim

    2011-01-01

    In this paper, the levitation and thrust control of a magnetically levitated (Maglev) LCD glass conveyor is introduced. In order to levitate the conveyor system, electromagnets (EM) and permanent magnets (PM) are used together. Due to the use of the PM, power consumption for levitation can be significantly reduced. To thrust the vehicle, a linear induction motor (LIM) is designed

  1. Energy Rate Prediction Using an Equivalent Thrust Setting Profile

    E-print Network

    Paris-Sud XI, Université de

    weight and an equivalent thrust profile. These parameters are not meant to be true, however is built. This thrust profile is designed in such a way that the estimated equivalent weight provides parameters and BADA standard parameters. Keywords: trajectory prediction, energy rate, equivalent weight

  2. Electronics Engineering Department Thrust Area report FY'84

    SciTech Connect

    Minichino, C.; Phelps, P.L. (eds.)

    1984-01-01

    This report describes the work of the Electronics Engineering Department Thrust Areas for FY'84: diagnostics and microelectronic engineering; signal and control engineering; microwave and pulsed power engineering; computer-aided engineering; engineering modeling and simulation; and systems engineering. For each Thrust Area, an overview and a description of the goals and achievements of each project is provided.

  3. Flyaround Maneuvers on a Satellite Orbit by Impulsive Thrust Control

    Microsoft Academic Search

    Yasuhiro Masutani; Motoshi Matsushita; Fumio Miyazaki

    2001-01-01

    Close circumnavigation is an important function indispensable for servicing satellites. We discuss the bielliptic flyaround maneuver by impulsive thrust control for a small and low cost servicing satellite flying around a target satellite. An optimal feedback control scheme for the thrust is proposed to maintain this trajectory in the presence of disturbances. The extended Kalman filter is employed to estimate

  4. Vector quantization

    Microsoft Academic Search

    Robert M. Gray

    1984-01-01

    A vector quantizer is a system for mapping a sequence of continuous or discrete vectors into a digital sequence suitable for communication over or storage in a digital channel. The goal of such a system is data compression: to reduce the bit rate so as to minimize communication channel capacity or digital storage memory requirements while maintaining the necessary fidelity

  5. Beam thrust cross section for Drell-Yan production at next-to-next-to-leading-logarithmic order.

    PubMed

    Stewart, Iain W; Tackmann, Frank J; Waalewijn, Wouter J

    2011-01-21

    At the LHC and Tevatron strong initial-state radiation (ISR) plays an important role. It can significantly affect the partonic luminosity available to the hard interaction or contaminate a signal with additional jets and soft radiation. An ideal process to study ISR is isolated Drell-Yan production, pp ? X?+ ?- without central jets, where the jet veto is provided by the hadronic event shape beam thrust ?B. Most hadron collider event shapes are designed to study central jets. In contrast, requiring ? B < 1 provides an inclusive veto of central jets and measures the spectrum of ISR. For ? B < 1 we carry out a resummation of ? s(n)ln(m)? B corrections at next-to-next-to-leading-logarithmic order. This is the first resummation at this order for a hadron-hadron collider event shape. Measurements of ? B at the Tevatron and LHC can provide crucial tests of our understanding of ISR and of ? B's utility as a central jet veto. PMID:21405266

  6. Beam Thrust Cross Section for Drell-Yan Production at Next-to-Next-to-Leading-Logarithmic Order

    SciTech Connect

    Stewart, Iain W.; Tackmann, Frank J.; Waalewijn, Wouter J. [Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2011-01-21

    At the LHC and Tevatron strong initial-state radiation (ISR) plays an important role. It can significantly affect the partonic luminosity available to the hard interaction or contaminate a signal with additional jets and soft radiation. An ideal process to study ISR is isolated Drell-Yan production, pp{yields}Xl{sup +}l{sup -} without central jets, where the jet veto is provided by the hadronic event shape beam thrust {tau}{sub B}. Most hadron collider event shapes are designed to study central jets. In contrast, requiring {tau}{sub B}<<1 provides an inclusive veto of central jets and measures the spectrum of ISR. For {tau}{sub B}<<1 we carry out a resummation of {alpha}{sub s}{sup n}ln{sup m{tau}}{sub B} corrections at next-to-next-to-leading-logarithmic order. This is the first resummation at this order for a hadron-hadron collider event shape. Measurements of {tau}{sub B} at the Tevatron and LHC can provide crucial tests of our understanding of ISR and of {tau}{sub B}'s utility as a central jet veto.

  7. Wave instabilities in combustion and thrust chambers

    NASA Astrophysics Data System (ADS)

    Yoon, W. S.; Chung, T. J.

    1990-06-01

    A new theory and computations for combustion instability analysis are presented. The basic theoretical foundation stems from the concept of entropy-controlled energy growth or decay. Third order perturbation expansion is performed on the entropy-controlled acoustic energy equation to obtain the stability integrodifferential equation for the energy growth factor in terms of the linear, second, and third order energy growth rate parameters. These parameters are calculated from Navier-Stokes solutions with space and time averages performed on as many Navier-Stokes time steps as required to cover at least one peak wave period. Applications are made for one-dimensional Navier-Stokes solution for the Space Shuttle main engine thrust chamber, with cross section area variations taken into account.

  8. Saturn: A Giant Thrust into Space

    NASA Technical Reports Server (NTRS)

    1962-01-01

    Saturn: A Giant Thrust into Space. The film provides an introduction and overview of the Saturn launch vehicle. It is designed with stages to drop off as fuel is spent. There may be two, three, or four stages, depending on the payload. The Saturn rocket will be used to send Apollo missions to the Moon and back. Guidance systems and booster engine rockets are based on proven mechanisms. Scale models are used to test the engines. Hardware, airframes, guidance systems, instrumentation, and the rockets are produced at sites throughout the country. The engines go to Marshall Space Flight Center for further tests. After partial assembly, the vehicle is shipped to Cape Canaveral in large pieces where it is assembled using specially built equipment and structures. Further trials are performed to assure successful launches. [Entire movie available on DVD from CASI as Doc ID 20070030961. Contact help@sti.nasa.gov

  9. Thrust Direction Optimization: Satisfying Dawn's Attitude Agility Constraints

    NASA Technical Reports Server (NTRS)

    Whiffen, Gregory J.

    2013-01-01

    The science objective of NASA's Dawn Discovery mission is to explore the two largest members of the main asteroid belt, the giant asteroid Vesta and the dwarf planet Ceres. Dawn successfully completed its orbital mission at Vesta. The Dawn spacecraft has complex, difficult to quantify, and in some cases severe limitations on its attitude agility. The low-thrust transfers between science orbits at Vesta required very complex time varying thrust directions due to the strong and complex gravity and various science objectives. Traditional thrust design objectives (like minimum (Delta)V or minimum transfer time) often result in thrust direction time evolutions that can not be accommodated with the attitude control system available on Dawn. This paper presents several new optimal control objectives, collectively called thrust direction optimization that were developed and necessary to successfully navigate Dawn through all orbital transfers at Vesta.

  10. Thrust Direction Optimization: Satisfying Dawn's Attitude Agility Constraints

    NASA Technical Reports Server (NTRS)

    Whiffen, Gregory J.

    2013-01-01

    The science objective of NASA's Dawn Discovery mission is to explore the giant asteroid Vesta and the dwarf planet Ceres, the two largest members of the main asteroid belt. Dawn successfully completed its orbital mission at Vesta. The Dawn spacecraft has complex, difficult to quantify, and in some cases severe limitations on its attitude agility. The low-thrust transfers between science orbits at Vesta required very complex time varying thrust directions due to the strong and complex gravity and various science objectives. Traditional low-thrust design objectives (like minimum change in velocity or minimum transfer time) often result in thrust direction time evolutions that cannot be accommodated with the attitude control system available on Dawn. This paper presents several new optimal control objectives, collectively called thrust direction optimization that were developed and turned out to be essential to the successful navigation of Dawn at Vesta.

  11. An Optimal Orthogonal Decomposition Method for Kalman Filter-Based Turbofan Engine Thrust Estimation

    NASA Technical Reports Server (NTRS)

    Litt, Jonathan S.

    2007-01-01

    A new linear point design technique is presented for the determination of tuning parameters that enable the optimal estimation of unmeasured engine outputs, such as thrust. The engine's performance is affected by its level of degradation, generally described in terms of unmeasurable health parameters related to each major engine component. Accurate thrust reconstruction depends on knowledge of these health parameters, but there are usually too few sensors to be able to estimate their values. In this new technique, a set of tuning parameters is determined that accounts for degradation by representing the overall effect of the larger set of health parameters as closely as possible in a least squares sense. The technique takes advantage of the properties of the singular value decomposition of a matrix to generate a tuning parameter vector of low enough dimension that it can be estimated by a Kalman filter. A concise design procedure to generate a tuning vector that specifically takes into account the variables of interest is presented. An example demonstrates the tuning parameters ability to facilitate matching of both measured and unmeasured engine outputs, as well as state variables. Additional properties of the formulation are shown to lend themselves well to diagnostics.

  12. An Optimal Orthogonal Decomposition Method for Kalman Filter-Based Turbofan Engine Thrust Estimation

    NASA Technical Reports Server (NTRS)

    Litt, Jonathan S.

    2007-01-01

    A new linear point design technique is presented for the determination of tuning parameters that enable the optimal estimation of unmeasured engine outputs, such as thrust. The engine s performance is affected by its level of degradation, generally described in terms of unmeasurable health parameters related to each major engine component. Accurate thrust reconstruction depends on knowledge of these health parameters, but there are usually too few sensors to be able to estimate their values. In this new technique, a set of tuning parameters is determined that accounts for degradation by representing the overall effect of the larger set of health parameters as closely as possible in a least-squares sense. The technique takes advantage of the properties of the singular value decomposition of a matrix to generate a tuning parameter vector of low enough dimension that it can be estimated by a Kalman filter. A concise design procedure to generate a tuning vector that specifically takes into account the variables of interest is presented. An example demonstrates the tuning parameters ability to facilitate matching of both measured and unmeasured engine outputs, as well as state variables. Additional properties of the formulation are shown to lend themselves well to diagnostics.

  13. Optimization of a Fully-Pulsed Jet in a Fluid of Similar Density

    NASA Astrophysics Data System (ADS)

    Krueger, Paul S.; Gharib, Morteza

    1998-11-01

    In a previous work, Gharib et al.(Morteza Gharib, Edmond Rambod, Karim Shariff, "A Universal Time Scale for Vortex Ring Formation," JFM, vol. 360, pp. 121-140, 1998) have studied vortex rings generated through impulsively started jets using a piston/cylinder arrangement. This work showed that the vortex ring that formed at the leading edge of the jet reached a maximum strength for a piston stroke to diameter ratio (L/D) of approximately 4 for a wide range of piston motions and jet exit boundaries. This result suggests interesting consequences for a fully-pulsed jet, which is simply a series of impulsively started jets strung together. Specifically, the thrust of the present investigation is to study how the physical behavior of a fully-pulsed jet varies as both L/D and the pulsing frequency of the jet (rate at which pulses are ejected) are varied. To this end, a piston/cylinder arrangement with a stepper motor is used to generate a fully-pulsed jet with different L/D and pulsing frequency (f) combinations. The thrust produced by these various jets is measured directly and used as a gauge of the effectiveness of the pulsed jet. Combinations of L/D and f leading to optimization of the pulsed jet will be presented.

  14. Deformation associated with transverse-thrust ramps: a field and experimental study

    E-print Network

    McCaskey, Michael Donald

    1982-01-01

    Thrust are- Several localities in the southern Canadian Thrust Belt have been shown to contain tra. nsverse-thrust ramps A cross section parallel to regional trend of the Front Ranges, west of Calgary, Alberta, (Bally and others, 1966), based...

  15. Anomalous Thrust Production from an RF Test Device Measured on a Low-Thrust Torsion Pendulum

    NASA Technical Reports Server (NTRS)

    Brady, David A.; White, Harold G.; March, Paul; Lawrence, James T.; Davies, Frank J.

    2014-01-01

    This paper describes the test campaigns designed to investigate and demonstrate viability of using classical magnetoplasmadynamics to obtain a propulsive momentum transfer via the quantum vacuum virtual plasma. This paper will not address the physics of the quantum vacuum plasma thruster (QVPT), but instead will describe the recent test campaign. In addition, it contains a brief description of the supporting radio frequency (RF) field analysis, lessons learned, and potential applications of the technology to space exploration missions. During the first (Cannae) portion of the campaign, approximately 40 micronewtons of thrust were observed in an RF resonant cavity test article excited at approximately 935 megahertz and 28 watts. During the subsequent (tapered cavity) portion of the campaign, approximately 91 micronewtons of thrust were observed in an RF resonant cavity test article excited at approximately 1933 megahertz and 17 watts. Testing was performed on a low-thrust torsion pendulum that is capable of detecting force at a single-digit micronewton level. Test campaign results indicate that the RF resonant cavity thruster design, which is unique as an electric propulsion device, is producing a force that is not attributable to any classical electromagnetic phenomenon and therefore is potentially demonstrating an interaction with the quantum vacuum virtual plasma.

  16. Characteristics of thrust fault imbrication near the frontal edge of the Blue Ridge thrust sheet, Buffalo Mountain, Tennessee

    Microsoft Academic Search

    M. M. Duddy; N. B. Woodward

    1985-01-01

    The Buffalo Mountain thrust sheet, located along the western margin of the Blue Ridge in northeastern Tennessee, provides an excellent opportunity to examine transitional structural styles and deformation mechanisms between the Valley and Ridge and Blue Ridge. Previous interpretation suggests that, because of pre-fault tilting, thrust faults within the Buffalo Mountain complex cut down stratigraphic section. Geometric data from the

  17. Synthetic jets

    Microsoft Academic Search

    Ari Glezer; Michael Amitay

    2002-01-01

    The evolution of a synthetic (zero-net mass flux) jet and the flow mechanisms of its interaction with a cross flow are reviewed. An isolated synthetic jet is produced by the interactions of a train of vortices that are typically formed by alternating momentary ejection and suction of fluid across an orifice such that the net mass flux is zero. A

  18. Composite Octet Searches with Jet Substructure

    SciTech Connect

    Bai, Yang; /SLAC; Shelton, Jessie; /Yale U.

    2012-02-14

    Many new physics models with strongly interacting sectors predict a mass hierarchy between the lightest vector meson and the lightest pseudoscalar mesons. We examine the power of jet substructure tools to extend the 7 TeV LHC sensitivity to these new states for the case of QCD octet mesons, considering both two gluon and two b-jet decay modes for the pseudoscalar mesons. We develop both a simple dijet search using only the jet mass and a more sophisticated jet substructure analysis, both of which can discover the composite octets in a dijet-like signature. The reach depends on the mass hierarchy between the vector and pseudoscalar mesons. We find that for the pseudoscalar-to-vector meson mass ratio below approximately 0.2 the simple jet mass analysis provides the best discovery limit; for a ratio between 0.2 and the QCD-like value of 0.3, the sophisticated jet substructure analysis has the best discovery potential; for a ratio above approximately 0.3, the standard four-jet analysis is more suitable.

  19. Vector Fields

    NSDL National Science Digital Library

    Dray, Tevian

    2006-01-01

    Vector fields are vectors which change from point to point. A standard example is the velocity of moving air, in other words, wind. For instance, the current wind pattern in the San Francisco area can be found at . This site has a 2-dimensional representation; careful reading of the webpage will tell you at what elevation the wind is shown. How would you represent a vector field in 3 dimensions? What features are important? Some simple examples are shown. Each can be rotated by clicking and dragging with the mouse. Explore!

  20. Cloning vector

    DOEpatents

    Guilfoyle, R.A.; Smith, L.M.

    1994-12-27

    A vector comprising a filamentous phage sequence containing a first copy of filamentous phage gene X and other sequences necessary for the phage to propagate is disclosed. The vector also contains a second copy of filamentous phage gene X downstream from a promoter capable of promoting transcription in a bacterial host. In a preferred form of the present invention, the filamentous phage is M13 and the vector additionally includes a restriction endonuclease site located in such a manner as to substantially inactivate the second gene X when a DNA sequence is inserted into the restriction site. 2 figures.

  1. Hamiltonian Vector Fields on Multiphase Spaces of Classical Field Theory

    E-print Network

    Michael Forger; Mário Otávio Salles

    2010-10-02

    We present a classification of hamiltonian vector fields on multisymplectic and polysymplectic fiber bundles closely analogous to the one known for the corresponding dual jet bundles that appear in the multisymplectic and polysymplectic approach to first order classical field theories.

  2. Thrust Stand Characterization of the NASA Evolutionary Xenon Thruster (NEXT)

    NASA Technical Reports Server (NTRS)

    Diamant, Kevin D.; Pollard, James E.; Crofton, Mark W.; Patterson, Michael J.; Soulas, George C.

    2010-01-01

    Direct thrust measurements have been made on the NASA Evolutionary Xenon Thruster (NEXT) ion engine using a standard pendulum style thrust stand constructed specifically for this application. Values have been obtained for the full 40-level throttle table, as well as for a few off-nominal operating conditions. Measurements differ from the nominal NASA throttle table 10 (TT10) values by 3.1 percent at most, while at 30 throttle levels (TLs) the difference is less than 2.0 percent. When measurements are compared to TT10 values that have been corrected using ion beam current density and charge state data obtained at The Aerospace Corporation, they differ by 1.2 percent at most, and by 1.0 percent or less at 37 TLs. Thrust correction factors calculated from direct thrust measurements and from The Aerospace Corporation s plume data agree to within measurement error for all but one TL. Thrust due to cold flow and "discharge only" operation has been measured, and analytical expressions are presented which accurately predict thrust based on thermal thrust generation mechanisms.

  3. Vector quantization

    NASA Technical Reports Server (NTRS)

    Gray, Robert M.

    1989-01-01

    During the past ten years Vector Quantization (VQ) has developed from a theoretical possibility promised by Shannon's source coding theorems into a powerful and competitive technique for speech and image coding and compression at medium to low bit rates. In this survey, the basic ideas behind the design of vector quantizers are sketched and some comments made on the state-of-the-art and current research efforts.

  4. Powered Descent Guidance with General Thrust-Pointing Constraints

    NASA Technical Reports Server (NTRS)

    Carson, John M., III; Acikmese, Behcet; Blackmore, Lars

    2013-01-01

    The Powered Descent Guidance (PDG) algorithm and software for generating Mars pinpoint or precision landing guidance profiles has been enhanced to incorporate thrust-pointing constraints. Pointing constraints would typically be needed for onboard sensor and navigation systems that have specific field-of-view requirements to generate valid ground proximity and terrain-relative state measurements. The original PDG algorithm was designed to enforce both control and state constraints, including maximum and minimum thrust bounds, avoidance of the ground or descent within a glide slope cone, and maximum speed limits. The thrust-bound and thrust-pointing constraints within PDG are non-convex, which in general requires nonlinear optimization methods to generate solutions. The short duration of Mars powered descent requires guaranteed PDG convergence to a solution within a finite time; however, nonlinear optimization methods have no guarantees of convergence to the global optimal or convergence within finite computation time. A lossless convexification developed for the original PDG algorithm relaxed the non-convex thrust bound constraints. This relaxation was theoretically proven to provide valid and optimal solutions for the original, non-convex problem within a convex framework. As with the thrust bound constraint, a relaxation of the thrust-pointing constraint also provides a lossless convexification that ensures the enhanced relaxed PDG algorithm remains convex and retains validity for the original nonconvex problem. The enhanced PDG algorithm provides guidance profiles for pinpoint and precision landing that minimize fuel usage, minimize landing error to the target, and ensure satisfaction of all position and control constraints, including thrust bounds and now thrust-pointing constraints.

  5. Electric sail control mode for amplified transverse thrust

    NASA Astrophysics Data System (ADS)

    Toivanen, P.; Janhunen, P.; Envall, J.

    2015-01-01

    The electric solar wind sail produces thrust by centrifugally spanned high voltage tethers interacting with the solar wind protons. The sail attitude can be controlled and attitude maneuvers are possible by tether voltage modulation synchronous with the sail rotation. Especially, the sail can be inclined with respect to the solar wind direction to obtain transverse thrust to change the osculating orbit angular momentum. Such an inclination has to be maintained by a continual control voltage modulation. Consequently, the tether voltage available for the thrust is less than the maximum voltage provided by the power system. Using a spherical pendulum as a model for a single rotating tether, we derive analytical estimations for the control efficiency for two separate sail control modes. One is a continuous control modulation that corresponds to strictly planar tether tip motion. The other is an on-off modulation with the tether tip moving along a closed loop on a saddle surface. The novel on-off mode is introduced here to both amplify the transverse thrust and reduce the power consumption. During the rotation cycle, the maximum voltage is applied to the tether only over two thrusting arcs when most of the transverse thrust is produced. In addition to the transverse thrust, we obtain the thrusting angle and electric power consumption for the two control modes. It is concluded that while the thrusting angle is about half of the sail inclination for the continuous modulation it approximately equals to the inclination angle for the on-off modulation. The efficiency of the on-off mode is emphasized when power consumption is considered, and the on-off mode can be used to improve the propulsive acceleration through the reduced power system mass.

  6. Thrust measurement in a 2-D scramjet nozzle

    NASA Technical Reports Server (NTRS)

    Tuttle, Sean

    1995-01-01

    The two-dimensional thrust nozzle presents a challenging problem. The loading is not axisymmetric as in the case of a cone and the internal flow presents some design difficulties. A two-sting system has been chosen to accomodate the internal flow and achieve some symmetry. The situation is complicated by the fact that with the small ramp angle and the internal pressure on the nozzle walls, loading is predominantly transverse. Yet it is the axial thrust which is to be measured (i.e., the tensile waves propagating in the stings). Although bending stress waves travel at most at only 60% of the speed of the axial stress waves, the system needs to be stiffened against bending. The second sting was originally only used to preserve symmetry. However, the pressures on each thrust surface may be quite different at some conditions, so at this stage the signals from both stings are being averaged as a first order approximation of the net thrust. The expected axial thrust from this nozzle is not large so thin stings are required. In addition, the contact area between nozzle and sting needs to be maximized. The result was that it was decided to twist the stings through 90 deg, without distorting their cross-sectional shape, just aft of the nozzle. Finite element analysis showed that this would not significantly alter the propagation of the axial stress wave in the sting, while the rigidity of the system is greatly increased. A Mach 4 contoured nozzle is used in the experiments. The thrust calculated by integrating the static pressure measurements on the thrust surfaces is compared with the deconvolved strain measurement of the net thrust for the cases of air only and hydrogen fuel injected into air at approximately 9 MJ/kg nozzle supply enthalpy. The gain in thrust due to combustion is visible in this result.

  7. Paleostress analysis of a subduction zone megasplay fault - An example from the Nobeoka Thrust, Japan

    NASA Astrophysics Data System (ADS)

    Kawasaki, R.; Hamahashi, M.; Hashimoto, Y.; Otsubo, M.; Yamaguchi, A.; Kitamura, Y.; Kameda, J.; Hamada, Y.; Fukuchi, R.; Kimura, G.

    2014-12-01

    The megasplay faults in subduction zones, branching from plate boundary thrusts, are thought to have a potential to generate earthquakes and accompany tsunamis. Paleo-splay faults exposed on land often preserve clear deformation features of the seismogenic zone and provide information on the fault mechanisms at depth. One of the important information that can be obtained from exhumed faults is paleo-stress field. Here we investigated the Nobeoka Thrust, a fossilized megasplay fault in the Shimanto Belt in Kyushu, which consists of phyllite and sandstone-shale mélanges that have experienced maximum burial temperatures of ~250 -320°C, [Kondo et al., 2005, Tectonics 24.6(2005)]. Kondo et al. (2005) described two orientations of slickensides from the outcrop, suggesting the existence of flexural gentle fold in kilometer scale. The paleo-stress fields preserved in the Nobeoka Thrust is likely to represent multiple stages occurring during burial and uplift, enabling the reconstruction of fault motions along the fault. In this study, we analyzed paleo-stress from slip vectors on small faults observed in the drilled cores of the Nobeoka Thrust obtained from scientific drilling performed in 2011. Small faults are expected to be less-reactivated and their population is much larger than that of large faults, providing high statistical reliability. Multiple inverse method [MIM; Yamaji, 2000, Journal of Structural Geology, 22, 441-452] was applied to the small faults. K-means clustering [Otsubo et al. , 2006, Journal of Structural Geology, 28, 991-997] was applied to stress tensors detected by the MIM for estimating optimal solutions. The results reveal stress solution of four directions existing throughout the drilled range. The stress solution is applied to faults distributed among different lithology, and therefore the paleo-stress is thought to have acted on the whole cores. By drawing the stress polygon from the direction of the stress solution and the stress rate, we estimate the stress state of the Nobeoka Thrust and discuss potential insights to the fault stress evolution of megasplay fault in a subduction zone.

  8. Multiphysics Thrust Chamber Modeling for Nuclear Thermal Propulsion

    NASA Technical Reports Server (NTRS)

    Wang, Ten-See; Cheng, Gary; Chen, Yen-Sen

    2006-01-01

    The objective of this effort is to develop an efficient and accurate thermo-fluid computational methodology to predict environments for a solid-core, nuclear thermal engine thrust chamber. The computational methodology is based on an unstructured-grid, pressure-based computational fluid dynamics formulation. A two-pronged approach is employed in this effort: A detailed thermo-fluid analysis on a multi-channel flow element for mid-section corrosion investigation; and a global modeling of the thrust chamber to understand the effect of heat transfer on thrust performance. Preliminary results on both aspects are presented.

  9. Breadboard RL10-11B low thrust operating mode

    NASA Technical Reports Server (NTRS)

    Kmiec, Thomas D.; Galler, Donald E.

    1987-01-01

    Cryogenic space engines require a cooling process to condition engine hardware to operating temperature before start. This can be accomplished most efficiently by burning propellants that would otherwise be dumped overboard after cooling the engine. The resultant low thrust operating modes are called Tank Head Idle and Pumped Idle. During February 1984, Pratt & Whitney conducted a series of tests demonstrating operation of the RL10 rocket engines at low thrust levels using a previously untried hydrogen/oxygen heat exchanger. The initial testing of the RL10-11B Breadboard Low Thrust Engine is described. The testing demonstrated operation at both tank head idle and pumped idle modes.

  10. Thrust stand for high-power electric propulsion devices

    NASA Technical Reports Server (NTRS)

    Haag, T. W.

    1991-01-01

    This paper describes a new high-power thrust stand developed for use with high-power (up to 250 kW) magnetoplasmadynamic (MPD) thrusters, which is installed in a high-vacuum MPD facility at Lewis Research Center. The design of the stand is based on inverted pendulum configuration, with the result of large displacements and high resolution. Calibration results showed that thrust measurements were linear and repeatable to within a fraction of 1 percent. The thrust stand was used for testing water-cooled MPD thrusters at power levels up to 125 kW. The thruster, however, is quite well suited for testing other types of electric propulsion devices.

  11. Dual-action gas thrust bearing for improving load capacity

    NASA Technical Reports Server (NTRS)

    Etsion, I.

    1976-01-01

    The principle of utilizing hydrodynamic effects in diverging films to improve the load carrying capacity in gas thrust bearings is discussed. A new concept of a dual action bearing based on that principle is described and analyzed. The potential of the new bearing is demonstrated both analytically for an infinitely long slider and by numerical solution for a flat sector shaped thrust bearing. It is shown that the dual action bearing can extend substantially the range of load carrying capacity in gas lubricated thrust bearings and can improve their efficiency.

  12. Electronegative Gas Thruster - Direct Thrust Measurement Project

    NASA Technical Reports Server (NTRS)

    Dankanich, John (Principal Investigator); Aanesland, Ane; Polzin, Kurt; Walker, Mitchell

    2015-01-01

    This effort is an international collaboration and academic partnership to mature an innovative electric propulsion (EP) thruster concept to TRL 3 through direct thrust measurement. The initial target application is for Small Satellites, but can be extended to higher power. The Plasma propulsion with Electronegative GASES (PEGASES) concept simplifies ion thruster operation, eliminates a neutralizer requirement and should yield longer life capabilities and lower cost implementation over conventional gridded ion engines. The basic proof-of concept has been demonstrated and matured to TRL 2 over the past several years by researchers at the Laboratoire de Physique des Plasma in France. Due to the low maturity of the innovation, there are currently no domestic investments in electronegative gas thrusters anywhere within NASA, industry or academia. The end product of this Center Innovation Fund (CIF) project will be a validation of the proof-of-concept, maturation to TRL 3 and technology assessment report to summarize the potential for the PEGASES concept to supplant the incumbent technology. Information exchange with the foreign national will be one-way with the exception of the test results. Those test results will first go through a standard public release ITAR/export control review, and the results will be presented in a public technical forum, and the results will be presented in a public technical forum.

  13. Business Jet

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The Citation Jet, developed by Cessna Aircraft Company, Wichita, KS, is the first business jet to employ Langley Research Center's natural laminar flow (NLF) technology. NLF reduces drag and therefore saves fuel by using only the shape of the wing to keep the airflow smooth, or laminar. This reduces friction between the air and wing, and therefore, reduces drag. NASA's Central Industrial Applications Center, Rural Enterprises, Inc., Durant, OK, its Kansas affiliate, and Wichita State University assisted in the technology transfer.

  14. Design and Analysis of an Electromagnetic Thrust Bearing

    NASA Technical Reports Server (NTRS)

    Banerjee, Bibhuti; Rao, Dantam K.

    1996-01-01

    A double-acting electromagnetic thrust bearing is normally used to counter the axial loads in many rotating machines that employ magnetic bearings. It essentially consists of an actuator and drive electronics. Existing thrust bearing design programs are based on several assumptions. These assumptions, however, are often violated in practice. For example, no distinction is made between maximum external loads and maximum bearing forces, which are assumed to be identical. Furthermore, it is assumed that the maximum flux density in the air gap occurs at the nominal gap position of the thrust runner. The purpose of this paper is to present a clear theoretical basis for the design of the electromagnetic thrust bearing which obviates such assumptions.

  15. Center for Theoretical Biological Physics Research Thrust Area's

    E-print Network

    Collar, Juan I.

    Center for Theoretical Biological Physics Research Thrust Area's: · Statistical Biophysics - Gene towards or away from a stimulus Center for Theoretical Biological Physics - University of California, San Gradients (Molecular Scale) Center for Theoretical Biological Physics - University of California, San Diego

  16. Center for Theoretical Biological Physics Research Thrust Area's

    E-print Network

    Collar, Juan I.

    Center for Theoretical Biological Physics Research Thrust Area's: · Statistical Biophysics - Gene #12;Center for Theoretical Biological Physics University of California, San Diego Using Molecular for Theoretical Biological Physics University of California, San Diego Photoisomerization of Rhodopsin Rhodopsin

  17. Development of pneumatic thrust-deflecting powered-lift systems

    NASA Technical Reports Server (NTRS)

    Englar, R. J.; Nichols, J. H., Jr.; Harris, M. J.; Eppel, J. C.; Shovlin, M. D.

    1986-01-01

    Improvements introduced into the Circulation Control Wing/Upper Surface Blowing (CCW/USB) STOL concept (Harris et al., 1982) are described along with results of the full-scale static ground tests and model-scale wind tunnel investigations. Tests performed on the full-scale pneumatic thrust-deflecting system installed on the NASA QSRA aircraft have demonstrated that, relative to the original baseline configuration, a doubling of incremental thrust deflection due to blowing resulted from improvements that increased the blowing span and momentum, as well as from variations in blowing slot height and geometry of the trailing edge. A CCW/Over the Wing model has been built and tested, which was shown to be equivalent to the CCW/USB system in terms of pneumatic thrust deflection and lift generation, while resolving the problem of cruise thrust loss due to exhaust scrubbing on the wing upper surface.

  18. The Development of NASA's Low Thrust Trajectory Tool Set

    NASA Technical Reports Server (NTRS)

    Sims, Jon; Artis, Gwen; Kos, Larry

    2006-01-01

    Highly efficient electric propulsion systems can enable interesting classes of missions; unfortunately, they provide only a limited amount of thrust. Low-thrust (LT) trajectories are much more difficult to design than impulsive-type (chemical propulsion) trajectories. Previous low-thrust (LT) trajectory optimization software was often difficult to use, often had difficulties converging, and was somewhat limited in the types of missions it could support. A new state-of-the-art suite (toolbox) of low-thrust (LT) tools along with improved algorithms and methods was developed by NASA's MSFC, JPL, JSC, and GRC to address the needs of our customers to help foster technology development in the areas of advanced LT propulsion systems, and to facilitate generation of similar results by different analysts.

  19. Thrust modulation methods for a subsonic V/STOL aircraft

    NASA Technical Reports Server (NTRS)

    Woollett, R. R.

    1981-01-01

    Low speed wind tunnel tests were conducted to assess four methods for attaining thrust modulation for V/STOL aircraft. The four methods were: (1) fan speed change, (2) fan nozzle exit area change, (3) variable pitch rotor (VPR) fan, and (4) variable inlet guide vanes (VIGV). The interrelationships between inlet and thrust modulation system were also investigated using a double slotted inlet and thick lip inlet. Results can be summarized as: (1) the VPR and VIGV systems were the most promising, (2) changes in blade angle to obtain changes in fan thrust have significant implications for the inlet, and (3) both systems attained required level of thrust with acceptable levels of fan blade stress.

  20. Peak thrust operation of linear induction machines from parameter identification

    SciTech Connect

    Zhang, Z.; Eastham, T.R.; Dawson, G.E. [Queen`s Univ., Kingston, Ontario (Canada). Dept. of Electrical and Computer Engineering

    1995-12-31

    Various control strategies are being used to achieve high performance operation of linear drives. To maintain minimum volume and weight of the power supply unit on board the transportation vehicle, peak thrust per unit current operation is a desirable objective. True peak thrust per unit current through slip control is difficult to achieve because the parameters of linear induction machines vary during normal operation. This paper first develops a peak thrust per unit current control law based on the per-phase equivalent circuit for linear induction machines. The algorithm for identification of the variable parameters in induction machines is then presented. Application to an operational linear induction machine (LIM) demonstrates the utility of this algorithm. The control strategy is then simulated, based on an operational transit LIM, to show the capability of achieving true peak thrust operation for linear induction machines.

  1. Recommended Practices in Thrust Measurements IEPC-2013-440

    E-print Network

    Walker, Mitchell

    Branch, Air Force Research Laboratory, Edwards AFB, CA 93523 Concept Innovation Methods Chief, JPL Haag , Scott King§ , Mitchell Walker¶ , Joseph Blakelyk , John Ziemer Accurate, direct measurement thrust stands based on experience from the community. These recommendations include best practices

  2. 53. THRUST SECTION HEATER AND GASEOUS NITROGEN PURGE CONTROLS ON ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    53. THRUST SECTION HEATER AND GASEOUS NITROGEN PURGE CONTROLS ON EAST SIDE OF LAUNCH DECK. LAUNCHER IN BACKGROUND. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  3. Emerging Jets

    E-print Network

    Pedro Schwaller; Daniel Stolarski; Andreas Weiler

    2015-05-11

    In this work, we propose a novel search strategy for new physics at the LHC that utilizes calorimeter jets that (i) are composed dominantly of displaced tracks and (ii) have many different vertices within the jet cone. Such emerging jet signatures are smoking guns for models with a composite dark sector where a parton shower in the dark sector is followed by displaced decays of dark pions back to SM jets. No current LHC searches are sensitive to this type of phenomenology. We perform a detailed simulation for a benchmark signal with two regular and two emerging jets, and present and implement strategies to suppress QCD backgrounds by up to six orders of magnitude. At the 14 TeV LHC, this signature can be probed with mediator masses as large as 1.5 TeV for a range of dark pion lifetimes, and the reach is increased further at the high-luminosity LHC. The emerging jet search is also sensitive to a broad class of long-lived phenomena, and we show this for a supersymmetric model with R-parity violation. Possibilities for discovery at LHCb are also discussed.

  4. Emerging jets

    NASA Astrophysics Data System (ADS)

    Schwaller, Pedro; Stolarski, Daniel; Weiler, Andreas

    2015-05-01

    In this work, we propose a novel search strategy for new physics at the LHC that utilizes calorimeter jets that (i) are composed dominantly of displaced tracks and (ii) have many different vertices within the jet cone. Such emerging jet signatures are smoking guns for models with a composite dark sector where a parton shower in the dark sector is followed by displaced decays of dark pions back to SM jets. No current LHC searches are sensitive to this type of phenomenology. We perform a detailed simulation for a benchmark signal with two regular and two emerging jets, and present and implement strategies to suppress QCD backgrounds by up to six orders of magnitude. At the 14 TeV LHC, this signature can be probed with mediator masses as large as 1.5 TeV for a range of dark pion lifetimes, and the reach is increased further at the high-luminosity LHC. The emerging jet search is also sensitive to a broad class of long-lived phenomena, and we show this for a supersymmetric model with R-parity violation. Possibilities for discovery at LHCb are also discussed.

  5. Emerging Jets

    E-print Network

    Schwaller, Pedro; Weiler, Andreas

    2015-01-01

    In this work, we propose a novel search strategy for new physics at the LHC that utilizes calorimeter jets that (i) are composed dominantly of displaced tracks and (ii) have many different vertices within the jet cone. Such emerging jet signatures are smoking guns for models with a composite dark sector where a parton shower in the dark sector is followed by displaced decays of dark pions back to SM jets. No current LHC searches are sensitive to this type of phenomenology. We perform a detailed simulation for a benchmark signal with two regular and two emerging jets, and present and implement strategies to suppress QCD backgrounds by up to six orders of magnitude. At the 14 TeV LHC, this signature can be probed with mediator masses as large as 1.5 TeV for a range of dark pion lifetimes, and the reach is increased further at the high-luminosity LHC. The emerging jet search is also sensitive to a broad class of long-lived phenomena, and we show this for a supersymmetric model with R-parity violation. Possibilit...

  6. Exploring fold and thrust belts in Google Earth

    NSDL National Science Digital Library

    Jack Loveless

    Google Earth enhances traditional geologic maps by allowing the viewer to explore three-dimensional map patterns and the interaction between structure and topography in dictating those map patterns. This activity overlays 4, 7.5' USGS quadrangles on Google Earth terrain and imagery data and encourages students to investigate common features of fold-and-thrust belts. Keywords: Google Earth, fold-and-thrust belt, visualization

  7. Thrust Performance of an Ideal Pulse Detonation Engine

    Microsoft Academic Search

    V. V. Mitrofanov; S. A. Zhdan

    2004-01-01

    Quasi-steady and two-dimensional unsteady formulations of the problem on the operation cycle of a pulse detonation engine are derived. A formula for the specific impulse is obtained, and the thrust performance of the engine is calculated. It is found that the thrust performance of this engine for flight Mach numbers M ? [0; 3.6] and compression ratios p2\\/p1 ? [1;

  8. Navigational Vectors

    NSDL National Science Digital Library

    2008-12-10

    This is a high school instructional unit that features nine lessons relating to vectors. Students build understanding of vector properties as they learn airplane navigation. Problem-based learning activities include reading real-time weather maps, tracking airplanes flying in U.S. skies, calculating vector components, analyzing effects of wind velocity, and completing training segments similar to a private pilot certification program. Participants have access to help from experts at the Polaris Career Center. Comprehensive teacher guides, student guides, reference materials, and assessments are included. This resource was developed by the Center for Innovation in Science and Engineering Education (CIESE). Participation is cost-free; additional options are available for registered users.

  9. Full Flight Envelope Direct Thrust Measurement on a Supersonic Aircraft

    NASA Technical Reports Server (NTRS)

    Conners, Timothy R.; Sims, Robert L.

    1998-01-01

    Direct thrust measurement using strain gages offers advantages over analytically-based thrust calculation methods. For flight test applications, the direct measurement method typically uses a simpler sensor arrangement and minimal data processing compared to analytical techniques, which normally require costly engine modeling and multisensor arrangements throughout the engine. Conversely, direct thrust measurement has historically produced less than desirable accuracy because of difficulty in mounting and calibrating the strain gages and the inability to account for secondary forces that influence the thrust reading at the engine mounts. Consequently, the strain-gage technique has normally been used for simple engine arrangements and primarily in the subsonic speed range. This paper presents the results of a strain gage-based direct thrust-measurement technique developed by the NASA Dryden Flight Research Center and successfully applied to the full flight envelope of an F-15 aircraft powered by two F100-PW-229 turbofan engines. Measurements have been obtained at quasi-steady-state operating conditions at maximum non-augmented and maximum augmented power throughout the altitude range of the vehicle and to a maximum speed of Mach 2.0 and are compared against results from two analytically-based thrust calculation methods. The strain-gage installation and calibration processes are also described.

  10. Thrust Stand for Vertically Oriented Electric Propulsion Performance Evaluation

    NASA Technical Reports Server (NTRS)

    Moeller, Trevor; Polzin, Kurt A.

    2010-01-01

    A variation of a hanging pendulum thrust stand capable of measuring the performance of an electric thruster operating in the vertical orientation is presented. The vertical orientation of the thruster dictates that the thruster must be horizontally offset from the pendulum pivot arm, necessitating the use of a counterweight system to provide a neutrally-stable system. Motion of the pendulum arm is transferred through a balance mechanism to a secondary arm on which deflection is measured. A non-contact light-based transducer is used to measure displacement of the secondary beam. The members experience very little friction, rotating on twisting torsional pivots with oscillatory motion attenuated by a passive, eddy current damper. Displacement is calibrated using an in situ thrust calibration system. Thermal management and self-leveling systems are incorporated to mitigate thermal and mechanical drifts. Gravitational restoring force and torsional spring constants associated with flexure pivots provide restoring moments. An analysis of the design indicates that the thrust measurement range spans roughly four decades, with the stand capable of measuring thrust up to 12 N for a 200 kg thruster and up to approximately 800 mN for a 10 kg thruster. Data obtained from calibration tests performed using a 26.8 lbm simulated thruster indicated a resolution of 1 mN on 100 mN-level thrusts, while those tests conducted on 200 lbm thruster yielded a resolution of roughly 2.5 micro at thrust levels of 0.5 N and greater.

  11. Thrust stand for vertically oriented electric propulsion performance evaluation

    SciTech Connect

    Moeller, Trevor [University of Tennessee Space Institute, Tullahoma, Tennessee 37388 (United States); Polzin, Kurt A. [NASA, Marshall Space Flight Center, Huntsville, Alabama 35812 (United States)

    2010-11-15

    A variation of a hanging pendulum thrust stand capable of measuring the performance of an electric thruster operating in the vertical orientation is presented. The vertical orientation of the thruster dictates that the thruster must be horizontally offset from the pendulum pivot arm, necessitating the use of a counterweight system to provide a neutrally stable system. Motion of the pendulum arm is transferred through a balance mechanism to a secondary arm on which deflection is measured. A noncontact light-based transducer is used to measure displacement of the secondary beam. The members experience very little friction, rotating on twisting torsional pivots with oscillatory motion attenuated by a passive, eddy-current damper. Displacement is calibrated using an in situ thrust calibration system. Thermal management and self-leveling systems are incorporated to mitigate thermal and mechanical drifts. Gravitational force and torsional spring constants associated with flexure pivots provide restoring moments. An analysis of the design indicates that the thrust measurement range spans roughly four decades, with the stand capable of measuring thrust up to 12 N for a 200 kg thruster and up to approximately 800 mN for a 10 kg thruster. Data obtained from calibration tests performed using a 26.8 lbm simulated thruster indicated a resolution of 1 mN on 100 mN level thrusts, while those tests conducted on a 200 lbm thruster yielded a resolution of roughly 2.5 mN at thrust levels of 0.5 N and greater.

  12. Thrust stand for vertically oriented electric propulsion performance evaluation.

    PubMed

    Moeller, Trevor; Polzin, Kurt A

    2010-11-01

    A variation of a hanging pendulum thrust stand capable of measuring the performance of an electric thruster operating in the vertical orientation is presented. The vertical orientation of the thruster dictates that the thruster must be horizontally offset from the pendulum pivot arm, necessitating the use of a counterweight system to provide a neutrally stable system. Motion of the pendulum arm is transferred through a balance mechanism to a secondary arm on which deflection is measured. A noncontact light-based transducer is used to measure displacement of the secondary beam. The members experience very little friction, rotating on twisting torsional pivots with oscillatory motion attenuated by a passive, eddy-current damper. Displacement is calibrated using an in situ thrust calibration system. Thermal management and self-leveling systems are incorporated to mitigate thermal and mechanical drifts. Gravitational force and torsional spring constants associated with flexure pivots provide restoring moments. An analysis of the design indicates that the thrust measurement range spans roughly four decades, with the stand capable of measuring thrust up to 12 N for a 200 kg thruster and up to approximately 800 mN for a 10 kg thruster. Data obtained from calibration tests performed using a 26.8 lbm simulated thruster indicated a resolution of 1 mN on 100 mN level thrusts, while those tests conducted on a 200 lbm thruster yielded a resolution of roughly 2.5 mN at thrust levels of 0.5 N and greater. PMID:21133502

  13. Measurements of the b quark forward-backward asymmetry around the Z $^0$ peak using jet charge and vertex charge

    Microsoft Academic Search

    Gideon Alexander; J Allison; N Altekamp; K A Ametewee; K J Anderson; S Anderson; S Arcelli; S Asai; D A Axen; Georges Azuelos; A H Ball; E Barberio; R J Barlow; R Bartoldus; J Richard Batley; J Bechtluft; C Beeston; T Behnke; A N Bell; K W Bell; G Bella; Stanislaus Cornelius Maria Bentvelsen; P Berlich; Siegfried Bethke; O Biebel; A Biguzzi; S D Bird; Volker Blobel; Ian J Bloodworth; J E Bloomer; M Bobinski; P Bock; H M Bosch; M Boutemeur; B T Bouwens; S Braibant; R M Brown; Helfried J Burckhart; C Burgard; R Bürgin; P Capiluppi; R K Carnegie; A A Carter; J R Carter; C Y Chang; D G Charlton; D Chrisman; P E L Clarke; I Cohen; J E Conboy; O C Cooke; M Cuffiani; S Dado; C Dallapiccola; G M Dallavalle; S De Jong; L A del Pozo; Klaus Desch; M S Dixit; E do Couto e Silva; M Doucet; E Duchovni; G Duckeck; I P Duerdoth; D Eatough; J E G Edwards; P G Estabrooks; H G Evans; M Evans; Franco Luigi Fabbri; M Fanti; P Fath; A A Faust; F Fiedler; M Fierro; H M Fischer; R Folman; D G Fong; M Foucher; A Fürtjes; P Gagnon; A Gaidot; J W Gary; J Gascon; S M Gascon-Shotkin; N I Geddes; C Geich-Gimbel; F X Gentit; T Geralis; G Giacomelli; P Giacomelli; R Giacomelli; V Gibson; W R Gibson; D M Gingrich; D A Glenzinski; J Goldberg; M J Goodrick; W Gorn; C Grandi; E Gross; Jacob Grunhaus; M Gruwé; C Hajdu; G G Hanson; M Hansroul; M Hapke; C K Hargrove; P A Hart; C Hartmann; M Hauschild; C M Hawkes; R Hawkings; Richard J Hemingway; M Herndon; G Herten; R D Heuer; M D Hildreth; J C Hill; S J Hillier; T Hilse; P R Hobson; R James Homer; A K Honma; D Horváth; R Howard; R E Hughes-Jones; D E Hutchcroft; P Igo-Kemenes; D C Imrie; M R Ingram; K Ishii; A Jawahery; P W Jeffreys; H Jeremie; Martin Paul Jimack; A Joly; C R Jones; G Jones; M Jones; R W L Jones; U Jost; P Jovanovic; T R Junk; D A Karlen; K Kawagoe; T Kawamoto; Richard K Keeler; R G Kellogg; B W Kennedy; J Kirk; S Kluth; T Kobayashi; M Kobel; D S Koetke; T P Kokott; M Kolrep; S Komamiya; T Kress; P Krieger; J Von Krogh; P Kyberd; G D Lafferty; H Lafoux; R Lahmann; W P Lai; D Lanske; J Lauber; S R Lautenschlager; J G Layter; D Lazic; A M Lee; E Lefebvre; Daniel Lellouch; J Letts; L Levinson; C Lewis; S L Lloyd; F K Loebinger; G D Long; Michael J Losty; J Ludwig; A Macchiolo; A L MacPherson; A Malik; M Mannelli; S Marcellini; C Markus; A J Martin; J P Martin; G Martínez; T Mashimo; W Matthews; P Mättig; W J McDonald; J A McKenna; E A McKigney; T J McMahon; A I McNab; R A McPherson; F Meijers; S Menke; F S Merritt; H Mes; J Meyer; Aldo Michelini; G Mikenberg; D J Miller; R Mir; W Mohr; A Montanari; T Mori; M Morii; U Müller; K Nagai; I Nakamura; H A Neal; B Nellen; B Nijjhar; R Nisius; S W O'Neale; F G Oakham; F Odorici; H O Ögren; N J Oldershaw; T Omori; M J Oreglia; S Orito; J Pálinkás; G Pásztor; J R Pater; G N Patrick; J Patt; M J Pearce; S Petzold; P Pfeifenschneider; J E Pilcher; James L Pinfold; D E Plane; P R Poffenberger; B Poli; A Posthaus; H Przysiezniak; D L Rees; D Rigby; S Robertson; S A Robins; N L Rodning; J M Roney; A M Rooke; E Ros; A M Rossi; M Rosvick; P Routenburg; Y Rozen; K Runge; O Runólfsson; U Ruppel; D R Rust; R Rylko; K Sachs; E Sarkisyan-Grinbaum; M Sasaki; C Sbarra; A D Schaile; O Schaile; F Scharf; P Scharff-Hansen; P Schenk; B Schmitt; S Schmitt; M Schröder; H C Schultz-Coulon; M Schulz; M Schumacher; P Schütz; W G Scott; T G Shears; B C Shen; C H Shepherd-Themistocleous; P Sherwood; G P Siroli; A Sittler; A Skillman; A Skuja; A M Smith; T J Smith; G A Snow; Randall J Sobie; S Söldner-Rembold; R W Springer; M Sproston; A Stahl; M Steiert; K Stephens; J Steuerer; B Stockhausen; D Strom; P Szymanski; R Tafirout; S D Talbot; S Tanaka; P Taras; S Tarem; M Thiergen; M A Thomson; E Von Törne; S Towers; I Trigger; T Tsukamoto; E Tsur; A S Turcot; M F Turner-Watson; P Utzat; R Van Kooten; G Vasseur; M Verzocchi; P Vikas; M G Vincter; E H Vokurka; F Wäckerle; A Wagner; C P Ward; D R Ward; J J Ward; P M Watkins; A T Watson; N K Watson; P S Wells; N Wermes; J S White; B Wilkens; G W Wilson; J A Wilson; G Wolf; S A Wotton; T R Wyatt; S Yamashita; G Yekutieli; V Zacek; D Zer-Zion

    1997-01-01

    The b quark forward-backward asymmetry has been measured using approximately four million hadronic Z$^0$ decays collected with the OPAL detector at LEP. Both jet charge and vertex charge were used to estimate whether the b quark was produced in the forward or backward thrust hemisphere. The measured values corrected to the hadron-level thrust axis are \\\\[ \\\\begin{array}{llll} A^{\\\\rm b}_{\\\\rm FB}

  14. Lower extremity thrust and non-thrust joint mobilization for patellofemoral pain syndrome: a case report

    PubMed Central

    Simpson, Brad G; Simon, Corey B

    2014-01-01

    A 40-year old female presented to physical therapy with a one-year history of insidious right anteromedial and anterolateral knee pain. Additionally, the patient had a history of multiple lateral ankle sprains bilaterally, the last sprain occurring on the right ankle 1 year prior to the onset of knee pain. The patient was evaluated and given a physical therapy diagnosis of patellofemoral pain syndrome (PFPS), with associated talocrural and tibiofemoral joint hypomobility limiting ankle dorsiflexion and knee extension, respectively. Treatment included a high-velocity low amplitude thrust manipulation to the talocrural joint, which helped restore normal ankle dorsiflexion range of motion. The patient also received tibiofemoral joint non-thrust manual therapy to regain normal knee extension mobility prior to implementing further functional progression exercises to her home program (HEP). This case report highlights the importance of a detailed evaluation of knee and ankle joint mobility in patients presenting with anterior knee pain. Further, manual physical therapy to the lower extremity was found to be successful in restoring normal movement patterns and pain-free function in a patient with chronic anterior knee pain. PMID:24976753

  15. A double pendulum plasma thrust balance and thrust measurement at a tandem mirror exhaust

    SciTech Connect

    Yang, T.F.; Liu, P.; Chang-Diaz, F.R.; Lander, H.; Childs, R.A.; Becker, H.D.; Fairfax, S.A. [Plasma Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)] [Plasma Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    1995-09-01

    For the purpose of measuring the plasma momentum flux in a plasma system, a highly sensitive and precision balance has been developed. It can measure a force, an impulse, or thrust as low as 0.1 mN free of mechanical noise, electrical and magnetic pickups. The double pendulum system consists of two parallel conducting plates. One or both of the plates can be suspended by needles. The needle suspended plate (or plates) can swing freely with negligible friction because of the sharp points of the needles. When one of the plates is impacted by an impulse it will swing relatively to the fixed plate or other movable plate. The capacitance between the plates changes as a result of such a motion. The change of capacitance as a function of time is recorded as an oscillating voltage signal. The amplitude of such a voltage signal is proportional to the impacting force or impulse. The proportional factor can be calibrated. The forces can thus be read out from the recorded value of the voltage. The equation of motion for the pendulum system has been solved analytically. The circuit equation for the electronic measurement system has been formulated and solved numerically. Using this balance the thrust at the exhaust of a Tandem Mirror plasma thruster has been measured. The analytical solution of the overall characteristics agrees greatly with the measurement. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  16. Thermal Effects on Inverted Pendulum Thrust Stands for Steady-state High-power Plasma Thrusters

    E-print Network

    Choueiri, Edgar

    Thermal Effects on Inverted Pendulum Thrust Stands for Steady-state High-power Plasma Thrusters A-power ( 10s of kWs) plasma thrusters using inverted-pendulum thrust stands are addressed. Three major sources of system- atic error exist in the determination of thrust using an inverted-pendulum thrust stand; tare

  17. Active thrusting in the inner forearc of an erosive convergent margin, Pacific coast, Costa Rica

    Microsoft Academic Search

    Donald M. Fisher; Thomas W. Gardner; Peter B. Sak; Joanna D. Sanchez; Katherine Murphy; Paola Vannucchi

    2004-01-01

    Structural and geomorphic analyses of the Fila Costeña thrust belt in southwest Costa Rica indicate active thrusting within the inner forearc. The Fila Costeña exposes three major thrust faults that imbricate the late Tertiary forearc basin sequence of the Térraba basin. The frontal thrust of the Fila Costeña marks the boundary between an uplifting inner forearc and a subsiding outer

  18. Noise from Supersonic Coaxial Jets. Part 2; Normal Velocity Profile

    NASA Technical Reports Server (NTRS)

    Dahl, M. D.; Morris, P. J.

    1997-01-01

    Instability waves have been established as noise generators in supersonic jets. Recent analysis of these slowly diverging jets has shown that these instability waves radiate noise to the far field when the waves have components with phase velocities that are supersonic relative to the ambient speed of sound. This instability wave noise generation model has been applied to supersonic jets with a single shear layer and is now applied to supersonic coaxial jets with two initial shear layers. In this paper the case of coaxial jets with normal velocity profiles is considered, where the inner jet stream velocity is higher than the outer jet stream velocity. To provide mean flow profiles at all axial locations, a numerical scheme is used to calculate the mean flow properties. Calculations are made for the stability characteristics in the coaxial jet shear layers and the noise radiated from the instability waves for different operating conditions with the same total thrust, mass flow and exit area as a single reference jet. The effects of changes in the velocity ratio, the density ratio and the area ratio are each considered independently.

  19. Coaxial supersonic jet-flows, shock structure and related problems with noise-suppression assessment and prediction

    NASA Technical Reports Server (NTRS)

    Dosanjh, D. S.; Mcafee, R. S., Jr.

    1983-01-01

    It is now reasonably well established that the intense noise radiated by a single turbulent, heated, under or overexpanded round jet of high specific thrust can be significantly reduced if instead, 'equivalent' multinozzle coaxial supersonic jet flows of the same total thrust and mass flow rate were to be operated in the inverted pressure mode. A summary of some of the relevant observations on the coaxial supersonic jet flows and their shock structure is presented. Attention is given to the scope of the optical studies, the development of shock structure, the effects of exit stagger, coaxial supersonic jet flows with inner nozzle overexpanded, the role of the lip thickness, the role of the exit area ratios, cold/heated coaxial supersonic jet flows, acoustic observations, the conventional pressure mode of operation, comparative noise reduction assessment, and problems and prospects of noise prediction.

  20. Coaxial supersonic jet-flows, shock structure and related problems with noise-suppression assessment and prediction

    NASA Astrophysics Data System (ADS)

    Dosanjh, D. S.; McAfee, R. S., Jr.

    1983-04-01

    It is now reasonably well established that the intense noise radiated by a single turbulent, heated, under or overexpanded round jet of high specific thrust can be significantly reduced if instead, 'equivalent' multinozzle coaxial supersonic jet flows of the same total thrust and mass flow rate were to be operated in the inverted pressure mode. A summary of some of the relevant observations on the coaxial supersonic jet flows and their shock structure is presented. Attention is given to the scope of the optical studies, the development of shock structure, the effects of exit stagger, coaxial supersonic jet flows with inner nozzle overexpanded, the role of the lip thickness, the role of the exit area ratios, cold/heated coaxial supersonic jet flows, acoustic observations, the conventional pressure mode of operation, comparative noise reduction assessment, and problems and prospects of noise prediction.

  1. Pipeline vectorization

    Microsoft Academic Search

    Markus Weinhardt; Wayne Luk

    2001-01-01

    This paper presents pipeline vectorization, amethod for synthesizing hardware pipelines based on softwarevectorizing compilers. The method improves eciencyand ease of development of hardware designs, particularlyfor users with little electronics design experience. We proposeseveral loop transformations to customize pipelinesto meet hardware resource constraints, while maximizingavailable parallelism. For run-time recongurable systems,we apply hardware specialization to increase...

  2. Cold-flow acoustic evaluation of a small scale, divergent, lobed nozzle for supersonic jet noise suppression

    NASA Technical Reports Server (NTRS)

    Huff, R. G.; Groesbeck, D. E.

    1975-01-01

    A supersonic jet noise suppressor was tested with cold flow for acoustic and thrust characteristics at nozzle- to atmospheric-pressure ratios of 1.5 to 4.0. Jet noise suppression and spectral characteristics of the divergent, lobed, suppressor (DLS) nozzle with and without an ejector are presented. Suppression was obtained at nozzle pressure ratios of 2.5 to 4.0. The largest, maximum-lobe, sound pressure level suppression with a hard-wall ejector was 14.6 decibels at a nozzle pressure ratio of 3.5. The thrust loss was 2 percent. In general, low-frequency jet noise was suppressed, leaving higher frequencies essentially unchanged. Without the ejector the nozzle showed a thrust loss of 11 percent together with slightly poorer noise suppression.

  3. APPENDIX D. VECTOR ANALYSIS 1 Vector Analysis

    E-print Network

    Callen, James D.

    APPENDIX D. VECTOR ANALYSIS 1 Appendix D Vector Analysis The following conventions are used in this appendix and throughout the book: f, g, , are scalar functions of x, t; A, B, C, D are vector functions of x, t; A = |A| A · A is the magnitude or length of the vector A; ^eA A/A is a unit vector

  4. Geologic mapping delineates new thrust sheets, duplex structures, and timing relationships between the Meade and Crawford thrusts in Wyoming, Idaho, and Utah

    Microsoft Academic Search

    Coogan

    1993-01-01

    New geologic maps of nine complete and six partial 7.5[prime] quadrangles delineate a large-scale duplex comprised of at least five thrust sheets that together form the Sheep Creek culmination in the footwall of the Meade thrust. From west to east, the Sheep Creek culmination includes the Home Canyon, Sheep Creek, Red Mountain, northern Crawford, and Afton thrust sheets. The thrusts

  5. Evolution of the Puente Hills Thrust Fault

    NASA Astrophysics Data System (ADS)

    Bergen, K. J.; Shaw, J. H.; Dolan, J. F.

    2013-12-01

    This study aims to assess the evolution of the blind Puente Hills thrust fault system (PHT) by determining its age of initiation, lateral propagation history, and changes in slip rate over time. The PHT presents one of the largest seismic hazards in the United States, given its location beneath downtown Los Angeles. The PHT is comprised of three fault segments: the Los Angeles (LA), Santa Fe Springs (SFS), and Coyote Hills (CH). The LA and SFS segments are characterized by growth stratigraphy where folds formed by uplift on the fault segments have been continually buried by sediment from the Los Angeles and San Gabriel rivers. The CH segment has developed topography and is characterized by onlapping growth stratigraphy. This depositional setting gives us the unique opportunity to measure uplift on the LA and SFS fault segments, and minimum uplift on the CH fault segment, as the difference in sediment thicknesses across the buried folds. We utilize depth converted oil industry seismic reflection data to image the fold geometries. Identifying time-correlative stratigraphic markers for slip rate determination in the basin has been a problem for researchers in the past, however, as the faunal assemblages observed in wells are time-transgressive by nature. To overcome this, we utilize the sequence stratigraphic model and well picks of Ponti et al. (2007) as a basis for mapping time-correlative sequence boundaries throughout our industry seismic reflection data from the present to the Pleistocene. From the Pleistocene to Miocene we identify additional sequence boundaries in our seismic reflection data from imaged sequence geometries and by correlating industry well formation tops. The sequence and formation top picks are then used to build 3-dimensional surfaces in the modeling program Gocad. From these surfaces we measure the change in thicknesses across the folds to obtain uplift rates between each sequence boundary. Our results show three distinct phases of deformation on the LA and SFS segments: an early period characterized by fault-propagation or structural wedge kinematics that terminates in the early Pleistocene, followed by a period of quiescence. The faults were subsequently reactivated in the middle Pleistocene and propagated upward to detachments, with the deformation characterized by fold-bend folding kinematics. Slip on the LA segment decreases to the West, suggesting lateral growth in that direction. Our work highlights the need to assess along-strike variability in slip rate when assessing the seismic hazard of a compressional fault, as marginal sites may significantly underestimate fault activity. Ponti, D. J. et al. A 3-Dimensional Model of Water-Bearing Sequences in the Dominguez Gap Region, Long Beach, California. US Geological Survey Open-File Report 1013 (2007).

  6. Piloted Simulation Study of a Dual Thrust-Cutback Procedure for Reducing High-Speed Civil Transport Takeoff Noise Levels

    NASA Technical Reports Server (NTRS)

    Riley, Donald R.; Glaab, Louis J.; Brandon, Jay M.; Person, Lee H., Jr.; Glaab, Patricia C.

    1999-01-01

    A piloted simulation study was performed for the purpose of indicating the noise reduction benefits and piloting performance that could occur for a typical 4-engine high-Speed Civil Transport (HSCT) configuration during takeoff when a dual thrust-cutback procedure was employed with throttle operation under direct computer control. Two thrust cutbacks were employed with the first cutback performed while the vehicle was accelerating on the run-way and the second cutback performed at a distance farther downrange. Added vehicle performance improvements included the incorporation of high-lift increments into the aerodynamic database of the vehicle and the use of limited engine oversizing. Four single-stream turbine bypass engines that had no noise suppression of any kind were used with this configuration. This approach permitted establishing the additional noise suppression level that was needed to meet Federal Air Regulation Part 36 Stage 3 noise levels for subsonic commercial jet aircraft. Noise level results were calculated with the jet mixing and shock noise modules of the Aircraft Noise Prediction Program (ANOPP).

  7. Thrusting and back-thrusting as post-emplacement kinematics of the Almora klippe: Insights from Low-temperature thermochronology

    NASA Astrophysics Data System (ADS)

    Patel, R. C.; Singh, Paramjeet; Lal, Nand

    2015-06-01

    Crystalline klippen over the Lesser Himalayan Sequence (LHS) in the Kumaon and Garhwal regions of NW-Himalaya, are the representative of southern portion of the Main Central Thrust (MCT) hanging wall. These were tectonically transported over the juxtaposed thrust sheets (Berinag, Tons and Ramgarh) of the LHS zone along the MCT. These klippen comprise of NW-SE trending synformal folded thrust sheet bounded by thrusts in the south and north. In the present study, the exhumation histories of two well-known klippen namely Almora and Baijnath, and the Ramgarh thrust sheet, in the Kumaon and Garhwal regions vis-a-vis Himalayan orogeny have been investigated using Apatite Fission Track (AFT) ages. Along a ~ 60 km long orogen perpendicular transect across the Almora klippe and the Ramgarh thrust sheet, 16 AFT cooling ages from the Almora klippe and 2 from the Ramgarh thrust sheet have been found to range from 3.7 ± 0.8 to 13.2 ± 2.7 Ma, and 6.3 ± 0.8 to 7.2 ± 1.0 Ma respectively. From LHS meta-sedimentary rocks only a single AFT age of 3.6 ± 0.8 Ma could be obtained. Three AFT ages from the Baijnath klippe range between 4.7 ± 0.5 and 6.6 ± 0.8 Ma. AFT ages and exhumation rates of different klippen show a dynamic coupling between tectonic and erosion processes in the Kumaon and Garhwal regions of NW-Himalaya. However, the tectonic processes play a dominant role in controlling the exhumation. Thrusting and back thrusting within the Almora klippe and Ramgarh thrust sheet are the post-emplacement kinematics that controlled the exhumation of the Almora klippe. Combining these results with the already published AFT ages from the crystalline klippen and the Higher Himalayan Crystalline (HHC), the kinematics of emplacement of the klippen over the LHS and exhumation pattern across the MCT in the Kumaon and Garhwal regions of NW-Himalaya have been investigated.

  8. Spreading characteristics of compressible jets from nozzles of various geometries

    NASA Astrophysics Data System (ADS)

    Zaman, K. B. M. Q.

    1999-03-01

    The spreading characteristics of jets from several asymmetric nozzles, and a set of rectangular orifices are compared, covering a jet Mach number range of 0.3 2.0. The effect of ‘tabs’ for a rectangular and a round nozzle is also included in the comparison. Compared to a round jet, the jets from the asymmetric nozzles spread only slightly more at subsonic conditions whereas at supersonic conditions, when ‘screech’ occurs, they spread much more. The dynamics of the azimuthal vortical structures of the jet, organized and intensified under the screeching condition, are thought to be responsible for the observed effect at supersonic conditions. Curiously, the jet from a ‘lobed’ nozzle spreads much less at supersonic condition compared to all other cases; this is due to the absence of screech with this nozzle. Screech stages inducing flapping, rather than varicose or helical, flow oscillation cause a more pronounced jet spreading. At subsonic conditions, only a slight increase in jet spreading with the asymmetric nozzles contrasts previous observations by others. The present results show that the spreading of most asymmetric jets is not much different from that of a round jet. This inference is further supported by data from the rectangular orifices. In fact, jets from the orifices with small aspect ratio (AR) exhibit virtually no increase in the spreading. A noticeable increase commences only when AR is larger than about 10. Thus, ‘shear layer perimeter stretching’, achieved with a larger AR for a given cross-sectional area of the orifice, by itself, proves to be a relatively inefficient mechanism for increasing jet spreading. In contrast, the presence of streamwise vortices or ‘natural excitation’ can cause a significant increase effects that might explain the observations in the previous investigations. Thus far, the biggest increase in jet spreading is observed with the tabs. This is true in the subsonic regime, as well as in the supersonic regime, in spite of the fact that screech is eliminated by the tabs. The characteristic spreading of the tabbed jets is explained by the induced motion of the tab-generated streamwise vortex pairs. The tabs, however, incur thrust loss; the flow blockage and loss in thrust coefficient, vis-à-vis the spreading increase, are evaluated for various configurations.

  9. Spreading Characteristics of Compressible Jets from Nozzles of Various Geometries

    NASA Technical Reports Server (NTRS)

    Zaman, K. B. M. Q.

    1999-01-01

    The spreading characteristics of jets from several asymmetric nozzles, and a set of rectangular orifices are compared, covering a jet Mach number range of 0.3-2.0. The effect of 'tabs' for a rectangular and a round nozzle is also included in the comparison. Compared to a round jet, the jets from the asymmetric nozzles spread only slightly more at subsonic conditions whereas at supersonic conditions, when 'screech' occurs, they spread much more. The dynamics of the azimuthal vortical structures of the jet, organized and intensified under the screeching condition, are thought to be responsible for the observed effect at supersonic conditions. Curiously, the jet from a 'lobed' nozzle spreads much less at supersonic condition compared to all other cases; this is due to the absence of screech with this nozzle. Screech stages inducing flapping, rather than varicose or helical, flow oscillation cause a more pronounced jet spreading. At subsonic conditions, only a slight increase in jet spreading with the asymmetric nozzles contrasts previous observations by others. The present results show that the spreading of most asymmetric jets is not much different from that of a round jet. This inference is further supported by data from the rectangular orifices. In fact, jets from the orifices with small aspect ratio (AR) exhibit virtually no increase in the spreading. A noticeable increase commences only when AR is larger than about 10. Thus, 'shear layer perimeter stretching', achieved with a larger AR for a given cross-sectional area of the orifice, by itself, proves to be a relatively inefficient mechanism for increasing jet spreading. In contrast, the presence of streamwise vortices or 'natural excitation' can cause a significant increase - effects that might explain the observations in the previous investigations. Thus far, the biggest increase in jet spreading is observed with the tabs. This is true in the subsonic regime, as well as in the supersonic regime, in spite of the fact that screech is eliminated by the tabs. The characteristic spreading of the tabbed jets is explained by the induced motion of the tab-generated streamwise vortex pairs. The tabs, however, incur thrust loss; the flow blockage and loss in thrust coefficient, vis-a-vis the spreading increase, are evaluated for various configurations.

  10. A guidance and navigation system for continuous low-thrust vehicles. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Jack-Chingtse, C.

    1973-01-01

    A midcourse guidance and navigation system for continuous low thrust vehicles was developed. The equinoctial elements are the state variables. Uncertainties are modelled statistically by random vector and stochastic processes. The motion of the vehicle and the measurements are described by nonlinear stochastic differential and difference equations respectively. A minimum time trajectory is defined; equations of motion and measurements are linearized about this trajectory. An exponential cost criterion is constructed and a linear feedback quidance law is derived. An extended Kalman filter is used for state estimation. A short mission using this system is simulated. It is indicated that this system is efficient for short missions, but longer missions require accurate trajectory and ground based measurements.

  11. The effects of profiles on supersonic jet noise

    NASA Technical Reports Server (NTRS)

    Tiwari, S. N.; Bhat, T. R. S.

    1994-01-01

    The effect of velocity profiles on supersonic jet noise are studied by using stability calculations made for a shock-free coannular jet, with both the inner and outer flows supersonic. The Mach wave emission process is modeled as the noise generated by the large scale turbulent structures or the instability waves in the mixing region. Both the vortex-sheet and the realistic finite thickness shear layer models are considered. The stability calculations were performed for both inverted and normal velocity profiles. Comparisons are made with the results for an equivalent single jet, based on equal thrust, mass flow rate and exit area to that of the coannular jet. The advantages and disadvantages of these velocity profiles as far as noise radiation is concerned are discussed. It is shown that the Rayleigh's model prediction of the merits and demerits of different velocity profiles are in good agreement with the experimental data.

  12. Numerical Simulation of the Flow Field in the Cascaded Multistage Impinging-Jet (CAMUI) Hybrid Rocket

    Microsoft Academic Search

    Mikio Watanabe; Harunori Nagata; Tsuyoshi Totani; Isao Kudo

    2005-01-01

    The authors have proposed an advanced fuel configuration to overcome the defect of conventional hybrid rockets, i.e., the low thrust level. The key feature of this new type of hybrid rocket, named Cascaded Multi-staged Impinging jet (CAMUI), is that the cylindrical fuel blocks with two ports parallel to the axis are arranged in a row in the combustion chamber. This

  13. Design and Structural Analysis of a Reduced Scale Tip-Jet Rotor

    Microsoft Academic Search

    Kyung-Hoon Park; Nam Seo Goo; Hoon-Cheol Park; Kwang-Joon Yoon

    The general helicopter uses the rotary power that is produced from the engine in order to get the vertical thrust. In the case of the tip-jet rotor helicopter, the compressed air is injected at the tip of the blade for rotation of the rotor. Since the anti-torque does not occur, the tail rotor is not needed in this case. The

  14. Ontogeny of squid mantle function: changes in the mechanics of escape-jet locomotion in the oval squid, Sepioteuthis lessoniana lesson, 1830.

    PubMed

    Thompson, Joseph T; Kier, William M

    2002-08-01

    In Sepioteuthis lessoniana, the oval squid, ontogenetic changes in the kinematics of the mantle during escape-jet locomotion imply a decline in the relative mass flux of the escape jet and may affect the peak weight-specific thrust of the escape jet. To examine the relationship between ontogenetic changes in the kinematics of the mantle and the thrust generated during the escape jet, we simultaneously measured the peak thrust and the kinematics of the mantle of squid tethered to a force transducer. We tested an ontogenetic series of S. lessoniana that ranged in size from 5 to 40 mm dorsal mantle length (DML). In newly hatched squids, thrust peaked 40 ms after the start of the escape jet and reached a maximum of between 0.10 mN and 0.80 mN. In the largest animals, thrust peaked 70 ms after the start of the escape jet and reached a maximum of between 18 mN and 110 mN. Peak thrust was normalized by the wet weight of the squid and also by the cross-sectional area of the circumferential muscle that provides power for the escape jet. The weight-specific peak thrust of the escape jet averaged 0.36 in newly hatched squid and increased significantly to an average of 1.5 in the largest squids measured (P < 0.01). The thrust per unit area of circumferential muscle averaged 0.25 mN/mm(2) in hatchlings and increased significantly to an average of 1.4 mN/mm(2) in the largest animals tested (P < 0.01). The impulse of the escape jet was also lowest in newly hatched individuals (1.3 mN. s) and increased significantly to 1000 mN. s in the largest squids measured (P < 0.01). These ontogenetic changes in the mechanics of the escape jet suggest (1) that propulsion efficiency of the exhalant phase of the jet is highest in hatchlings, and (2) that the mechanics of the circumferential muscles of the mantle change during growth. PMID:12200252

  15. Space shuttle orbit maneuvering engine reusable thrust chamber program

    NASA Technical Reports Server (NTRS)

    Senneff, J. M.

    1975-01-01

    Reusable thrust chamber and injector concepts were evaluated for the space shuttle orbit maneuvering engine (OME). Parametric engine calculations were carried out by computer program for N2O4/amine, LOX/amine and LOX/hydrocarbon propellant combinations for engines incorporating regenerative cooled and insulated columbium thrust chambers. The calculation methods are described including the fuel vortex film cooling method of combustion gas temperature control, and performance prediction. A method of acceptance of a regeneratively cooled heat rejection reduction using a silicone oil additive was also demonstrated by heated tube heat transfer testing. Regeneratively cooled thrust chamber operation was also demonstrated where the injector was characterized for the OME application with a channel wall regenerative thrust chamber. Bomb stability testing of the demonstration chambers/injectors demonstrated recovery for the nominal design of acoustic cavities. Cavity geometry changes were also evaluated to assess their damping margin. Performance and combustion stability was demonstrated of the originally developed 10 inch diameter combustion pattern operating in an 8 inch diameter thrust chamber.

  16. Grenville foreland thrust belt hidden beneath the eastern US midcontinent

    SciTech Connect

    Hauser, E.C. (Cornell Univ., Ithaca, NY (United States))

    1993-01-01

    Grenville foreland thrust structures are observed beneath the eastern US midcontinent on COCORP (Consortium for Continental Reflection Profiling) line OH-1 and a short seismic line in southwest Ohio. These structures represent the first evidence for a significant Grenville foreland thrust belt preserved in eastern North America. On the COCORP lines, the structures include a thrust ramp anticline and an associated asymmetric syncline. The Grenville front tectonic zone appears to truncate these foreland structures, indicating a later, second phase expressed as a deeply penetrating, out-of-sequence thrust zone associated with the main uplift of the Grenville province on the east. A short, shallow seismic line in southwestern Ohio reveals an east-dipping sequence of prominently layered rocks that may lie above a footwall ramp to a deeper Grenville thrust fault. A drill hole into the less reflective top of this dipping sequence encountered unmetamorphosed sedimentary rocks like those increasingly reported from other drill holes in southwestern Ohio and adjacent states. Although possibly part of a late Precambrian (Keweenawan ) rift, these clastic sedimentary rocks may instead preserve evidence of a heretofore unrecognized Grenville foreland basin in eastern North America. Alternatively these Precambrian sedimentary rocks together with an underlying, but yet undrilled, strongly layered sequence may correlate with similarly layered rocks observed on COCORP and industrial seismic lines within the Middle Proterozoic granite-rhyolite province to the west in Indiana and Illinois and indicate that unmetamorphosed sedimentary material is an important constituent of the granite-rhyolite province. 25 refs., 6 figs.

  17. Demand thrust pumped propulsion with automatic warm gas valving

    SciTech Connect

    Whitehead, J.C.

    1992-06-09

    Operation of a thrust-on-demand, monopropellant rocket propulsion system which uses lightweight low-pressure tankage, free-piston pumps, and a small high-pressure thrust chamber, is explained. The pump intake-exhaust valves use warm gas pneumatic signals to ensure that two reciprocating pumps are alternately pressurized, with overlap during switchover to permit uninterrupted propellant flow. Experiments demonstrate that the miniature pumps operate at any speed depending on downstream demand, and can deliver nearly their own mass in hydrazine per second, at 7 MPa (1000 psi). The valves, which use the alternating layers of metal and graphite to mitigate the effects of differential thermal expansion, have been warm-gas tested for thousands of cycles. For biopropellant operation, a pair of reciprocating oxidizer pumps would be slaved to the fuel pumps` pneumatic oscillator, to provide for pulsed or continuous demand-driven flow of both liquids. Mass ratios and thrust-to-weight ratios of demand-thrust pumped propulsion systems compare quite favorably to those of pressure-fed and turbo-pumped systems. Due to the relatively high densities of storable propellants, liquid mass fractions greater than 0.95 are attainable with these novel pumps, with thrust/weight ratios above 10. The high performance potential of small propulsion systems which use reciprocating pumps suggests that this technology can significantly increase the capability of many types of small spacecraft.

  18. Demand thrust pumped propulsion with automatic warm gas valving

    NASA Astrophysics Data System (ADS)

    Whitehead, J. C.

    1992-06-01

    Operation of a thrust-on-demand, monopropellant rocket propulsion system which uses lightweight low-pressure tankage, free-piston pumps, and a small high-pressure thrust chamber, is explained. The pump intake-exhaust valves use warm gas pneumatic signals to ensure that two reciprocating pumps are alternately pressurized, with overlap during switchover to permit uninterrupted propellant flow. Experiments demonstrate that the miniature pumps operate at any speed depending on downstream demand, and can deliver nearly their own mass in hydrazine per second, at 7 MPa (1000 psi). The valves, which use the alternating layers of metal and graphite to mitigate the effects of differential thermal expansion, have been warm-gas tested for thousands of cycles. For biopropellant operation, a pair of reciprocating oxidizer pumps would be slaved to the fuel pumps' pneumatic oscillator, to provide for pulsed or continuous demand-driven flow of both liquids. Mass ratios and thrust-to-weight ratios of demand-thrust pumped propulsion systems compare quite favorably to those of pressure-fed and turbo-pumped systems. Due to the relatively high densities of storable propellants, liquid mass fractions greater than 0.95 are attainable with these novel pumps, with thrust/weight ratios above 10. The high performance potential of small propulsion systems which use reciprocating pumps suggests that this technology can significantly increase the capability of many types of small spacecraft.

  19. Simple control laws for low-thrust orbit transfers

    NASA Technical Reports Server (NTRS)

    Petropoulos, Anastassios E.

    2003-01-01

    Two methods are presented by which to determine both a thrust direction and when to apply thrust to effect specified changes in any of the orbit elements except for true anomaly, which is assumed free. The central body is assumed to be a point mass, and the initial and final orbits are assumed closed. Thrust, when on, is of a constant value, and specific impulse is constant. The thrust profiles derived from the two methods are not propellant-optimal, but are based firstly on the optimal thrust directions and location on the osculating orbit for changing each of the orbit elements and secondly on the desired changes in the orbit elements. Two examples of transfers are presented, one in semimajor axis and inclination, and one in semimajor axis and eccentricity. The latter compares favourably with a propellant-optimized transfer between the same orbits. The control laws have few input parameters, but can still capture the complexity of a wide variety of orbit transfers.

  20. Gas Jets

    NASA Technical Reports Server (NTRS)

    Chaplygin, S.

    1944-01-01

    A brief summary of the contents of this paper is presented here. In part I the differential equations of the problem of a gas flow in two dimensions is derived and the particular integrals by which the problem on jets is solved are given. Use is made of the same independent variables as Molenbroek used, but it is found to be more suitable to consider other functions. The stream function and velocity potential corresponding to the problem are given in the form of series. The investigation on the convergence of these series in connection with certain properties of the functions entering them forms the subject of part II. In part III the problem of the outflow of a gas from an infinite vessel with plane walls is solved. In part IV the impact of a gas jet on a plate is considered and the limiting case where the jet expands to infinity changing into a gas flow is taken up in more detail. This also solved the equivalent problem of the resistance of a gaseous medium to the motion of a plate. Finally, in part V, an approximate method is presented that permits a simpler solution of the problem of jet flows in the case where the velocities of the gas (velocities of the particles in the gas) are not very large.

  1. Noise from Supersonic Coaxial Jets. Part 3; Inverted Velocity Profile

    NASA Technical Reports Server (NTRS)

    Dahl, Milo D.; Morris, Philip J.

    1997-01-01

    The instability wave noise generation model is used to study the instability waves in the two shear layers of an inverted velocity profile, supersonic, coaxial jet and the noise radiated from the dominant wave. The inverted velocity profile jet has a high speed outer stream surrounding a low speed inner stream and the outer shear layer is always larger than the inner shear layer. The jet mean flows are calculated numerically. The operating conditions are chosen to exemplify the effect of the coaxial jet outer shear layer initial spreading rates. Calculations are made for the stability characteristics in the coaxial jet shear layers and the noise radiated from the instability waves for different operating conditions with the same total thrust, mass flow and exit area as a single reference jet. Results for inverted velocity profile jets indicate that relative maximum instability wave amplitudes and far field peak noise levels can be reduced from that of the reference jet by having higher spreading rates for the outer shear layer, low velocity ratios, and outer streams hotter than the inner stream.

  2. Neotectonics and structure of the Himalayan deformation front in the Kashmir Himalaya, India: Implication in defining what controls a blind thrust front in an active fold-thrust belt

    NASA Astrophysics Data System (ADS)

    Gavillot, Y. G.; Meigs, A.; Yule, J. D.; Rittenour, T. M.; Malik, M. O. A.

    2014-12-01

    Active tectonics of a deformation front constrains the kinematic evolution and structural interaction between the fold-thrust belt and most-recently accreted foreland basin. In Kashmir, the Himalayan Frontal thrust (HFT) is blind, characterized by a broad fold, the Suruin-Mastargh anticline (SMA), and displays no emergent faults cutting either limb. A lack of knowledge of the rate of shortening and structural framework of the SMA hampers quantifying the earthquake potential for the deformation front. Our study utilized the geomorphic expression of dated deformed terraces on the Ujh River in Kashmir. Six terraces are recognized, and three yield OSL ages of 53 ka, 33 ka, and 0.4 ka. Vector fold restoration of long terrace profiles indicates a deformation pattern characterized by regional uplift across the anticlinal axis and back-limb, and by fold limb rotation on the forelimb. Differential uplift across the fold trace suggests localized deformation. Dip data and stratigraphic thicknesses suggest that a duplex structure is emplaced at depth along the basal décollement, folding the overlying roof thrust and Siwalik-Muree strata into a detachment-like fold. Localized faulting at the fold axis explains the asymmetrical fold geometry. Folding of the oldest dated terrace, suggest that rock uplift rates across the SMA range between 2.0-1.8 mm/yr. Assuming a 25° dipping ramp for the blind structure on the basis of dip data constraints, the shortening rate across the SMA ranges between 4.4-3.8 mm/yr since ~53 ka. Of that rate, ~1 mm/yr is likely absorbed by minor faulting in the near field of the fold axis. Given that Himalaya-India convergence is ~18.8-11 mm/yr, internal faults north of the deformation front, such as the Riasi thrust absorbs more of the Himalayan shortening than does the HFT in Kashmir. We attribute a non-emergent thrust at the deformation front to reflect deformation controlled by pre-existing basin architecture in Kashmir, in which the thick succession of foreland strata Murree-Siwalik (8-9 km) overlie a deepened basal décollement. Blind thrusting reflects some combination of layer-parallel shortening, high stratigraphic overburden, relative youth of the HFT, and/or sustained low shortening rate on 10^5 yrs to longer timescales.

  3. Medium-frequency impulsive-thrust-activated liquid hydrogen reorientation with Geyser

    NASA Technical Reports Server (NTRS)

    Hung, R. J.; Shyu, K. L.

    1992-01-01

    Efficient technique are studied for accomplishing propellant resettling through the minimization of propellant usage through impulsive thrust. A comparison between the use of constant-thrust and impulsive-thrust accelerations for the activation of propellant resettlement shows that impulsive thrust is superior to constant thrust for liquid reorientation in a reduced-gravity environment. This study shows that when impulsive thrust with 0.1-1.0-, and 10-Hz frequencies for liquid-fill levels in the range between 30-80 percent is considered, the selection of 1.0-Hz-frequency impulsive thrust over the other frequency ranges of impulsive thrust is the optimum. Characteristics of the slosh waves excited during the course of 1.0-Hz-frequency impulsive-thrust liquid reorientation were also analyzed.

  4. Seismic data, geometry, evolution, and shortening in the active Sulaiman fold-and-thrust belt of Pakistan, southwest of the Himalayas

    SciTech Connect

    Jadoon, I.A.K. (Quaid-i-Azam Univ., Islamabad (Panama)); Lawrence, R.D.; Lillie, R.J. (Oregon State Univ., Corvallis, OR (United States))

    1994-05-01

    Despite its long history of exploration, the Sulaiman fold and thrust belt is a poorly known structure and detailed structural and geochemical investigations are vital for the successful exploration, evaluation and exploitation of any hydrocarbons. Recent nappe and duplex structural models provide a framework for exploration. Surface and subsurface data from the Sulaiman fold-and-thrust belt are integrated to analyze the deep structure, tectonic, shortening, and kinematics of the Sulaiman fold-and-thrust belt at the western margin of the Indian subcontinent. Seismic reflection data show that nearly all the 10-km-thick sequence of dominantly platform (>7 km) and molasse strata is detached at the deformation front. The strata thicken tectonically to about 20 km in the hinterland without significant thrust faults in the foreland. A balanced structural cross-section suggests that structural uplift in the Sulaiman fold-and-thrust belt is a result of a thin-skinned, passive-roof duplex style of deformation. Sequential restoration of the balanced section reveals a series of structural and geometrical features including: (1) development of low-amplitude, broad concentric folds at the tip of the decollement; (2) increase in amplitude of a detachment fold to a critical level for development of ramp and duplex structures; and (3) out-of-sequence thrusting to create required critical taper for an outward translation of the foreland fold-and-thrust belt. A balanced structural cross-section 349 km long from the Sulaiman fold-and-thrust belt restores to an original length of 727 km, suggesting a maximum of 378 km of shortening since 21 Ma in the cover strata of the Indian subcontinent. Calculation of displacement rates over the Sulaiman fold-and-thrust belt (18 mm/yr) added to the resolved rate of the Chaman fault vector for the component parallel to the plate convergence direction (15 mm/yr) are close to the current India-Asia plate convergence rate (37 mm/yr). 68 refs., 13 figs.

  5. Was Himalayan normal faulting triggered by initiation of the Ramgarh-Munsiari Thrust?

    USGS Publications Warehouse

    Robinson, Delores M.; Pearson, Ofori N.

    2013-01-01

    The Ramgarh–Munsiari thrust is a major orogen-scale fault that extends for more than 1,500 km along strike in the Himalayan fold-thrust belt. The fault can be traced along the Himalayan arc from Himachal Pradesh, India, in the west to eastern Bhutan. The fault is located within the Lesser Himalayan tectonostratigraphic zone, and it translated Paleoproterozoic Lesser Himalayan rocks more than 100 km toward the foreland. The Ramgarh–Munsiari thrust is always located in the proximal footwall of the Main Central thrust. Northern exposures (toward the hinterland) of the thrust sheet occur in the footwall of the Main Central thrust at the base of the high Himalaya, and southern exposures (toward the foreland) occur between the Main Boundary thrust and Greater Himalayan klippen. Although the metamorphic grade of rocks within the Ramgarh–Munsiari thrust sheet is not significantly different from that of Greater Himalayan rock in the hanging wall of the overlying Main Central thrust sheet, the tectonostratigraphic origin of the two different thrust sheets is markedly different. The Ramgarh–Munsiari thrust became active in early Miocene time and acted as the roof thrust for a duplex system within Lesser Himalayan rocks. The process of slip transfer from the Main Central thrust to the Ramgarh–Munsiari thrust in early Miocene time and subsequent development of the Lesser Himalayan duplex may have played a role in triggering normal faulting along the South Tibetan Detachment system.

  6. Identifying Blind Thrust Anticlines in the Subsurface using Drainage Patterns: Andean Foreland of Central Argentina

    NASA Astrophysics Data System (ADS)

    Enderlin, P. A.; Schoenbohm, L. M.; Brooks, B. A.; Costa, C.

    2009-12-01

    The identification of blind thrust faults has traditionally been limited to seismic exploration and/or the recognition of anticlinal hills above the projected fault tip. However, even if there is no topographic expression, blind thrust faults can be identified geomorphically. Deviations in drainage patterns, such as longitudinal and lateral changes in stream gradient (i.e. river diversions, shifts in sinuosity, and gradient changes), as well as overall changes in basin shape, have been associated with tectonics. Our work refines methods for recognizing previously unidentified blind thrusts by examining ephemeral streams draining the Western Andes through the Andean Foreland, Central Argentina. Active deformation in this region has resulted in the topographic expression of several blind thrust faults, and their affect on drainage morphology can be used for comparison. Regional drainage was mapped by comparing stream locations seen on high resolution satellite imagery to two stream-network vector files: HydroSHEDS, derived from 3 arc-second SRTM DEMs, and ASTER GDEM, derived from 1 arc-second data. We identified drainage anomalies as locations where streams crossing 20-m contour lines deviate more than 10° for 5-km or more from perpendicular to the topographic contour. A total of 174 anomalies were identified using the HydroSHEDS DEMs and 106 anomalies from the ASTER GDEMs. We also applied the methods of Burrato et al. (2003), identifying drainage anomalies as locations where streams deviate for 10° for 5-km or more from the tangential to generalized 10 m contour intervals. Preliminary examination by this approach reveals 91 anomalies using the HydroSHEDS DEMs and 44 anomalies using the ASTER GDEMs. The spatial distributions of these river diversions are similar, with the highest number of anomalies between lat 32°30’-33°30’S and long 67°30’-68°W. Preliminary interpretation suggests fewer anomalies exist where rivers were more active since the Pleistocene. We further examine the influence of surface tilting on the lateral migration of rivers by observing the symmetry/asymmetry of river channels, meander scars, and alluvial fans. The predominantly east-west flowing Rio San Juan shows symmetric meander scars, whereas the predominantly north-south flowing Rio Desaguadero shows asymmetric meander scars and eastward migration. This could suggest regional tilting along an east-west axis, possibly due to uplift in the foreland or active subsidence along the east-bounding structures. These remote observations will be verified in the field during a Fall 2009 field-season and using regional seismic profile lines. This project is part of ongoing research on the Quaternary spatial and temporal deformation history of the central Andean thrust front. References cited: Burrato, P., Ciucci, F., and G. Valensise, 2003, An inventory of river anomalies in the Po Valley, Northern Italy: evidence for active blind thrust faulting. Annals of Geophysics, 46(5): 865-882.

  7. Viscoplastic analysis of an experimental cylindrical thrust chamber liner

    NASA Technical Reports Server (NTRS)

    Arya, Vinod K.; Arnold, Steven M.

    1992-01-01

    A viscoplastic stress-strain analysis of an experimental cylindrical thrust chamber is presented. A viscoelastic constitutive model incorporating a single internal state variable that represents kinematic hardening was employed to investigate whether such a viscoplastic model could predict the experimentally observed behavior of the thrust chamber. Two types of loading cycles were considered: a short cycle of 3.5-s duration that corresponded to the experiments, and an extended loading cycle of 485.1 s duration that is typical of the Space Shuttle Main Engine (SSME) operating cycle. The analysis qualitatively replicated the deformation behavior of the component as observed in experiments designed to simulate SSME operating conditions. The analysis also showed that the mode and location of failure in the component may depend on the loading cycle. The results indicate that using viscoplastic models for structural analysis can lead to a more realistic life assessment of thrust chambers.

  8. Viscoplastic analysis of an experimental cylindrical thrust chamber liner

    NASA Technical Reports Server (NTRS)

    Arya, Vinod K.; Arnold, Steven M.

    1991-01-01

    A viscoplastic stress-strain analysis of an experimental cylindrical thrust chamber is presented. A viscoelastic constitutive model incorporating a single internal state variable that represents kinematic hardening was employed to investigate whether such a viscoplastic model could predict the experimentally observed behavior of the thrust chamber. Two types of loading cycles were considered: a short cycle of 3.5 sec. duration that corresponded to the experiments, and an extended loading cycle of 485.1 sec. duration that is typical of the Space Shuttle Main Engine (SSME) operating cycle. The analysis qualitatively replicated the deformation behavior of the component as observed in experiments designed to simulate SSME operating conditions. The analysis also showed that the mode and location in the component may depend on the loading cycle. The results indicate that using viscoplastic models for structural analysis can lead to a more realistic life assessment of thrust chambers.

  9. Numerical grid generation and flow simulation in SSME thrust chamber

    SciTech Connect

    Gross, K.W.; Daley, P.L.; Przekwas, A.J.

    1987-01-01

    The development of liquid and solid rocket engines for future space projects demands a detailed optimization process for highly efficient performance and cost reasons. Also, testing of full size engines may not be feasible when the large size requires test facilities which are cost prohibitive or if vacuum operation cannot be acquired. For such situations only scaling from small test scale measurements or accurate analytical predictions will provide the performance prior to actually flying the mission. A rigorous approach for simulating the combustion processes in liquid rocket engines by employing a direct solution of Navier-Stokes equations within the entire volume of the thrust chambers is presented. This method is illustrated in the solution of reactive flow in the Space Shuttle Main Engine (SSME) thrust chamber. The objective is to review recent improvements in the mathematical model and to present the grid generation methodology suitable for rocket thrust chamber geometries.

  10. Sinistral strike-slip dominated inclined transpression along the Pai-Khoi fold-and-thrust belt, Russian Arctic

    NASA Astrophysics Data System (ADS)

    Curtis, Michael

    2014-05-01

    The Arctic Uralides comprise Pai-Khoi, Novaya Zemlya and the Taimyr Peninsula. Together they form a margin controlled salient in the former Baltica margin of Laurussia. This arcuate orogen forms a fundamental tectonic boundary between major hydrocarbon provinces; Timan-Pechora and Barents Sea to the southwest and west, respectively, and the South Kara Sea to the east. To understand the complex regional tectonic relationship between the Arctic Uralides and the South Kara Sea, it is essential to establish the structural and kinematic style of the various sectors of this remote orogen. This contribution focuses on the southern limb of the salient, the NW-SE trending, Pai-Khoi fold-and-thrust belt (PKFB), which links the Polar Urals with Novaya Zemlya approximately 600 km to the northwest. The PKFB comprises a highly deformed, Late Cambrian to Mississippian age, passive margin succession, with allochthonous deep-water and continental slope facies rocks thrust over a shallow-water carbonate platform succession along the Main Pai-Khoi Thrust. Deformation is interpreted to have occurred between the Late Palaeozoic and end Triassic resulting in the formation of an apparent southwesterly verging fold-and-thrust belt with an associated foreland basin. Analysis of regional scale geological maps reveals the presence of large scale en-echelon folds, together with late stage, orogen-parallel faults, indicating that the evolution of PKFB has been influenced by a component of sinistral strike-slip. Detailed field data from a transect across the largest structure in the orogen, the Main Pai-Khoi Thrust, confirms the obliquity of both planar structures and finite stretching lineations to this major allochthon bounding thrust. Subtle but consistent variations in the orientation of finite stretching directions within zones of qualitatively differing finite strain were identified. Comparison of these variations with theoretical models of inclined transpression suggests that deformation within the PKFB is consistent with a model of strike-slip dominated, inclined transpression, where ? (angle of far field displacement vector to transpression zone) is ~20° , and the inclination of the deformation zone (?) is shallowly to moderately inclined (20-50° ). Sinistral strike-slip dominated transpression along the Pai-Khoi sector the Arctic Uralides is consistent with a Carpathian/Pannonian analogue model for the evolution of the South Kara Sea and its peripheral orogen.

  11. Differential displacement and rotation in thrust fronts: A magnetic, calcite twinning and palinspastic study of the Jones Valley

    E-print Network

    and palinspastic study of the Jones Valley thrust, Alabama, US Appalachians James S. Hnat a,*, Ben A. van der-displacement Jones Valley thrust fault of the Appalachian thrust belt in Alabama. Paleomagnetism, anisotropy of the thrust fault. Rather than rotation, therefore, we interpret the Jones Valley thrust sheet as a structure

  12. Thrust augmentor application for STOL and V/STOL

    NASA Technical Reports Server (NTRS)

    Aiken, T. N.

    1977-01-01

    A general parametric description is suggested for thrust augmentor application to STOL and V/STOL aircraft. The parameters and their relationships are discussed using several aircraft augmentor integration problems. For a STOL transport design, the ram drag is a key consideration, limiting the maximum gross augmentation that can be utilized. Maximizing gross augmentation and balancing the aircraft are key considerations for a V/STOL fighter design. Results from wind tunnel investigations on several different thrust augmentor concepts and system studies on STOL transport designs are also included.

  13. Thrust Bearing with Rough Surfaces Lubricated by an Ellis Fluid

    NASA Astrophysics Data System (ADS)

    Walicka, A.; Walicki, E.; Jurczak, P.; Falicki, J.

    2014-11-01

    In the paper the influence of bearing surfaces roughness on the pressure distribution and load-carrying capacity of a thrust bearing is discussed. The equations of motion of an Ellis pseudo-plastic fluid are used to derive the Reynolds equation. After general considerations on the flow in a bearing clearance and using the Christensen theory of hydrodynamic rough lubrication the modified Reynolds equation is obtained. The analytical solutions of this equation for the cases of a squeeze film bearing and an externally pressurized bearing are presented. As a result one obtains the formulae expressing pressure distribution and load-carrying capacity. A thrust radial bearing is considered as a numerical example.

  14. Low-thrust chemical propulsion system pump technology

    NASA Technical Reports Server (NTRS)

    Sabiers, R. L.; Siebenhaar, A.

    1981-01-01

    Candidate pump and driver systems for low thrust cargo orbit transfer vehicle engines which deliver large space structures to geosynchronous equatorial orbit and beyond are evaluated. The pumps operate to 68 atmospheres (1000 psi) discharge pressure and flowrates suited to cryogenic engines using either LOX/methane or LOX/hydrogen propellants in thrust ranges from 445 to 8900 N (100 to 2000 lb F). Analysis of the various pumps and drivers indicate that the low specific speed requirement will make high fluid efficiencies difficult to achieve. As such, multiple stages are required. In addition, all pumps require inducer stages. The most attractive main pumps are the multistage centrifugal pumps.

  15. Velocity field measurement of a round jet using quantitative schlieren

    SciTech Connect

    Iffa, Emishaw D.; Aziz, A. Rashid A.; Malik, Aamir S.

    2011-02-10

    This paper utilizes the background oriented schlieren (BOS) technique to measure the velocity field of a variable density round jet. The density field of the jet is computed based on the light deflection created during the passage of light through the understudy jet. The deflection vector estimation was carried out using phase-based optical flow algorithms. The density field is further exploited to extract the axial and radial velocity vectors with the aid of continuity and energy equations. The experiment is conducted at six different jet-exit temperature values. Additional turbulence parameters, such as velocity variance and power spectral density of the vector field, are also computed. Finally, the measured velocity parameters are compared with the hot wire anemometer measurements and their correlation is displayed.

  16. Turbulent Jets?

    NASA Astrophysics Data System (ADS)

    Wilde, B. H.; Rosen, P. A.; Foster, J. M.; Perry, T. S.; Steinkamp, M. J.; Robey, H. F.; Khokhlov, A. M.; Gittings, M. L.; Coker, R. F.; Keiter, P. A.; Knauer, J. P.; Drake, R. P.; Remington, B. A.; Bennett, G. R.; Sinars, D. B.; Campbell, R. B.; Mehlhorn, T. A.

    2003-10-01

    Over the last few years we have fielded numerous supersonic jet experiments on the NOVA and OMEGA lasers and Sandia's pulsed-power Z-machine in a collaboration between Los Alamos National Laboratory, the Atomic Weapons Establishment, Lawrence Livermore National Laboratory, and Sandia National Laboratory. These experiments are being conducted to help validate our radiation-hydrodynamic codes, especially the newly developing ASC codes. One of the outstanding questions is whether these types of jets should turn turbulent given their high Reynolds number. Recently we have modified our experiments to have more Kelvin-Helmholtz shear, run much later in time and therefore have a better chance of going turbulent. In order to diagnose these large (several mm) jets at very late times ( 1000 ns) we are developing point-projection imaging on both the OMEGA laser, the Sandia Z-Machine, and ultimately at NIF. Since these jets have similar Euler numbers to jets theorized to be produced in supernovae explosions, we are also collaborating with the astrophysics community to help in the validation of their new codes. This poster will present a review of the laser and pulsed-power experiments and a comparison of the data to simulations by the codes from the various laboratories. We will show results of simulations wherein these jets turn highly 3-dimensional and show characteristics of turbulence. With the new data, we hope to be able to validate the sub-grid-scale turbulent mix models (e. g. BHR) that are being incorporated into our codes.*This work is performed under the auspices of the U. S. Department of Energy by the Los Alamos National Laboratory Laboratory under Contract No. W-7405-ENG-36, Lawrence Livermore National Laboratory under Contract No. W-7405-ENG-48, the Laboratory for Laser Energetics under Contract No. DE-FC03-92SF19460, Sandia National Laboratories under Contract No. DE-AC04-94AL85000, the Office of Naval Research, and the NASA Astrophysical Theory Grant.

  17. Aircraft Spin Recovery, with and without Thrust Vectoring, Using Nonlinear Dynamic Inversion

    Microsoft Academic Search

    P. K. Raghavendra; Tuhin Sahai; P. Ashwani Kumar; Manan Chauhan; N. Ananthkrishnan

    2005-01-01

    The present paper addresses the problem of spin recovery of an aircraft as a nonlinear inverse dynamics problem of determining the control inputs that need to be applied to transfer the aircraft from a spin state to a level trim flight condition. A stable, oscillatory, flat, left spin state is first identified from a standard bifurcation analysis of the aircraft

  18. Dichotomy of Solar Coronal Jets: Standard Jets and Blowout Jets

    NASA Technical Reports Server (NTRS)

    Moore, R. L.; Cirtain, J. W.; Sterling, A. C.; Falconer, D. A.

    2010-01-01

    By examining many X-ray jets in Hinode/XRT coronal X-ray movies of the polar coronal holes, we found that there is a dichotomy of polar X-ray jets. About two thirds fit the standard reconnection picture for coronal jets, and about one third are another type. We present observations indicating that the non-standard jets are counterparts of erupting-loop H alpha macrospicules, jets in which the jet-base magnetic arch undergoes a miniature version of the blowout eruptions that produce major CMEs. From the coronal X-ray movies we present in detail two typical standard X-ray jets and two typical blowout X-ray jets that were also caught in He II 304 Angstrom snapshots from STEREO/EUVI. The distinguishing features of blowout X-ray jets are (1) X-ray brightening inside the base arch in addition to the outside bright point that standard jets have, (2) blowout eruption of the base arch's core field, often carrying a filament of cool (T 10(exp 4) - 10(exp 5) K) plasma, and (3) an extra jet-spire strand rooted close to the bright point. We present cartoons showing how reconnection during blowout eruption of the base arch could produce the observed features of blowout X-ray jets. We infer that (1) the standard-jet/blowout-jet dichotomy of coronal jets results from the dichotomy of base arches that do not have and base arches that do have enough shear and twist to erupt open, and (2) there is a large class of spicules that are standard jets and a comparably large class of spicules that are blowout jets.

  19. Numerical simulations of volcanic jets: Importance of vent overpressure

    NASA Astrophysics Data System (ADS)

    Ogden, Darcy E.; Wohletz, Kenneth H.; Glatzmaier, Gary A.; Brodsky, Emily E.

    2008-02-01

    Explosive volcanic eruption columns are generally subdivided into a gas-thrust region and a convection-dominated plume. Where vents have greater than atmospheric pressure, the gas-thrust region is overpressured and develops a jet-like structure of standing shock waves. Using a pseudogas approximation for a mixture of tephra and gas, we numerically simulate the effects of shock waves on the gas-thrust region. These simulations are of free-jet decompression of a steady state high-pressure vent in the absence of gravity or a crater. Our results show that the strength and position of standing shock waves are strongly dependent on the vent pressure and vent radius. These factors control the gas-thrust region's dimensions and the character of vertical heat flux into the convective plume. With increased overpressure, the gas-thrust region becomes wider and develops an outer sheath in which the erupted mixture moves at higher speeds than it does near the column center. The radius of this sheath is linearly dependent on the vent radius and the square root of the overpressure. The sheath structure results in an annular vertical heat flux profile at the base of the convective plume, which is in stark contrast to the generally applied Gaussian or top-hat profile. We show that the magnitude of expansion is larger than that predicted from previous 1D analyses, resulting in much slower average vertical velocities after expansion. These new relationships between vent pressure and plume expansion may be used with observations of plume diameter to constrain the pressure at the vent.

  20. Jets from compact objects

    E-print Network

    H. C. Spruit

    2000-03-03

    Some topics in the theory of jets are reviewed. These include jet precession, unconfined jets, the origin of knots, the internal shock model as a unifying theme from protostellar jets to Gamma-ray bursts, relations between the Blandford-Znajek and MHD disk-wind models, and jet collimation in magnetic acceleration models.

  1. The interaction between deepwater channel systems and growing thrusts and folds, toe-thrust region of the deepwater Niger Delta

    NASA Astrophysics Data System (ADS)

    Jolly, B.; Lonergan, L.; Whittaker, A.

    2012-04-01

    Gravity-driven seaward-verging thrusts, landward-verging back-thrusts and associated folds often characterize the slope and deepwater settings of passive margins. These structures, found in the "toe-thrust" region of the system, exert a significant control on sediment gravity flows because they create and determine the location and configuration of sediment depocentres and transport systems. However, to fully understand the interaction between sediment gravity flows and seabed topography we need to evaluate and quantify the geomorphic response of sub-marine channels to faulting in an area where the degree of tectonic shortening can be well constrained. This study exploits 3D seismic data in the outer toe-thrust region of the deepwater Niger Delta to analyze the interaction between Plio-Pleistocene channel systems and actively growing folds and thrusts. We first mapped folds and thrusts from the seismic data and we used this data to reconstruct the history of fold growth. We then used the sea-bed seismic horizon to build a 50 m resolution Digital Elevation Model (DEM) of the sea floor in Arc-GIS. From the DEM, we extracted channel long profiles across growing structures for both the current channel thalwegs and for the associated channel cut-and-fill sequences identified from the seismic data. We measured channel geometry at regular intervals along the channel length to evaluate system response to tectonic perturbation, and we used this data to help us approximate the down-system distribution of bed shear stress, and hence incision capacity. Initial results show that changes in submarine channel longitudinal profiles are directly correlated to underlying seabed thrusts and folds. Channels gradients are typically linear to slightly concave, and have an average gradient of 0.90. Actively growing thrusts are associated with a local steepening in channel gradient (up to 200% change), which typically extends 0.5 to 2 km upstream of the fault. Within these "knickzones", channel incision increases by approximately 50%, with a corresponding width decrease of approximately 25% or less. Our data demonstrate that submarine channel systems dynamically adjust their geometry and basal gradient in order to keep pace with the growth of tectonic structures and our results provide new data to test models of turbidite incision.

  2. Interim noise correlation for some OTW configurations using external jet-flow deflectors

    NASA Technical Reports Server (NTRS)

    Vonglahn, U. H.; Groesbeck, D. E.

    1977-01-01

    Jet flap interaction acoustic data obtained statically from a model-scale study of STOL-OTW configurations with a conical nozzle mounted above the wing and using various external deflectors to provide jet-flow attachment are correlated. The acoustic data are correlated in terms that consider the jet/flap interaction noise contributions associated primarily with fluctuating lift, trailing edge, and configuration wake noise sources. Variables considered include deflector geometry, flap setting and wing size. Finally, the configuration overall noise levels are related to static lift and thrust measurements in order to provide insight into possible acoustic/aerodynamic performance trade-off benefits.

  3. The wake structure and thrust performance of a rigid low-aspect-ratio pitching panel

    PubMed Central

    BUCHHOLZ, JAMES H. J.; SMITS, ALEXANDER J.

    2009-01-01

    Thrust performance and wake structure were investigated for a rigid rectangular panel pitching about its leading edge in a free stream. For ReC = O(104), thrust coefficient was found to depend primarily on Strouhal number St and the aspect ratio of the panel AR. Propulsive efficiency was sensitive to aspect ratio only for AR less than 0.83; however, the magnitude of the peak efficiency of a given panel with variation in Strouhal number varied inversely with the amplitude to span ratio A/S, while the Strouhal number of optimum efficiency increased with increasing A/S. Peak efficiencies between 9 % and 21 % were measured. Wake structures corresponding to a subset of the thrust measurements were investigated using dye visualization and digital particle image velocimetry. In general, the wakes divided into two oblique jets; however, when operating at or near peak efficiency, the near wake in many cases represented a Kármán vortex street with the signs of the vortices reversed. The three-dimensional structure of the wakes was investigated in detail for AR = 0.54, A/S = 0.31 and ReC = 640. Three distinct wake structures were observed with variation in Strouhal number. For approximately 0.20 < St < 0.25, the main constituent of the wake was a horseshoe vortex shed by the tips and trailing edge of the panel. Streamwise variation in the circulation of the streamwise horseshoe legs was consistent with a spanwise shear layer bridging them. For St > 0.25, a reorganization of some of the spanwise vorticity yielded a bifurcating wake formed by trains of vortex rings connected to the tips of the horseshoes. For St > 0.5, an additional structure formed from a perturbation of the streamwise leg which caused a spanwise expansion. The wake model paradigm established here is robust with variation in Reynolds number and is consistent with structures observed for a wide variety of unsteady flows. Movies are available with the online version of the paper. PMID:19746195

  4. The wake structure and thrust performance of a rigid low-aspect-ratio pitching panel.

    PubMed

    Buchholz, James H J; Smits, Alexander J

    2008-04-30

    Thrust performance and wake structure were investigated for a rigid rectangular panel pitching about its leading edge in a free stream. For Re(C) = O(10(4)), thrust coefficient was found to depend primarily on Strouhal number St and the aspect ratio of the panel AR. Propulsive efficiency was sensitive to aspect ratio only for AR less than 0.83; however, the magnitude of the peak efficiency of a given panel with variation in Strouhal number varied inversely with the amplitude to span ratio A/S, while the Strouhal number of optimum efficiency increased with increasing A/S. Peak efficiencies between 9 % and 21 % were measured. Wake structures corresponding to a subset of the thrust measurements were investigated using dye visualization and digital particle image velocimetry. In general, the wakes divided into two oblique jets; however, when operating at or near peak efficiency, the near wake in many cases represented a Kármán vortex street with the signs of the vortices reversed. The three-dimensional structure of the wakes was investigated in detail for AR = 0.54, A/S = 0.31 and Re(C) = 640. Three distinct wake structures were observed with variation in Strouhal number. For approximately 0.20 < St < 0.25, the main constituent of the wake was a horseshoe vortex shed by the tips and trailing edge of the panel. Streamwise variation in the circulation of the streamwise horseshoe legs was consistent with a spanwise shear layer bridging them. For St > 0.25, a reorganization of some of the spanwise vorticity yielded a bifurcating wake formed by trains of vortex rings connected to the tips of the horseshoes. For St > 0.5, an additional structure formed from a perturbation of the streamwise leg which caused a spanwise expansion. The wake model paradigm established here is robust with variation in Reynolds number and is consistent with structures observed for a wide variety of unsteady flows. Movies are available with the online version of the paper. PMID:19746195

  5. Managing momentum on the dawn low thrust mission

    Microsoft Academic Search

    Brett A. Smith; Charles A. Vanelli; Edward R. Swenka

    2009-01-01

    Dawn is low-thrust interplanetary spacecraft enroute to the asteroids Vesta and Ceres in an effort to better understand the early creation of the solar system. After launch in September 2007, the spacecraft will flyby Mars in February 2009 before arriving at Vesta in summer of 2011 and Ceres in early 2015. Three solar electric ion-propulsion engines are used to provide

  6. Extraction of Thrust from Quantum Vacuum Using Squeezed Light

    Microsoft Academic Search

    Yoshinari Minami

    2007-01-01

    One promising Field propulsion system which gets ahead of all existing methods of propulsion systems utilizes the ubiquitous infinite space, more specifically, vacuum. An extraction of thrust from the excited quantum vacuum is indispensable to the development of field propulsion. It is possible to decrease the local energy density below its value in the vacuum state by manipulating the field;

  7. Sub-micronewton thrust measurements of indium field emission thrusters

    NASA Technical Reports Server (NTRS)

    Ziemer, J. K.

    2003-01-01

    The performance of three indium field emission thrusters (In-FETs) developed by the Austrian Research Center Seibersdorf (ARCS) have been measured up to 200 muN, 2 mA, and 20 W using a submicronewton resolution thrust stand.

  8. Asymptotic solution to the tangential low thrust energy increase trajectory

    NASA Technical Reports Server (NTRS)

    Schwenzfeger, K. J.

    1973-01-01

    A approximate analytic solution to the low thrust constant acceleration energy increase trajectory using a tangential steering program is presented. The solution is based on a two-variable asymptotic expansion of the equations of motion formulated in regularized variables. The high accuracy of the second order solution derived is demonstrated by comparing it with numerically integrated trajectories.

  9. Test results for second-generation low thrust bipropellant engines

    NASA Astrophysics Data System (ADS)

    Schwende, M. A.; Schulte, G.

    1993-01-01

    An account is given of the development priorities, design features, and performance of second-generation, low-thrust (10 N) thrusters for satellite orbit and attitude correction maneuvers. Detailed information is presented for the qualification trials of a related, 4-N thruster. The bipropellant fuels used are MMH and MON-1.

  10. The Effect of Atmospheric Pressure on Rocket Thrust -- Part I.

    ERIC Educational Resources Information Center

    Leitner, Alfred

    1982-01-01

    The first of a two-part question asks: Does the total thrust of a rocket depend on the surrounding pressure? The answer to this question is provided, with accompanying diagrams of rockets. The second part of the question (and answer) are provided in v20 n7, p479, Oct 1982 of this journal. (Author/JN)

  11. INTRODUCTION The importance of blind thrust faults as sources

    E-print Network

    Mueller, Karl

    detach- ments (Crouch and Suppe, 1993), and may pose significant hazards to coastal California and Thirtymile Bank detachments, extend south from Laguna Beach and Catalina Island, respectively, to at least.Inmigratedseismicreflection profiles, the thrust is imaged as a coherent set of strong reflections that dip to the northeast

  12. Columbia, Orbiter Vehicle (OV) 102, RCS engines thrusting

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Columbia, Orbiter Vehicle (OV) 102, reaction control system (RCS) engine thrusting and one plume fire glow. One of the thruster firings of the forward RCS is captured with an astronaut's 35mm camera. Astronauts aimed their 35mm camera through the front windows to capture various firings of several of the thrusters which control the orbiter's movements in space.

  13. Blueschist-facies metamorphism related to regional thrust faulting

    USGS Publications Warehouse

    Blake, M.C., Jr.; Irwin, W.P.; Coleman, R.G.

    1969-01-01

    Rocks of the blueschist (glaucophane schist) facies occur throughout the world in narrow tectonic belts associated with ultramafic rocks. In the Coast Range province of California, blueschist rocks are devloped in the eugeosynclinal Franciscan Formation of Late Mesozoic age. The blueschist rocks form a narrow belt for more than 800 km along the eastern margin of this province and commonly are separated from rocks of an overlying thrust plate by serpentinite. Increasing metamorphism upward toward the thrust fault is indicated mineralogically by a transition from pumpellyite to lawsonite and texturally by a transition from metagraywacke to schist. The blueschist metamorphism probably occurred during thrusting in a zone of anomalously high water pressure in the lower plate along the sole of the thrust fault. This tectonic mode of origin for blueschist differs from the generally accepted hypothesis involving extreme depth of burial. Other belts of blueschist-facies rocks, including the Sanbagawa belt of Japan, the marginal synclinal belt of New Zealand, and the blueschist-ultramafic belts of Venezuela, Kamchatka, Ural mountains, and New Caledonia have similar geologic relations and might be explained in the same manner. ?? 1969.

  14. Digital field trip to the Central Nevada Thrust Belt

    SciTech Connect

    Chamberlain, A.K. (Cedar Strat Corp., Hiko, NV (United States)); Hook, S.C. (Texaco E P Technology Department, Houston, TX (United States)); Frost, K.R. (Texaco Exploration and Production, Inc., Houston, TX (United States))

    1996-01-01

    Hydrocarbon exploration in the Central Nevada Thrust Belt is still in its infancy. However, this thrust belt contains all the elements necessary for hydrocarbon accumulations: thick, organically-rich shales; reefs, regional unconformities, karst surfaces, porous sandstones, and extensive and pervasive fractures; anticlines tens of miles long by miles wide; thrust faults that juxtapose potential source and reservoir rocks; and oil seeps. Along a fairway from Las Vegas to Elko, for example, thick Mississippian shales contain 4-6% total organic carbon and are oil-prone and thermally mature. This presentation from a laptop computer and LCD projector is a multimedia version of our October 12-14, 1995 field trip to document the hydrocarbon potential of the thrust belt in Clark, Lincoln, and Nye Counties. Outcrop images were recorded by a digital camera that has a resolution equivalent to a 14 inch computer screen; these images were then downloaded to the computer. All of the images were processed digitally on location to enhance picture quality and color contrast. Many were annotated on location with our observations, measurements, and interpretations. These field annotations are supplemented in this presentation by laboratory analyses. The presentation includes full-color, annotated outcrop images, sounds, and animations. The results show the viability of the new, inexpensive digital cameras to geologic field work in which a multimedia report, ready for presentation to management, can be generated in the field.

  15. Digital field trip to the Central Nevada Thrust Belt

    SciTech Connect

    Chamberlain, A.K. [Cedar Strat Corp., Hiko, NV (United States); Hook, S.C. [Texaco E& P Technology Department, Houston, TX (United States); Frost, K.R. [Texaco Exploration and Production, Inc., Houston, TX (United States)

    1996-12-31

    Hydrocarbon exploration in the Central Nevada Thrust Belt is still in its infancy. However, this thrust belt contains all the elements necessary for hydrocarbon accumulations: thick, organically-rich shales; reefs, regional unconformities, karst surfaces, porous sandstones, and extensive and pervasive fractures; anticlines tens of miles long by miles wide; thrust faults that juxtapose potential source and reservoir rocks; and oil seeps. Along a fairway from Las Vegas to Elko, for example, thick Mississippian shales contain 4-6% total organic carbon and are oil-prone and thermally mature. This presentation from a laptop computer and LCD projector is a multimedia version of our October 12-14, 1995 field trip to document the hydrocarbon potential of the thrust belt in Clark, Lincoln, and Nye Counties. Outcrop images were recorded by a digital camera that has a resolution equivalent to a 14 inch computer screen; these images were then downloaded to the computer. All of the images were processed digitally on location to enhance picture quality and color contrast. Many were annotated on location with our observations, measurements, and interpretations. These field annotations are supplemented in this presentation by laboratory analyses. The presentation includes full-color, annotated outcrop images, sounds, and animations. The results show the viability of the new, inexpensive digital cameras to geologic field work in which a multimedia report, ready for presentation to management, can be generated in the field.

  16. Frictional Characteristics of Thrust Bearing in Scroll Compressor

    NASA Astrophysics Data System (ADS)

    Sato, Hajime; Itoh, Takahide; Kobayashi, Hiroyuki

    This paper presents frictional characteristics of thrust bearing in scroll compressor focusing on the behavior of sliding portion which affects the generation of oil film. The coefficient of friction and tilt angle of sliding portion in the thrust bearing are obtained through both elemental friction test and cylinder pressure measurement of actual scroll compressor. Both tests showed that the coefficient of friction in low contact pressure rose with increase of tilt angle of sliding portion. The value of contact pressure which the coefficient of friction turns into increase was in agreement of the value which tilt angle become to increase. Numerical analysis using mixed lubrication theory was also performed. Analytical result indicated the same characteristics as the experiments, and the correlation between the coefficient of friction and the behavior of sliding portion was confirmed. Based on the experimental and the analytical results obtained here, the optimization of thrust bearing for commercial scroll compressor was applied. 2% improvement of total efficiency in rated condition was archived by optimization of thrust bearing.

  17. Thrust Improvement of the Magnetically Enhanced Vacuum Arc Thruster (MVAT)

    Microsoft Academic Search

    Benjamin Tang; Luke Idzkowski; Michael Au; Don Parks; Mahadevan Krishnan; John Ziemer

    The Magnetically enhanced Vacuum Arc Thruster (MVAT) is a solid propellant micro-thruster based on a pulsed vacuum arc thruster (VAT) that produces precisely controlled impulse bits. The addition of a co-axial magnetic field to the VAT enhances the thrust efficiency of the thruster and collimates the plasma plume, which reduces contamination of the spacecraft. Alameda Applied Sciences Corporation, along with

  18. Engineering Research, Development and Technology, FY95: Thrust area report

    SciTech Connect

    NONE

    1996-02-01

    The mission of the Engineering Research, Development, and Technology Program at Lawrence Livermore National Laboratory (LLNL) is to develop the knowledge base, process technologies, specialized equipment, tools and facilities to support current and future LLNL programs. Engineering`s efforts are guided by a strategy that results in dual benefit: first, in support of Department of Energy missions, such as national security through nuclear deterrence; and second, in enhancing the nation`s economic competitiveness through their collaboration with US industry in pursuit of the most cost-effective engineering solutions to LLNL programs. To accomplish this mission, the Engineering Research, Development, and Technology Program has two important goals: (1) identify key technologies relevant to LLNL programs where they can establish unique competencies, and (2) conduct high-quality research and development to enhance their capabilities and establish themselves as the world leaders in these technologies. To focus Engineering`s efforts, technology thrust areas are identified and technical leaders are selected for each area. The thrust areas are comprised of integrated engineering activities, staffed by personnel from the nine electronics and mechanical engineering divisions, and from other LLNL organizations. This annual report, organized by thrust area, describes Engineering`s activities for fiscal year 1995. The report provides timely summaries of objectives methods, and key results from eight thrust areas: computational electronics and electromagnetics; computational mechanics; microtechnology; manufacturing technology; materials science and engineering; power conversion technologies; nondestructive evaluation; and information engineering.

  19. 49. VIEW OF EAST SIDE OF LAUNCH PAD. THRUST SECTION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    49. VIEW OF EAST SIDE OF LAUNCH PAD. THRUST SECTION HEATER AND DUCTS ON RIGHT; UMBILICAL MAST POWER CONNECTORS ON LEFT; RAIL SYSTEM AND FIRE SUPPRESSION NOZZLES IN FOREGROUND. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  20. Jet and photon measurements from ATLAS

    NASA Astrophysics Data System (ADS)

    Saraiva, J. G.

    2013-11-01

    Differential cross-section measurements of inclusive-jet and di-jet production provide stringent tests of perturbative QCD predictions and provide inputs for determination of parton density functions. Ratios of jet multiplicities are sensitive to ?s and have reduced theoretical uncertainties. Measurements of the inclusive isolated-photon and di-photon cross-sections provide a direct probe of short-distance physics, complementary to that from measurements of jets or vector-bosons and are sensitive to the gluon density in the proton. The measurements are compared to next-to-leading-order or higher-order QCD calculations. Acknowledgments are due to GRICES and FCT. With the FCT grant SFRH/BPD/73474/2010.

  1. 14 CFR 23.1155 - Turbine engine reverse thrust and propeller pitch settings below the flight regime.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 false Turbine engine reverse thrust and propeller pitch settings below...Accessories § 23.1155 Turbine engine reverse thrust and propeller pitch settings below...engine installations, each control for reverse thrust and for propeller pitch...

  2. 14 CFR 23.1155 - Turbine engine reverse thrust and propeller pitch settings below the flight regime.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 false Turbine engine reverse thrust and propeller pitch settings below...Accessories § 23.1155 Turbine engine reverse thrust and propeller pitch settings below...engine installations, each control for reverse thrust and for propeller pitch...

  3. Performance of Simple Gas Foil Thrust Bearings in Air

    NASA Technical Reports Server (NTRS)

    Bruckner, Robert J.

    2012-01-01

    Foil bearings are self-acting hydrodynamics devices used to support high speed rotating machinery. The advantages that they offer to process fluid lubricated machines include: high rotational speed capability, no auxiliary lubrication system, non-contacting high speed operation, and improved damping as compared to rigid hydrodynamic bearings. NASA has had a sporadic research program in this technology for almost 6 decades. Advances in the technology and understanding of foil journal bearings have enabled several new commercial products in recent years. These products include oil-free turbochargers for both heavy trucks and automobiles, high speed electric motors, microturbines for distributed power generation, and turbojet engines. However, the foil thrust bearing has not received a complimentary level of research and therefore has become the weak link of oil-free turbomachinery. In an effort to both provide machine designers with basic performance parameters and to elucidate the underlying physics of foil thrust bearings, NASA Glenn Research Center has completed an effort to experimentally measure the performance of simple gas foil thrust bearing in air. The database includes simple bump foil supported thrust bearings with full geometry and manufacturing techniques available to the user. Test conditions consist of air at ambient pressure and temperatures up to 500 C and rotational speeds to 55,000 rpm. A complete set of axial load, frictional torque, and rotational speed is presented for two different compliant sub-structures and inter-pad gaps. Data obtained from commercially available foil thrust bearings both with and without active cooling is presented for comparison. A significant observation made possible by this data set is the speed-load capacity characteristic of foil thrust bearings. Whereas for the foil journal bearing the load capacity increases linearly with rotational speed, the foil thrust bearing operates in the hydrodynamic high speed limit. In this case, the load capacity is constant and in fact often decreases with speed if other factors such as thermal conditions and runner distortions are permitted to dominate the bearing performance.

  4. Geometry and sequential evolution of thrust systems in the thrust belt of northwest Montana: Support for the critical-wedge model

    SciTech Connect

    Boyer, S.E. (Univ. of Washington, Seattle, WA (United States). Dept. of Geological Sciences)

    1993-04-01

    Cross sections of the northwest Montana thrust belt, constructed principally from published geologic maps and a number of cross-strike traverses, provide constraints on the geometry and sequential evolution of thrust systems, which in turn are compatible with the critical-wedge model of thrust-belt mechanics. Sequential restorations of Sawtooth Range thrust systems, in map and cross section, indicate that earlier formed thrusts to the west remained active during the eastern advance of the thrust front. Three-dimensional balancing arguments likewise suggest that the Lewis thrust, to the north and west, continued to move during the development of the Sawtooth Range. Continuous or periodically reactivated motion on the Lewis was responsible for the maintenance of critical taper in the northern and western Sawtooth Range, the footwall Paleozoic were strengthened by the overlying sheet and experienced little internal imbrication. However, where the thrust front advanced in front of the leading edge of the Lewis, the thinly-tapered Paleozoic package was imbricated to from the characteristic sawtooth-shaped ranges of the Montana thrust belt. Thus, critical taper in the Sawtooths was maintained by duplexing of Paleozoic rocks and back-rotation accompanying piggy-back thrusting. Additional duplexes of Paleozoic rocks in the footwall of the Lewis may have developed late in the orogeny to compensate for erosion of the overlying Lewis sheet. Continuing motion on the Lewis, as it was folded over footwall duplexes, produced out-of-sequence imbricates within the Lewis sheet.

  5. Design of a thrust stand for high power electric propulsion devices

    NASA Technical Reports Server (NTRS)

    Haag, Thomas W.

    1989-01-01

    A thrust stand for use with high power electric propulsion devices was designed and tested. The thrust stand was specifically tailored to the needs of a 100 to 250 kW magnetoplasmadynamic (MPD) thruster program currently in progress at the NASA Lewis Research Center. The thrust stand structure was built as an inverted pendulum arrangement, supported at the base by water-cooled electrical power flexures. Thrust stand tares due to thruster discharge current were demonstrated to be negligible. Tares due to an applied field magnet current, after considerable effort, were reduced to less than 3.0 percent of measured thrust. These tares, however, could be determined independently and subtracted from the indicated thrust measurement. A detailed description is given for the thrust stand design and operation with a 100 kW class MPD device. Other thrust stand tares due to vibration and thermal effects are discussed, along with issues of accuracy and repeatability.

  6. Design of a thrust stand for high power electric propulsion devices

    NASA Technical Reports Server (NTRS)

    Haag, Thomas W.

    1989-01-01

    A thrust stand for use with high power electric propulsion devices has been designed and tested. The thrust stand was specifically tailored to the needs of a 0.1 to 0.25 MW magnetoplasmadynamic (MPD) thruster program currently in progress at the NASA Lewis Research Center. The thrust stand structure was built as an inverted pendulum arrangement, supported at the base by water-cooled electrical power flexures. Thrust stand tares due to thruster discharge current were demonstrated to be negligible. Tares due to an applied field magnet current, after considerable effort, were reduced to less than 3.0 percent of measured thrust. These tares, however, could be determined independently and subtracted from the indicated thrust measurement. The paper gives a detailed description of the thrust stand design and operation with a 0.1 MW class MPD device. Other thrust stand tares due to vibration and thermal effects are discussed, along with issues of accuracy and repeatability.

  7. Distributed Exhaust Nozzles for Jet Noise Reduction

    NASA Technical Reports Server (NTRS)

    Ahuja, K. K.; Gaeta, R. J.; Hellman, B.; Schein, D. B.; Solomon, W. D., Jr.; Huff, Dennis (Technical Monitor)

    2001-01-01

    The main objective of this study is to validate the jet noise reduction potential of a concept associated with distributed exhaust nozzles. Under this concept the propulsive thrust is generated by a larger number of discrete plumes issuing from an array of small or mini-nozzles. The potential of noise reduction of this concept stems from the fact that a large number of small jets will produce very high frequency noise and also, if spaced suitably, they will coalesce at a smaller velocity to produce low amplitude, low frequency noise. This is accomplished through detailed acoustic and fluid measurements along with a Computational Fluidic Dynamic (CFD) solution of the mean (DE) Distributed Exhaust nozzle flowfield performed by Northrop-Grumman. The acoustic performance is quantified in an anechoic chamber. Farfield acoustic data is acquired for a DE nozzle as well as a round nozzle of the same area. Both these types of nozzles are assessed numerically using Computational Fluid Dynamic (CFD) techniques. The CFD analysis ensures that both nozzles issued the same amount of airflow for a given nozzle pressure ratio. Data at a variety of nozzle pressure ratios are acquired at a range of polar and azimuthal angles. Flow visualization of the DE nozzle is used to assess the fluid dynamics of the small jet interactions. Results show that at high subsonic jet velocities, the DE nozzle shifts its frequency of peak amplitude to a higher frequency relative to a round nozzle of equivalent area (from a S(sub tD) = 0.24 to 1. 3). Furthermore, the DE nozzle shows reduced sound pressure levels (as much as 4 - 8 dB) in the low frequency part of the spectrum (less than S(sub tD) = 0.24 ) compared to the round nozzle. At supersonic jet velocities, the DE nozzle does not exhibit the jet screech and the shock-associated broadband noise is reduced by as much as 12 dB.

  8. Trajectory computation during a maneuver: Thrust estimation with the Goddard Trajectory Determination System (GTDS)

    Microsoft Academic Search

    A. C. Beri; M. V. Samii; C. E. Doll

    1988-01-01

    Existing thrust modeling capabilities of the Goddard Trajectory Determination System (GTDS) have been enhanced to allow calibration of the onboard propulsion system. These enhancements provide one or more thrust scale factors, based on estimation using the batch least-squares technique, for the case of along-track thrust and the case of attitude-dependent thrust. The enhancements are evaluated using simulated tracking measurements for

  9. Simulation Analysis of Pressure Regulation of Hydraulic Thrust System on a Shield Tunneling Machine

    Microsoft Academic Search

    Zhibin Liu; Haibo Xie; Huayong Yang

    2009-01-01

    Hydraulic thrust system is an important system on a shield tunneling machine. Pressure regulation of thrust cylinders is the\\u000a most important function of thrust system during tunnel excavation. In this article, a hydraulic thrust system is illuminated,\\u000a and a corresponding simulation model is carried out in order to study the system characteristics. Pressure regulation of a\\u000a certain group’s cylinders has

  10. Simulation analysis of pressure regulation of hydraulic thrust system on a shield tunneling machine

    Microsoft Academic Search

    Zhibin Liu; Haibo Xie; Huayong Yang

    2011-01-01

    Hydraulic thrust system is an important system in a shield tunneling machine. Pressure regulation of thrust cylinders is the\\u000a most important function for thrust system during tunnel excavation. In this paper, a hydraulic thrust system is explained,\\u000a and a corresponding simulation model is carried out in order to study the system characteristics. Pressure regulation of a\\u000a certain group’s cylinders has

  11. QCD -Jets: The thrust of SCET Bjrn O. Lange, Ph.D. (Cornell)

    E-print Network

    Rossak, Wilhelm R.

    regions. ["Strategy of regions", Beneke, Smirnov, 1997] There is a close relationship between] There is a close relationship between the expansion of full theory diagrams and an Effective Field Theory Soft

  12. Free-flight Performance of a Rocket-boosted, Air-launched 16-inch-diameter Ram-jet Engine at Mach Numbers up to 2.20

    NASA Technical Reports Server (NTRS)

    Disher, John H; Kohl, Robert C; Jones, Merle L

    1953-01-01

    The investigation of air-launched ram-jet engines has been extended to include a study of models with a nominal design free-stream Mach number of 2.40. These models require auxiliary thrust in order to attain a flight speed at which the ram jet becomes self-accelerating. A rocket-boosting technique for providing this auxiliary thrust is described and time histories of two rocket-boosted ram-jet flights are presented. In one flight, the model attained a maximum Mach number of 2.20 before a fuel system failure resulted in the destruction of the engine. Performance data for this model are presented in terms of thrust and drag coefficients, diffuser pressure recovery, mass-flow ratio, combustion efficiency, specific fuel consumption, and over-all engine efficiency.

  13. Advanced Methods for Aircraft Engine Thrust and Noise Benefits: Nozzle-Inlet Flow Analysis

    NASA Technical Reports Server (NTRS)

    Morgan, Morris H.; Gilinsky, Mikhail M.

    2001-01-01

    Three connected sub-projects were conducted under reported project. Partially, these sub-projects are directed to solving the problems conducted by the HU/FM&AL under two other NASA grants. The fundamental idea uniting these projects is to use untraditional 3D corrugated nozzle designs and additional methods for exhaust jet noise reduction without essential thrust lost and even with thrust augmentation. Such additional approaches are: (1) to add some solid, fluid, or gas mass at discrete locations to the main supersonic gas stream to minimize the negative influence of strong shock waves forming in propulsion systems; this mass addition may be accompanied by heat addition to the main stream as a result of the fuel combustion or by cooling of this stream as a result of the liquid mass evaporation and boiling; (2) to use porous or permeable nozzles and additional shells at the nozzle exit for preliminary cooling of exhaust hot jet and pressure compensation for non-design conditions (so-called continuous ejector with small mass flow rate; and (3) to propose and analyze new effective methods fuel injection into flow stream in air-breathing engines. Note that all these problems were formulated based on detailed descriptions of the main experimental facts observed at NASA Glenn Research Center. Basically, the HU/FM&AL Team has been involved in joint research with the purpose of finding theoretical explanations for experimental facts and the creation of the accurate numerical simulation technique and prediction theory for solutions for current problems in propulsion systems solved by NASA and Navy agencies. The research is focused on a wide regime of problems in the propulsion field as well as in experimental testing and theoretical and numerical simulation analysis for advanced aircraft and rocket engines. The F&AL Team uses analytical methods, numerical simulations, and possible experimental tests at the Hampton University campus. We will present some management activity and theoretical numerical simulation results obtained by the FM&AL Team in the reporting period in accordance with the schedule of the work.

  14. Extended performance solar electric propulsion thrust system study. Volume 3: Tradeoff studies of alternate thrust system configurations

    NASA Technical Reports Server (NTRS)

    Hawthorne, E. I.

    1977-01-01

    Several thrust system design concepts were evaluated and compared using the specifications of the most advanced 30 cm engineering model thruster as the technology base. Emphasis was placed on relatively high power missions. The extensions in thruster performance required for the Halley's comet mission were defined and alternative thrust system concepts were designed in sufficient detail for comparing mass, efficiency, reliability, structure, and thermal characteristics. Confirmation testing and analysis of thruster and power-processing components were performed. A baseline design was selected from the alternatives considered, and the design analysis and documentation were refined. A program development plan was formulated that outlines the work structure considered necessary for developing, qualifying, and fabricating the flight hardware for the baseline thrust system within the time frame of a project to rendezvous with Halley's comet. An assessment was made of the costs and risks associated with a baseline thrust system as provided to the mission project under this plan. Critical procurements and interfaces were identified and defined.

  15. Thrust Measurement of Dielectric Barrier Discharge (DBD) Plasma Actuators: New Anti-Thrust Hypothesis, Frequency Sweeps Methodology, Humidity and Enclosure Effects

    NASA Technical Reports Server (NTRS)

    Ashpis, David E.; Laun, Matthew C.

    2014-01-01

    We discuss thrust measurements of Dielectric Barrier Discharge (DBD) plasma actuators devices used for aerodynamic active flow control. After a review of our experience with conventional thrust measurement and significant non-repeatability of the results, we devised a suspended actuator test setup, and now present a methodology of thrust measurements with decreased uncertainty. The methodology consists of frequency scans at constant voltages. The procedure consists of increasing the frequency in a step-wise fashion from several Hz to the maximum frequency of several kHz, followed by frequency decrease back down to the start frequency of several Hz. This sequence is performed first at the highest voltage of interest, then repeated at lower voltages. The data in the descending frequency direction is more consistent and selected for reporting. Sample results show strong dependence of thrust on humidity which also affects the consistency and fluctuations of the measurements. We also observed negative values of thrust, or "anti-thrust", at low frequencies between 4 Hz and up to 64 Hz. The anti-thrust is proportional to the mean-squared voltage and is frequency independent. Departures from the parabolic anti-thrust curve are correlated with appearance of visible plasma discharges. We propose the anti-thrust hypothesis. It states that the measured thrust is a sum of plasma thrust and anti-thrust, and assumes that the anti-thrust exists at all frequencies and voltages. The anti-thrust depends on actuator geometry and materials and on the test installation. It enables the separation of the plasma thrust from the measured total thrust. This approach enables more meaningful comparisons between actuators at different installations and laboratories. The dependence on test installation was validated by surrounding the actuator with a grounded large-diameter metal sleeve. Strong dependence on humidity is also shown; the thrust significantly increased with decreasing humidity, e.g., 44 percent increase as relative humidity changed from 18 percent and dew point 33 degF to 50 percent and dew point of 57 degF.

  16. Syntectonic fluid-flow along thrust faults: Example of the South Pyrenean fold-and-thrust belt

    NASA Astrophysics Data System (ADS)

    Lacroix, B.; Travé, A.; Buatier, M.; Labaume, P.

    2012-04-01

    Estimation of the P-T conditions during evolution of sedimentary basins and characterization of petrophysical properties of fault zone are of major interests to oil companies, since they could allow to understand paleohydrological characteristics of potential reservoirs. In fold-and-thrust belts, faults are supposed to constitute channelized pathways for fluids coming from external, either deep or meteoric sources. However, the different available studies suggest that fluid flow through such discontinuities is not so evident. In order to constrain the paleofluid flow through the south Pyrenean fold-and-thrust belt we focus on thrust faults located at different structural levels. The microstructures observed in the different studied fault zones are similar and consist of pervasive cleavage, calcite shear and extension veins (respectively SV1 and EV1) and late dilatation veins (EV3). Thus, the presence of veins attests to the involvement of fluids during deformation. In order to characterize the nature and origin of fluid, petrological and geochemical (stable isotopes and trace elements) analyses were performed on calcite veins. The results suggest a high complexity in the hydrological behaviours of thrust faults evidencing a reservoir compartmentalization in the South-Pyrenean fold-and-thrust belt. In the southern part of the Axial Zone, different studies evidence the contribution of deep metamorphic water, probably derived from the Paleozoic basement, along Gavarnie related fault zones during deformation. In the Jaca basin, during the Monte Perdido thrust fault activity, we evidence the contribution of formation water. These data suggest a very closed hydrological fluid system where fluid flow didn't exceeded 70 m. In the other hand, the Jaca and Cotiella thrust faults located in the southern part of the basin, are characterized by a composite fluid-flow system. Indeed, stable isotopes and trace elements compositions of the first generation of calcite veins evidence relatively closed paleohydrological system whereas the second calcite vein generation, which is probably associated to the exhumation of the basin, suggests the contribution of both, meteoric and marine waters.

  17. 14 CFR 25.1155 - Reverse thrust and propeller pitch settings below the flight regime.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Reverse thrust and propeller pitch settings below...Controls and Accessories § 25.1155 Reverse thrust and propeller pitch settings below the flight regime. Each control for reverse thrust and for propeller pitch...

  18. 14 CFR 25.1155 - Reverse thrust and propeller pitch settings below the flight regime.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Reverse thrust and propeller pitch settings below...Controls and Accessories § 25.1155 Reverse thrust and propeller pitch settings below the flight regime. Each control for reverse thrust and for propeller pitch...

  19. On the problem of optimal thrust programming for a lunar soft landing

    Microsoft Academic Search

    J. Meditch; V. G. Boltyanskii; R. V. Gamkrelidze; E. F. Llischenko

    1964-01-01

    The problem of minimal fuel thrust programming for the terminal phase of a lunar soft landing mission is shown to be equivalent to the minimal time problem for the mission. The existence of an optimal (minimal fuel) thrust program for the problem is then assured by appealing to existence theorems for time optimal controls, and the optimal thrust program is

  20. Evaluation of various thrust calculation techniques on an F404 engine

    NASA Technical Reports Server (NTRS)

    Ray, Ronald J.

    1990-01-01

    In support of performance testing of the X-29A aircraft at the NASA-Ames, various thrust calculation techniques were developed and evaluated for use on the F404-GE-400 engine. The engine was thrust calibrated at NASA-Lewis. Results from these tests were used to correct the manufacturer's in-flight thrust program to more accurately calculate thrust for the specific test engine. Data from these tests were also used to develop an independent, simplified thrust calculation technique for real-time thrust calculation. Comparisons were also made to thrust values predicted by the engine specification model. Results indicate uninstalled gross thrust accuracies on the order of 1 to 4 percent for the various in-flight thrust methods. The various thrust calculations are described and their usage, uncertainty, and measured accuracies are explained. In addition, the advantages of a real-time thrust algorithm for flight test use and the importance of an accurate thrust calculation to the aircraft performance analysis are described. Finally, actual data obtained from flight test are presented.

  1. The Vector Product Introduction

    E-print Network

    Vickers, James

    The Vector Product 9.4 Introduction In this section we describe how to find the vector product of two vectors. Like the scalar product its definition may seem strange when first met but the definition is chosen because of its many applications. When vectors are multiplied using the vector product the result

  2. Timing of thrust activity in the High Zagros fold-thrust belt, Iran, from (U-Th)/He thermochronometry

    NASA Astrophysics Data System (ADS)

    Gavillot, Yann; Axen, Gary J.; Stockli, Daniel F.; Horton, Brian K.; Fakhari, Mohammad D.

    2010-08-01

    Apatite and zircon (U-Th)/He cooling ages are used to quantify the timing of exhumation associated with thrust faulting in the High Zagros fold-thrust belt. Single-grain cooling age data were collected from (1) Cambrian sandstone in various thrust sheets, (2) sandstone and basement clasts derived from structurally controlled salt plugs or fault-bounded slices, and (3) syntectonic Neogene siliciclastics strata. In the northwestern (Kuhrang) and central (Kuh-e Lajin) High Zagros, apatite (U-Th)/He (AHe) ages range from ˜26.7 to ˜0.38 Ma. Most cooling and exhumation occurred in the early to middle Miocene, constrained by AHe ages ˜19-15 Ma from the High Zagros thrust sheet, localized faults, and reset cooling ages from Bakhtiyari deposits. In the southeastern High Zagros (Kuh-e Dinar), cooling occurred later with AHe ages ranging from ˜16.5 to ˜0.79 Ma. Here most cooling and exhumation occurred in the late Miocene, constrained by AHe ages ˜12-8 Ma from the High Zagros fault, and exhumed Paleozoic clasts in synorogenic strata. Zircon (U-Th)/He (ZHe) ages from bedrock samples across the High Zagros are reflective of the precollisional thermal history. The preservation of precollisional ZHe ages limits the pre-Miocene maximum burial temperature of the exhumed strata to < 180°C, and indicate < 7-9 km of maximum exhumation in the central Zagros. This study shows that thrust activity in the High Zagros and continental suturing along the Zagros suture was underway by at least 19 Ma, and initiated no later than latest Oligocene to early Miocene time (˜23 Ma).

  3. Space shuttle orbit maneuvering engine reusable thrust chamber. Task 10: Data dump comparison of 8- and 10- inch diameter thrust chambers

    NASA Technical Reports Server (NTRS)

    Pauckert, R. P.; Tobin, R. D.

    1975-01-01

    An analytical and design study was conducted to compare the high and low contraction ratio thrust chambers for regenratively cooled orbit maneuvering engines for the space shuttle was conducted. The design concepts were evaluated on the basis of weight, pressure drop, and performance. Only the basic thrust chamber assembly was considered. The assembly consists of the injector, the regeneratively cooled thrust chamber, and the radiation cooled nozzle. A two dimensional thermal analysis of the channel section is provided.

  4. Inclusive Jets in PHP

    NASA Astrophysics Data System (ADS)

    Roloff, P.

    Differential inclusive-jet cross sections have been measured in photoproduction for boson virtualities Q^2 < 1 GeV^2 with the ZEUS detector at HERA using an integrated luminosity of 300 pb^-1. Jets were identified in the laboratory frame using the k_T, anti-k_T or SIScone jet algorithms. Cross sections are presented as functions of the jet pseudorapidity, eta(jet), and the jet transverse energy, E_T(jet). Next-to-leading-order QCD calculations give a good description of the measurements, except for jets with low E_T(jet) and high eta(jet). The cross sections have the potential to improve the determination of the PDFs in future QCD fits. Values of alpha_s(M_Z) have been extracted from the measurements based on different jet algorithms. In addition, the energy-scale dependence of the strong coupling was determined.

  5. The effect of velocity profiles on supersonic jet noise

    NASA Astrophysics Data System (ADS)

    Bhat, T. R. S.; Seiner, J. M.

    1993-10-01

    This paper presents stability calculations made for a shock-free coannular jet, with both the inner and outer flows supersonic, using the instability wave model. The Mach wave emission process is modeled as the noise generated by the large scale turbulent structures or the instability waves in the mixing region. Both the vortex-sheet and the realistic finite thickness shear layer models are considered. The stability calculations have been performed for both inverted and normal velocity profiles. Comparisons are made with the results for an equivalent single jet, based on equal thrust, mass flow rate and exit area to that of the coannular jet. The advantages and disadvantages of these velocity profiles as far as noise radiation is concerned are discussed.

  6. Characterization of Space Shuttle Reusable Rocket Motor Static Test Stand Thrust Measurements

    NASA Technical Reports Server (NTRS)

    Cook, Mart L.; Gruet, Laurent; Cash, Stephen F. (Technical Monitor)

    2003-01-01

    Space Shuttle Reusable Solid Rocket Motors (RSRM) are static tested at two ATK Thiokol Propulsion facilities in Utah, T-24 and T-97. The newer T-97 static test facility was recently upgraded to allow thrust measurement capability. All previous static test motor thrust measurements have been taken at T-24; data from these tests were used to characterize thrust parameters and requirement limits for flight motors. Validation of the new T-97 thrust measurement system is required prior to use for official RSRM performance assessments. Since thrust cannot be measured on RSRM flight motors, flight motor measured chamber pressure and a nominal thrust-to-pressure relationship (based on static test motor thrust and pressure measurements) are used to reconstruct flight motor performance. Historical static test and flight motor performance data are used in conjunction with production subscale test data to predict RSRM performance. The predicted motor performance is provided to support Space Shuttle trajectory and system loads analyses. Therefore, an accurate nominal thrust-to-pressure (F/P) relationship is critical for accurate RSRM flight motor performance and Space Shuttle analyses. Flight Support Motors (FSM) 7, 8, and 9 provided thrust data for the validation of the T-97 thrust measurement system. The T-97 thrust data were analyzed and compared to thrust previously measured at T-24 to verify measured thrust data and identify any test-stand bias. The T-97 FIP data were consistent and within the T-24 static test statistical family expectation. The FSMs 7-9 thrust data met all NASA contract requirements, and the test stand is now verified for future thrust measurements.

  7. Investigation of Thrust Augmentation of a 1600-pound Thrust Centrifugal-flow-type Turbojet Engine by Injection of Refrigerants at Compressor Inlets

    NASA Technical Reports Server (NTRS)

    Jones, William L.; Dowman, Harry W.

    1947-01-01

    Investigations were conducted to determine effectiveness of refrigerants in increasing thrust of turbojet engines. Mixtures of water an alcohol were injected for a range of total flows up to 2.2 lb/sec. Kerosene was injected into inlets covering a range of injected flows up to approximately 30% of normal engine fuel flow. Injection of 2.0 lb/sec of water alone produced an increase in thrust of 35.8% of rate engine conditions and kerosene produced a negligible increase in thrust. Carbon dioxide increased thrust 23.5 percent.

  8. Vectors: Tip to Tail

    NSDL National Science Digital Library

    Sharon Linamen

    2012-07-23

    In this lesson students will learn the characteristics and appropriate use of vectors. They will find the magnitude and direction of vectors, they will add and subtract vectors and use an interactive website to practice what they have learned.

  9. The interaction between deepwater channel systems and growing thrusts and folds, toe-thrust region of the deepwater Niger Delta

    NASA Astrophysics Data System (ADS)

    Jolly, Byami; Whittaker, Alex; Lonergan, Lidia

    2015-04-01

    Gravity-driven seaward-verging thrusts, landward-verging back-thrusts and associated folds often characterize the slope and deepwater settings of passive margins. These structures, found in the 'toe-thrust' region of the system, exert a significant control on sediment gravity flows because they create and determine the location and configuration of sediment depocentres and transport systems. Consequently, a quantitative understanding of the interaction between sediment gravity flows and seabed topography is required to understand these systems effectively. Here we make quantitative measurements of the geomorphic response of submarine channels to growing tectonic structures with the aim of providing new constraints on the long-term erosional dynamics of submarine channel systems. This study exploits 3D seismic data in the outer toe-thrust region of the deepwater Niger Delta to analyze the interaction between Plio-Pleistocene channel systems and actively growing folds and thrusts. We mapped folds and thrusts from the seismic data and we used this data to reconstruct the history of fold growth. We then used the sea-bed seismic horizon to build a 50 m resolution Digital Elevation Model (DEM) of the sea floor in Arc-GIS. We extracted channel long- profiles across growing structures from the DEM, and made measurements of channel geometries at regular intervals along the channel length. This information was used to infer morphodyanamic processes that sculpted the channel systems through time, and to estimate the bed shear stresses and fluid velocities of typical flow events. The bathymetric long profiles of these channels are relatively linear with concavity that range from -0.08 to -0.34, and an average gradient of ~1o. Actively growing thrusts are typically associated with a local steepening in channel gradient by a factor of up to 3, and this effect extends 0.5 - 2 km upstream of the thrust. Within these knickzones, channel incision increases by approximately by a factor of > 2, with a corresponding width decrease of approximately 25%. Channel incision across growing structures is achieved through enhanced bed-shear stress driven incision (up to 200 Pa) and flow velocity (up to 5 ms-1), assuming typical bulk sediment concentrations of 0.6%. Comparison of structural uplift since 1.7 Ma, and channel incision over an equivalent period, shows that some of these channels are able to keep pace with the time-integrated uplift since 1.7 Ma, and may have reached a topographic (bathymetric) steady-state with respect to on-going thrusting. However, some of the sea-bed channels are yet to reach topographic steady-state because of factors which include recent change in gradient caused by structural uplift, and the impact of active channel diversion by growing structures. Generally, bed-shear stresses of ~150 Pa are sufficient to keep pace with structural strain rates of 10-15 s-1. More widely, our data demonstrates that submarine channel systems dynamically adjust their geometry and basal gradient in order to keep pace with growth of tectonic structures and our results suggest that these factors must be incorporated into models to fully predict the downslope pathways of sea-bed channels in structurally complex areas.

  10. Direct thrust measurement of a permanent magnet helicon double layer thruster

    SciTech Connect

    Takahashi, K.; Lafleur, T.; Charles, C.; Alexander, P.; Boswell, R. W. [Space Plasma, Power and Propulsion Group, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia); Perren, M.; Laine, R. [ASTRIUM-EADS, 6 rue Laurent Pichat, 75016 Paris (France); Pottinger, S.; Lappas, V.; Harle, T.; Lamprou, D. [Surrey Space Centre, University of Surrey, Guildford GU2 7XH (United Kingdom)

    2011-04-04

    Direct thrust measurements of a permanent magnet helicon double layer thruster have been made using a pendulum thrust balance and a high sensitivity laser displacement sensor. At the low pressures used (0.08 Pa) an ion beam is detected downstream of the thruster exit, and a maximum thrust force of about 3 mN is measured for argon with an rf input power of about 700 W. The measured thrust is proportional to the upstream plasma density and is in good agreement with the theoretical thrust based on the maximum upstream electron pressure.

  11. Electro-Hydrodynamic (EHD) Thrust Analysis in Wire-Cylinder Electrode Arrangement

    NASA Astrophysics Data System (ADS)

    Konstantinos, N. Kiousis; Antonios, X. Moronis; Wolf, G. Fruh

    2014-04-01

    The thrust generation by electro-hydrodynamic (EHD) effect has been studied for a wire-cylinder arrangement under high DC voltage. Series of measurements have been conducted in order to determine the relationship between generated thrust and corona discharge current, as well as its dependence on geometrical characteristics of the electrodes, e.g. electrode gap, wire and cylinder radii. The experimental investigation has shown a linear relationship between the generated thrust and the discharge current, while parametric analysis showed that increased electrode gap and emitter radius reduces the thrust. On the other hand, large gaps favor the thrust per unit power ratio.

  12. Design and analysis report for the RL10-2B breadboard low thrust engine

    NASA Technical Reports Server (NTRS)

    Brown, J. R.; Foust, R. R.; Galler, D. E.; Kanic, P. G.; Kmiec, T. D.; Limerick, C. D.; Peckham, R. J.; Swartwout, T.

    1984-01-01

    The breadboard low thrust RL10-2B engine is described. A summary of the analysis and design effort to define the multimode thrust concept applicable to the requirements for the upper stage vehicles is provided. Baseline requirements were established for operation of the RL10-2B engine under the following conditions: (1) tank head idle at low propellant tank pressures without vehicle propellant conditioning or settling thrust; (2) pumped idle at a ten percent thrust level for low G deployment and/or vehicle tank pressurization; and (3) full thrust (15,000 lb.). Several variations of the engine configuration were investigated and results of the analyses are included.

  13. An analytical investigation of the impingement of jets on curved deflectors.

    NASA Technical Reports Server (NTRS)

    Schnurr, N. M.; Williamson, J. W.; Tatom, J. W.

    1972-01-01

    Numerical solutions are obtained for the cases of straight circular jets impinging on axisymmetric curved surfaces, and plane jets impinging symmetrically on two-dimensional curved surfaces. These geometries are representative of some types of thrust reversers for transport aircraft. The solutions are based on the assumptions of incompressible and potential flow. The velocity field, pressure distribution at the deflector surface, and reverser effectiveness are predicted for deflector turning angles of 15 to 75 deg, deflector width to jet diameter ratios of 1.5-2.0, and ratios of deflector clearance to jet diameter of 1.0-3.0. Reverser effectiveness is found to be a maximum for a ratio of deflector clearance to jet diameter of about 2.0. The effect of back pressuring resulting from the presence of the deflector is predicted.

  14. Low-thrust trajectory optimization in a full ephemeris model

    NASA Astrophysics Data System (ADS)

    Cai, Xing-Shan; Chen, Yang; Li, Jun-Feng

    2014-10-01

    The low-thrust trajectory optimization with complicated constraints must be considered in practical engineering. In most literature, this problem is simplified into a two-body model in which the spacecraft is subject to the gravitational force at the center of mass and the spacecraft's own electric propulsion only, and the gravity assist (GA) is modeled as an instantaneous velocity increment. This paper presents a method to solve the fuel-optimal problem of low-thrust trajectory with complicated constraints in a full ephemeris model, which is closer to practical engineering conditions. First, it introduces various perturbations, including a third body's gravity, the nonspherical perturbation and the solar radiation pressure in a dynamic equation. Second, it builds two types of equivalent inner constraints to describe the GA. At the same time, the present paper applies a series of techniques, such as a homotopic approach, to enhance the possibility of convergence of the global optimal solution.

  15. An experimental investigation of flow mixing on thrust ejection efficiency

    NASA Astrophysics Data System (ADS)

    Morfitt, Donald J., Jr.

    1988-12-01

    The purpose of this study was to determine the effect flow mixing has on the thrust augmentation of an ejector. The experimental studies were divided into four phases. The four phases were baseline verification, a nozzle tip inclination study, a primary flow pulsing study, and a study of the quality of the ejector. The baseline verification study showed that thrust augmentation is dependent upon the injection angle and height of the primary nozzles. The nozzle tip inclination study investigated the effects of having the tips inclined from the inlet surface of the ejector. The nozzle tips were inclined in four different configurations. The different configurations established a baseline or attempted to promote flow mixing and swirling.

  16. SSME thrust chamber modeling with Navier Stokes equations

    NASA Technical Reports Server (NTRS)

    Przekwas, A. J.; Edwards, J.; Gross, K.

    1986-01-01

    The capability of predicting two-dimensional, compressible and reacting flow in the combustion chamber and nozzle of the Space Shuttle Main Engine (SSME) is demonstrated. A nonorthogonal body fitted coordinate system has been used to represent the combustor and nozzle geometry. The Navier-Stokes equations are solved for the entire thrust chamber with the k-epsilon turbulence model accounting for compressibility and large pressure gradients effects. Results of the computational test cases reveal all expected features of the transonic nozzle flows including location of sonic line, internal shock and boundary layer build-up. Calculated performance parameters such as thrust, flow rate, and specific impulse are also in reasonble agreement with available data. The results show promising potential of solving full Navier-Stokes equations with heat transfer and two-phase combustion in truly comprehensive modeling of rocket engines.

  17. Investigation of electroforming techniques. [fabrication of regeneratively cooled thrust chambers

    NASA Technical Reports Server (NTRS)

    Malone, G. A.

    1975-01-01

    Copper and nickel electroforming was examined for the purpose of establishing the necessary processes and procedures for repeatable, successful fabrication of the outer structures of regeneratively cooled thrust chambers. The selection of electrolytes for copper and nickel deposition is described. The development studies performed to refine and complete the processes necessary for successful chamber shell fabrication and the testing employed to verify the applicability of the processes and procedures to small scale hardware are described. Specifications were developed to afford a guideline for the electroforming of high quality outer shells on regeneratively cooled thrust chamber liners. Test results indicated repeatable mechanical properties could be produced in copper deposits from the copper sulfate electrolyte with periodic current reversal and in nickel deposits from the sulfamate solution. Use of inert, removable channel fillers and the conductivizing of such is described. Techniques (verified by test) which produce high integrity bonds to copper and copper alloy liners are discussed.

  18. SSME thrust chamber simulation using Navier-Stokes equations

    NASA Technical Reports Server (NTRS)

    Przekwas, A. J.; Singhal, A. K.; Tam, L. T.

    1984-01-01

    The capability of the PHOENICS fluid dynamics code in predicting two-dimensional, compressible, and reacting flow in the combustion chamber and nozzle of the space shuttle main engine (SSME) was evaluated. A non-orthogonal body fitted coordinate system was used to represent the nozzle geometry. The Navier-Stokes equations were solved for the entire nozzle with a turbulence model. The wall boundary conditions were calculated based on the wall functions which account for pressure gradients. Results of the demonstration test case reveal all expected features of the transonic nozzle flows. Of particular interest are the locations of normal and barrel shocks, and regions of highest temperature gradients. Calculated performance (global) parameters such as thrust chamber flow rate, thrust, and specific impulse are also in good agreement with available data.

  19. Benefits and costs of low thrust propulsion systems

    NASA Technical Reports Server (NTRS)

    Robertson, R. I.; Rose, L. J.; Maloy, J. E.

    1983-01-01

    The results of costs/benefits analyses of three chemical propulsion systems that are candidates for transferring high density, low volume STS payloads from LEO to GEO are reported. Separate algorithms were developed for benefits and costs of primary propulsion systems (PPS) as functions of the required thrust levels. The life cycle costs of each system were computed based on the developmental, production, and deployment costs. A weighted criteria rating approach was taken for the benefits, with each benefit assigned a value commensurate to its relative worth to the overall system. Support costs were included in the costs modeling. Reference missions from NASA, commercial, and DoD catalog payloads were examined. The program was concluded reliable and flexible for evaluating benefits and costs of launch and orbit transfer for any catalog mission, with the most beneficial PPS being a dedicated low thrust configuration using the RL-10 system.

  20. Optimization of Low-Thrust Spiral Trajectories by Collocation

    NASA Technical Reports Server (NTRS)

    Falck, Robert D.; Dankanich, John W.

    2012-01-01

    As NASA examines potential missions in the post space shuttle era, there has been a renewed interest in low-thrust electric propulsion for both crewed and uncrewed missions. While much progress has been made in the field of software for the optimization of low-thrust trajectories, many of the tools utilize higher-fidelity methods which, while excellent, result in extremely high run-times and poor convergence when dealing with planetocentric spiraling trajectories deep within a gravity well. Conversely, faster tools like SEPSPOT provide a reasonable solution but typically fail to account for other forces such as third-body gravitation, aerodynamic drag, solar radiation pressure. SEPSPOT is further constrained by its solution method, which may require a very good guess to yield a converged optimal solution. Here the authors have developed an approach using collocation intended to provide solution times comparable to those given by SEPSPOT while allowing for greater robustness and extensible force models.

  1. Higgs Production with a Central Jet Veto at NNLL+NNLO

    E-print Network

    Carola F. Berger; Claudio Marcantonini; Iain W. Stewart; Frank J. Tackmann; Wouter J. Waalewijn

    2011-04-09

    A major ingredient in Higgs searches at the Tevatron and LHC is the elimination of backgrounds with jets. In current H -> WW -> lnulnu searches, jet algorithms are used to veto central jets to obtain a 0-jet sample, which is then analyzed to discover the Higgs signal. Imposing this tight jet veto induces large double logarithms which significantly modify the Higgs production cross section. These jet-veto logarithms are presently only accounted for at fixed order or with the leading-logarithmic summation from parton-shower Monte Carlos. Here we consider Higgs production with an inclusive event-shape variable for the jet veto, namely beam thrust Tau_cm, which has a close correspondence with a traditional p_T jet veto. Tau_cm allows us to systematically sum the large jet-veto logarithms to higher orders and to provide better estimates for theoretical uncertainties. We present results for the 0-jet Higgs production cross section from gluon fusion at next-to-next-to-leading-logarithmic order (NNLL), fully incorporating fixed-order results at next-to-next-to-leading order (NNLO). At this order the scale uncertainty is 15-20%, depending on the cut, implying that a larger scale uncertainty should be used in current Tevatron bounds on the Higgs.

  2. An Experimental Study of Lubrication at Thrust Slide-Bearing of Scroll Compressors

    NASA Astrophysics Data System (ADS)

    Ishii, Noriaki; Oku, Tatsuya; Anami, Keiko; Tsuji, Takuma; Ozasa, Toshihiro; Sawai, Kiyoshi; Morimoto, Takashi; Iida, Noboru

    The previous studies have revealed that the wedge formation at the periphery of the thrust plate, caused by the elastic deformation due to pressure difference across the orbiting thrust plate, is a significant key factor to keep and improve the high performance in lubrication of the thrust-slide bearing. The present study focuses on the effect of the thickness and inner form of the thrust plate upon the lubrication features. A simplified model of cylindrical thrust slide-bearing with thinner thrust plate submerged in a refrigerant oil VG-56 was operated under pressurized conditions using R-22 as the pressurizing gas, where the pressure difference was adjusted from 0 to 1.0 MPa and the friction force and coefficient of friction were measured over a wide range of orbiting speeds, first. The wedge angle by elastic deformation is naturally increased with decreasing the thrust plate thickness, thus resulting in a clear improvement in lubrication at the thrust slide-bearing. On the contrast, secondly, the similar lubrication tests were conducted for the thrust plate with a real inner form, as complicated as in the real scroll compressors, where the thickness of the thrust plate was kept as in the original tests. As a result, no significant change in lubrication features, from those for the simplified cylindrical model, was not addressed, thus confirming that the test results addressed from the simplified cylindrical model tests can be effectively used to examine the basic characteristics in lubrication of thrust slide bearing of scroll compressors.

  3. Computer program for flat sector thrust bearing performance

    NASA Technical Reports Server (NTRS)

    Presler, A. F.; Etsion, I.

    1977-01-01

    A versatile computer program is presented which achieves a rapid, numerical solution of the Reynolds equation for a flat sector thrust pad bearing with either compressible or liquid lubricants. Program input includes a range in values of the geometric and operating parameters of the sector bearing. Performance characteristics are obtained from the calculated bearing pressure distribution. These are the load capacity, center of pressure coordinates, frictional energy dissipation, and flow rates of liquid lubricant across the bearing edges. Two sample problems are described.

  4. Lift, drag and thrust measurement in a hypersonic impulse facility

    NASA Technical Reports Server (NTRS)

    Tuttle, S. L.; Mee, D. J.; Simmons, J. M.

    1995-01-01

    This paper reports the extension of the stress wave force balance to the measurement of forces on models which are non-axisymmetric or which have non-axisymmetric load distributions. Recent results are presented which demonstrate the performance of the stress wave force balance for drag measurement, for three-component force measurement and preliminary results for thrust measurement on a two-dimensional scramjet nozzle. In all cases, the balances respond within a few hundred microseconds.

  5. Structural analysis of cylindrical thrust chambers, volume 3

    NASA Technical Reports Server (NTRS)

    Pearson, M. L.

    1981-01-01

    A system of three computer programs is described for use in conjunction with the BOPAGE finite element program. The programs are demonstrated by analyzing cumulative plastic deformation in a regeneratively cooled rocket thrust chamber. The codes provide the capability to predict geometric and material nonlinear behavior of cyclically loaded structures without performing a cycle-by-cycle analysis over the life of the structure. The program set consists of a BOPACE restart tape reader routine, and extrapolation program and a plot package.

  6. Supersonic Jet Control

    Microsoft Academic Search

    Mo Samimy

    2004-01-01

    Supersonic jets could be controlled via various means, for example, by imparting streamwise vorticity into the jet or by exciting one of the jet instabilities. The jet control in the first category has been achieved mostly passively through the use of vortex generating tabs or chevrons. The primary mechanism in such a device is spanwise\\/azimuthal pressure gradient imposed by the

  7. Evaluation of an Outer Loop Retrofit Architecture for Intelligent Turbofan Engine Thrust Control

    NASA Technical Reports Server (NTRS)

    Litt, Jonathan S.; Sowers, T. Shane

    2006-01-01

    The thrust control capability of a retrofit architecture for intelligent turbofan engine control and diagnostics is evaluated. The focus of the study is on the portion of the hierarchical architecture that performs thrust estimation and outer loop thrust control. The inner loop controls fan speed so the outer loop automatically adjusts the engine's fan speed command to maintain thrust at the desired level, based on pilot input, even as the engine deteriorates with use. The thrust estimation accuracy is assessed under nominal and deteriorated conditions at multiple operating points, and the closed loop thrust control performance is studied, all in a complex real-time nonlinear turbofan engine simulation test bed. The estimation capability, thrust response, and robustness to uncertainty in the form of engine degradation are evaluated.

  8. Low Thrust, Deep Throttling, US/CIS Integrated NTRE

    NASA Astrophysics Data System (ADS)

    Culver, Donald W.; Kolganov, Vyacheslav; Rochow, Richard F.

    1994-07-01

    In 1993 our international team performed a follow-on ``Nuclear Thermal Rocket Engine (NTRE) Extended Life Feasibility Assessment'' study for the Nuclear Propulsion Office (NPO) at NASAs Lewis Research Center. The main purpose of this study was to complete the 1992 study matrix to assess NTRE designs at thrust levels of 22.5, 11.3, and 6.8 tonnes, using Commonwealth of Independent States (CIS) reactor technology. An additional Aerojet goal was to continue improving the NTRE concept we had generated. Deep throttling, mission performance optimized engine design parametrics, and reliability/cost enhancing engine system simplifications were studied, because they seem to be the last three basic design improvements sorely needed by post-NERVA NTRE. Deep throttling improves engine life by eliminating damaging thermal and mechanical shocks caused by after-cooling with pulsed coolant flow. Alternately, it improves mission performance with steady flow after-cooling by minimizing reactor over-cooling. Deep throttling also provides a practical transition from high pressures and powers of the high thrust power cycle to the low pressures and powers of our electric power generating mode. Two deep throttling designs are discussed; a workable system that was studied and a simplified system that is recommended for future study. Mission-optimized engine thrust/weight (T/W) and Isp predictions are included along with system flow schemes and concept sketches.

  9. Static tests of a large scale swivel nozzle thrust deflector

    NASA Technical Reports Server (NTRS)

    Federspiel, J. F.

    1978-01-01

    Tests were conducted on a swivel nozzle thrust deflector installed on a 91 centimeter (36 inch) low pressure ratio tip turbine fan. Fan power was supplied by a J-85 hot gas generator. The configuration was typical of a vertical/short takeoff and landing (V/STOL) aircraft propulsion system employing lift cruise fans. The performance was compared to results obtained on an 0.15 scale cold flow model. Data were obtained at fan pressure ratios from 1.1 to 1.2 and at nozzle deflections from cruise (0 deg) to VTOL (90 deg). The nozzle thrust performance was in good agreement with small scale VTOL thrust coefficients. Configurations with increased nozzle area showed lower performance. Fan operation was routine and nozzle rotation caused no circumferential distortions of the fan exit flow. Nozzle flow characteristics did not repeat small scale model results. Measured flow coefficients were smaller on the large scale test. It was concluded that lack of simulation of pressure and temperature profiles of the tip driven fan was the most probable cause of the discrepancy.

  10. Strain analysis in a cover thrust zone, external French Alps

    NASA Astrophysics Data System (ADS)

    Beach, Alastair

    1982-10-01

    The La Grave thrust zone is situated in the external French Alps north of the Pelvoux basement massif. Jurassic cover rocks are deformed and imbricated in a region some 15 km square. Strains have been measured using the statistical reorientation of belemnites, the extension of belemnites and the shapes of pyrite pressure shadows. Orientation data are treated statistically, following Sanderson (1977). Groups of 100 measurements do not provide very accurate results and generally underestimate the strain when compared with more accurate determinations from extension measurements. In addition to providing reliable finite strain markers, pyrite pressure shadows allow interpretation of the incremental strain history. In the area studied, strains accumulated irrotationally in the plane of the bedding. The deformed autochthon to the basement massif and the lower thrust sheets were deformed by layer parallel shear and extensional flow, which produced LS fabrics with a down dip lineation. The higher thrust sheets were deformed by layer parallel shear and compressive flow, which produced LS to L fabrics with a strike-parallel lineation.

  11. Computational approach for investigation of thrust and acoustic performances of present-day nozzles

    NASA Astrophysics Data System (ADS)

    Vlasenko, V.; Bosniakov, S.; Mikhailov, S.; Morozov, A.; Troshin, A.

    2010-05-01

    A computational viewpoint on the problems of design and numerical simulation for the nozzles of modern aircraft turbofan engines is presented. Modern concepts of noise-suppressing nozzles for civil aircraft are reviewed. Examples of application of CFD (computational fluid dynamics) methods to the analysis of nozzle flow structure and assessment of nozzle thrust characteristics are given. Errors of turbulence models in simulation of jets are analyzed. The authors’ experience in simulation of noise-suppressing nozzles for supersonic civil aircrafts is demonstrated. Insufficient accuracy of acoustic analogies for this class of tasks is shown, but a possible area of acoustic analogies application is noted. The essential elements of computational aeroacoustics (CAA) approach and numerical methods characteristic of CAA are reviewed. Numerical methodology for the simulation of nozzle acoustic performance is described in detail, including methods for simulation of near and far field of a nozzle, for generation of input perturbations and for the processing the far-field noise. Results of verification and methodical analysis of this acoustic methodology are presented.

  12. Corporate Jet

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Gulfstream Aerospace Corporation, Savannah, GA, used a version of a NASA program called WIBCO to design a wing for the Gulfstream IV (G-IV) which will help to reduce transonic drag (created by shock waves that develop as an airplane approaches the speed of sound). The G-IV cruises at 88 percent of the speed of sound, and holds the international record in its class for round-the-world flight. They also used the STANS5 and Profile programs in the design. They will use the NASA program GASP to help determine the gross weight, range, speed, payload and optimum wing area of an intercontinental supersonic business jet being developed in cooperation with Sukhoi Design Bureau, a Soviet organization.

  13. Noise Radiation by Instability Waves in Coaxial Jets

    NASA Technical Reports Server (NTRS)

    Dahl, Milo D.; Morris, Philip J.

    1994-01-01

    In this paper predictions are made for the noise radiation from supersonic coaxial jets. The noise in the downstream arc of a supersonic jet is dominated by highly directional radiation from the supersonically convecting large scale structures in the jet mixing layer. Since the mean flow is not described easily in terms of simple analytic functions, a numerical prediction is made for its development. The compressible Reynolds-averaged boundary layer equations in cylindrical polar coordinates are solved. A mixing length turbulence model is used. Empirical correlations are developed the effects of velocity and temperature ratio and Mach number. Both normal and inverted velocity profiles are considered. Comparisons with measurements for both single and coaxial jets show good agreement. The large scale structures are modeled as instability waves. The noise radiation generated by the instability waves is determined by a matching between the inner instability wave solution and the outer acoustic solution. Predictions are made for the differences between the noise radiated by coaxial jets with different operating conditions and a single equivalent jet with the same exit area, thrust, and mass-flow.

  14. An analytical investigation of the impingement jets on curved deflectors

    NASA Technical Reports Server (NTRS)

    Schnurr, N. M.; Williamson, J. W.; Tatom, J. W.

    1972-01-01

    Numerical solutions are obtained for the cases of straight circular jets impinging on axisymmetric curved surfaces and plane jets impinging symmetrically on two-dimensional curved surfaces. These geometries are representative of some types of thrust reversers for transport aircraft. The solutions are based on the assumptions of incompressible and potential flow. The velocity field, pressure distribution at the deflector surface and reverser effectiveness are predicted for deflector turning angles of 15 to 75 deg, deflector width to jet diameter ratios of 1.5 to 2.0, and ratios of deflector clearance to jet diameter of 1.0 to 3.0. Reverser effectiveness is found to be a maximum for a ratio of deflector clearance to jet diameter of about 2.0. The effect of back pressuring due to the presence of the deflector is predicted. Experimental verification of the theoretical predictions is obtained. A compressible solution obtained for a limited number of cases indicates that the incompressible solution is satisfactory for jet exit Mach numbers less than 0.8.

  15. Dynamic of astrophysical jets in the complex octonion space

    E-print Network

    Zi-Hua Weng

    2015-06-12

    The paper aims to consider the strength gradient force as the dynamic of astrophysical jets, explaining the movement phenomena of astrophysical jets. J. C. Maxwell applied the quaternion analysis to describe the electromagnetic theory. This encourages others to adopt the complex quaternion and octonion to depict the electromagnetic and gravitational theories. In the complex octonion space, it is capable of deducing the field potential, field strength, field source, angular momentum, torque, force and so forth. As one component of the force, the strength gradient force relates to the gradient of the norm of field strength only, and is independent of not only the direction of field strength but also the mass and electric charge for the test particle. When the strength gradient force is considered as the thrust of the astrophysical jets, one can deduce some movement features of astrophysical jets, including the bipolarity, matter ingredient, precession, symmetric distribution, emitting, collimation, stability, continuing acceleration and so forth. The above results reveal that the strength gradient force is able to be applied to explain the main mechanical features of astrophysical jets, and is the competitive candidate of the dynamic of astrophysical jets.

  16. On the Scaling of Small, Heat Simulated Jet Noise Measurements to Moderate Size Exhaust Jets

    NASA Technical Reports Server (NTRS)

    McLaughlin, Dennis K.; Bridges, James; Kuo, Ching-Wen

    2010-01-01

    Modern military aircraft jet engines are designed with variable geometry nozzles to provide optimum thrust in different operating conditions, depending on the flight envelope. However, the acoustic measurements for such nozzles are scarce, due to the cost involved in making full scale measurements and the lack of details about the exact geometry of these nozzles. Thus the present effort at The Pennsylvania State University and the NASA Glenn Research Center- in partnership with GE Aviation is aiming to study and characterize the acoustic field produced by supersonic jets issuing from converging-diverging military style nozzles. An equally important objective is to validate methodology for using data obtained from small and moderate scale experiments to reliably predict the most important components of full scale engine noise. The experimental results presented show reasonable agreement between small scale and moderate scale jet acoustic data, as well as between heated jets and heat-simulated ones. Unresolved issues however are identified that are currently receiving our attention, in particular the effect of the small bypass ratio airflow. Future activities will identify and test promising noise reduction techniques in an effort to predict how well such concepts will work with full scale engines in flight conditions.

  17. Fluidic Chevrons for Jet Noise Reduction

    NASA Technical Reports Server (NTRS)

    Kinzie, Kevin; Henderson, Brenda; Whitmire, Julia

    2004-01-01

    Chevron mixing devices are used to reduce noise from commercial separate-flow turbofan engines. Mechanical chevron serrations at the nozzle trailing edge generate axial vorticity that enhances jet plume mixing and consequently reduces far-field noise. Fluidic chevrons generated with air injected near the nozzle trailing edge create a vorticity field similar to that of the mechanical chevrons and allow more flexibility in controlling acoustic and thrust performance than a passive mechanical design. In addition, the design of such a system has the future potential for actively controlling jet noise by pulsing or otherwise optimally distributing the injected air. Scale model jet noise experiments have been performed in the NASA Langley Low Speed Aeroacoustic Wind Tunnel to investigate the fluidic chevron concept. Acoustic data from different fluidic chevron designs are shown. Varying degrees of noise reduction are achieved depending on the injection pattern and injection flow conditions. CFD results were used to select design concepts that displayed axial vorticity growth similar to that associated with mechanical chevrons and qualitatively describe the air injection flow and the impact on acoustic performance.

  18. Performance of large-bore tapered-roller bearings under combined radial and thrust load at shaft speeds to 15,000 rpm

    NASA Technical Reports Server (NTRS)

    Parker, R. J.; Signer, H. R.

    1977-01-01

    The performance of 120.65-mm bore tapered roller bearings was investigated at shaft speeds up to 15,000 rpm. Temperature distribution and bearing heat generation were determined as a function of shaft speed, radial and thrust loads, lubricant flow rate, and lubricant inlet temperature. Lubricant was supplied by either jets or by a combination of holes through the cone directly to the cone-rib contact and jets at the roller small-end side. Cone-rib lubrication significantly improved high-speed tapered-roller bearing performance, yielding lower cone-face temperatures and lower power loss and allowing lower lubricant flow rates for a given speed condition. Bearing temperatures increased with increased shaft speed and decreased with increased lubricant flow rate. Bearing power loss increased with increased shaft speed and increased lubricant flow rate.

  19. Subduction mega-thrust beneath Mt. Fuji, central Japan

    NASA Astrophysics Data System (ADS)

    Sato, H.; Ishiyama, T.; Iwasaki, T.; Abe, S.; Kato, N.; Imaizumi, T.; Hirata, N.

    2012-12-01

    The Philippine Sea plate (PHS) is being subducted beneath Honshu, associated with the buoyant subduction of the Izu-Bonin arc. Many scientists estimated the plate boundary along the northwestern part of the Izu collision zone, however, covered by volcanic products from Mt. Fuji and Hakone volcanoes, no active fault system is recognized. To reveal the location of plate boundary mega-trust and to evaluate the seismic hazards produced by these active faults, we performed deep and shallow high -resolution seismic reflection profiling across the flank of Mt. Fuji and Hakone volcanoes. Deep seismic data were acquired for 34-km-long seismic line, using four vibroseis trucks and explosives (<50 kg), 780 fixed channels. Shallow high-resolution seismic reflection data were collected across the frontal part of the fault system, using Mini-vib (IVI) and a 200 channels recording system. On the deep seismic section, westward dipping reflectors are dominant beneath the Hakone volcano on the PHS and extend to the west at the depth of 7 km beneath sub-horizontal reflectors. The top surface of the west dipping reflectors is interpreted as a plate boundary mega-thrust. The velocity profile obtained by refraction tomography suggests that the high velocity zone on the hanging wall and low velocity westward dipping layer in the footwall, which corresponds the volcanic products of Hakone volcano. The hanging-wall unit consists of the accreted arc crust from the Izu-Bonin arc, Quaternary coarse trough fill and Quaternary volcanic products. On the seismic section, the vertical offset of the top of Vp 5.4 km/sec zone is 2.5 km. Probable Quaternary coarse trough fill, deposited in the trough between the Izu-Bonin arc and Honshu arc, distributed on the mega-thrust forming wedge-shaped geometry. The high-resolution seismic section suggests that the plate boundary fault zone consists of several branching faults. The frontal thrust controlled the thickness of the deposits, probably younger than 300 ka, for 1-km-vertical offset, suggesting that the net slip rate of the major thrust is about 10 mm/y. Based on morphotectonic observation and high-resolution shallow seismic sections, it is highly probable that the thrust displaced the Gotemba debris avalanche deposits dated 2.9 ka (Miyachi et al., 2004). From the seismic hazard point of view, such large slip rate of this thrust indicates that the estimated magnitude of earthquake reaches to be M8-. As the seismogenic source fault is located beneath Mt. Fuji, strong ground motions produced by the movement of this fault, may cause the debris avalanche of the flank of Mt. Fuji and it has potential to produce devastative damage to the cities distributed on the flank of Mt. Fuji. Further research will be needed to obtain more precise estimate the seismic hazards produced by this mega-thrust.

  20. Cataclasites-ultracataclasites in a major thrust zone: Gaissa Thrust, N. Norwegian Caledonides.

    NASA Astrophysics Data System (ADS)

    Rice, A. Hugh N.; Grasemann, Bernhard

    2015-04-01

    Narrow fault zones of intense deformation imply strain localisation. This is superbly shown by the ~horizontal Caledonian basal décollement in N. Norway, where ~127 km of top E-to-ESE thrust displacement is concentrated in a ~3 cm thick principle slip zone within lower strain hanging wall and footwall cataclasites less than a few centimetres thick. A scan of a transport-direction parallel 8.5x11.5cm thin-section of the fault is enlarged to 0.7x1.0m in the poster. The Caledonian external imbricate zone here places anchizone pre-Marinoan quartzite/shales onto diagenetic-zone post-Gaskiers red/green shales, silts and fine sandstones. Carbonates are absent. The displacement was estimated from balanced cross-sections and branch-line restorations. In the hangingwall cataclastic zone, a coarse qtz-rich/clay-rich cataclastic compositional layering dips at <30° towards the hinterland. Sedimentary features are nowhere seen in this pervasively, cyclically fractured rock. A cataclastic foliation is locally present parallel to the compositional layering. Close to the principle slip zone, an irregular fabric develops parallel to the detachment. The hangingwall cataclasites are cut by foreland-dipping (<70°) fractures at all scales, with offsets of up to a few mm, rarely with a reverse shear-sense, creating lozenge shaped clasts of earlier cataclasites. Fractures concentrate darker material, indicating pressure solution; similar layers lie parallel to the compositional layering. The principle slip zone has at least 11 distinct bands, although these contain microstructural variations; not all persist across the sample. Three types of band can be distinguished, separated generally by principle slip surfaces. (1) layers containing abundant angular fragments of earlier cataclasite. A variably oriented cataclastic foliation is irregularly developed, dipping towards both foreland and hinterland and wrapping larger clasts. Some elongate clasts have an (oblique) earlier internal cataclastic foliation. (2) layers with a fine, essentially planar ultracataclastic foliation (0.05 mm thick layers visible on poster) parallel to the core-zone boundary. Clasts of cataclasite are rare but typically rounded. (3) ultracataclasite layers with no, or relatively coarse, banding and more abundant rounded clasts of cataclasite. These layers may be only 0.15 mm thick (seen in the enlarged thin-section), separating type 1 layers. Boundaries between the three types are generally sharp (principle slip surfaces). The excision of some layers and one markedly irregular boundary between type 2 and 3 layers indicates late movement oblique to the regional transport direction. No evidence of pseudotachylite has been seen. The footwall cataclastic zone is more disturbed than in the hanging wall. Variations in cataclasites define an irregular, poor compositional layering. No sedimentary features are preserved. Foreland dipping fractures (<20° to detachment) cut the cataclasites with offsets of <1cm. High angle (conjugate) thin fractures, some with very minor offsets, cut across the whole fault. Thicker, irregular detachment parallel fractures also occur in the principle slip zone. These very late fractures, as well as minor voids in the principle slip zone, are filled with carbonate. Further work is in progress on the age, chemistry and textural evolution of the fault.

  1. Liftable Vector Kevin Houston

    E-print Network

    Houston, Kevin

    Liftable Vector Fields Kevin Houston Motivation Liftable Vector Fields Minimal Cross-cap The Three Families Applications Shameless Plug Vector Fields Liftable Over Stable Maps Kevin Houston Joint on Singularities in Generic Geometry and Applications, Valencia, Spain 2009 #12;Liftable Vector Fields Kevin

  2. Interpretations of anomalous LHC events with electrons and jets

    E-print Network

    Dobrescu, Bogdan A

    2014-01-01

    The CMS Collaboration has recently reported some excess events in final states with electrons and jets, in searches for leptoquarks and $W'$ bosons. Although these excesses may be due to some yet-to-be-understood background mis-modelling, it is useful to seek realistic interpretations involving new particles that could generate such events. We show that resonant pair production of vector-like leptons that decay to an electron and two jets leads to kinematic distributions consistent with the CMS data.

  3. Vector Boson Fusion Higgs to Tau Tau Searches at the ATLAS Experiment

    E-print Network

    K. J. C. Leney; for the ATLAS Collaboration

    2008-10-17

    The search for a Higgs boson produced via Vector Boson Fusion and subsequently decaying to two tau leptons is discussed. Significances for the di-lepton and lepton-hadron decay channels are presented, and the fully hadronic decay channel is shown to be feasible in terms of trigger, mass reconstruction and signal efficiency. We consider performance issues for tau ID, missing transverse energy, forward jet identification, and central jet and b-jet vetoes, and outline several methods to estimate background contributions.

  4. Supersonic jet noise reduction by coaxial rectangular nozzles

    NASA Technical Reports Server (NTRS)

    Ahuja, K. K.; Manes, J. P.; Massey, K. C.

    1992-01-01

    A physical understanding of noise reduction mechanisms in supersonic, single, and coaxial rectangular jets is quantified and obtained, with emphasis on shock noise reduction. For all conditions, corresponding acoustic measurements for an equivalent round jet are also obtained so that the noise characteristics of the two types of jets can be compared directly to quantify the noise reductions. Comparisons are thus provided for a single rectangular nozzle vs a single equivalent round nozzle, and a coaxial rectangular nozzle vs an equivalent round nozzle. It is shown that different operating conditions and nozzle arrangements for the same thrust, total exit area, and mass flow rate can produce different noise levels. With at least one stream operated supersonically, the coaxial rectangular nozzle operated in the inverted-velocity profile is always quieter than in the normal velocity profile mode for the same thrust, exit area, and mass flow rate. In general, the coaxial rectangular nozzle is shown to be quieter than an equivalent circular nozzle only for those conditions for which both nozzles are operated supersonically.

  5. Why do airlines want and use thrust reversers? A compilation of airline industry responses to a survey regarding the use of thrust reversers on commercial transport airplanes

    NASA Technical Reports Server (NTRS)

    Yetter, Jeffrey A.

    1995-01-01

    Although thrust reversers are used for only a fraction of the airplane operating time, their impact on nacelle design, weight, airplane cruise performance, and overall airplane operating and maintenance expenses is significant. Why then do the airlines want and use thrust reversers? In an effort to understand the airlines need for thrust reversers, a survey of the airline industry was made to determine why and under what situations thrust reversers are currently used or thought to be needed. The survey was intended to help establish the cost/benefits trades for the use of thrust reversers and airline opinion regarding alternative deceleration devices. A compilation and summary of the responses given to the survey questionnaire is presented.

  6. Structural evidence for northeastward movement on the Chocolate Mountains thrust, southeasternmost Calfornia

    SciTech Connect

    Dillon, J.T. (Alaska Div. of Geological and Geophysical Surveys, Fairbanks (USA)); Haxel, G.B. (Geological Survey, Flagstaff, AZ (USA)); Tosdal, R.M. (Geological Survey, Menlo Park, CA (USA))

    1990-11-10

    The Late Cretaceous Chocolate Mountains thrust of southeastern California and southwestern Arizona places a block of Proterozoic and Mesozoic continental crust over the late Mesozoic continental margin oceanic sedimentary and volcanic rocks of the regionally distinctive Orocopia Schist. The Chocolate Mountains thrust is interpreted as a thrust (burial, subduction) fault rather than a low-angle normal (exhumation, unroofing, uplift) fault. The Chocolate Mountains thrust zone contains sparse to locally abundant mesoscopic asymmetric folds. Fabric relations indicate that these folds are an integral part of and coeval with the thrust zone. On a lower hemisphere equal-area plot representing the orientation and sense of asymmetry of 80 thrust zone folds from 36 localities, spread over an area 60 by 10 km, Z folds plot northwest of and S folds plot southeast of a northeast-southwest striking vertical plane of overall monoclinic symmetry. The only sense of movement consistent with the collective asymmetry of the thrust zone folds is top to the northeast. Paleomagnetic data suggest that the original sense of thrusting, prior to Neogene vertical axis tectonic rotation related to the San Andreas fault system, was northward. The essential point is that movement of the upper plate of the Chocolate Mountains thrust evidently was continentward. Continentward thrusting suggests a tectonic scenario in which an insular or peninsular microcontinental fragment collided with mainland southern California. Alternative tectonic models involving subduction of the Orocopia Schist eastward beneath continental southern California circumvent the suture problem but are presently not supported by any direct structural evidence.

  7. Interim noise correlation for some OTW configurations using external jet-flow deflectors. [engine Over The Wing

    NASA Technical Reports Server (NTRS)

    Von Glahn, U.; Groesbeck, D.

    1977-01-01

    Jet/flap interaction acoustic data obtained statically from a model-scale study of STOL-OTW configurations with a conical nozzle mounted above the wing and using various external deflectors to provide jet-flow attachment are correlated. The acoustic data are correlated in terms that consider the jet/flap interaction noise contributions associated primarily with fluctuating lift, trailing edge, and configuration wake noise sources. Variables considered include deflector geometry, flap setting and wing size. Finally, the configuration overall noise levels are related to static lift and thrust measurements in order to provide insight into possible acoustic/aerodynamic performance trade-off benefits.

  8. Mixing Characteristics of Elliptical and Rectangular Subsonic Jets with Swirling Co-flow

    NASA Astrophysics Data System (ADS)

    Gopinath, S.; Sundararaj, M.; Elangovan, S.; Rathakrishnan, E.

    2015-04-01

    This paper presents a computational analysis of effects of swirling co-flow and non-circular subsonic compressible inner jets on centerline velocity decay, mass entrainment and jet spreading rate. Three different exit shapes of elliptical, rectangular and circular inner jets were compared for three different co-flow conditions such as no co-flow, straight co-flow and swirling co-flow. Co-flow is issuing from a circular annular duct. Swirling co-flow is created in the co-flow duct by introducing a swirler with stationary angular vanes of 50° oblique to the jet axis. Reynolds number of inner jet is calculated based on its equivalent diameter as 200342. It is found that the swirling co-flow has strong influence on the boundary condition of inner jet and alters the major features of the jet such as jet potential core length, centerline velocity decay rate and jet spread rate. Streamwise corner vortices of different jet conditions have been captured using velocity vector plot to show the effect of swirling co-flow on the jet flow field. Swirling co-flow with elliptical inner jet exhibits higher velocity decay rate and jet spreading rate than the equivalent area circular and rectangular jet.

  9. Jet-induced ground effects on a parametric flat-plate model in hover

    NASA Technical Reports Server (NTRS)

    Wardwell, Douglas A.; Hange, Craig E.; Kuhn, Richard E.; Stewart, Vearl R.

    1993-01-01

    The jet-induced forces generated on short takeoff and vertical landing (STOVL) aircraft when in close proximity to the ground can have a significant effect on aircraft performance. Therefore, accurate predictions of these aerodynamic characteristics are highly desirable. Empirical procedures for estimating jet-induced forces during the vertical/short takeoff and landing (V/STOL) portions of the flight envelope are currently limited in accuracy. The jet-induced force data presented significantly add to the current STOVL configurations data base. Further development of empirical prediction methods for jet-induced forces, to provide more configuration diversity and improved overall accuracy, depends on the viability of this STOVL data base. The data base may also be used to validate computational fluid dynamics (CFD) analysis codes. The hover data obtained at the NASA Ames Jet Calibration and Hover Test (JCAHT) facility for a parametric flat-plate model is presented. The model tested was designed to allow variations in the planform aspect ratio, number of jets, nozzle shape, and jet location. There were 31 different planform/nozzle configurations tested. Each configuration had numerous pressure taps installed to measure the pressures on the undersurface of the model. All pressure data along with the balance jet-induced lift and pitching-moment increments are tabulated. For selected runs, pressure data are presented in the form of contour plots that show lines of constant pressure coefficient on the model undersurface. Nozzle-thrust calibrations and jet flow-pressure survey information are also provided.

  10. The MOCHI LabJet Experiment

    NASA Astrophysics Data System (ADS)

    You, Setthivoine; von der Linden, Jens; Vereen, Keon; Lavine, Eric Sander; Carroll, Evan; Card, Alex; Rosales, Manuel Azuara; Quinley, Morgan

    2014-10-01

    The MOCHI LabJet experiment aims to simulate a magnetically driven jet launched by an accretion disk in the laboratory. The design uses three concentric planar electrodes linked by a vacuum magnetic field to drive azimuthal and axial shear flows in a jet configuration. Azimuthally symmetric gas sources reduce any anchoring effects on azimuthal rotation of the plasma. Two pulse-forming networks bias the electrodes to control the radial electric field profile and the azimuthal shear rotation profile. The dynamics of plasma jets are observed with 3D high-resolution magnetic probe arrays and computed vector tomography of ion Doppler spectroscopy. Vector tomography is capable of reconstructing 3D ion flow fields. Time-resolved measurements will determine if magnetic helicity is converted into ion kinetic helicity as predicted by the theory of canonical helicity transport. The theory suggests that fundamental tubes of magnetic flux with helical flows (canonical flux tubes) could be stabilized to large aspect-ratios by converting helical magnetic pitch into helical shear flows. This work is supported by US DOE Grant DE-SC0010340.

  11. Ultra High Jet Signals from Stringy No-Scale Supergravity

    E-print Network

    Tianjun Li; James A. Maxin; Dimitri V. Nanopoulos; Joel W. Walker

    2011-03-11

    We present distinctive signatures of flipped F-Theory models with TeV-scale vector-like particles, a \\sqrt{s} = 7 TeV 1 fb^{-1} test at LHC of a class of models well-motivated from string theory. The characteristic feature is a light stop and gluino, both sparticles lighter than all other squarks. This unique aspect of the supersymmetry spectrum generates an ultra-high multiplicity of hadronic jets. We find the optimal signal to background ratio is realized for 9 or more jets. Exclusion of the essential cuts presented here could leave the ultra-high jet signal severely attenuated and concealed.

  12. Ultra High Jet Signals from Stringy No-Scale Supergravity

    E-print Network

    Li, Tianjun; Nanopoulos, Dimitri V; Walker, Joel W

    2011-01-01

    We present distinctive signatures of flipped F-Theory models with TeV-scale vector-like particles, a \\sqrt{s} = 7 TeV 1 fb^{-1} test at LHC of a class of models well-motivated from string theory. The characteristic feature is a light stop and gluino, both sparticles lighter than all other squarks. This unique aspect of the supersymmetry spectrum generates an ultra-high multiplicity of hadronic jets. We find the optimal signal to background ratio is realized for 9 or more jets. Exclusion of the essential cuts presented here could leave the ultra-high jet signal severely attenuated and concealed.

  13. Preliminary Design of Low-Thrust Interplanetary Missions

    NASA Technical Reports Server (NTRS)

    Sims, Jon A.; Flanagan, Steve N.

    1997-01-01

    For interplanetary missions, highly efficient electric propulsion systems can be used to increase the mass delivered to the destination and/or reduce the trip time over typical chemical propulsion systems. This technology is being demonstrated on the Deep Space 1 mission - part of NASA's New Millennium Program validating technologies which can lower the cost and risk and enhance the performance of future missions. With the successful demonstration on Deep Space 1, future missions can consider electric propulsion as a viable propulsion option. Electric propulsion systems, while highly efficient, produce only a small amount of thrust. As a result, the engines operate during a significant fraction of the trajectory. This characteristic makes it much more difficult to find optimal trajectories. The methods for optimizing low-thrust trajectories are typically categorized as either indirect, or direct. Indirect methods are based on calculus of variations, resulting in a two-point boundary value problem that is solved by satisfying terminal constraints and targeting conditions. These methods are subject to extreme sensitivity to the initial guess of the variables - some of which are not physically intuitive. Adding a gravity assist to the trajectory compounds the sensitivity. Direct methods parameterize the problem and use nonlinear programming techniques to optimize an objective function by adjusting a set of variables. A variety of methods of this type have been examined with varying results. These methods are subject to the limitations of the nonlinear programming techniques. In this paper we present a direct method intended to be used primarily for preliminary design of low-thrust interplanetary trajectories, including those with multiple gravity assists. Preliminary design implies a willingness to accept limited accuracy to achieve an efficient algorithm that executes quickly.

  14. Evolution and dynamics of a fold-thrust belt: the Sulaiman Range of Pakistan

    NASA Astrophysics Data System (ADS)

    Reynolds, Kirsty; Copley, Alex; Hussain, Ekbal

    2015-05-01

    We present observations and models of the Sulaiman Range of western Pakistan that shed new light on the evolution and deformation of fold-thrust belts. Earthquake source inversions show that the seismic deformation in the range is concentrated in the thick pile of sediments overlying the underthrusting lithosphere of the Indian subcontinent. The slip vectors of the earthquakes vary in strike around the margin of the range, in tandem with the shape of the topography, suggesting that gravitational driving forces arising from the topography play an important role in governing the deformation of the region. Numerical models suggest that the active deformation, and the extreme plan-view curvature of the range, are governed by the presence of weak sediments in a pre-existing basin on the underthrusting Indian Plate. These sediments affect the stress-state in the over-riding mountain range and allow for the rapid propagation of the nose of the range and the development of extreme curvature and laterally varying surface gradients.

  15. Laboratory simulation of the rocket motor thrust as a follower force

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Ground tests of solid propellant rocket motors have shown that metal-containing propellants produce various amounts of slag (primarily aluminum oxide), which is trapped in the motor case causing a loss of specific impulse. Although not yet definitely established, the presence of a liquid pool of slag also may contribute to nutational instabilities that have been observed with certain spin-stabilized, upper-stage vehicles. Because of the rocket's axial acceleration - absent in the ground tests - estimates of in-flight slag mass have been very uncertain. Yet such estimates are needed to determine the magnitude of the control authority of the systems required for eliminating the instability. A test rig with an eccentrically mounted hemispherical bowl was designed and built that incorporates a follower force that properly aligns the thrust vector along the axis of spin. A program that computes the motion of a point mass in the spinning and precessing bowl was written. Using various rpm, friction factors, and initial starting conditions, plots were generated showing the trace of the point mass around the inside of the fuel tank. The apparatus will be used extensively during the 1990 to 1991 academic year and incorporate future design features such as a variable nutation angle and a film height measuring instrument. Data obtained on the nutational instability characteristics will be used to determine order-of-magnitude estimates of control authority needed to minimize the sloshing effect.

  16. Numerical Investigations of a Wall Jet with Tabs

    NASA Astrophysics Data System (ADS)

    Rahai, Hamid; Orrala, Carlos; Hoang, Huy

    2010-11-01

    Numerical investigations of a wall jet with tabs were performed. The tabs were rectangular thin metal plates placed at the jet outlet, either at the top mid boundary, or at the mid-sections of the three unbounded boundaries, perturbing into the jet. The analyses were carried out at a maximum mean velocity of 15 m/sec., which corresponds to an approximate jet Reynolds number based on the vertical jet dimension of 13027. The numerical calculations were performed using the Reynolds-Averaged Navier-Stokes equations with the Wilcox K-? turbulence model. Results that include axial and spanwise variations of the mean velocity, velocity vector, turbulent kinetic energy and vorticity at different axial locations show that with a single tab, the spanwise entrainment is enhanced while with the three tabs, both the vertical and spanwise entrainments are increased. The increase in the spanwise entrainment should result in enhanced film cooling applications.

  17. Advanced thrust chamber technology for in-space propulsion system

    NASA Technical Reports Server (NTRS)

    Chiu, H. H.; Jiang, T. L.; Gross, K. W.

    1991-01-01

    Two new concepts, the afterburning technique and the spray optimization method for the purpose of upgrading the combustion efficiency and C efficiency, are examined to assess the technical merits and hurdles that need to be resolved. Details of combustion and aerodynamic processes of monomethylhydrazine and nitrogen tetroxides in a toroidal shaped combustion chamber of a variable thrust engine, devised with a wall impingement cooling system and the secondary injection of an oxidizer from the chamber wall for an afterburning, are investigated for the selected secondary injection conditions. With an appropriate injection condition, the combustion efficiency was found to be almost 23 percent higher than that of an engine without afterburning.

  18. Hybrid methods for interplanetary low-thrust trajectory optimization 

    E-print Network

    Aroonwilairut, Krisada

    2002-01-01

    and costates. This chapter will begin with the s?nplest model a?d progress toward thc more contplicated problems. The simplest model for an mterplanetary trajectory is the planar two-body problem with thrust. This model is applicable when the spacecraft... to reduce the number of parameters to be optimized by specifying all the initial states. The only terminal constraint is the energy at the final time which is required to be zero. The initial position of the spacecraft is (10, 0, 0) DUrtt. The velocity...

  19. Earth tides can trigger shallow thrust fault earthquakes.

    PubMed

    Cochran, Elizabeth S; Vidale, John E; Tanaka, Sachiko

    2004-11-12

    We show a correlation between the occurrence of shallow thrust earthquakes and the occurrence of the strongest tides. The rate of earthquakes varies from the background rate by a factor of 3 with the tidal stress. The highest correlation is found when we assume a coefficient of friction of mu = 0.4 for the crust, although we see good correlation for mu between 0.2 and 0.6. Our results quantify the effect of applied stress on earthquake triggering, a key factor in understanding earthquake nucleation and cascades whereby one earthquake triggers others. PMID:15498971

  20. Guidance Law for a Flight Vehicle after Thrust Cutoff

    NASA Astrophysics Data System (ADS)

    Dohi, Naoto; Baba, Yoriaki; Takano, Hiroyuki

    This paper deals with a guidance law for a flight vehicle with varying velocity after thrust cutoff. This guidance law is mechanized by combining the proportional navigation and the pure pursuit navigation with the mixture ratio. Since the performance of the guidance law depends on the ratio, the discussion is focused on the determination of the ratio. Finally, the simulation results show that if the LOS angle noises are small, the proposed guidance law is effective even if the missile velocity decreases and has higher off-boresight ability than the proportional navigation.

  1. A continuous proportional low-thrust propulsion system

    NASA Technical Reports Server (NTRS)

    Chen, J.-H.; Bull, J.; Debra, D. B.

    1990-01-01

    Helium gas flows continuously from a low-temperature dewar supplying propellant for satellite thrusters. Thrust is obtained by movement of a spool located between two opposing nozzles, thus differentially restricting the helium flow. The design procedure and test results of a high bandwidth, low power, linear electromagnetic actuator for the pool movement are presented. Two mathematical models are used to describe the helium flow through the thruster under different flow conditions. The experimental data measured in the vacuum chamber and the computational results from the mathematical models are compared. The models agree with the experiment to 3 percent except near a Knudsen number of 1.

  2. Passive Thrust Oscillation Mitigation for the CEV Crew Pallet System

    NASA Technical Reports Server (NTRS)

    Sammons, Matthew; Powell, Cory; Pellicciotti, Joseph; Buehrle, Ralph; Johnson, Keith

    2012-01-01

    The Crew Exploration Vehicle (CEV) was intended to be the next-generation human spacecraft for the Constellation Program. The CEV Isolator Strut mechanism was designed to mitigate loads imparted to the CEV crew caused by the Thrust Oscillation (TO) phenomenon of the proposed Ares I Launch Vehicle (LV). The Isolator Strut was also designed to be compatible with Launch Abort (LA) contingencies and landing scenarios. Prototype struts were designed, built, and tested in component, sub-system, and system-level testing. The design of the strut, the results of the tests, and the conclusions and lessons learned from the program will be explored in this paper.

  3. Three dimensional thermal analysis of rocket thrust chambers

    NASA Technical Reports Server (NTRS)

    Naraghi, M. H. N.; Armstrong, E. S.

    1988-01-01

    A numerical model for the three dimensional thermal analysis of rocket thrust chambers and nozzles has been developed. The input to the model consists of the composition of the fuel/oxidant mixture and flow rates, chamber pressure, coolant entrance temperature and pressure, dimensions of the engine, materials and the number of nodes in different parts of the engine. The model allows for temperature variation in three dimensions: axial, radial and circumferential directions and by implementing an iterative scheme, it provides nodal temperature distribution, rates of heat transfer, hot gas and coolant thermal and transport properties.

  4. Three dimensional thermal analysis of rocket thrust chambers

    NASA Technical Reports Server (NTRS)

    Naraghi, M. H. N.; Armstrong, E. S.

    1988-01-01

    A numerical model for the three-dimensional thermal analysis of rocket thrust chambers and nozzles has been developed. The input to the model consists of the composition of the fuel/oxidant mixture and flow rates, chamber pressure, coolant entrance temperature and pressure, dimensions of the engine, materials and the number of nodes in different parts of the engine. The model allows for temperature variation in three dimensions: axial, radial and circumferential directions and by implementing an iterative scheme, it provides nodal temperature distribution, rates of heat transfer, hot gas and coolant thermal and transport properties.

  5. Experiments on heat transfer in a cryogenic engine thrust chamber

    NASA Astrophysics Data System (ADS)

    Sugathan, N.; Srinivasan, K.; Srinivasa Murthy, S.

    1993-04-01

    Tests are conducted on a cryogenic engine using liquid oxygen as oxidizer and gaseous hydrogen as fuel with water as a coolant. The coolant flow passage of the thrust chamber is of milled channel configuration. Measured heat transfer results compare well with those predicted by a thermal analysis using the standard Bartz correlation and the Hess and Kunz correlation for hot gas side and coolant side heat transfer coefficients, respectively. This confirms the conclusions of a recent theoretical study by the authors in which a comparison of various heat transfer correlations was made.

  6. Computer Tomography Analysis of Fastrac Composite Thrust Chamber Assemblies

    NASA Technical Reports Server (NTRS)

    Beshears, Ronald D.

    2000-01-01

    Computed tomography (CT) inspection has been integrated into the production process for NASA's Fastrac composite thrust chamber assemblies (TCAs). CT has been proven to be uniquely qualified to detect the known critical flaw for these nozzles, liner cracks that are adjacent to debonds between the liner and overwrap. CT is also being used as a process monitoring tool through analysis of low density indications in the nozzle overwraps. 3d reconstruction of CT images to produce models of flawed areas is being used to give program engineers better insight into the location and nature of nozzle flaws.

  7. Direct thrust measurements and modelling of a radio-frequency expanding plasma thruster

    SciTech Connect

    Lafleur, T.; Charles, C.; Boswell, R. W. [Space Plasma, Power and Propulsion Group, Research School of Physics and Engineering, The Australian National University, Canberra ACT 0200 (Australia); Takahashi, K. [Space Plasma, Power and Propulsion Group, Research School of Physics and Engineering, The Australian National University, Canberra ACT 0200 (Australia); Department of Electrical Engineering and Computer Science, Iwate University, Morioka 020-8551 (Japan)

    2011-08-15

    It is shown analytically that the thrust from a simple plasma thruster (in the absence of a magnetic field) is given by the maximum upstream electron pressure, even if the plasma diverges downstream. Direct thrust measurements of a thruster are then performed using a pendulum thrust balance and a laser displacement sensor. A maximum thrust of about 2 mN is obtained at 700 W for a thruster length of 17.5 cm and a flow rate of 0.9 mg s{sup -1}, while a larger thrust of 4 mN is obtained at a similar power for a length of 9.5 cm and a flow rate of 1.65 mg s{sup -1}. The measured thrusts are in good agreement with the maximum upstream electron pressure found from measurements of the plasma parameters and in fair agreement with a simple global approach used to model the thruster.

  8. Thrust-breakthrough of asymmetric anticlines: Observational constraints from surveys in the Brooks Range, Alaska

    NASA Astrophysics Data System (ADS)

    Jadamec, Margarete A.; Wallace, Wesley K.

    2014-05-01

    To gain insights into the processes governing the thrust-truncation of anticlines, we conducted a field study of the thrust-truncated folds in the remote Brooks Range of northern Alaska, where there is a transition in fold style from symmetric detachment folds to thrust-truncated asymmetric folds. In order to document the detailed geometry of the km-scale folds exposed in cliff-forming, largely inaccessible outcrops, a new surveying technique was developed that combines data from a theodolite and laser range finder. The field observations, survey profiles, and cross section reconstructions, indicate that late-stage thrust breakthrough of the anticlines within the mechanically competent Lisburne Group carbonates accommodated continued shortening when other mechanisms became unfeasible, including fold tightening, forelimb rotation, and parasitic folding in the anticline forelimbs. These results provide constraints on the processes that govern the transition from buckle folding to thrust truncation in fold-and-thrust belts worldwide.

  9. SYNCHROTRON RADIATION OF SELF-COLLIMATING RELATIVISTIC MAGNETOHYDRODYNAMIC JETS

    SciTech Connect

    Porth, Oliver; Fendt, Christian; Vaidya, Bhargav [Max Planck Institute for Astronomy, Koenigstuhl 17, 69117 Heidelberg (Germany); Meliani, Zakaria, E-mail: porth@mpia.de, E-mail: fendt@mpia.de [Centre for Plasma Astrophysics, K. U. Leuven, Celestijnenlaan 200B, 3001 Leuven (Belgium)

    2011-08-10

    The goal of this paper is to derive signatures of synchrotron radiation from state-of-the-art simulation models of collimating relativistic magnetohydrodynamic (MHD) jets featuring a large-scale helical magnetic field. We perform axisymmetric special relativistic MHD simulations of the jet acceleration region using the PLUTO code. The computational domain extends from the slow-magnetosonic launching surface of the disk up to 6000{sup 2} Schwarzschild radii allowing jets to reach highly relativistic Lorentz factors. The Poynting-dominated disk wind develops into a jet with Lorentz factors of {Gamma} {approx_equal} 8 and is collimated to 1{sup 0}. In addition to the disk jet, we evolve a thermally driven spine jet emanating from a hypothetical black hole corona. Solving the linearly polarized synchrotron radiation transport within the jet, we derive very long baseline interferometry radio and (sub-) millimeter diagnostics such as core shift, polarization structure, intensity maps, spectra, and Faraday rotation measure (RM) directly from the Stokes parameters. We also investigate depolarization and the detectability of a {lambda}{sup 2}-law RM depending on beam resolution and observing frequency. We find non-monotonic intrinsic RM profiles that could be detected at a resolution of 100 Schwarzschild radii. In our collimating jet geometry, the strict bimodality in the polarization direction (as predicted by Pariev et al.) can be circumvented. Due to relativistic aberration, asymmetries in the polarization vectors across the jet can hint at the spin direction of the central engine.

  10. Flight and Preflight Tests of a Ram Jet Burning Magnesium Slurry Fuel and Utilizing a Solid-propellant Gas Generator for Fuel Expulsion

    NASA Technical Reports Server (NTRS)

    Bartlett, Walter, A , jr; Hagginbotham, William K , Jr

    1955-01-01

    Data obtained from the first flight test of a ram jet utilizing a magnesium slurry fuel are presented. The ram jet accelerated from a Mach number of 1.75 to a Mach number of 3.48 in 15.5 seconds. During this period a maximum values of air specific impulse and gross thrust coefficient were calculated to be 151 seconds and 0.658, respectively. The rocket gas generator used as a fuel-pumping system operated successfully.

  11. Extending acoustic data measured with small-scale supersonic model jets to practical aircraft exhaust jets

    NASA Astrophysics Data System (ADS)

    Kuo, Ching-Wen

    2010-06-01

    Modern military aircraft jet engines are designed with variable geometry nozzles to provide optimum thrust in different operating conditions within the flight envelope. However, the acoustic measurements for such nozzles are scarce, due to the cost involved in making full-scale measurements and the lack of details about the exact geometry of these nozzles. Thus the present effort at The Pennsylvania State University and the NASA Glenn Research Center, in partnership with GE Aviation, is aiming to study and characterize the acoustic field produced by supersonic jets issuing from converging-diverging military style nozzles. An equally important objective is to develop a scaling methodology for using data obtained from small- and moderate-scale experiments which exhibits the independence of the jet sizes to the measured noise levels. The experimental results presented in this thesis have shown reasonable agreement between small-scale and moderate-scale jet acoustic data, as well as between heated jets and heat-simulated ones. As the scaling methodology is validated, it will be extended to using acoustic data measured with small-scale supersonic model jets to the prediction of the most important components of full-scale engine noise. When comparing the measured acoustic spectra with a microphone array set at different radial locations, the characteristics of the jet noise source distribution may induce subtle inaccuracies, depending on the conditions of jet operation. A close look is taken at the details of the noise generation region in order to better understand the mismatch between spectra measured at various acoustic field radial locations. A processing methodology was developed to correct the effect of the noise source distribution and efficiently compare near-field and far-field spectra with unprecedented accuracy. This technique then demonstrates that the measured noise levels in the physically restricted space of an anechoic chamber can be appropriately extrapolated to represent the expected noise levels at different noise monitoring locations of practical interest. With the emergence of more powerful fighter aircraft, supersonic jet noise reduction devices are being intensely researched. Small-scale measurements are a crucial step in evaluating the potential of noise reduction concepts at an early stage in the design process. With this in mind, the present thesis provides an acoustic assessment methodology for small-scale military-style nozzles with chevrons. Comparisons are made between the present measurements and those made by NASA at moderate-scale. The effect of chevrons on supersonic jets was investigated, highlighting the crucial role of the jet operating conditions on the effects of chevrons on the jet flow and the subsequent acoustic benefits. A small-scale heat simulated jet is investigated in the over-expanded condition and shows no substantial noise reduction from the chevrons. This is contrary to moderate-scale measurements. The discrepancy is attributed to a Reynolds number low enough to sustain an annular laminar boundary layer in the nozzle that separates in the over-expanded flow condition. These results are important in assessing the limitations of small-scale measurements in this particular jet noise reduction method. Lastly, to successfully present the results from the acoustic measurements of small-scale jets with high quality, a newly developed PSU free-field response was empirically derived to match the specific orientation and grid cap geometry of the microphones. Application to measured data gives encouraging results validating the capability of the method to produce superior accuracy in measurements even at the highest response frequencies of the microphones.

  12. Control of jet noise

    NASA Technical Reports Server (NTRS)

    Schreck, Stefan

    1993-01-01

    This reports describes experiments conducted at the High-Speed Jet Facility at the University of Southern California on supersonic jets. The goal of the study was to develop methods for controlling the noise emitted from supersonic jets by passive and/or active means. Work by Seiner et al (1991) indicates that eddy Mach wave radiation is the dominant noise source in a heated high speed jet. Eddy Mach radiation is caused by turbulent eddies traveling at supersonic speed in the shear layer of the jet. The convection velocity of the eddies decays with increasing distance from the nozzle exit due to the mixing of the jet stream with the ambient fluid. Once the convection speed reaches subsonic velocities, eddy Mach wave radiation ceases. To control noise, a rapid decay of the convection velocity is desired. This may be accomplished by enhanced mixing in the jet. In this study, small aspect ratio rectangular jet nozzles were tested. A flapping mode was noticed in the jets. By amplifying screech components of the jets and destabilizing the jet columns with a collar device, the flapping mode was excited. The result was a rapid decay of the jet velocity. A reduction in eddy Mach radiation in rectangular supersonic jets may be achieved with this device.

  13. Analysis of the flow field generated near an aircraft engine operating in reverse thrust. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Ledwith, W. A., Jr.

    1972-01-01

    A computer solution is developed to the exhaust gas reingestion problem for aircraft operating in the reverse thrust mode on a crosswind-free runway. The computer program determines the location of the inlet flow pattern, whether the exhaust efflux lies within the inlet flow pattern or not, and if so, the approximate time before the reversed flow reaches the engine inlet. The program is written so that the user is free to select discrete runway speeds or to study the entire aircraft deceleration process for both the far field and cross-ingestion problems. While developed with STOL applications in mind, the solution is equally applicable to conventional designs. The inlet and reversed jet flow fields involved in the problem are assumed to be noninteracting. The nacelle model used in determining the inlet flow field is generated using an iterative solution to the Neuman problem from potential flow theory while the reversed jet flow field is adapted using an empirical correlation from the literature. Sample results obtained using the program are included.

  14. Vector Boson Scattering at High Mass with ATLAS

    SciTech Connect

    Davison, Adam [Department of Physics and Astronomy, University College London (United Kingdom)

    2008-11-23

    In the absence of a light Higgs boson, the mechanism of electroweak symmetry breaking will be best studied in processes of vector boson scattering at high mass. Various models predict resonances in this channel. Scalar and vector resonances have been investigated in the WW, WZ and ZZ channels. The ability of ATLAS to measure the di-boson cross-section over a range of centre-of-mass energies has been studied with particular attention paid to the reconstruction of jet pairs with low opening angle resulting from the decays of highly boosted vector bosons.

  15. Vector boson scattering at high mass with ATLAS

    E-print Network

    Adam Davison

    2008-10-14

    In the absence of a light Higgs boson, the mechanism of electroweak symmetry breaking will be best studied in processes of vector boson scattering at high mass. Various models predict resonances in this channel. Scalar and vector resonances have been investigated in the WW, WZ and ZZ channels. The ability of ATLAS to measure the di-boson cross-section over a range of centre-of-mass energies has been studied with particular attention paid to the reconstruction of jet pairs with low opening angle resulting from the decays of highly boosted vector bosons.

  16. A study to estimate and compare the total particulate matter emission indices (EIN) between traditional jet fuel and two blends of Jet A/Camelina biofuel used in a high by-pass turbofan engine: A case study of Honeywell TFE-109 engine

    NASA Astrophysics Data System (ADS)

    Shila, Jacob Joshua Howard

    The aviation industry is expected to grow at an annual rate of 5% until the year 2031 according to Boeing Outlook Report of 2012. Although the aerospace manufacturers have introduced new aircraft and engines technologies to reduce the emissions generated by aircraft engines, about 15% of all aircraft in 2032 will be using the older technologies. Therefore, agencies such as the National Aeronautics and Astronautics Administration (NASA), Federal Aviation Administration (FAA), the Environmental Protection Agency (EPA) among others together with some academic institutions have been working to characterize both physical and chemical characteristics of the aircraft particulate matter emissions to further understand their effects to the environment. The International Civil Aviation Organization (ICAO) is also working to establish an inventory with Particulate Matter emissions for all the aircraft turbine engines for certification purposes. This steps comes as a result of smoke measurements not being sufficient to provide detailed information on the effects of Particulate Matter (PM) emissions as far as the health and environmental concerns. The use of alternative fuels is essential to reduce the impacts of emissions released by Jet engines since alternative aviation fuels have been studied to lower particulate matter emissions in some types of engines families. The purpose of this study was to determine whether the emission indices of the biofuel blended fuels were lower than the emission indices of the traditional jet fuel at selected engine thrust settings. The biofuel blends observed were 75% Jet A-25% Camelina blend biofuel, and 50% Jet A-50% Jet A blend biofuel. The traditional jet fuel in this study was the Jet A fuel. The results of this study may be useful in establishing a baseline for aircraft engines' PM inventory. Currently the International Civil Aviation Organization (ICAO) engines emissions database contains only gaseous emissions data for only the TFE 731 and JT15D engines' families as representatives of other engines with rated thrust of 6000 pounds or below. The results of this study may be used to add to the knowledge of PM emission data that has been collected in other research studies. This study was quantitative in nature. Three factors were designated which were the types of fuels studied. The TFE-109 turbofan engine was the experimental subject. The independent variable was the engine thrust setting while the response variable was the emission index. Four engine runs were conducted for each fuel. In each engine run, four engine thrust settings were observed. The four engine thrust levels were 10%, 30%, 85%, and 100% rated thrusts levels. Therefore, for each engine thrust settings, there four replicates. The experiments were conducted using a TFE-109 engine test cell located in the Niswonger Aviation Technology building at the Purdue University Airport. The testing facility has the capability to conduct the aircraft PM emissions tests. Due to the equipment limitations, the study was limited to observe total PM emissions instead of specifically measuring the non-volatile PM emissions. The results indicate that the emissions indices of the blended biofuels were not statistically significantly lower compared to the emissions of the traditional jet fuel at rated thrust levels of 100% and 85% of TFE-109 turbofan engine. However, the emission indices for the 50%Jet A - 50%Camelina biofuel blend were statistically significantly lower compared to the emission indices of the 100% Jet A fuel at 10% and 30% engine rated thrusts levels of TFE-109 engine. The emission indices of the 50%-50% biofuel blend were lower by reductions of 15% and 17% at engine rated thrusts of 10% and 30% respectively compared to the emissions indices of the traditional jet fuel at the same engine thrust levels. Experimental modifications in future studies may provide estimates of the emissions indices range for this particular engine these estimates may be used to estimate the levels of PM emissions for other similar engines. Additional me

  17. Measurements of $W/Z$ Production in Association with Jets at D0

    SciTech Connect

    Kumar, Ashish; /SUNY, Buffalo

    2011-10-01

    Understanding the associated production of jets and vector bosons is of paramount importance for the top quark physics, for the Higgs boson and for many new physics searches. In this contribution, recent measurements of W/Z+jets and Z+b-jets processes by the D0 experiment are presented. The measurements are compared to theoretical predictions from next-to-leading order (NLO) perturbative QCD calculations where available, and to several Monte Carlo model predictions.

  18. Deepwater North West Borneo: hydrocarbon accumulation in an active fold and thrust belt

    Microsoft Academic Search

    G. M Ingram; T. J Chisholm; C. J Grant; C. A Hedlund; P Stuart-Smith; J Teasdale

    2004-01-01

    In the deepwater acreage of North West Borneo an active offshore fold and thrust belt hosts a number of proven hydrocarbon accumulations and promises to deliver considerable additional hydrocarbon volumes as a result of ongoing exploration campaigns. Typical trapping geometries observed in this Neogene large-scale linked fold and thrust belt are hanging-wall anticlines, foreland folds and ridges and sub-thrust footwall

  19. Three-dimensional geometry of thrust surfaces and the origin of sinuous thrust traces in orogenic belts: Insights from scaled sandbox experiments

    NASA Astrophysics Data System (ADS)

    Chattopadhyay, A.; Jain, M.; Bhattacharjee, D.

    2014-12-01

    Sinuous traces of emerging thrust tips, comprising multiple salients and recesses, are commonly observed in orogenic belts (e.g. Lesser Himalayas of India, Nepal and Bhutan) and in accretionary prisms (e.g. Nankai Trough off the coast of Japan). Lateral (along the strike of the deformation zone) variation in the depths of foreland basins (i.e. variable sediment thickness) or in the strength of the basal detachment, or presence of a curved indenter has been traditionally cited to explain the formation of salients in fold-and-thrust belts, although they are not applicable in all cases. In the present work, we have carried out four series of scaled analog model experiments using dry quartz sand, changing the dip of the basal decollément (? = 0° or 5°) and the basal friction (?b = 0.5 or 0.3) to investigate the 3D shape of thrust surfaces under varying overall boundary conditions, but without any lateral variation of these parameters, within the models. The experimental results show that under all boundary conditions, thrust surfaces are curved both in their dip and strike directions (i.e. spoon-shaped in 3D). Multiple concave-upward and convex-upward segments constitute a thrust surface, which produces a sinuous trace when the tip line intersects the Earth's surface. It is also shown that thrust surface curvatures occur at different scales, and the overall thrust surface roughness (corrugations) has a self-affine fractal geometry.

  20. Exclusive search for Higgs boson to gamma-gamma decay via vector boson fusion production mechanism

    E-print Network

    Rankin, Dylan Sheldon

    2012-01-01

    We perform an exclusive search for the Higgs boson to gamma-gamma decay via vector boson fusion. We utilize the characteristic features of vector boson fusion, such as the di-jet [Delta][eta] and mass, as well as the ...