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Sample records for iii supersonic transport

  1. The Edge supersonic transport

    NASA Technical Reports Server (NTRS)

    Agosta, Roxana; Bilbija, Dushan; Deutsch, Marc; Gallant, David; Rose, Don; Shreve, Gene; Smario, David; Suffredini, Brian

    1992-01-01

    As intercontinental business and tourism volumes continue their rapid expansion, the need to reduce travel times becomes increasingly acute. The Edge Supersonic Transport Aircraft is designed to meet this demand by the year 2015. With a maximum range of 5750 nm, a payload of 294 passengers and a cruising speed of M = 2.4, The Edge will cut current international flight durations in half, while maintaining competitive first class, business class, and economy class comfort levels. Moreover, this transport will render a minimal impact upon the environment, and will meet all Federal Aviation Administration Part 36, Stage III noise requirements. The cornerstone of The Edge's superior flight performance is its aerodynamically efficient, dual-configuration design incorporating variable-geometry wingtips. This arrangement combines the benefits of a high aspect ratio wing at takeoff and low cruising speeds with the high performance of an arrow-wing in supersonic cruise. And while the structural weight concerns relating to swinging wingtips are substantial, The Edge looks to ever-advancing material technologies to further increase its viability. Heeding well the lessons of the past, The Edge design holds economic feasibility as its primary focus. Therefore, in addition to its inherently superior aerodynamic performance, The Edge uses a lightweight, largely windowless configuration, relying on a synthetic vision system for outside viewing by both pilot and passengers. Additionally, a fly-by-light flight control system is incorporated to address aircraft supersonic cruise instability. The Edge will be produced at an estimated volume of 400 aircraft and will be offered to airlines in 2015 at $167 million per transport (1992 dollars).

  2. A corporate supersonic transport

    NASA Technical Reports Server (NTRS)

    Greene, Randall; Seebass, Richard

    1996-01-01

    This talk address the market and technology for a corporate supersonic transport. It describes a candidate configuration. There seems to be a sufficient market for such an aircraft, even if restricted to supersonic operation over water. The candidate configuration's sonic boom overpressure may be small enough to allow overland operation as well.

  3. The Trojan. [supersonic transport

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The Trojan is the culmination of thousands of engineering person-hours by the Cones of Silence Design Team. The goal was to design an economically and technologically viable supersonic transport. The Trojan is the embodiment of the latest engineering tools and technology necessary for such an advanced aircraft. The efficient design of the Trojan allows for supersonic cruise of Mach 2.0 for 5,200 nautical miles, carrying 250 passengers. The per aircraft price is placed at $200 million, making the Trojan a very realistic solution for tomorrows transportation needs. The following is a detailed study of the driving factors that determined the Trojan's super design.

  4. Tesseract supersonic business transport

    NASA Technical Reports Server (NTRS)

    Reshotko, Eli; Garbinski, Gary; Fellenstein, James; Botting, Mary; Hooper, Joan; Ryan, Michael; Struk, Peter; Taggart, Ben; Taillon, Maggie; Warzynski, Gary

    1992-01-01

    This year, the senior level Aerospace Design class at Case Western Reserve University developed a conceptual design of a supersonic business transport. Due to the growing trade between Asia and the United States, a transpacific range was chosen for the aircraft. A Mach number of 2.2 was chosen, too, because it provides reasonable block times and allows the use of a large range of materials without a need for active cooling. A payload of 2,500 lbs. was assumed corresponding to a complement of nine passengers and crew, plus some light cargo. With these general requirements set, the class was broken down into three groups. The aerodynamics of the aircraft were the responsibility of the first group. The second developed the propulsion system. The efforts of both the aerodynamics and propulsion groups were monitored and reviewed for weight considerations and structural feasibility by the third group. Integration of the design required considerable interaction between the groups in the final stages. The fuselage length of the final conceptual design was 107.0 ft, while the diameter of the fuselage was 7.6 ft. The delta wing design consisted of an aspect ratio of 1.9 with a wing span of 47.75 ft and mid-chord length of 61.0 ft. A SNECMA MCV 99 variable-cycle engine design was chosen for this aircraft.

  5. Tesseract: Supersonic business transport

    NASA Technical Reports Server (NTRS)

    Reshotko, Eli; Garbinski, Gary

    1992-01-01

    This year, the senior level Aerospace Design class at Case Western Reserve University developed a conceptual design of a supersonic business transport. Due to the growing trade between Asia and the United States, a transpacific range has been chosen for the aircraft. A Mach number of 2.2 was chosen too because it provides reasonable block times and allows the use of a large range of materials without a need for active cooling. A payload of 2500 lbs. has been assumed corresponding to a complement of nine (passengers and crew) plus some light cargo. With these general requirements set, the class was broken down into three groups. The aerodynamics of the aircraft were the responsibility of the first group. The second developed the propulsion system. The efforts of both the aerodynamics and propulsion groups were monitored and reviewed for weight considerations and structural feasibility by the third group. Integration of the design required considerable interaction between the groups in the final stages. The fuselage length of the final conceptual design was 107.0 ft. while the diameter of the fuselage was 7.6 ft. The delta wing design consisted of an aspect ratio of 1.9 with a wing span of 47.75 ft and midcord length of 61.0 ft. A SNEMCA MCV 99 variable-cycle engine design was chosen for this aircraft.

  6. Supersonic transport. [using canard surfaces

    NASA Technical Reports Server (NTRS)

    Coe, P. L., Jr. (Inventor)

    1978-01-01

    An aircraft of supersonic transport configuration is described, featuring thrust vectoring in conjunction with wing apex segments used as canard surfaces during takeoff, landing, and low-speed flight. The angle of incidence of the wing apex segments, when the segments were functioning as canard surfaces, was variable with respect to the aircraft angle of attack. The wing apex segments furthermore formed a portion of the main wing panel swept leading edge when not functioning as canard surfaces. The combination of thrust vectoring and deployable wing apex segments resulted in increased aircraft range and improved low speed longitudinal stability while providing acceptable takeoff length capabilities.

  7. Optimization of Supersonic Transport Trajectories

    NASA Technical Reports Server (NTRS)

    Ardema, Mark D.; Windhorst, Robert; Phillips, James

    1998-01-01

    This paper develops a near-optimal guidance law for generating minimum fuel, time, or cost fixed-range trajectories for supersonic transport aircraft. The approach uses a choice of new state variables along with singular perturbation techniques to time-scale decouple the dynamic equations into multiple equations of single order (second order for the fast dynamics). Application of the maximum principle to each of the decoupled equations, as opposed to application to the original coupled equations, avoids the two point boundary value problem and transforms the problem from one of a functional optimization to one of multiple function optimizations. It is shown that such an approach produces well known aircraft performance results such as minimizing the Brequet factor for minimum fuel consumption and the energy climb path. Furthermore, the new state variables produce a consistent calculation of flight path angle along the trajectory, eliminating one of the deficiencies in the traditional energy state approximation. In addition, jumps in the energy climb path are smoothed out by integration of the original dynamic equations at constant load factor. Numerical results performed for a supersonic transport design show that a pushover dive followed by a pullout at nominal load factors are sufficient maneuvers to smooth the jump.

  8. Investigations for Supersonic Transports at Transonic and Supersonic Conditions

    NASA Technical Reports Server (NTRS)

    Rivers, S. Melissa B.; Owens, Lewis R.; Wahls, Richard A.

    2007-01-01

    Several computational studies were conducted as part of NASA s High Speed Research Program. Results of turbulence model comparisons from two studies on supersonic transport configurations performed during the NASA High-Speed Research program are given. The effects of grid topology and the representation of the actual wind tunnel model geometry are also investigated. Results are presented for both transonic conditions at Mach 0.90 and supersonic conditions at Mach 2.48. A feature of these two studies was the availability of higher Reynolds number wind tunnel data with which to compare the computational results. The transonic wind tunnel data was obtained in the National Transonic Facility at NASA Langley, and the supersonic data was obtained in the Boeing Polysonic Wind Tunnel. The computational data was acquired using a state of the art Navier-Stokes flow solver with a wide range of turbulence models implemented. The results show that the computed forces compare reasonably well with the experimental data, with the Baldwin-Lomax with Degani-Schiff modifications and the Baldwin-Barth models showing the best agreement for the transonic conditions and the Spalart-Allmaras model showing the best agreement for the supersonic conditions. The transonic results were more sensitive to the choice of turbulence model than were the supersonic results.

  9. Drag Reduction Tests on Supersonic Transport Design

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Langley researchers recently completed supersonic tests in the Unitary Plan Wind Tunnel on a nonlinear design for a supersonic transport. Although the drag reduction measured during the tests was not as great as that predicted using computational methods, significant drag reductions were achieved. Future tests will be conducted at a higher Reynolds number, which will be more representative of flight conditions. These tests will be used to identify a supersonic transport configuration that provides maximum drag reduction. Reducing drag decreases operating cost by improving fuel consumption and lowering aircraft weight. As a result, this research has the potential to help make a future high-speed civil transport (HSCT) an affordable means of travel for the flying public.

  10. Variable cycle engines for advanced supersonic transports

    NASA Technical Reports Server (NTRS)

    Howlett, R. A.; Kozlowski, H.

    1975-01-01

    Variable Cycle Engines being studied for advanced commercial supersonic transports show potential for significant environmental and economic improvements relative to 1st generation SST engines. The two most promising concepts are: a Variable Stream Control Engine and a Variable Cycle Engine with a rear flow-control valve. Each concept utilizes variable components and separate burners to provide independent temperature and velocity control for two coannular flow streams. Unique fuel control techniques are combined with cycle characteristics that provide low fuel consumption, similar to a turbojet engine, for supersonic operation. This is accomplished while retaining the good subsonic performance features of a turbofan engine. A two-stream coannular nozzle shows potential to reduce jet noise to below FAR Part 36 without suppressors. Advanced burner concepts have the potential for significant reductions in exhaust emissions. In total, these unique engine concepts have the potential for significant overall improvements to the environmental and economic characteristics of advanced supersonic transports.

  11. Study of active cooling for supersonic transports

    NASA Technical Reports Server (NTRS)

    Brewer, G. D.; Morris, R. E.

    1975-01-01

    The potential benefits of using the fuel heat sink of hydrogen fueled supersonic transports for cooling large portions of the aircraft wing and fuselage are examined. The heat transfer would be accomplished by using an intermediate fluid such as an ethylene glycol-water solution. Some of the advantages of the system are: (1) reduced costs by using aluminum in place of titanium, (2) reduced cabin heat loads, and (3) more favorable environmental conditions for the aircraft systems. A liquid hydrogen fueled, Mach 2.7 supersonic transport aircraft design was used for the reference uncooled vehicle. The cooled aircraft designs were analyzed to determine their heat sink capability, the extent and location of feasible cooled surfaces, and the coolant passage size and spacing.

  12. A second-generation supersonic transport

    NASA Technical Reports Server (NTRS)

    Humphrey, W.; Grayson, G.; Gump, J.; Hutko, G.; Kubicko, R.; Obrien, J.; Orndorff, R.; Oscher, R.; Polster, M.; Ulrich, C.

    1989-01-01

    Ever since the advent of commercial flight vehicles, one goal of designers has been to develop aircraft that can fly faster and carry more passengers than before. After the development of practical supersonic military aircraft, this desire was naturally manifested in a search for a practical supersonic commercial aircraft. The first and, to date, only supersonic civil transport is the Concorde, manufactured by a consortium of British and French aerospace companies. Unfortunately, due to a number of factors, including low passenger capacity and limited range, the Concorde has not been an economic success. It is for this reason that there is considerable interest in developing a design for a supersonic civil transport that addresses some of the inadequacies of the Concorde. For the design of such an aircraft to be feasible in the near term, certain guidelines must be established at the outset. Based upon the experience with the Concorde, whose 100-passenger capacity is not large enough for profitable operation, a minimum capacity of 250 passengers is desired. Second, to date, because of the limited range of the Concorde, supersonic commercial flight has been restricted to trans-Atlantic routes. In order to broaden the potential market, any new design must have the capability of trans-Pacific flight. A summary of the potential markets involved is presented. Also, because of both the cost and complexity involved with actively cooling an entire aircraft, an additional design constraint is that the aircraft as a whole be passively cooled. One additional design constraint is somewhat less quantitative in nature but of great importance nonetheless. Any time a new design is attempted, the tendency is to assume great strides in technology that serve as the basis for actual realization of the design. While it is not always possible to avoid this dependence on 'enabling technology,' since this design is desired for the near term, it is prudent, wherever possible, to rely on

  13. Supersonic transport vis-a-vis energy savings

    NASA Technical Reports Server (NTRS)

    Cormery, G.

    1979-01-01

    The energy and economic saving modifications in supersonic transportation are studied. Modifications in the propulsion systems and in the aerodynamic configurations of the Concorde aircraft to reduce noise generation and increase fuel efficiency are discussed. The conversion of supersonic aircraft from fuel oils to synthetic fuels is examined.

  14. A supersonic fan equipped variable cycle engine for a Mach 2.7 supersonic transport

    NASA Technical Reports Server (NTRS)

    Tavares, T. S.

    1985-01-01

    The concept of a variable cycle turbofan engine with an axially supersonic fan stage as powerplant for a Mach 2.7 supersonic transport was evaluated. Quantitative cycle analysis was used to assess the effects of the fan inlet and blading efficiencies on engine performance. Thrust levels predicted by cycle analysis are shown to match the thrust requirements of a representative aircraft. Fan inlet geometry is discussed and it is shown that a fixed geometry conical spike will provide sufficient airflow throughout the operating regime. The supersonic fan considered consists of a single stage comprising a rotor and stator. The concept is similar in principle to a supersonic compressor, but differs by having a stator which removes swirl from the flow without producing a net rise in static pressure. Operating conditions peculiar to the axially supersonic fan are discussed. Geometry of rotor and stator cascades are presented which utilize a supersonic vortex flow distribution. Results of a 2-D CFD flow analysis of these cascades are presented. A simple estimate of passage losses was made using empirical methods.

  15. The challenges and opportunities of supersonic transport propulsion technology

    NASA Technical Reports Server (NTRS)

    Strack, William C.; Morris, Shelby J., Jr.

    1988-01-01

    The major challenges confronting the propulsion community for civil supersonic transport applications are identified: high propulsion system efficiency at both supersonic and subsonic cruise conditions, low-cost fuel with adequate thermal stability at high temperatures, low noise cycles and exhaust systems, low emission combustion systems, and low drag installations. Both past progress and future opportunities are discussed in relation to perceived technology shortfalls for an economically successful airplane that satisfies environmental constraints.

  16. Turbulence Model Comparisons for Supersonic Transports at Transonic and Supersonic Conditions

    NASA Technical Reports Server (NTRS)

    Rivers, S. M. B.; Wahls, R. A.

    2003-01-01

    Results of turbulence model comparisons from two studies on supersonic transport configurations performed during the NASA High-speed Research program are given. Results are presented for both transonic conditions at Mach 0.90 and supersonic conditions at Mach 2.48. A feature of these two studies was the availability of higher Reynolds number wind tunnel data with which to compare the computational results. The transonic wind tunnel data was obtained in the National Transonic Facility at NASA Langley, and the supersonic data was obtained in the Boeing Polysonic Wind Tunnel. The computational data was acquired using a state of the art Navier-Stokes flow solver with a wide range of turbulence models implemented. The results show that the computed forces compare reasonably well with the experimental data, with the Baldwin- Lomax with Degani-Schiff modifications and the Baldwin-Barth models showing the best agreement for the transonic conditions and the Spalart-Allmaras model showing the best agreement for the supersonic conditions. The transonic results were more sensitive to the choice of turbulence model than were the supersonic results.

  17. Stratospheric aerosol modification by supersonic transport operations with climate implications

    NASA Technical Reports Server (NTRS)

    Toon, O. B.; Turco, R. P.; Pollack, J. B.; Whitten, R. C.; Poppoff, I. G.; Hamill, P.

    1980-01-01

    The potential effects on stratospheric aerosois of supersonic transport emissions of sulfur dioxide gas and submicron size soot granules are estimated. An interactive particle-gas model of the stratospheric aerosol is used to compute particle changes due to exhaust emissions, and an accurate radiation transport model is used to compute the attendant surface temperature changes. It is shown that a fleet of several hundred supersonic aircraft, operating daily at 20 km, could produce about a 20% increase in the concentration of large particles in the stratosphere. Aerosol increases of this magnitude would reduce the global surface temperature by less than 0.01 K.

  18. IPCS implications for future supersonic transport aircraft

    NASA Technical Reports Server (NTRS)

    Billig, L. O.; Kniat, J.; Schmidt, R. D.

    1976-01-01

    The Integrated Propulsion Control System (IPCS) demonstrates control of an entire supersonic propulsion module - inlet, engine afterburner, and nozzle - with an HDC 601 digital computer. The program encompasses the design, build, qualification, and flight testing of control modes, software, and hardware. The flight test vehicle is an F-111E airplane. The L.H. inlet and engine will be operated under control of a digital computer mounted in the weapons bay. A general description and the current status of the IPCS program are given.

  19. The impact of emerging technologies on an advanced supersonic transport

    NASA Technical Reports Server (NTRS)

    Driver, C.; Maglieri, D. J.

    1986-01-01

    The effects of advances in propulsion systems, structure and materials, aerodynamics, and systems on the design and development of supersonic transport aircraft are analyzed. Efficient propulsion systems with variable-cycle engines provide the basis for improved propulsion systems; the propulsion efficienies of supersonic and subsonic engines are compared. Material advances consist of long-life damage-tolerant structures, advanced material development, aeroelastic tailoring, and low-cost fabrication. Improvements in the areas of aerodynamics and systems are examined. The environmental problems caused by engine emissions, airport noise, and sonic boom are studied. The characteristics of the aircraft designed to include these technical advances are described.

  20. Off-Design Reynolds Number Effects for a Supersonic Transport

    NASA Technical Reports Server (NTRS)

    Owens, Lewis R.; Wahls, Richard A.; Rivers, S. Melissa

    2005-01-01

    A high Reynolds number wind tunnel test was conducted to assess Reynolds number effects on the aerodynamic performance characteristics of a realistic, second-generation supersonic transport concept. The tests included longitudinal studies at transonic and low-speed, high-lift conditions across a range of chord Reynolds numbers (8 million to 120 million). Results presented focus on Reynolds number and static aeroelastic sensitivities at Mach 0.30 and 0.90 for a configuration without a tail. Static aeroelastic effects, which mask Reynolds number effects, were observed. Reynolds number effects were generally small and the drag data followed established trends of skin friction as a function of Reynolds number. A more nose-down pitching moment was produced as Reynolds number increased because of an outward movement of the inboard leading-edge separation at constant angles of attack. This study extends the existing Reynolds number database for supersonic transports operating at off-design conditions.

  1. Supersonic transport grid generation, validation, and optimization

    NASA Technical Reports Server (NTRS)

    Aaronson, Philip G.

    1995-01-01

    The ever present demand for reduced flight times has renewed interest in High Speed Civil Transports (HSCT). The need for an HSCT becomes especially apparent when the long distance, over-sea, high growth Pacific rim routes are considered. Crucial to any successful HSCT design are minimal environmental impact and economic viability. Vital is the transport's aerodynamic efficiency, ultimately effecting both the environmental impact and the operating cost. Optimization, including numerical optimization, coupled with the use of computational fluid dynamics (CFD) technology, has and will offer a significant improvement beyond traditional methods.

  2. Overview of Boeing supersonic transport efforts, 1971 - 1979

    NASA Technical Reports Server (NTRS)

    Sigalla, A.

    1980-01-01

    Following cancellation of the United States Supersonic Transport program, the status of the technology was assessed carefully and emphasis was put on finding solutions for what were considered the major technical difficulties. In particular, work on the breakthroughs needed to advance the technology was emphasized. Currently, solutions to all major technical problems are identified. Depending on the subject, either the problem is no longer a concern or the steps needed to bring about a solution are mapped out clearly. Throughout the NASA SCR program, important strides were made in the identification of design advances which would greatly improve supersonic airplane fuel efficiency, noise, and other performance and cost affecting parameters. Furthermore, these efforts created an atmosphere in which it was possible for new ideas to flourish and positive inventions to take place such as the variable cycle engine and the blended fuselage. These technical gains show that, given availability of such technology, advanced supersonic transports could be developed that would be economically successful and environmentally acceptable.

  3. Application of natural laminar flow to a supersonic transport concept

    NASA Technical Reports Server (NTRS)

    Fuhrmann, Henri D.

    1993-01-01

    Results are presented of a preliminary investigation into an application of supersonic natural laminar flow (NLF) technology for a high speed civil transport (HSCT) configuration. This study focuses on natural laminar flow without regard to suction devices which are required for laminar flow control (LFC) or hybrid laminar flow control (HLFC). An HSCT design is presented with a 70 deg inboard leading-edge sweep and a 20 deg leading-edge outboard crank to obtain NLF over the outboard crank section. This configuration takes advantage of improved subsonic performance and NLF on the low-sweep portion of the wing while minimizing the wave drag and induced drag penalties associated with low-sweep supersonic cruise aircraft. In order to assess the benefits of increasing natural laminar flow wetted area, the outboard low-sweep wing area is parametrically increased. Using a range of supersonic natural laminar flow transition Reynolds numbers, these aircraft are then optimized and sized for minimum take-off gross weight (TOGW) subject to mission constraints. Results from this study indicate reductions in TOGW for the NLF concepts, due mainly to reductions in wing area and total wing weight. Furthermore, significant reductions in block fuel are calculated throughout the range of transition Reynolds numbers considered. Observations are made on the benefits of unsweeping the wingtips with all turbulent flow.

  4. A study of altitude-constrained supersonic cruise transport concepts

    NASA Technical Reports Server (NTRS)

    Tice, David C.; Martin, Glenn L.

    1992-01-01

    The effect of restricting maximum cruise altitude on the mission performance of two supersonic transport concepts across a selection of cruise Mach numbers is studied. Results indicate that a trapezoidal wing concept can be competitive with an arrow wing depending on the altitude and Mach number constraints imposed. The higher wing loading of trapezoidal wing configurations gives them an appreciably lower average cruise altitude than the lower wing loading of the arrow wing configurations, and this advantage increases as the maximum allowable cruise altitude is reduced.

  5. Integrated Flight-propulsion Control Concepts for Supersonic Transport Airplanes

    NASA Technical Reports Server (NTRS)

    Burcham, Frank W., Jr.; Gilyard, Glenn B.; Gelhausen, Paul A.

    1990-01-01

    Integration of propulsion and flight control systems will provide significant performance improvements for supersonic transport airplanes. Increased engine thrust and reduced fuel consumption can be obtained by controlling engine stall margin as a function of flight and engine operating conditions. Improved inlet pressure recovery and decreased inlet drag can result from inlet control system integration. Using propulsion system forces and moments to augment the flight control system and airplane stability can reduce the flight control surface and tail size, weight, and drag. Special control modes may also be desirable for minimizing community noise and for emergency procedures. The overall impact of integrated controls on the takeoff gross weight for a generic high speed civil transport is presented.

  6. Reynolds Number Effects on a Supersonic Transport at Transonic Conditions

    NASA Technical Reports Server (NTRS)

    Wahls, R. N.; Owens, L. R.; Rivers, S. M. B.

    2001-01-01

    A High Speed Civil Transport configuration was tested in the National Transonic Facility at the NASA Langley Research Center as part of NASA's High Speed Research Program. The primary purposes of the tests were to assess Reynolds number scale effects and the high Reynolds number aerodynamic characteristics of a realistic, second generation supersonic transport while providing data for the assessment of computational methods. The tests included longitudinal and lateral/directional studies at low speed high-lift and transonic conditions across a range of Reynolds numbers from that available in conventional wind tunnels to near flight conditions. Results are presented which focus on both the Reynolds number and static aeroelastic sensitivities of longitudinal characteristics at Mach 0.90 for a configuration without an empennage.

  7. 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.

  8. Supersonic Transport Analysis on the IBM Parallel System SP2

    NASA Technical Reports Server (NTRS)

    Jameson, Antony; Cliff, Susan; Thomas, Scott; Baker, Timothy; Cheng, Wu-Sun

    1995-01-01

    Several studies of supersonic transport (SST) configurations have been undertaken by members of the High Speed Aerodynamics branch at NASA Ames. These computational investigations involved the analysis of shapes to study the sonic boom signatures, aerodynamic performance characteristics, as well as studies of nacelle/airframe integration. A variety of different computer codes were employed including both structured and unstructured codes. The AIRPLANE code has been used extensively in these investigations. This computer code solves the Euler equations for inviscid flow by exploiting an explicit finite volume method on a mesh of tetrahedral cells. AIRPLANE is capable of handling complete aircraft configurations including nacelles and diverters. An example of a generic SST configuration is shown and a comparison of computed and experimental force coefficients is presented. Most of the computations in support of the SST investigations have been run on the YMP and C-90 computers currently installed at NASA Ames. Additional information is contained in the original extended abstract.

  9. Skin Friction and Transition Location Measurement on Supersonic Transport Models

    NASA Technical Reports Server (NTRS)

    Kennelly, Robert A., Jr.; Goodsell, Aga M.; Olsen, Lawrence E. (Technical Monitor)

    2000-01-01

    Flow visualization techniques were used to obtain both qualitative and quantitative skin friction and transition location data in wind tunnel tests performed on two supersonic transport models at Mach 2.40. Oil-film interferometry was useful for verifying boundary layer transition, but careful monitoring of model surface temperatures and systematic examination of the effects of tunnel start-up and shutdown transients will be required to achieve high levels of accuracy for skin friction measurements. A more common technique, use of a subliming solid to reveal transition location, was employed to correct drag measurements to a standard condition of all-turbulent flow on the wing. These corrected data were then analyzed to determine the additional correction required to account for the effect of the boundary layer trip devices.

  10. Expanding the Natural Laminar Flow Boundary for Supersonic Transports

    NASA Technical Reports Server (NTRS)

    Lynde, Michelle N.; Campbell, Richard L.

    2016-01-01

    A computational design and analysis methodology is being developed to design a vehicle that can support significant regions of natural laminar flow (NLF) at supersonic flight conditions. The methodology is built in the CDISC design module to be used in this paper with the flow solvers Cart3D and USM3D, and the transition prediction modules BLSTA3D and LASTRAC. The NLF design technique prescribes a target pressure distribution for an existing geometry based on relationships between modal instability wave growth and pressure gradients. The modal instability wave growths (both on- and off-axes crossflow and Tollmien-Schlichting) are balanced to produce a pressure distribution that will have a theoretical maximum NLF region for a given streamwise wing station. An example application is presented showing the methodology on a generic supersonic transport wingbody configuration. The configuration has been successfully redesigned to support significant regions of NLF (approximately 40% of the wing upper surface by surface area). Computational analysis predicts NLF with transition Reynolds numbers (ReT) as high as 36 million with 72 degrees of leading-edge sweep (?LE), significantly expanding the current boundary of ReT - ?LE combinations for NLF. This NLF geometry provides a total drag savings of 4.3 counts compared to the baseline wing-body configuration (approximately 5% of total drag). Off-design evaluations at near-cruise and low-speed, high-lift conditions are discussed, as well as attachment line contamination/transition concerns. This computational NLF design effort is a part of an ongoing cooperative agreement between NASA and JAXA researchers.

  11. Judgements of relative noisiness of a supersonic transport and several commercial-service aircraft

    NASA Technical Reports Server (NTRS)

    Powell, C. A.

    1977-01-01

    Two laboratory experiments were conducted on the relative noisiness of takeoff and landing operations of a supersonic transport and several other aircraft in current commercial service. A total of 96 subjects made noisiness judgments on 120 tape-recorded flyover noises in the outdoor-acoustic-simulation experiment; 32 different subjects made judgments on the noises in the indoor-acoustic-simulation experiment. The judgments were made by using the method of numerical category scaling. The effective perceived noise level underestimated the noisiness of the supersonic transport by 3.5 db. For takeoff operations, no difference was found between the noisiness of the supersonic transport and the group of other aircraft for the A-weighted rating scale; however, for landing operations, the noisiness of the supersonic transport was overestimated by 3.7 db. Very high correlation was found between the outdoor-simulation experiment and the indoor-simulation experiment.

  12. A Qualitative Piloted Evaluation of the Tupolev Tu-144 Supersonic Transport

    NASA Technical Reports Server (NTRS)

    Rivers, Robert A.; Jackson, E. Bruce; Fullerton, C. Gordon; Cox, Timothy H.; Princen, Norman H.

    2000-01-01

    Two U.S. research pilots evaluated the Tupolev Tu-144 supersonic transport aircraft on three dedicated flights: one subsonic and two supersonic profiles. The flight profiles and maneuvers were developed jointly by Tupolev and U.S. engineers. The vehicle was found to have unique operational and flight characteristics that serve as lessons for designers of future supersonic transport aircraft. Vehicle subsystems and observed characteristics are described as are flight test planning and ground monitoring facilities. Maneuver descriptions and extended pilot narratives for each flight are included as appendices.

  13. Final Report for the Advanced Concept Studies for Supersonic Commercial Transports Entering Service in the 2030 to 2035 Period, N+3 Supersonic Program

    NASA Technical Reports Server (NTRS)

    Morgenstern, John; Norstrud, Nicole; Stelmack, Marc; Skoch, Craig

    2010-01-01

    The N+3 Final Report documents the work and progress made by Lockheed Martin Aeronautics in response to the NASA sponsored program "N+3 NRA Advanced Concept Studies for Supersonic Commercial Transports Entering Service in the 2030 to 2035 Period." The key technical objective of this effort was to generate promising supersonic concepts for the 2030 to 2035 timeframe and to develop plans for maturing the technologies required to make those concepts a reality. The N+3 program is aligned with NASA's Supersonic Project and is focused on providing alternative system-level solutions capable of overcoming the efficiency, environmental, and performance barriers to practical supersonic flight

  14. Application of laminar flow control to supersonic transport configurations

    NASA Technical Reports Server (NTRS)

    Parikh, P. G.; Nagel, A. L.

    1990-01-01

    The feasibility and impact of implementing a laminar flow control system on a supersonic transport configuration were investigated. A hybrid laminar flow control scheme consisting of suction controlled and natural laminar flow was developed for a double-delta type wing planform. The required suction flow rates were determined from boundary layer stability analyses using representative wing pressure distributions. A preliminary design of structural modifications needed to accommodate suction through a perforated titanium skin was carried out together with the ducting and systems needed to collect, compress and discharge the suction air. The benefits of reduced aerodynamic drag were weighed against the weight, volume and power requirement penalties of suction system installation in a mission performance and sizing program to assess the net benefits. The study showed a feasibility of achieving significant laminarization of the wing surface by use of a hybrid scheme, leading to an 8.2 percent reduction in the cruise drag. This resulted in an 8.5 percent reduction in the maximum takeoff weight and a 12 percent reduction in the fuel burn after the inclusion of the LFC system installation penalties. Several research needs were identified for a resolution of aerodynamics, structural and systems issues before these potential benefits could be realized in a practical system.

  15. Advanced Concept Studies for Supersonic Commercial Transports Entering Service in the 2018 to 2020 Period

    NASA Technical Reports Server (NTRS)

    Morgenstern, John; Norstrud, Nicole; Sokhey, Jack; Martens, Steve; Alonso, Juan J.

    2013-01-01

    Lockheed Martin Aeronautics Company (LM), working in conjunction with General Electric Global Research (GE GR), Rolls-Royce Liberty Works (RRLW), and Stanford University, herein presents results from the "N+2 Supersonic Validations" contract s initial 22 month phase, addressing the NASA solicitation "Advanced Concept Studies for Supersonic Commercial Transports Entering Service in the 2018 to 2020 Period." This report version adds documentation of an additional three month low boom test task. The key technical objective of this effort was to validate integrated airframe and propulsion technologies and design methodologies. These capabilities aspired to produce a viable supersonic vehicle design with environmental and performance characteristics. Supersonic testing of both airframe and propulsion technologies (including LM3: 97-023 low boom testing and April-June nozzle acoustic testing) verified LM s supersonic low-boom design methodologies and both GE and RRLW's nozzle technologies for future implementation. The N+2 program is aligned with NASA s Supersonic Project and is focused on providing system-level solutions capable of overcoming the environmental and performance/efficiency barriers to practical supersonic flight. NASA proposed "Initial Environmental Targets and Performance Goals for Future Supersonic Civil Aircraft". The LM N+2 studies are built upon LM s prior N+3 100 passenger design studies. The LM N+2 program addresses low boom design and methodology validations with wind tunnel testing, performance and efficiency goals with system level analysis, and low noise validations with two nozzle (GE and RRLW) acoustic tests.

  16. A Preliminary Evaluation of Supersonic Transport Category Vehicle Operations in the National Airspace System

    NASA Technical Reports Server (NTRS)

    Underwood, Matthew C.; Guminsky, Michael D.

    2015-01-01

    Several public sector businesses and government agencies, including the National Aeronautics and Space Administration are currently working on solving key technological barriers that must be overcome in order to realize the vision of low-boom supersonic flights conducted over land. However, once these challenges are met, the manner in which this class of aircraft is integrated in the National Airspace System may become a potential constraint due to the significant environmental, efficiency, and economic repercussions that their integration may cause. Background research was performed on historic supersonic operations in the National Airspace System, including both flight deck procedures and air traffic controller procedures. Using this information, an experiment was created to test some of these historic procedures in a current-day, emerging Next Generation Air Transportation System (NextGen) environment and observe the interactions between commercial supersonic transport aircraft and modern-day air traffic. Data was gathered through batch simulations of supersonic commercial transport category aircraft operating in present-day traffic scenarios as a base-lining study to identify the magnitude of the integration problems and begin the exploration of new air traffic management technologies and architectures which will be needed to seamlessly integrate subsonic and supersonic transport aircraft operations. The data gathered include information about encounters between subsonic and supersonic aircraft that may occur when supersonic commercial transport aircraft are integrated into the National Airspace System, as well as flight time data. This initial investigation is being used to inform the creation and refinement of a preliminary Concept of Operations and for the subsequent development of technologies that will enable overland supersonic flight.

  17. The aerodynamic design of the oblique flying wing supersonic transport

    NASA Technical Reports Server (NTRS)

    Vandervelden, Alexander J. M.; Kroo, Ilan

    1990-01-01

    The aerodynamic design of a supersonic oblique flying wing is strongly influenced by the requirement that passengers must be accommodated inside the wing. It was revealed that thick oblique wings of very high sweep angle can be efficient at supersonic speeds when transonic normal Mach numbers are allowed on the upper surface of the wing. The goals were motivated by the ability to design a maximum thickness, minimum size oblique flying wing. A 2-D Navier-Stokes solver was used to design airfoils up to 16 percent thickness with specified lift, drag and pitching moment. A new method was developed to calculate the required pressure distribution on the wing based on the airfoil loading, normal Mach number distribution and theoretical knowledge of the minimum drag of oblique configurations at supersonic speeds. The wing mean surface for this pressure distribution was calculated using an inverse potential flow solver. The lift to drag ratio of this wing was significantly higher than that of a comparable delta wing for cruise speeds up to Mach 2.

  18. THE DELAY OF POPULATION III STAR FORMATION BY SUPERSONIC STREAMING VELOCITIES

    SciTech Connect

    Greif, Thomas H.; White, Simon D. M.; Klessen, Ralf S.; Springel, Volker

    2011-08-01

    It has recently been demonstrated that coherent relative streaming velocities of order 30 km s{sup -1} between dark matter and gas permeated the universe on scales below a few Mpc directly after recombination. Here we use a series of high-resolution moving-mesh calculations to show that these supersonic motions significantly influence the virialization of the gas in minihalos and delay the formation of the first stars. As the gas streams into minihalos with bulk velocities around 1 km s{sup -1} at z {approx} 20, the additional momentum and energy input reduces the gas fractions and central densities of the halos, increasing the typical virial mass required for efficient cooling by a factor of three and delaying Population III star formation by {Delta}z {approx_equal} 4. Since the distribution of the magnitude of the streaming velocities is narrowly peaked around a non-negligible value, this effect is important in most regions of the universe. As a consequence, the increased minimum halo mass implies a reduction of the absolute number of minihalos that can be expected to cool and form Population III stars by up to an order of magnitude. We further find that the streaming velocities increase the turbulent velocity dispersion of the minihalo gas, which could affect its ability to fragment and hence alter the mass function of the first stars.

  19. Aerodynamic design and analysis of the AST-200 supersonic transport configuration concept

    NASA Technical Reports Server (NTRS)

    Walkley, K. B.; Martin, G. L.

    1979-01-01

    The design and analysis of a supersonic transport configuration was conducted using linear theory methods in conjunction with appropriate constraints. Wing optimization centered on the determination of the required twist and camber and proper integration of the wing and fuselage. Also included in the design are aerodynamic refinements to the baseline wing thickness distribution and nacelle shape. Analysis to the baseline and revised configurations indicated an improvement in lift-to-drag ratio of 0.36 at the Mach 2.7 cruise condition. Validation of the design is planned through supersonic wing tunnel tests.

  20. Aerodynamic Optimization of Supersonic Transport at Near-Sonic Regime

    NASA Astrophysics Data System (ADS)

    Yamazaki, Wataru; Matsushima, Kisa; Obayashi, Shigeru; Nakahashi, Kazuhiro

    Recently, an airplane cruising at near-sonic regime is watched with keen interest. The Sonic-Cruiser, of which the Boeing Company has examined and challenged the development, is the most remarkable case. In this paper, motivated by this trend, aerodynamic performance optimization for an airplane cruising at near-sonic regime is discussed based on CFD simulations. NAL’s experimental supersonic airplane, called NEXST-1, was employed as the baseline model for optimization. Aerodynamic performance was evaluated by solving the Euler equations with the unstructured grid method. It was confirmed that the performance Euler simulation predicted was qualitatively correct. By the evaluation to select a baseline model for optimization, NEXST-1 was accepted as a candidate of sonic plane because of the existence of drag bucket at near-sonic regime. In the optimization, Genetic Algorithm was used with Euler simulations. The objective was to reduce drag keeping lift constant, at the flying speed of Mach 0.98. The optimized result showed L/D improvement not only for near-sonic regime but also for transonic regime. The mechanism of design to reduce drag force was found through the analysis and comparison of the geometries and aerodynamic phenomena about the baseline model and the optimized one.

  1. Comparison of Flamelet Models with the Transported Mass Fraction Approach for Supersonic Combustion

    NASA Astrophysics Data System (ADS)

    Li, Wenhai; Alabi, Ken; Ladeinde, Foluso

    2015-11-01

    In this study, two fully compressible RANS, LES, and combined RANS/LES flow solvers - AEROFLO and VULCAN, both of which were originally developed by the United States Department of Defense but have since been significantly enhanced and commercialized by our organization, are used to investigate the accuracy of flamelet-based approach when employed to model supersonic combustion. The flamelet results from both codes are assessed relative to solutions obtained by solving the transport equations for the mass fractions - which is also supported by one of the codes, and making familiar assumptions about the closure of the reaction rate. The studies are carried out in the flamelet regime, and the numerical procedures are based on high-order schemes, which are also used to solve the level-set and mixture fraction transport equations used to study, respectively, premixed and non-premixed combustion. The effects of supersonic Mach numbers on the results are discussed.

  2. Effect of the supersonic transport configuration on the sonic boom parameters

    NASA Astrophysics Data System (ADS)

    Fomin, V. M.; Chirkashenko, V. F.; Volkov, V. F.; Kharitonov, A. M.

    2011-12-01

    Results of numerical and experimental investigations of the sonic boom parameters for two configurations of civil supersonic transport are presented. Numerical modelling is performed by a combined method based on calculating the spatial flow in the near zone of the aircraft configuration and subsequent determination of disturbed flow parameters at large distances from the examined model. Numerical results are compared with experimental sonic boom parameters measured in the near zone and with results of their recalculation to large distances within the framework of the quasi-linear theory. This validation allows the degree of adequacy of the inviscid Euler model for solving the posed problem to be determined. Reasons for certain disagreement between the calculated and experimental data are discussed. The analysis confirms the possibility of attenuating the sonic boom generated by supersonic transport with an unconventional configuration based on a tandem arrangement of two wings on the fuselage.

  3. Application of sonic-boom minimization concepts in supersonic transport design

    NASA Technical Reports Server (NTRS)

    Carlson, H. W.; Barger, R. L.; Mack, R. J.

    1973-01-01

    The applicability of sonic boom minimization concepts in the design of large supersonic transport airplanes capable of a 2500-nautical-mile range at a cruise Mach number of 2.7 is considered. Aerodynamics, weight and balance, and mission performance as well as sonic boom factors, have been taken into account. The results indicate that shock-strength nominal values of somewhat less than 48 newtons/sq m during cruise are within the realm of possibility. Because many of the design features are in direct contradiction to presently accepted design practices, further study of qualified airplane design teams is required to ascertain sonic boom shock strength levels actually attainable for practical supersonic transports.

  4. Parametric Study of a Mach 2.4 Transport Engine with Supersonic Through-Flow Rotor and Supersonic Counter-Rotating Diffuser (SSTR/SSCRD)

    NASA Technical Reports Server (NTRS)

    Tran, Donald H.

    2004-01-01

    A parametric study is conducted to evaluate a mixed-flow turbofan equipped with a supersonic through-flow rotor and a supersonic counter-rotating diffuser (SSTR/SSCRD) for a Mach 2.4 civil transport. Engine cycle, weight, and mission analyses are performed to obtain a minimum takeoff gross weight aircraft. With the presence of SSTR/SSCRD, the inlet can be shortened to provide better pressure recovery. For the same engine airflow, the inlet, nacelle, and pylon weights are estimated to be 73 percent lighter than those of a conventional inlet. The fan weight is 31 percent heavier, but overall the installed engine pod weight is 11 percent lighter than the current high-speed civil transport baseline conventional mixed-flow turbofan. The installed specific fuel consumption of the supersonic fan engine is 2 percent higher than that of the baseline turbofan at supersonic cruise. Finally, the optimum SSTR/SSCRD airplane meets the FAR36 Stage 3 noise limit and is within 7 percent of the baseline turbofan airplane takeoff gross weight over a 5000-n mi mission.

  5. Supersonic jet noise and the high speed civil transport

    NASA Astrophysics Data System (ADS)

    Seiner, John M.; Krejsa, Eugene A.

    1989-07-01

    An evaluation is made of the comparative advantages of prospective SST engine noise-suppression systems, with a view to their effectiveness in meeting the federally-mandated community noise standards of FAR 36 Stage III. A noise-suppression system must be capable of removing at least 4 EPNdB of noise percent thrust loss at takeoff. While none of the suppressors presently discussed is capable of meeting this goal, the inverted velocity profile/annular convergent-divergent plug/acoustically-treated ejector suppressor combination of configurational elements appears to represent the most efficient noise-control apparatus. Noncircular cross-section nozzle geometries also furnish a general noise reduction advantage over circular ones.

  6. A Simulator Study of Take-Off Characteristics of Proposed Supersonic Transports

    NASA Technical Reports Server (NTRS)

    Jackson, Charles T., Jr.; Snyder, C. Thomas

    1965-01-01

    Fixed-cockpit piloted simulator studies of delta-planform and variable-wing-sweep supersonic transport configurations are being conducted at the Ames Research Center to investigate the handling qualities and certification requirements related to the take-off maneuver. Validation of the simulation was achieved by duplicating the take-off certification program of a subsonic jet transport. Evaluation of the simulator was made by NASA pilots as well as company and FAA pilots involved in the actual certification flights of the airplane. The present paper is limited to a discussion of normal take-off, minimum control speed (ground), rotation characteristics, and initial climbout. Comparisons of the take-off characteristics are made between the supersonic transport and the current class of subsonic jet transports. Results indicate that minimum control speed (ground) characteristics are a function of thrust-weight ratio, the time provided for SST rotation should be at least as long as that for the subsonic jet transports, abused take-offs are more likely to result in tail scrapes, and climbout below the minimum drag speed requires that the pilot carefully monitor airspeed.

  7. Application of multidisciplinary optimization methods to the design of a supersonic transport

    NASA Technical Reports Server (NTRS)

    Barthelemy, J.-F. M.; Coen, P. G.; Wrenn, Gregory A.; Riley, M. F.; Dovi, Augustine R.; Hall, L. E.

    1991-01-01

    An optimization design method is discussed. This method is based on integrating existing disciplinary analysis and sensitivity analysis techniques by means of generalized sensitivity equations. A generic design system implementing this method is described. The system is being used to design the configuration and internal structure of a supersonic transport wing for optimum performance. This problem combines the disciplines of linear aerodynamics, structures, and performance. Initial results which include the disciplines of aerodynamics and structures in a conventional minimum weight design under static aeroelastic constraints are presented.

  8. Aeroelastic Tailoring Study of N+2 Low-Boom Supersonic Commercial Transport Aircraft

    NASA Technical Reports Server (NTRS)

    Pak, Chan-gi

    2015-01-01

    The Lockheed Martins N+2 Low-boom Supersonic Commercial Transport (LSCT) aircraft is optimized in this study through the use of a multidisciplinary design optimization tool developed at the NASA Armstrong Flight Research Center. A total of 111 design variables are used in the first optimization run. Total structural weight is the objective function in this optimization run. Design requirements for strength, buckling, and flutter are selected as constraint functions during the first optimization run. The MSC Nastran code is used to obtain the modal, strength, and buckling characteristics. Flutter and trim analyses are based on ZAERO code and landing and ground control loads are computed using an in-house code.

  9. Piloted Simulation Investigation of a Supersonic Transport Configuration (LaRC.4)

    NASA Technical Reports Server (NTRS)

    Jackson, E. Bruce; Martinez, Debbie; Derry, Stephen D.

    1999-01-01

    This report contains a description of the test facilities and software utilized during a joint NASA/aerospace industry study of improved control laws and desired inceptor characteristics for a candidate supersonic transport air-craft design. Details concerning the characteristics of the simulation cockpit, image generator and display systems, and motion platform are described. Depictions of the various display formats are included. The test schedule, session log, and flight cards describing the maneuvers performed is included. A brief summary of high-lights of the study is given. Modifications made to the industry-provided simulation model are described. This report is intended to serve as a reference document for industry researchers.

  10. Development of Naphthalene PLIF for Making Quantitative Measurements of Ablation Products Transport in Supersonic Flows

    NASA Astrophysics Data System (ADS)

    Combs, Christopher; Clemens, Noel

    2014-11-01

    Ablation is a multi-physics process involving heat and mass transfer and codes aiming to predict ablation are in need of experimental data pertaining to the turbulent transport of ablation products for validation. Low-temperature sublimating ablators such as naphthalene can be used to create a limited physics problem and simulate ablation at relatively low temperature conditions. At The University of Texas at Austin, a technique is being developed that uses planar laser-induced fluorescence (PLIF) of naphthalene to visualize the transport of ablation products in a supersonic flow. In the current work, naphthalene PLIF will be used to make quantitative measurements of the concentration of ablation products in a Mach 5 turbulent boundary layer. For this technique to be used for quantitative research in supersonic wind tunnel facilities, the fluorescence properties of naphthalene must first be investigated over a wide range of state conditions and excitation wavelengths. The resulting calibration of naphthalene fluorescence will be applied to the PLIF images of ablation from a boundary layer plug, yielding 2-D fields of naphthalene mole fraction. These images may help provide data necessary to validate computational models of ablative thermal protection systems for reentry vehicles. Work supported by NASA Space Technology Research Fellowship Program under grant NNX11AN55H.

  11. Reynolds Number Effects on Leading Edge Radius Variations of a Supersonic Transport at Transonic Conditions

    NASA Technical Reports Server (NTRS)

    Rivers, S. M. B.; Wahls, R. A.; Owens, L. R.

    2001-01-01

    A computational study focused on leading-edge radius effects and associated Reynolds number sensitivity for a High Speed Civil Transport configuration at transonic conditions was conducted as part of NASA's High Speed Research Program. The primary purposes were to assess the capabilities of computational fluid dynamics to predict Reynolds number effects for a range of leading-edge radius distributions on a second-generation supersonic transport configuration, and to evaluate the potential performance benefits of each at the transonic cruise condition. Five leading-edge radius distributions are described, and the potential performance benefit including the Reynolds number sensitivity for each is presented. Computational results for two leading-edge radius distributions are compared with experimental results acquired in the National Transonic Facility over a broad Reynolds number range.

  12. Model predictions of latitude-dependent ozone depletion due to supersonic transport operations

    NASA Technical Reports Server (NTRS)

    Borucki, W. J.; Whitten, R. C.; Watson, V. R.; Woodward, H. T.; Riegel, C. A.; Capone, L. A.; Becker, T.

    1976-01-01

    Results are presented from a two-dimensional model of the stratosphere that simulates the seasonal movement of ozone by both wind and eddy transport, and contains all the chemistry known to be important. The calculated reductions in ozone due to NO2 injection from a fleet of supersonic transports are compared with the zonally averaged results of a three-dimensional model for a similar episode of injection. The agreement is good in the northern hemisphere, but is not as good in the southern hemisphere. Both sets of calculations show a strong corridor effect in that the predicted ozone depletions are largest to the north of the flight corridor for aircraft operating in the northern hemisphere.

  13. Aerodynamic shape optimization directed toward a supersonic transport using sensitivity analysis

    NASA Technical Reports Server (NTRS)

    Baysal, Oktay

    1995-01-01

    This investigation was conducted from March 1994 to August 1995, primarily, to extend and implement the previously developed aerodynamic design optimization methodologies for the problems related to a supersonic transport design. These methods had demonstrated promise to improve the designs (more specifically, the shape) of aerodynamic surfaces, by coupling optimization algorithms (OA) with Computational Fluid Dynamics (CFD) algorithms via sensitivity analyses (SA) with surface definition methods from Computer Aided Design (CAD). The present extensions of this method and their supersonic implementations have produced wing section designs, delta wing designs, cranked-delta wing designs, and nacelle designs, all of which have been reported in the open literature. Despite the fact that these configurations were highly simplified to be of any practical or commercial use, they served the algorithmic and proof-of-concept objectives of the study very well. The primary cause for the configurational simplifications, other than the usual simplify-to-study the fundamentals reason, were the premature closing of the project. Only after the first of the originally intended three-year term, both the funds and the computer resources supporting the project were abruptly cut due to their severe shortages at the funding agency. Nonetheless, it was shown that the extended methodologies could be viable options in optimizing the design of not only an isolated single-component configuration, but also a multiple-component configuration in supersonic and viscous flow. This allowed designing with the mutual interference of the components being one of the constraints all along the evolution of the shapes.

  14. Low Order Equivalent System Identification for the Tu-144LL Supersonic Transport Aircraft

    NASA Technical Reports Server (NTRS)

    Morelli, Eugene A.

    2000-01-01

    Low order equivalent system models were identified from flight test data for the Tu-144LL supersonic transport aircraft. Flight test maneuvers were executed by Russian and American test Pilots flying the aircraft from Zhukovsky airfield outside Moscow, Russia. Flight tests included longitudinal and lateral / directional maneuvers at supersonic cruise flight conditions. Piloted frequency sweeps and multi-step maneuvers were used to generate data for closed loop low order equivalent system modeling. Model parameters were estimated using a flexible. high accuracy Fourier transform and an equation error / output error (EE/OE) formulation in the frequency domain. Results were compared to parameter estimates obtained using spectral estimation and subsequent least squares fit to frequency response data in Bode plots. Modeling results from the two methods agreed well for both a frequency sweep and multiple concatenated multi-step maneuvers. For a single multi-step maneuvers the EE/OE method gave a better model fit with improved prediction capability. A summary of closed loop low order equivalent system identification results for the Tu-144LL, including estimated parameters, standard errors, and flying qualities level predictions, were computed and tabulated.

  15. Evaluation of High-Speed Civil Transport Handling Qualities Criteria with Supersonic Flight Data

    NASA Technical Reports Server (NTRS)

    Cox, Timothy H.; Jackson, Dante W.

    1997-01-01

    Most flying qualities criteria have been developed from data in the subsonic flight regime. Unique characteristics of supersonic flight raise questions about whether these criteria successfully extend into the supersonic flight regime. Approximately 25 years ago NASA Dryden Flight Research Center addressed this issue with handling qualities evaluations of the XB-70 and YF-12. Good correlations between some of the classical handling qualities parameters, such as the control anticipation parameter as a function of damping, were discovered. More criteria have been developed since these studies. Some of these more recent criteria are being used in designing the High-Speed Civil Transport (HSCT). A second research study recently addressed this issue through flying qualities evaluations of the SR-71 at Mach 3. The research goal was to extend the high-speed flying qualities experience of large airplanes and to evaluate more recent MIL-STD-1797 criteria against pilot comments and ratings. Emphasis was placed on evaluating the criteria used for designing the HSCT. XB-70 and YF-12 data from the previous research supplemented the SR-71 data. The results indicate that the criteria used in the HSCT design are conservative and should provide good flying qualities for typical high-speed maneuvering. Additional results show correlation between the ratings and comments and criteria for gradual maneuvering with precision control. Correlation is shown between ratings and comments and an extension of the Neal/Smith criterion using normal acceleration instead of pitch rate.

  16. Procedure for generating global atmospheric engine emissions data from future supersonic transport aircraft. The 1990 high speed civil transport studies

    NASA Technical Reports Server (NTRS)

    Sohn, R. A.; Stroup, J. W.

    1990-01-01

    The input for global atmospheric chemistry models was generated for baseline High Speed Civil Transport (HSCT) configurations at Mach 1.6, 2.2, and 3.2. The input is supplied in the form of number of molecules of specific exhaust constituents injected into the atmosphere per year by latitude and by altitude (for 2-D codes). Seven exhaust constituents are currently supplied: NO, NO2, CO, CO2, H2O, SO2, and THC (Trace Hydrocarbons). An eighth input is also supplied, NO(x), the sum of NO and NO2. The number of molecules of a given constituent emitted per year is a function of the total fuel burned by a supersonic fleet and the emission index (EI) of the aircraft engine for the constituent in question. The EIs for an engine are supplied directly by the engine manufacturers. The annual fuel burn of a supersonic fleet is calculated from aircraft performance and economic criteria, both of which are strongly dependent on basic design parameters such as speed and range. The altitude and latitude distribution of the emission is determined based on 10 Intern. Air Transport Assoc. (IATA) regions chosen to define the worldwide route structure for future HSCT operations and the mission flight profiles.

  17. Analysis and testing of stability augmentation systems. [for supersonic transport aircraft wing and B-52 aircraft control system

    NASA Technical Reports Server (NTRS)

    Sevart, F. D.; Patel, S. M.; Wattman, W. J.

    1972-01-01

    Testing and evaluation of stability augmentation systems for aircraft flight control were conducted. The flutter suppression system analysis of a scale supersonic transport wing model is described. Mechanization of the flutter suppression system is reported. The ride control synthesis for the B-52 aeroelastic model is discussed. Model analyses were conducted using equations of motion generated from generalized mass and stiffness data.

  18. Noise and economic characteristics of an advanced blended supersonic transport concept

    NASA Technical Reports Server (NTRS)

    Molloy, J. K.; Grantham, W. D.; Neubauer, M. J., Jr.

    1982-01-01

    Noise and economic characteristics were obtained for an advanced supersonic transport concept that utilized wing body blending, a double bypass variable cycle engine, superplastically formed and diffusion bonded titanium in both the primary and secondary structures, and an alternative interior arrangement that provides increased seating capacity. The configuration has a cruise Mach number of 2.62, provisions for 290 passengers, a mission range of 8.19 Mm (4423 n.mi.), and an average operating cruise lift drag ratio of 9.23. Advanced operating procedures, which have the potential to reduce airport community noise, were explored by using a simulator. Traded jet noise levels of 105.7 and 103.4 EPNdB were obtained by using standard and advanced takeoff operational procedures, respectively. A new method for predicting lateral attenuation was utilized in obtaining these jet noise levels.

  19. Cyclic-stress analysis of notches for supersonic transport conditions. [using finite element method

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The feasibility of using the finite element method to account for the effects of cyclic load and temperature on local stresses and strains at a notch was demonstrated. The behavior of a notched titanium panel was studied under variable loads and temperatures representative of flight conditions for the lower wing surface of a Supersonic Transport (SST). The analysis was performed with the use of the BOPACE finite-element computer program which provides capability to determine high temperature and large viscoplastic effects caused by cyclic thermal and mechanical loads. The analysis involves the development of the finite-element model as well as determination of the structural behavior of the notched panel. Results are presented for twelve SST flights comprised of five different load-temperature cycles. The results show the approach is feasible, but material response to cyclic loads, temperatures, and hold times requires improved understanding to allow proper modeling of the material.

  20. Electron trapping and transport by supersonic solitons in one-dimensional systems

    NASA Technical Reports Server (NTRS)

    Zmuidzinas, J. S.

    1978-01-01

    A one-dimensional chain of ions or molecules and electrons described by a Froehlich-type Hamiltonian with quartic phonon anharmonicities is investigated. It is shown that the anharmonic lattice supports supersonic solitons which under favorable circumstances may trap electrons and transport them along the lattice. For a lattice constant/soliton spatial extent quotient of the order of 0.1, rough estimates give electron trapping energies in the meV range. They imply a useful temperature range, up to tens of degrees K, for observing the new effect. The activation energy of a lattice soliton is proportional to the molecular mass and is therefore quite high (about 1 eV) for typical quasi-one-dimensional organic systems.

  1. A study to determine the feasibility of a low sonic boom supersonic transport

    NASA Technical Reports Server (NTRS)

    Kane, E. J.

    1973-01-01

    A study was made to determine the feasibility of supersonic transport configurations designed to produce a goal sonic boom signature with low overpressure. The results indicate that, in principle, such a concept represents a potentially realistic design approach assuming technology of the 1985 time period. Two sonic boom goals were selected which included: (1) A high speed design that would produce shock waves no stronger than 48 Newtons per square meter (1.0 psf); and an intermediate Mach number (mid-Mach) design that would produce shock waves no stronger than 24 Newtons per square meter. The high speed airplane design was a Mach 2.7 blended arrow wing configuration which was capable of carrying 183 passengers a distance of 7000 km (3780 nmi) while meeting the signature goal. The mid-Mach airplane designed was a Mach 1.5 low arrow wing configuration with a horizontal tail which could carry 180 passengers a distance of 5960 km (3220 nmi).

  2. Motion-base simulator results of advanced supersonic transport handling qualities with active controls

    NASA Technical Reports Server (NTRS)

    Feather, J. B.; Joshi, D. S.

    1981-01-01

    Handling qualities of the unaugmented advanced supersonic transport (AST) are deficient in the low-speed, landing approach regime. Consequently, improvement in handling with active control augmentation systems has been achieved using implicit model-following techniques. Extensive fixed-based simulator evaluations were used to validate these systems prior to tests with full motion and visual capabilities on a six-axis motion-base simulator (MBS). These tests compared the handling qualities of the unaugmented AST with several augmented configurations to ascertain the effectiveness of these systems. Cooper-Harper ratings, tracking errors, and control activity data from the MBS tests have been analyzed statistically. The results show the fully augmented AST handling qualities have been improved to an acceptable level.

  3. Supersonic laminar flow control

    NASA Technical Reports Server (NTRS)

    Bushnell, D. M.

    1992-01-01

    A development status evaluation is presented for the theoretical understanding and design conceptualization of boundary layer control (BLC) systems applicable to supersonic transports, such as the currently envisioned NASA High Speed Civil Transport. By reducing fuel burned, supersonic BLC techniques could expand ranges to Pacific-crossing scales, while lowering sonic boom effects and upper-atmosphere pollution and even reducing skin friction temperature. The critical consideration for supersonic BLC is the presence of wave effects.

  4. Reynolds Number Effects on a Supersonic Transport at Subsonic High-Lift Conditions (Invited)

    NASA Technical Reports Server (NTRS)

    Owens, L.R.; Wahls, R. A.

    2001-01-01

    A High Speed Civil Transport configuration was tested in the National Transonic Facility at the NASA Langley Research Center as part of NASA's High Speed Research Program. The primary purposes of the tests were to assess Reynolds number scale effects and high Reynolds number aerodynamic characteristics of a realistic, second generation supersonic transport while providing data for the assessment of computational methods. The tests included longitudinal and lateral/directional studies at transonic and low-speed, high-lift conditions across a range of Reynolds numbers from that available in conventional wind tunnels to near flight conditions. Results are presented which focus on Reynolds number and static aeroelastic sensitivities of longitudinal characteristics at Mach 0.30 for a configuration without an empennage. A fundamental change in flow-state occurred between Reynolds numbers of 30 to 40 million, which is characterized by significantly earlier inboard leading-edge separation at the high Reynolds numbers. Force and moment levels change but Reynolds number trends are consistent between the two states.

  5. Effect of supersonic molecular-beam injection on edge fluctuation and particle transport in Heliotron J

    SciTech Connect

    Zang, L. Kasajima, K.; Hashimoto, K.; Kenmochi, N.; Ohshima, S.; Mizuuchi, T.; Yamamoto, S.; Sha, M.; Nagasaki, K.; Kado, S.; Okada, H.; Minami, T.; Kobayashi, S.; Shi, N.; Konoshima, S.; Nakamura, Y.; Sano, F.; Nishino, N.; Takeuchi, M.; Mukai, K.; and others

    2014-04-15

    Edge fluctuation in a supersonic molecular-beam injection (SMBI) fueled plasma has been measured using an electrostatic probe array. After SMBI, the plasma stored energy (W{sub p}) temporarily decreased then started to increase. The local plasma fluctuation and fluctuation induced particle transport before and after SMBI have been analyzed. In a short duration (∼4 ms) just after SMBI, the density fluctuation of broad-band low frequency increased, and the probability density function (PDF) changed from a nearly Gaussian to a positively skewed non-Gaussian one. This suggests that intermittent structures were produced due to SMBI. Also the fluctuation induced particle transport was greatly enhanced during this short duration. About 4 ms after SMBI, the low frequency broad-band density fluctuation decreased, and the PDF returned to a nearly Gaussian shape. Also the fluctuation induced particle transport was reduced. Compared with conventional gas puff, W{sub p} degradation window is very short due to the short injection period of SMBI. After this short degradation window, fluctuation induced particle transport was reduced and W{sub p} started the climbing phase. Therefore, the short period of the influence to the edge fluctuation might be an advantage of this novel fueling technique. On the other hand, although their roles are not identified at present, coherent MHD modes are also suppressed as well by the application of SMBI. These MHD modes are thought to be de-exited due to a sudden change of the edge density and/or excitation conditions.

  6. A study of the effects of aeroelastic divergence on the wing structure of an oblique-wing supersonic transport configuration

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The aerodynamic characteristics of transport aircraft with oblique wing flying at supersonic speeds are discussed. Aeroelastic divergence of the forward swept portion of the wing is analyzed. The effect of aspect ratio as a method for avoiding aeroelastic divergence is examined. A relatively low aspect ratio appears necessary for an oblique wing when constructed of conventional aluminum alloy materials. The aspect ratio may be increased by increasing the wing thickness ratio and by utilizing materials with higher moduli of elasticity and rigidity.

  7. Analysis and testing of aeroelastic model stability augmentation systems. [for supersonic transport aircraft wing and B-52 aircraft control system

    NASA Technical Reports Server (NTRS)

    Sevart, F. D.; Patel, S. M.

    1973-01-01

    Testing and evaluation of a stability augmentation system for aircraft flight control were performed. The flutter suppression system and synthesis conducted on a scale model of a supersonic wing for a transport aircraft are discussed. Mechanization and testing of the leading and trailing edge surface actuation systems are described. The ride control system analyses for a 375,000 pound gross weight B-52E aircraft are presented. Analyses of the B-52E aircraft maneuver load control system are included.

  8. Controlling the potential hazards of government-sponsored technology. [such as weather modification and the supersonic transports

    NASA Technical Reports Server (NTRS)

    Wollan, M. J.

    1975-01-01

    The ability was examined of governmental agencies to adequately assess technological programs or projects to which they are committed. The hazards of government-sponsored activities are discussed; these include weather modification, supersonic transport noise, and the value conflicts involved in the fluoridation controversy. These three case studies indicate that the Federal vested interests in the continuation of its technological programs limit its ability to provide adequate technology assessment.

  9. Towards an Aero-Propulso-Servo-Elasticity Analysis of a Commercial Supersonic Transport

    NASA Technical Reports Server (NTRS)

    Connolly, Joseph W.; Kopasakis, George; Chwalowski, Pawel; Sanetrik, Mark D.; Carlson, Jan-Renee; Silva, Walt A.; McNamara, Jack

    2016-01-01

    This paper covers the development of an aero-propulso-servo-elastic (APSE) model using computational fluid dynamics (CFD) and linear structural deformations. The APSE model provides the integration of the following two previously developed nonlinear dynamic simulations: a variable cycle turbofan engine and an elastic supersonic commercial transport vehicle. The primary focus of this study is to provide a means to include relevant dynamics of a turbomachinery propulsion system into the aeroelastic studies conducted during a vehicle design, which have historically neglected propulsion effects. A high fidelity CFD tool is used here for the integration platform. The elastic vehicle neglecting the propulsion system serves as a comparison of traditional approaches to the APSE results. An overview of the methodology is presented for integrating the propulsion system and elastic vehicle. Static aeroelastic analysis comparisons between the traditional and developed APSE models for a wing tip detection indicate that the propulsion system impact on the vehicle elastic response could increase the detection by approximately ten percent.

  10. The Impact of Structural Vibration on Flying Qualities of a Supersonic Transport

    NASA Technical Reports Server (NTRS)

    Raney, David L.; Jackson, E. Bruce; Buttrill, Carey S.; Adams, William M.

    2001-01-01

    A piloted simulation experiment has been conducted in the NASA Langley Visual/Motion Simulator facility to address the impact of dynamic aeroelastic effects on flying qualities of a supersonic transport. The intent of this experiment was to determine the effectiveness of several measures that may be taken to reduce the impact of aircraft flexibility on piloting tasks. Potential solutions that were examined included structural stiffening, active vibration suppression, and elimination of visual cues associated with the elastic modes. A series of parametric configurations was evaluated by six test pilots for several types of maneuver tasks. During the investigation, several incidents were encountered in which cockpit vibrations due to elastic modes fed back into the control stick through involuntary motions of the pilot's upper body and arm. The phenomenon, referred to as biodynamic coupling, is evidenced by a resonant peak in the power spectrum of the pilot's stick inputs at a structural mode frequency. The results of the investigation indicate that structural stiffening and compensation of the visual display were of little benefit in alleviating the impact of elastic dynamics on the piloting tasks, while increased damping and elimination of control-effector excitation of the lowest frequency modes offered great improvements when applied in sufficient degree.

  11. Aeroelastic Tailoring Study of N+2 Low Boom Supersonic Commerical Transport Aircraft

    NASA Technical Reports Server (NTRS)

    Pak, Chan-Gi

    2015-01-01

    The Lockheed Martin N+2 Low - boom Supersonic Commercial Transport (LSCT) aircraft was optimized in this study through the use of a multidisciplinary design optimization tool developed at the National Aeronautics and S pace Administration Armstrong Flight Research Center. A total of 111 design variables we re used in the first optimization run. Total structural weight was the objective function in this optimization run. Design requirements for strength, buckling, and flutter we re selected as constraint functions during the first optimization run. The MSC Nastran code was used to obtain the modal, strength, and buckling characteristics. Flutter and trim analyses we re based on ZAERO code, and landing and ground control loads were computed using an in - house code. The w eight penalty to satisfy all the design requirement s during the first optimization run was 31,367 lb, a 9.4% increase from the baseline configuration. The second optimization run was prepared and based on the big-bang big-crunch algorithm. Six composite ply angles for the second and fourth composite layers were selected as discrete design variables for the second optimization run. Composite ply angle changes can't improve the weight configuration of the N+2 LSCT aircraft. However, this second optimization run can create more tolerance for the active and near active strength constraint values for future weight optimization runs.

  12. Estimation of Handling Qualities Parameters of the Tu-144 Supersonic Transport Aircraft from Flight Test Data

    NASA Technical Reports Server (NTRS)

    Curry, Timothy J.; Batterson, James G. (Technical Monitor)

    2000-01-01

    Low order equivalent system (LOES) models for the Tu-144 supersonic transport aircraft were identified from flight test data. The mathematical models were given in terms of transfer functions with a time delay by the military standard MIL-STD-1797A, "Flying Qualities of Piloted Aircraft," and the handling qualities were predicted from the estimated transfer function coefficients. The coefficients and the time delay in the transfer functions were estimated using a nonlinear equation error formulation in the frequency domain. Flight test data from pitch, roll, and yaw frequency sweeps at various flight conditions were used for parameter estimation. Flight test results are presented in terms of the estimated parameter values, their standard errors, and output fits in the time domain. Data from doublet maneuvers at the same flight conditions were used to assess the predictive capabilities of the identified models. The identified transfer function models fit the measured data well and demonstrated good prediction capabilities. The Tu-144 was predicted to be between level 2 and 3 for all longitudinal maneuvers and level I for all lateral maneuvers. High estimates of the equivalent time delay in the transfer function model caused the poor longitudinal rating.

  13. Preliminary study of turbojets with rotary flow inductors for a low-noise supersonic transport

    NASA Technical Reports Server (NTRS)

    Dugan, J. F., Jr.

    1973-01-01

    In a simplified airplane-mission study for a Mach 2.61 supersonic transport, dry turbojets with and without real suppressors and dry turbojets with ideal rotary flow inductors were studied for sideline noise levels as low as FAR 36-20. Compressor pressure ratio was varied from 5 to 30 and turbine temperature from 1800 to 3000 F. For no noise constraint and without a suppressor, the best dry turbojet gave a payload of 9.0 percent of gross weight and a sideline noise of 126 effective perceived noise decibels. Payload dropped rapidly for lower noise goals, becoming 6.3 percent of gross weight at FAR 36. At FAR 36, the turbojet with suppressor gave a payload of 8.3 percent and the turbojet with ideal rotary flow inductor, 7.3 percent. Below FAR 36, the ideal inductor was far superior to the real suppressor, giving payloads of 6.6 percent at FAR 36-10 and 5.7 percent at FAR 36-20.

  14. Technique for studying ablation-products transport in supersonic boundary layers by using PLIF of naphthalene

    NASA Astrophysics Data System (ADS)

    Combs, C. S.; Lochman, B. J.; Clemens, N. T.

    2016-05-01

    A technique is developed that uses planar laser-induced fluorescence (PLIF) of sublimated gas-phase naphthalene to visualize the transport of ablation products in a high-speed turbulent boundary layer. The naphthalene is molded into a rectangular insert that is mounted flush with the floor of a Mach 5 wind tunnel, where the test gas is air. The naphthalene fluorescence is excited with 266 nm laser light, and broadband detection of the emitted light is used. Using spectroscopic data from a previous study and a first-order approximation for the mean temperature profile across the boundary layer, naphthalene PLIF images collected in a Mach 5 turbulent boundary layer are converted into two-dimensional fields of naphthalene mole fraction with an instantaneous uncertainty of ±20 %. These quantitative naphthalene PLIF images in the Mach 5 boundary layer reveal large-scale naphthalene vapor structures that are regularly ejected out to wall distances of approximately y/ δ = 0.6 for a field of view that spans 3 δ-5 δ downstream of the trailing edge of the naphthalene insert. The magnitude of the calculated naphthalene mole fraction in these structures at y/ δ = 0.2 ranges from approximately 1 to 6 % of the saturation mole fraction at the wind tunnel recovery temperature and static pressure. Mean mole fraction profiles taken at different streamwise locations collapse into one "universal" mole fraction profile when properly normalized and are in agreement with previous scalar dispersion measurements. The results indicate that PLIF of sublimating naphthalene can be an effective tool for studying scalar transport in supersonic and hypersonic flows.

  15. Takeoff certification considerations for large subsonic and supersonic transport airplanes using the Ames flight simulator for advanced aircraft

    NASA Technical Reports Server (NTRS)

    Snyder, C. T.; Drinkwater, F. J., III; Fry, E. B.; Forrest, R. D.

    1973-01-01

    Data for use in development of takeoff airworthiness standards for new aircraft designs such as the supersonic transport (SST) and the large wide-body subsonic jet transport are provided. An advanced motion simulator was used to compare the performance and handling characteristics of three representative large jet transports during specific flight certification tasks. Existing regulatory constraints and methods for determining rotation speed were reviewed, and the effects on takeoff performance of variations in rotation speed, pitch attitude, and pitch attitude rate during the rotation maneuver were analyzed. A limited quantity of refused takeoff information was obtained. The aerodynamics, wing loading, and thrust-to-weight ratio of the subject SST resulted in takeoff speeds limited by climb (rather than lift-off) considerations. Take-off speeds based on U.S. subsonic transport requirements were found unacceptable because of the criticality of rotation-abuse effects on one-engine-inoperative climb performance. Adequate safety margin was provided by takeoff speeds based on proposed Anglo-French supersonic transport (TSS) criteria, with the limiting criterion being that takeoff safety speed be at least 1.15 times the one-engine-inoperative zero-rate-of-climb speed. Various observations related to SST certification are presented.

  16. Nonlinear Dynamic Modeling of a Supersonic Commercial Transport Turbo-Machinery Propulsion System for Aero-Propulso-Servo-Elasticity Research

    NASA Technical Reports Server (NTRS)

    Connolly, Joe; Carlson, Jan-Renee; Kopasakis, George; Woolwine, Kyle

    2015-01-01

    This paper covers the development of an integrated nonlinear dynamic model for a variable cycle turbofan engine, supersonic inlet, and convergent-divergent nozzle that can be integrated with an aeroelastic vehicle model to create an overall Aero-Propulso-Servo-Elastic (APSE) modeling tool. The primary focus of this study is to provide a means to capture relevant thrust dynamics of a full supersonic propulsion system by using relatively simple quasi-one dimensional computational fluid dynamics (CFD) methods that will allow for accurate control algorithm development and capture the key aspects of the thrust to feed into an APSE model. Previously, propulsion system component models have been developed and are used for this study of the fully integrated propulsion system. An overview of the methodology is presented for the modeling of each propulsion component, with a focus on its associated coupling for the overall model. To conduct APSE studies the described dynamic propulsion system model is integrated into a high fidelity CFD model of the full vehicle capable of conducting aero-elastic studies. Dynamic thrust analysis for the quasi-one dimensional dynamic propulsion system model is presented along with an initial three dimensional flow field model of the engine integrated into a supersonic commercial transport.

  17. Nonlinear Dynamic Modeling of a Supersonic Commercial Transport Turbo-Machinery Propulsion System for Aero-Propulso-Servo-Elasticity Research

    NASA Technical Reports Server (NTRS)

    Connolly, Joseph W.; Kopasakis, George; Carlson, Jan-Renee; Woolwine, Kyle

    2015-01-01

    This paper covers the development of an integrated nonlinear dynamic model for a variable cycle turbofan engine, supersonic inlet, and convergent-divergent nozzle that can be integrated with an aeroelastic vehicle model to create an overall Aero-Propulso-Servo-Elastic (APSE) modeling tool. The primary focus of this study is to provide a means to capture relevant thrust dynamics of a full supersonic propulsion system by using relatively simple quasi-one dimensional computational fluid dynamics (CFD) methods that will allow for accurate control algorithm development and capture the key aspects of the thrust to feed into an APSE model. Previously, propulsion system component models have been developed and are used for this study of the fully integrated propulsion system. An overview of the methodology is presented for the modeling of each propulsion component, with a focus on its associated coupling for the overall model. To conduct APSE studies the de- scribed dynamic propulsion system model is integrated into a high fidelity CFD model of the full vehicle capable of conducting aero-elastic studies. Dynamic thrust analysis for the quasi-one dimensional dynamic propulsion system model is presented along with an initial three dimensional flow field model of the engine integrated into a supersonic commercial transport.

  18. Data Driven Model Development for the SuperSonic SemiSpan Transport (S(sup 4)T)

    NASA Technical Reports Server (NTRS)

    Kukreja, Sunil L.

    2011-01-01

    In this report, we will investigate two common approaches to model development for robust control synthesis in the aerospace community; namely, reduced order aeroservoelastic modelling based on structural finite-element and computational fluid dynamics based aerodynamic models, and a data-driven system identification procedure. It is shown via analysis of experimental SuperSonic SemiSpan Transport (S4T) wind-tunnel data that by using a system identification approach it is possible to estimate a model at a fixed Mach, which is parsimonious and robust across varying dynamic pressures.

  19. Assessment of hoist failure rate for Payload Transporter III

    SciTech Connect

    Demmie, P.N.

    1994-02-01

    Assessment of the hoist failure rate for the Payload Transporter Type III (PT-III) hoist was completed as one of the ground transportation tasks for the Minuteman II (MMIII) Weapon System Safety Assessment. The failures of concern are failures that lead to dropping a reentry system (RS) during hoist operations in a silo or the assembly, storage, and inspection building for a MMIII wing. After providing a brief description of the PT-III hoist system, the author summarizes his search for historical data from industry and the military services for failures of electric hoist systems. Since such information was not found, the strategy for assessing a failure rate was to consider failure mechanisms which lead to load-drop accidents, estimate their rates, and sum the rates for the PT-III hoist failure rate. The author discusses failure mechanisms and describes his assessment of a chain failure rate that is based on data from destructive testing of a chain of the type used for the PT-III hoist and projected usage rates for hoist operations involving the RS. The main result provides upper bounds for chain failure rates that are based on these data. No test data were found to estimate failure rates due to mechanisms other than chain failure. The author did not attempt to quantify the effects of human factors on the PT-III hoist failure rate.

  20. An Overview of the Semi-Span Super-Sonic Transport (S4T) Wind-Tunnel Model Program

    NASA Technical Reports Server (NTRS)

    Silva, Walter A.; Perry, Boyd, III; Florance, James R.; Sanetrik, Mark D.; Wieseman, Carol D.; Stevens, William L.; Funk, Christie J.; Christhilf, David M.; Coulson, David A.

    2012-01-01

    A summary of computational and experimental aeroelastic (AE) and aeroservoelastic (ASE) results for the Semi-Span Super-Sonic Transport (S4T) wind-tunnel model is presented. A broad range of analyses and multiple AE and ASE wind-tunnel tests of the S4T wind-tunnel model have been performed in support of the ASE element in the Supersonics Program, part of the NASA Fundamental Aeronautics Program. This paper is intended to be an overview of multiple papers that comprise a special S4T technical session. Along those lines, a brief description of the design and hardware of the S4T wind-tunnel model will be presented. Computational results presented include linear and nonlinear aeroelastic analyses, and rapid aeroelastic analyses using CFD-based reduced-order models (ROMs). A brief survey of some of the experimental results from two open-loop and two closed-loop wind-tunnel tests performed at the NASA Langley Transonic Dynamics Tunnel (TDT) will be presented as well.

  1. Room-temperature ballistic transport in III-nitride heterostructures.

    PubMed

    Matioli, Elison; Palacios, Tomás

    2015-02-11

    Room-temperature (RT) ballistic transport of electrons is experimentally observed and theoretically investigated in III-nitrides. This has been largely investigated at low temperatures in low band gap III-V materials due to their high electron mobilities. However, their application to RT ballistic devices is limited by their low optical phonon energies, close to KT at 300 K. In addition, the short electron mean-free-path at RT requires nanoscale devices for which surface effects are a limitation in these materials. We explore the unique properties of wide band-gap III-nitride semiconductors to demonstrate RT ballistic devices. A theoretical model is proposed to corroborate experimentally their optical phonon energy of 92 meV, which is ∼4× larger than in other III-V semiconductors. This allows RT ballistic devices operating at larger voltages and currents. An additional model is described to determine experimentally a characteristic dimension for ballistic transport of 188 nm. Another remarkable property is their short carrier depletion at device sidewalls, down to 13 nm, which allows top-down nanofabrication of very narrow ballistic devices. These results open a wealth of new systems and basic transport studies possible at RT. PMID:25614931

  2. Study of structural design concepts for an arrow wing supersonic transport configuration, volume 1. Tasks 1 and 2

    NASA Technical Reports Server (NTRS)

    1976-01-01

    A structural design study was made, based on a 1975 level of technology, to assess the relative merits of structural concepts and materials for an advanced supersonic transport cruising at Mach 2.7. Preliminary studies were made to insure compliance of the configuration with general design criteria, to integrate the propulsion system with the airframe, to select structural concepts and materials, and to define an efficient structural arrangement. An advanced computerized structural design system was used, in conjunction with a relatively large, complex finite element model, for detailed analysis and sizing of structural members to satisfy strength and flutter criteria. A baseline aircraft design was developed for assessment of current technology and for use in future studies of aerostructural trades, and application of advanced technology. Criteria, analysis methods, and results are presented.

  3. Advanced Concept Studies for Supersonic Commercial Transports Entering Service in the 2018-2020 Period Phase 2

    NASA Technical Reports Server (NTRS)

    Morgenstern, John; Buonanno, Michael; Yao, Jixian; Murugappan, Mugam; Paliath, Umesh; Cheung, Lawrence; Malcevic, Ivan; Ramakrishnan, Kishore; Pastouchenko, Nikolai; Wood, Trevor; Martens, Steve; Viars, Phil; Tersmette, Trevor; Lee, Jason; Simmons, Ron; Plybon, David; Alonso, Juan; Palacios, Francisco; Lukaczyk, Trent; Carrier, Gerald

    2015-01-01

    Lockheed Martin Aeronautics Company (LM), working in conjunction with General Electric Global Research (GE GR) and Stanford University, executed a 19 month program responsive to the NASA sponsored "N+2 Supersonic Validation: Advanced Concept Studies for Supersonic Commercial Transports Entering Service in the 2018-2020 Period" contract. The key technical objective of this effort was to validate integrated airframe and propulsion technologies and design methodologies necessary to realize a supersonic vehicle capable of meeting the N+2 environmental and performance goals. The N+2 program is aligned with NASA's Supersonic Project and is focused on providing system level solutions capable of overcoming the efficiency, environmental, and performance barriers to practical supersonic flight. The N+2 environmental and performance goals are outlined in the technical paper, AIAA-2014-2138 (Ref. 1) along with the validated N+2 Phase 2 results. Our Phase 2 efforts built upon our Phase 1 studies (Ref. 2) and successfully demonstrated the ability to design and test realistic configurations capable of shaped sonic booms over the width of the sonic boom carpet. Developing a shaped boom configuration capable of meeting the N+2 shaped boom targets is a key goal for the N+2 program. During the LM Phase 1 effort, LM successfully designed and tested a shaped boom trijet configuration (1021) capable of achieving 85 PLdB under track (forward and aft shock) and up to 28 deg off-track at Mach 1.6. In Phase 2 we developed a refined configuration (1044-2) that extended the under 85 PLdB sonic boom level over the entire carpet of 52 deg off-track at a cruise Mach number of 1.7. Further, the loudness level of the configuration throughout operational conditions calculates to an average of 79 PLdB. These calculations rely on propagation employing Burger's (sBOOM) rounding methodology, and there are indications that the configuration average loudness would actually be 75 PLdB. We also added

  4. Design of Supersonic Transport Flap Systems for Thrust Recovery at Subsonic Speeds

    NASA Technical Reports Server (NTRS)

    Mann, Michael J.; Carlson, Harry W.; Domack, Christopher S.

    1999-01-01

    A study of the subsonic aerodynamics of hinged flap systems for supersonic cruise commercial aircraft has been conducted using linear attached-flow theory that has been modified to include an estimate of attainable leading edge thrust and an approximate representation of vortex forces. Comparisons of theoretical predictions with experimental results show that the theory gives a reasonably good and generally conservative estimate of the performance of an efficient flap system and provides a good estimate of the leading and trailing-edge deflection angles necessary for optimum performance. A substantial reduction in the area of the inboard region of the leading edge flap has only a minor effect on the performance and the optimum deflection angles. Changes in the size of the outboard leading-edge flap show that performance is greatest when this flap has a chord equal to approximately 30 percent of the wing chord. A study was also made of the performance of various combinations of individual leading and trailing-edge flaps, and the results show that aerodynamic efficiencies as high as 85 percent of full suction are predicted.

  5. Coannular nozzle noise characteristics and application to advanced supersonic transport engines

    NASA Technical Reports Server (NTRS)

    Kozlowski, H.

    1976-01-01

    Recent programs in the field of jet noise, sponsored by the NASA Lewis Research Center, have indicated that the variable stream control engines (VSCE) which are being considered for advanced supersonic cruise aircraft have inherent jet noise advantages over earlier engines. This characteristic is associated with the exit velocity profile produced by such an engine. The high velocity fan stream, on the outer periphery, is acoustically dominant while the primary stream is held to a low velocity and therefore contributes little to the overall noise. Scale model tests have indicated low noise levels. Operation under static conditions, as well as in a relative velocity field (simulating take-off speeds) has indicated large reductions are available from the coannular nozzle and the VSCE. The inherently low levels of jet noise prompted changes in the cycle, which allowed an increase in the amount of augmentation incorporated in the fan stream, without exceeding the suggested noise guidelines, thereby allowing the use of a considerably smaller engine, with obvious vehicle advantages.

  6. Stability and performance characteristics of a fixed arrow wing supersonic transport configuration (SCAT 15F-9898) at Mach numbers from 0.60 to 1.20

    NASA Technical Reports Server (NTRS)

    Decker, J. P.; Jacobs, P. F.

    1978-01-01

    Tests on a 0.015 scale model of a supersonic transport were conducted at Mach numbers from 0.60 to 1.20. Tests of the complete model with three wing planforms, two different leading-edge radii, and various combinations of component parts, including both leading- and trailing-edge flaps, were made over an angle-of-attack range from about -6 deg to 13 deg and at sideslip angles of 0 deg and 2 deg.

  7. Comparison of low-frequency noise levels of the Concorde supersonic transport with other commercial service airplanes

    NASA Technical Reports Server (NTRS)

    Powell, C. A.; Mccurdy, D. A.

    1978-01-01

    Fifty-two airplane noise recordings, made at several locations around Dulles International Airport, were analyzed to compare the low-frequency noise levels of the Concorde supersonic transport with those of other commercial jet airplanes. Comparisons of the relative low-frequency noise levels which were produced at close and distant locations for departures and arrivals were made for three noise measures: the sound pressure level in the 1/3 octave band centered at 20 Hz, the total sound pressure level in the 1/3 octave bands with center frequencies less than or equal to 125 Hz, and the total sound pressure level in the 1/3 octave bands with center frequencies less than or equal to 500 Hz. Although the absolute noise levels for Concorde were found, in general, to be higher than those for the other airplane types, the level of low-frequency noise of the Concorde relative to the perceived noise level (PNL), effective perceived noise level (EPNL), and overall sound pressure level (OASPL) was within the range established by the other airplane types, except for the arrival operations of four-engine, narrow-body airplanes. The measure OASPL was found to be a significantly better predictor of low-frequency noise level than PNL or EPNL.

  8. Incorporation of SemiSpan SuperSonic Transport (S4T) Aeroservoelastic Models into SAREC-ASV Simulation

    NASA Technical Reports Server (NTRS)

    Christhilf, David M.; Pototzky, Anthony S.; Stevens, William L.

    2010-01-01

    The Simulink-based Simulation Architecture for Evaluating Controls for Aerospace Vehicles (SAREC-ASV) was modified to incorporate linear models representing aeroservoelastic characteristics of the SemiSpan SuperSonic Transport (S4T) wind-tunnel model. The S4T planform is for a Technology Concept Aircraft (TCA) design from the 1990s. The model has three control surfaces and is instrumented with accelerometers and strain gauges. Control laws developed for wind-tunnel testing for Ride Quality Enhancement, Gust Load Alleviation, and Flutter Suppression System functions were implemented in the simulation. The simulation models open- and closed-loop response to turbulence and to control excitation. It provides time histories for closed-loop stable conditions above the open-loop flutter boundary. The simulation is useful for assessing the potential impact of closed-loop control rate and position saturation. It also provides a means to assess fidelity of system identification procedures by providing time histories for a known plant model, with and without unmeasured turbulence as a disturbance. Sets of linear models representing different Mach number and dynamic pressure conditions were implemented as MATLAB Linear Time Invariant (LTI) objects. Configuration changes were implemented by selecting which LTI object to use in a Simulink template block. A limited comparison of simulation versus wind-tunnel results is shown.

  9. A Reynolds Number Study of Wing Leading-Edge Effects on a Supersonic Transport Model at Mach 0.3

    NASA Technical Reports Server (NTRS)

    Williams, M. Susan; Owens, Lewis R., Jr.; Chu, Julio

    1999-01-01

    A representative supersonic transport design was tested in the National Transonic Facility (NTF) in its original configuration with small-radius leading-edge flaps and also with modified large-radius inboard leading-edge flaps. Aerodynamic data were obtained over a range of Reynolds numbers at a Mach number of 0.3 and angles of attack up to 16 deg. Increasing the radius of the inboard leading-edge flap delayed nose-up pitching moment to a higher lift coefficient. Deflecting the large-radius leading-edge flap produced an overall decrease in lift coefficient and delayed nose-up pitching moment to even higher angles of attack as compared with the undeflected large- radius leading-edge flap. At angles of attack corresponding to the maximum untrimmed lift-to-drag ratio, lift and drag coefficients decreased while lift-to-drag ratio increased with increasing Reynolds number. At an angle of attack of 13.5 deg., the pitching-moment coefficient was nearly constant with increasing Reynolds number for both the small-radius leading-edge flap and the deflected large-radius leading-edge flap. However, the pitching moment coefficient increased with increasing Reynolds number for the undeflected large-radius leading-edge flap above a chord Reynolds number of about 35 x 10 (exp 6).

  10. The Philosophy which underlies the structural tests of a supersonic transport aircraft with particular attention to the thermal cycle

    NASA Technical Reports Server (NTRS)

    Ripley, E. L.

    1972-01-01

    The information presented is based on data obtained from the Concorde. Much of this data also applies to other supersonic transport aircraft. The design and development of the Concorde is a joint effort of the British and French, and the structural test program is shared, as are all the other activities. Vast numbers of small specimens have been tested to determine the behavior of the materials used in the aircraft. Major components of the aircraft structure, totalling almost a complete aircraft, have been made and are being tested to help the constructors in each country in the design and development of the structure. Tests on two complete airframes will give information for the certification of the aircraft. A static test was conducted in France and a fatigue test in the United Kingdom. Fail-safe tests are being made to demonstrate the crack-propagation characteristics of the structure and its residual strength. Aspects of the structural test program are described in some detail, dealing particularly with the problems associated with the thermal cycle. The biggest of these problems is the setting up of the fatigue test on the complete airframe; therefore, this is covered more extensively with a discussion about how the test time can be shortened and with a description of the practical aspects of the test.

  11. Fatigue-test acceleration with flight-by-flight loading and heating to simulate supersonic-transport operation

    NASA Technical Reports Server (NTRS)

    Imig, L. A.; Garrett, L. E.

    1973-01-01

    Possibilities for reducing fatigue-test time for supersonic-transport materials and structures were studied in tests with simulated flight-by-flight loading. In order to determine whether short-time tests were feasible, the results of accelerated tests (2 sec per flight) were compared with the results of real-time tests (96 min per flight). The effects of design mean stress, the stress range for ground-air-ground cycles, simulated thermal stress, the number of stress cycles in each flight, and salt corrosion were studied. The flight-by-flight stress sequences were applied to notched sheet specimens of Ti-8Al-1Mo-1V and Ti-6Al-4V titanium alloys. A linear cumulative-damage analysis accounted for large changes in stress range of the simulated flights but did not account for the differences between real-time and accelerated tests. The fatigue lives from accelerated tests were generally within a factor of two of the lives from real-time tests; thus, within the scope of the investigation, accelerated testing seems feasible.

  12. Supersonic compressor

    DOEpatents

    Lawlor, Shawn P.; Novaresi, Mark A.; Cornelius, Charles C.

    2008-02-26

    A gas compressor based on the use of a driven rotor having an axially oriented compression ramp traveling at a local supersonic inlet velocity (based on the combination of inlet gas velocity and tangential speed of the ramp) which forms a supersonic shockwave axially, between adjacent strakes. In using this method to compress inlet gas, the supersonic compressor efficiently achieves high compression ratios while utilizing a compact, stabilized gasdynamic flow path. Operated at supersonic speeds, the inlet stabilizes an oblique/normal shock system in the gasdyanamic flow path formed between the gas compression ramp on a strake, the shock capture lip on the adjacent strake, and captures the resultant pressure within the stationary external housing while providing a diffuser downstream of the compression ramp.

  13. Transport Properties of III-N Hot Electron Transistors

    NASA Astrophysics Data System (ADS)

    Suntrup, Donald J., III

    Unipolar hot electron transistors (HETs) represent a tantalizing alternative to established bipolar transistor technologies. During device operation electrons are injected over a large emitter barrier into the base where they travel along the device axis with very high velocity. Upon arrival at the collector barrier, high-energy electrons pass over the barrier and contribute to collector current while low-energy electrons are quantum mechanically reflected back into the base. Designing the base with thickness equal to or less than the hot electron mean free path serves to minimize scattering events and thus enable quasi-ballistic operation. Large current gain is achieved by increasing the ratio of transmitted to reflected electrons. Although III-N HETs have undergone substantial development in recent years, there remain ample opportunities to improve key device metrics. In order to engineer improved device performance, a deeper understanding of the operative transport physics is needed. Fortunately, the HET provides fertile ground for studying several prominent electron transport phenomena. In this thesis we present results from several studies that use the III-N HET as both emitter and analyzer of hot electron momentum states. The first provides a measurement of the hot electron mean free path and the momentum relaxation rate in GaN; the second relies on a new technique called electron injection spectroscopy to investigate the effects of barrier height inhomogeneity in the emitter. To supplement our analysis we develop a comprehensive theory of coherent electron transport that allows us to model the transfer characteristics of complex heterojunctions. Such a model provides a theoretical touchstone with which to compare our experimental results. While these studies are of potential interest in their own right, we interpret the results with an eye toward improving next-generation device performance.

  14. Lessons in the Design and Characterization Testing of the Semi-Span Super-Sonic Transport (S4T) Wind-Tunnel Model

    NASA Technical Reports Server (NTRS)

    2012-01-01

    This paper focuses on some of the more challenging design processes and characterization tests of the Semi-Span Super-Sonic Transport (S4T)-Active Controls Testbed (ACT). The model was successfully tested in four entries in the National Aeronautics and Space Administration Langley Transonic Dynamics Tunnel to satisfy the goals and objectives of the Fundamental Aeronautics Program Supersonic Project Aero-Propulso-Servo-Elastic effort. Due to the complexity of the S4T-ACT, only a small sample of the technical challenges for designing and characterizing the model will be presented. Specifically, the challenges encountered in designing the model include scaling the Technology Concept Airplane to model scale, designing the model fuselage, aileron actuator, and engine pylons. Characterization tests included full model ground vibration tests, wing stiffness measurements, geometry measurements, proof load testing, and measurement of fuselage static and dynamic properties.

  15. An Overview of Preliminary Computational and Experimental Results for the Semi-Span Super-Sonic Transport (S4T) Wind-Tunnel Model

    NASA Technical Reports Server (NTRS)

    Silva, Walter A.; Perry, Boyd, III; Florance, James R.; Sanetrik, Mark D.; Wieseman, Carol D.; Stevens, William L.; Funk, Christie J.; Hur, Jiyoung; Christhilf, David M.; Coulson, David A.

    2011-01-01

    A summary of computational and experimental aeroelastic and aeroservoelastic (ASE) results for the Semi-Span Super-Sonic Transport (S4T) wind-tunnel model is presented. A broad range of analyses and multiple ASE wind-tunnel tests of the S4T have been performed in support of the ASE element in the Supersonics Program, part of NASA's Fundamental Aeronautics Program. The computational results to be presented include linear aeroelastic and ASE analyses, nonlinear aeroelastic analyses using an aeroelastic CFD code, and rapid aeroelastic analyses using CFD-based reduced-order models (ROMs). Experimental results from two closed-loop wind-tunnel tests performed at NASA Langley's Transonic Dynamics Tunnel (TDT) will be presented as well.

  16. The conceptual design of a Mach 2 Oblique Flying Wing supersonic transport

    NASA Technical Reports Server (NTRS)

    Vandervelden, Alexander J. M.

    1989-01-01

    This paper is based on a performance and economics study of a Mach two oblique flying wing transport aircraft that is to replace the B747B. In order to fairly compare our configuration with the B747B an equal structural technology level is assumed. It will be shown that the oblique flying wing configuration will equal or outperform the B747 in speed, economy and comfort while a modern stability and control system will balance the aircraft and smooth out gusts. The aircraft is designed to comply with the FAR25 airworthiness requirements and FAR36 stage 3 noise regulations. Geometry, aerodynamics, stability and control parameters of the oblique flying wing transport are discussed.

  17. Data Driven Model Development for the Supersonic Semispan Transport (S(sup 4)T)

    NASA Technical Reports Server (NTRS)

    Kukreja, Sunil L.

    2011-01-01

    We investigate two common approaches to model development for robust control synthesis in the aerospace community; namely, reduced order aeroservoelastic modelling based on structural finite-element and computational fluid dynamics based aerodynamic models and a data-driven system identification procedure. It is shown via analysis of experimental Super- Sonic SemiSpan Transport (S4T) wind-tunnel data using a system identification approach it is possible to estimate a model at a fixed Mach, which is parsimonious and robust across varying dynamic pressures.

  18. Characteristics of Control Laws Tested on the Semi-Span Super-Sonic Transport (S4T) Wind-Tunnel Model

    NASA Technical Reports Server (NTRS)

    Christhilf, David M.; Moulin, Boris; Ritz, Erich; Chen, P. C.; Roughen, Kevin M.; Perry, Boyd

    2012-01-01

    The Semi-Span Supersonic Transport (S4T) is an aeroelastically scaled wind-tunnel model built to test active controls concepts for large flexible supersonic aircraft in the transonic flight regime. It is one of several models constructed in the 1990's as part of the High Speed Research (HSR) Program. Control laws were developed for the S4T by M4 Engineering, Inc. and by Zona Technologies, Inc. under NASA Research Announcement (NRA) contracts. The model was tested in the NASA-Langley Transonic Dynamics Tunnel (TDT) four times from 2007 to 2010. The first two tests were primarily for plant identification. The third entry was used for testing control laws for Ride Quality Enhancement, Gust Load Alleviation, and Flutter Suppression. Whereas the third entry only tested FS subcritically, the fourth test demonstrated closed-loop operation above the open-loop flutter boundary. The results of the third entry are reported elsewhere. This paper reports on flutter suppression results from the fourth wind-tunnel test. Flutter suppression is seen as a way to provide stability margins while flying at transonic flight conditions without penalizing the primary supersonic cruise design condition. An account is given for how Controller Performance Evaluation (CPE) singular value plots were interpreted with regard to progressing open- or closed-loop to higher dynamic pressures during testing.

  19. Reynolds Number Effects on the Stability and Control Characteristics of a Supersonic Transport

    NASA Technical Reports Server (NTRS)

    Owens, L. R.; Wahls, R. A.; Elzey, M. B.; Hamner, M. P.

    2002-01-01

    A High Speed Civil Transport (HSCT) configuration was tested in the National Transonic Facility at the NASA Langley Research Center as part of NASA's High Speed Research Program. A series of tests included longitudinal and lateral/directional studies at transonic and low speed, high-lift conditions across a range of Reynolds numbers from that available in conventional wind tunnels to near flight conditions. Results presented focus on Reynolds number sensitivities of the stability and control characteristics at Mach 0.30 and 0.95 for a complete HSCT aircraft configuration including empennage. The angle of attack where the pitching-moment departure occurred increased with higher Reynolds numbers for both the landing and transonic configurations. The stabilizer effectiveness increased with Reynolds number for both configurations. The directional stability also increased with Reynolds number for both configurations. The landing configuration without forebody chines exhibited a large yawing-moment departure at high angles of attack and zero sideslip that varied with increasing Reynolds numbers. This departure characteristic nearly disappeared when forebody chines were added. The landing configuration's rudder effectiveness also exhibited sensitivities to changes in Reynolds number.

  20. Simulator study of the low-speed handling qualities of a supersonic cruise arrow-wing transport configuration during approach and landing

    NASA Technical Reports Server (NTRS)

    Grantham, W. D.; Nguyen, L. T.; Neubauer, M. J., Jr.; Smith, P. M.

    1976-01-01

    A fixed-based simulator study was conducted to determine the low-speed flight characteristics of an advanced supersonic cruise transport having an arrow wing, a horizontal tail, and four dry turbojets with variable geometry turbines. The primary piloting task was the approach and landing. The statically unstable (longitudinally) subject configuration has unacceptable low-speed handling qualities with no augmentation. Therefore, a hardened stability augmentation system is required to achieve acceptable handling qualities, should the normal operational stability and control augmentation system fail. In order to achieve satisfactory handling qualities, considerable augmentation was required.

  1. 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.

  2. Selective transport of Fe(III) using ionic imprinted polymer (IIP) membrane particle

    NASA Astrophysics Data System (ADS)

    Djunaidi, Muhammad Cholid; Jumina, Siswanta, Dwi; Ulbricht, Mathias

    2015-12-01

    The membrane particles was prepared from polyvinyl alcohol (PVA) and polymer IIP with weight ratios of 1: 2 and 1: 1 using different adsorbent templates and casting thickness. The permeability of membrane towards Fe(III) and also mecanism of transport were studied. The selectivity of the membrane for Fe(III) was studied by performing adsorption experiments also with Cr(III) separately. In this study, the preparation of Ionic Imprinted Polymer (IIP) membrane particles for selective transport of Fe (III) had been done using polyeugenol as functional polymer. Polyeugenol was then imprinted with Fe (III) and then crosslinked with PEGDE under alkaline condition to produce polyeugenol-Fe-PEGDE polymer aggregates. The agrregates was then crushed and sieved using mesh size of 80 and the powder was then used to prepare the membrane particles by mixing it with PVA (Mr 125,000) solution in 1-Methyl-2-pyrrolidone (NMP) solvent. The membrane was obtained after casting at a speed of 25 m/s and soaking in NaOH solution overnight. The membrane sheet was then cut and Fe(III) was removed by acid to produce IIP membrane particles. Analysis of the membrane and its constituent was done by XRD, SEM and size selectivity test. Experimental results showed the transport of Fe(III) was faster with the decrease of membrane thickness, while the higher concentration of template ion correlates with higher Fe(III) being transported. However, the transport of Fe(III) was slower for higher concentration of PVA in the membrane. IImparticles works through retarded permeation mechanism, where Fe(III) was bind to the active side of IIP. The active side of IIP membrane was dominated by the -OH groups. The selectivity of all IIP membranes was confirmed as they were all unable to transport Cr (III), while NIP (Non-imprinted Polymer) membrane was able transport Cr (III).

  3. Supersonic compressor

    DOEpatents

    Roberts, II, William Byron; Lawlor, Shawn P.; Breidenthal, Robert E.

    2016-04-12

    A supersonic compressor including a rotor to deliver a gas at supersonic conditions to a diffuser. The diffuser includes a plurality of aerodynamic ducts that have converging and diverging portions, for deceleration of gas to subsonic conditions and then for expansion of subsonic gas, to change kinetic energy of the gas to static pressure. The aerodynamic ducts include vortex generating structures for controlling boundary layer, and structures for changing the effective contraction ratio to enable starting even when the aerodynamic ducts are designed for high pressure ratios, and structures for boundary layer control. In an embodiment, aerodynamic ducts are provided having an aspect ratio of in excess of two to one, when viewed in cross-section orthogonal to flow direction at an entrance to the aerodynamic duct.

  4. 46 CFR Appendix III to Part 390 - U.S. Department of Transportation, Maritime Administration-Sample Semiannual Report

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 8 2013-10-01 2013-10-01 false U.S. Department of Transportation, Maritime Administration-Sample Semiannual Report III Appendix III to Part 390 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION REGULATIONS UNDER PUBLIC LAW 91-469 CAPITAL CONSTRUCTION FUND Pt. 390, App. III Appendix III to Part 390—U.S. Department...

  5. 46 CFR Appendix III to Part 390 - U.S. Department of Transportation, Maritime Administration-Sample Semiannual Report

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false U.S. Department of Transportation, Maritime Administration-Sample Semiannual Report III Appendix III to Part 390 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION REGULATIONS UNDER PUBLIC LAW 91-469 CAPITAL CONSTRUCTION FUND Pt. 390, App. III Appendix III to Part 390—U.S. Department...

  6. Supersonic market and economic analyses

    NASA Technical Reports Server (NTRS)

    Rochte, L. S.

    1980-01-01

    Advanced supersonic transport markets of the free world were projected for the period 1985 to 2004. Passenger traffic volume and airplane range and seat capacity requirements were estimated for Mach 2.2 service by international regional area market areas and by city pairs within and between these areas. Market factors and traffic factors examined include variable loads, growth rates, supersonic transport market shares, and schedule frequencies considering the different makeup of passenger traffic and individual city pairs. Direct, indirect, and total operating costs and yield levels were economically analyzed for first class and full fare economy class traffic.

  7. Diversity in ABC transporters: Type I, II and III importers

    PubMed Central

    Rice, Austin J.; Park, Aekyung

    2014-01-01

    ATP-binding cassette transporters are multi-subunit membrane pumps that transport substrates across membranes. While significant in the transport process, transporter architecture exhibits a range of diversity that we are only beginning to recognize. This divergence may provide insight into the mechanisms of substrate transport and homeostasis. Until recently, ABC importers have been classified into two types, but with the emergence of energy-coupling factor (ECF) transporters there are potentially three types of ABC importers. In this review, we summarize an expansive body of research on the three types of importers with an emphasis on the basics that underlie ABC importers, such as structure, subunit composition and mechanism. PMID:25155087

  8. Turbofan Volume Dynamics Model for Investigations of Aero-Propulso-Servo-Elastic Effects in a Supersonic Commercial Transport

    NASA Technical Reports Server (NTRS)

    Connolly, Joseph W.; Kopasakis, George; Lemon, Kimberly A.

    2010-01-01

    A turbofan simulation has been developed for use in aero-propulso-servo-elastic coupling studies, on supersonic vehicles. A one-dimensional lumped volume approach is used whereby each component (fan, high-pressure compressor, combustor, etc.) is represented as a single volume using characteristic performance maps and conservation equations for continuity, momentum and energy. The simulation is developed in the MATLAB/SIMULINK (The MathWorks, Inc.) environment in order to facilitate controls development, and ease of integration with a future aero-servo-elastic vehicle model being developed at NASA Langley. The complete simulation demonstrated steady state results that closely match a proposed engine suitable for a supersonic business jet at the cruise condition. Preliminary investigation of the transient simulation revealed expected trends for fuel flow disturbances as well as upstream pressure disturbances. A framework for system identification enables development of linear models for controller design. Utilizing this framework, a transfer function modeling an upstream pressure disturbance s impacts on the engine speed is developed as an illustrative case of the system identification. This work will eventually enable an overall vehicle aero-propulso-servo-elastic model

  9. A Full Navier-Stokes Analysis of Subsonic Diffuser of a Bifurcated 70/30 Supersonic Inlet for High Speed Civil Transport Application

    NASA Technical Reports Server (NTRS)

    Kapoor, Kamlesh; Anderson, Bernhard H.; Shaw, Robert J.

    1994-01-01

    A full Navier-Stokes analysis was performed to evaluate the performance of the subsonic diffuser of a NASA Lewis Research Center 70/30 mixed-compression bifurcated supersonic inlet for high speed civil transport application. The PARC3D code was used in the present study. The computations were also performed when approximately 2.5 percent of the engine mass flow was allowed to bypass through the engine bypass doors. The computational results were compared with the available experimental data which consisted of detailed Mach number and total pressure distribution along the entire length of the subsonic diffuser. The total pressure recovery, flow distortion, and crossflow velocity at the engine face were also calculated. The computed surface ramp and cowl pressure distributions were compared with experiments. Overall, the computational results compared well with experimental data. The present CFD analysis demonstrated that the bypass flow improves the total pressure recovery and lessens flow distortions at the engine face.

  10. A simulator study for the development and evaluation of operating procedures on a supersonic cruise research transport to minimize airport-community noise

    NASA Technical Reports Server (NTRS)

    Grantham, W. D.; Smith, P. M.; Deal, P. L.

    1980-01-01

    Piloted-simulator studies were conducted to determine takeoff and landing operating procedures for a supersonic cruise research transport concept that result in predicted noise levels which meet current Federal Aviation Administration (FAA) certification standards. With the use of standard FAA noise certification test procedures, the subject simulated aircraft did not meet the FAA traded-noise-level standards during takeoff and landing. However, with the use of advanced procedures, this aircraft meets the traded-noise-level standards for flight crews with average skills. The advanced takeoff procedures developed involved violating some of the current Federal Aviation Regulations (FAR), but it was not necessary to violate any FAR noise-test conditions during landing approach. Noise contours were also determined for some of the simulated takeoffs and landings in order to indicate the noise-reduction advantages of using operational procedures other than standard.

  11. Low-speed wind-tunnel tests of a large scale blended arrow advanced supersonic transport model having variable cycle engines and vectoring exhaust nozzles

    NASA Technical Reports Server (NTRS)

    Parlett, L. P.; Shivers, J. P.

    1976-01-01

    A low-speed wind-tunnel investigation was conducted in a full-scale tunnel to determine the performance and static stability and control characteristics of a large-scale model of a blended-arrow advanced supersonic transport configuration incorporating variable-cycle engines and vectoring exhaust nozzles. Configuration variables tested included: (1) engine mode (cruise or low-speed), (2) engine exit nozzle deflection, (3) leading-edge flap geometry, and (4) trailing-edge flap deflection. Test variables included values of C sub micron from 0 to 0.38, values of angle of attack from -10 degrees to 30 degrees, values of angle of sideslip, from -5 degrees to 5 degrees, and values of Reynolds number, from 3.5 million to 6.8 million.

  12. Low-speed wind-tunnel investigation of a large scale advanced arrow-wing supersonic transport configuration with engines mounted above wing for upper-surface blowing

    NASA Technical Reports Server (NTRS)

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

    1976-01-01

    Tests have been conducted in a full scale tunnel to determine the low speed aerodynamic characteristics of a large scale advanced arrow wing supersonic transport configuration with engines mounted above the wing for upper surface blowing. Tests were made over an angle of attack range of -10 deg to 32 deg, sideslip angles of + or - 5 deg, and a Reynolds number range of 3,530,000 to 7,330,000. Configuration variables included trailing edge flap deflection, engine jet nozzle angle, engine thrust coefficient, engine out operation, and asymmetrical trailing edge boundary layer control for providing roll trim. Downwash measurements at the tail were obtained for different thrust coefficients, tail heights, and at two fuselage stations.

  13. Semiconducting III-V nanowires with nanogaps for molecular junctions: DFT transport simulations.

    PubMed

    Kallesøe, Christian; Fürst, Joachim A; Mølhave, Kristian; Bøggild, Peter; Brandbyge, Mads

    2009-11-18

    We consider here the possibility of using III-V heterostructure nanowires as electrodes for molecular electronics instead of metal point contacts. Using ab initio electronic structure and transport calculations, we study the effect on electronic properties of placing a small molecule with thiol linking groups, benzene-di-thiol (BDT), within a nanosize gap in a III-V nanowire. Furthermore, it is investigated how surface states affect the transport through pristine III-V nanowires and through the BDT molecule situated within the nanogap. Using GaAs and GaP as III-V materials we find that the BDT molecule provides transport through the entire system comparable to the case of gold electrodes. PMID:19843997

  14. Suspended-Sediment Transport Rates for Level III Ecoregions of EPA Region 4: the Southeast

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Historic flow and sediment transport data from about 750 sites across the southeastern United States were analyzed for the purpose of developing "background" or "reference" rates of suspended-sediment transport by Level III ecoregion. Rapid Geomorphic Assessments (RGAs) were conducted at most sites...

  15. Reaction-based reactive transport modeling of Fe(III)

    SciTech Connect

    Kemner, K.M.; Kelly, S.D.; Burgos, Bill; Roden, Eric

    2006-06-01

    This research project (started Fall 2004) was funded by a grant to Argonne National Laboratory, The Pennsylvania State University, and The University of Alabama in the Integrative Studies Element of the NABIR Program (DE-FG04-ER63914/63915/63196). Dr. Eric Roden, formerly at The University of Alabama, is now at the University of Wisconsin, Madison. Our project focuses on the development of a mechanistic understanding and quantitative models of coupled Fe(III)/U(VI) reduction in FRC Area 2 sediments. This work builds on our previous studies of microbial Fe(III) and U(VI) reduction, and is directly aligned with the Scheibe et al. NABIR FRC Field Project at Area 2.

  16. Supersonic through-flow fan assessment

    NASA Technical Reports Server (NTRS)

    Kepler, C. E.; Champagne, G. A.

    1988-01-01

    A study was conducted to assess the performance potential of a supersonic through-flow fan engine for supersonic cruise aircraft. It included a mean-line analysis of fans designed to operate with in-flow velocities ranging from subsonic to high supersonic speeds. The fan performance generated was used to estimate the performance of supersonic fan engines designed for four applications: a Mach 2.3 supersonic transport, a Mach 2.5 fighter, a Mach 3.5 cruise missile, and a Mach 5.0 cruise vehicle. For each application an engine was conceptualized, fan performance and engine performance calculated, weight estimates made, engine installed in a hypothetical vehicle, and mission analysis was conducted.

  17. Economic benefits of supersonic overland operation

    NASA Technical Reports Server (NTRS)

    Metwally, Munir

    1992-01-01

    Environmental concerns are likely to impose some restrictions on the next generation of supersonic commercial transport. There is a global concern over the effects of engine emissions on the ozone layer which protects life on Earth from ultraviolet radiation. There is also some concern over community noise. The High Speed Civil Transport (HSCT) must meet at least the current subsonic noise certification standards to be compatible with the future subsonic fleet. Concerns over sonic boom represent another environmental and marketing challenge to the HSCT program. The most attractive feature of the supersonic transport is speed, which offers the traveling public significant time-savings on long range routes. The sonic boom issue represents a major environmental and economic challenge as well. Supersonic operation overland produces the most desirable economic results. However, unacceptable overland sonic boom raise levels may force HSCT to use subsonic speeds overland. These environmental and economic challenges are likely to impose some restrictions on supersonic operation, thus introducing major changes to existing route structures and future supersonic network composition. The current subsonic route structure may have to be altered for supersonic transports to avoid sensitive areas in the stratosphere or to minimize overland flight tracks. It is important to examine the alternative route structure and the impact of these restrictions on the economic viability of the overall supersonic operation. Future market potential for HSCT fleets must be large enough to enable engine and airframe manufacturers to build the plane at a cost that provides them with an attractive return on investment and to sell it at a price that allows the airlines to operate with a reasonable margin of profit. Subsonic overland operation of a supersonic aircraft hinders its economic viability. Ways to increase the market potential of supersonic operation are described.

  18. NASA's Role in Aeronautics: A Workshop. Volume III - Transport Aircraft.

    ERIC Educational Resources Information Center

    National Academy of Sciences - National Research Council, Washington, DC. Assembly of Engineering.

    The central task of a 1980 workshop on the role of the National Aeronautics and Space Administration (NASA) in aeronautics was to examine the relationship of NASA's research capabilities to the state of U.S. aviation and to make recommendations about NASA's future role in aeronautics. The specific task of the Panel on Transport Aircraft was to…

  19. System-Level Experimental Validations for Supersonic Commercial Transport Aircraft Entering Service in the 2018-2020 Time Period

    NASA Technical Reports Server (NTRS)

    Magee, Todd E.; Wilcox, Peter A.; Fugal, Spencer R.; Acheson, Kurt E.; Adamson, Eric E.; Bidwell, Alicia L.; Shaw, Stephen G.

    2013-01-01

    This report describes the work conducted by The Boeing Company under American Recovery and Reinvestment Act (ARRA) and NASA funding to experimentally validate the conceptual design of a supersonic airliner feasible for entry into service in the 2018 to 2020 timeframe (NASA N+2 generation). The report discusses the design, analysis and development of a low-boom concept that meets aggressive sonic boom and performance goals for a cruise Mach number of 1.8. The design is achieved through integrated multidisciplinary optimization tools. The report also describes the detailed design and fabrication of both sonic boom and performance wind tunnel models of the low-boom concept. Additionally, a description of the detailed validation wind tunnel testing that was performed with the wind tunnel models is provided along with validation comparisons with pretest Computational Fluid Dynamics (CFD). Finally, the report describes the evaluation of existing NASA sonic boom pressure rail measurement instrumentation and a detailed description of new sonic boom measurement instrumentation that was constructed for the validation wind tunnel testing.

  20. N plus 3 Advanced Concept Studies for Supersonic Commercial Transport Aircraft Entering Service in the 2030-2035 Period

    NASA Technical Reports Server (NTRS)

    Welge, H. Robert; Bonet, John; Magee, Todd; Tompkins, Daniel; Britt, Terry R.; Nelson, Chet; Miller, Gregory; Stenson, Douglas; Staubach, J. Brent; Bala, Naushir; Duge, Robert; OBrien, Mark; Cedoz, Robert; Barlow, Andrew; Martins, Steve; Viars, Phil; Rasheed, Adam; Kirby, Michelle; Raczynski, Chris; Roughen, Kevin; Doyle, Steven; Alston, Katherine; Page, Juliet; Plotkin, Kenneth J.

    2011-01-01

    Boeing, with Pratt & Whitney, General Electric, Rolls-Royce, M4 Engineering, Wyle Laboratories and Georgia Institute of Technology, conducted a study of supersonic commercial aircraft concepts and enabling technologies for the year 2030-2035 timeframe. The work defined the market and environmental/regulatory conditions that could evolve by the 2030/35 time period, from which vehicle performance goals were derived. Relevant vehicle concepts and technologies are identified that are anticipated to meet these performance and environmental goals. A series of multidisciplinary analyses trade studies considering vehicle sizing, mission performance and environmental conformity determined the appropriate concepts. Combinations of enabling technologies and the required technology performance levels needed to meet the desired goals were identified. Several high priority technologies are described in detail, including roadmaps with risk assessments that outline objectives, key technology challenges, detailed tasks and schedules and demonstrations that need to be performed. A representative configuration is provided for reference purposes, along with associated performance estimates based on these key technologies.

  1. Supersonic throughflow fans

    NASA Technical Reports Server (NTRS)

    Ball, C. L.; Moore, R. D.

    1988-01-01

    Supersonic throughflow fan research, and technology needs are reviewed. The design of a supersonic throughflow fan stage, a facility inlet, and a downstream diffuser is described. The results from the analysis codes used in executing the design are shown. An engine concept intended to permit establishing supersonic throughflow within the fan on the runway and maintaining the supersonic throughflow condition within the fan throughout the flight envelope is presented.

  2. System-Level Experimental Validations for Supersonic Commercial Transport Aircraft Entering Service in the 2018-2020 Time Period

    NASA Technical Reports Server (NTRS)

    Magee, Todd E.; Fugal, Spencer R.; Fink, Lawrence E.; Adamson, Eric E.; Shaw, Stephen G.

    2015-01-01

    This report describes the work conducted under NASA funding for the Boeing N+2 Supersonic Experimental Validation project to experimentally validate the conceptual design of a supersonic airliner feasible for entry into service in the 2018 -to 2020 timeframe (NASA N+2 generation). The primary goal of the project was to develop a low-boom configuration optimized for minimum sonic boom signature (65 to 70 PLdB). This was a very aggressive goal that could be achieved only through integrated multidisciplinary optimization tools validated in relevant ground and, later, flight environments. The project was split into two phases. Phase I of the project covered the detailed aerodynamic design of a low boom airliner as well as the wind tunnel tests to validate that design (ref. 1). This report covers Phase II of the project, which continued the design methodology development of Phase I with a focus on the propulsion integration aspects as well as the testing involved to validate those designs. One of the major airplane configuration features of the Boeing N+2 low boom design was the overwing nacelle. The location of the nacelle allowed for a minimal effect on the boom signature, however, it added a level of difficulty to designing an inlet with acceptable performance in the overwing flow field. Using the Phase I work as the starting point, the goals of the Phase 2 project were to design and verify inlet performance while maintaining a low-boom signature. The Phase II project was successful in meeting all contract objectives. New modular nacelles were built for the larger Performance Model along with a propulsion rig with an electrically-actuated mass flow plug. Two new mounting struts were built for the smaller Boom Model, along with new nacelles. Propulsion integration testing was performed using an instrumented fan face and a mass flow plug, while boom signatures were measured using a wall-mounted pressure rail. A side study of testing in different wind tunnels was

  3. Probabilistic description of particle transport. III. Inelastic scattering

    SciTech Connect

    Goulet, T.; Keszei, E.; Jay-Gerin, J. Departement de Medecine Nucleaire et de Radiobiologie, Faculte de Medecine, Universite de Sherbrooke, Sherbrooke, PQ )

    1990-06-01

    We extend our probabilistic model of quasielastic particle transport to include possible inelastic scatterings of the particles in the bulk of the studied media. We show that this extended model can be used to describe different types of experiments involving electrons that go through or are reflected by a plane-parallel layer deposited on a substrate. In particular, we reanalyze the experimental results of low-energy ({approx lt}10 eV) electron transmission through solid xenon and solid molecular nitrogen. This analysis shows that the extended model is consistent with the quasielastic one, but is more powerful since we can now determine both the elastic and inelastic electron mean free paths. The analysis allows one to study the threshold creation of excitons that can be observed at about 8.5 and 9.5 eV in solid xenon, and around 7.5 eV in solid molecular nitrogen.

  4. Supersonic gas jets

    NASA Astrophysics Data System (ADS)

    Dulov, V. G.

    The papers presented in this volume provide an overview of the current state of research in the gas dynamics of jet flows. In particular, attention is given to free supersonic jets and to the interaction of supersonic jets with one another and with obstacles under stationary and nonstationary flow conditions. Papers are presented on a method for calculating a weakly anisotropic supersonic turbulent jet in a subsonic slipstream; composite supersonic jets; the principal gas-dynamic characteristics of the processes occurring in gas-jet-driven shock-wave generators; and the construction of models for supersonic jet flows. For individual items see A84-16902 to A84-16918

  5. ARSENIC TRANSPORT AND FATE IN SULFIDIC ENVIRONMENTS: AS(III) - FES INTERACTIONS: SYMPOSIUM

    EPA Science Inventory

    NRMRL-ADA-01151 Wilkin*, R.T., Ford*, R., and Wallschlaeger, D. "Arsenic Transport and Fate in Sulfidic Environments: As(III) - FeS Interactions." In: Geological Society of America, Abstracts with Programs, Geological Society of America Annual Meeting, Boston, MA, 11/05-08/2001....

  6. Analytical and Experimental Evaluation of Digital Control Systems for the Semi-Span Super-Sonic Transport (S4T) Wind Tunnel Model

    NASA Technical Reports Server (NTRS)

    Wieseman, Carol D.; Christhilf, David; Perry, Boyd, III

    2012-01-01

    An important objective of the Semi-Span Super-Sonic Transport (S4T) wind tunnel model program was the demonstration of Flutter Suppression (FS), Gust Load Alleviation (GLA), and Ride Quality Enhancement (RQE). It was critical to evaluate the stability and robustness of these control laws analytically before testing them and experimentally while testing them to ensure safety of the model and the wind tunnel. MATLAB based software was applied to evaluate the performance of closed-loop systems in terms of stability and robustness. Existing software tools were extended to use analytical representations of the S4T and the control laws to analyze and evaluate the control laws prior to testing. Lessons were learned about the complex windtunnel model and experimental testing. The open-loop flutter boundary was determined from the closed-loop systems. A MATLAB/Simulink Simulation developed under the program is available for future work to improve the CPE process. This paper is one of a series of that comprise a special session, which summarizes the S4T wind-tunnel program.

  7. Aeroelastic Analyses of the SemiSpan SuperSonic Transport (S4T) Wind Tunnel Model at Mach 0.95

    NASA Technical Reports Server (NTRS)

    Hur, Jiyoung

    2014-01-01

    Detailed aeroelastic analyses of the SemiSpan SuperSonic Transport (S4T) wind tunnel model at Mach 0.95 with a 1.75deg fixed angle of attack are presented. First, a numerical procedure using the Computational Fluids Laboratory 3-Dimensional (CFL3D) Version 6.4 flow solver is investigated. The mesh update method for structured multi-block grids was successfully applied to the Navier-Stokes simulations. Second, the steady aerodynamic analyses with a rigid structure of the S4T wind tunnel model are reviewed in transonic flow. Third, the static analyses were performed for both the Euler and Navier-Stokes equations. Both the Euler and Navier-Stokes equations predicted a significant increase of lift forces, compared to the results from the rigid structure of the S4T wind-tunnel model, over various dynamic pressures. Finally, dynamic aeroelastic analyses were performed to investigate the flutter condition of the S4T wind tunnel model at the transonic Mach number. The condition of flutter was observed at a dynamic pressure of approximately 75.0-psf for the Navier-Stokes simulations. However, it was observed that the flutter condition occurred a dynamic pressure of approximately 47.27-psf for the Euler simulations. Also, the computational efficiency of the aeroelastic analyses for the S4T wind tunnel model has been assessed.

  8. Cr(VI) retention and transport through Fe(III)-coated natural zeolite.

    PubMed

    Du, Gaoxiang; Li, Zhaohui; Liao, Libing; Hanson, Renee; Leick, Samantha; Hoeppner, Nicole; Jiang, Wei-Teh

    2012-06-30

    Cr(VI) is a group A chemical based on the weight of evidence of carcinogenicity. Its transport and retention in soils and groundwater have been studied extensively. Zeolite is a major component in deposits originated from volcanic ash and tuff after alteration. In this study, zeolite aggregates with the particle size of 1.4-2.4mm were preloaded with Fe(III). The influence of present Fe(III) on Cr(VI) retention by and transport through zeolite was studied under batch and column experiments. The added Fe(III) resulted in an enhanced Cr(VI) retention by the zeolite with a capacity of 82mg/kg. The Cr(VI) adsorption on Fe(III)-zeolite followed a pseudo-second order kinetically and the Freundlich adsorption isotherm thermodynamically. Fitting the column experimental data to HYDRUS-1D resulted in a retardation factor of 3 in comparison to 5 calculated from batch tests at an initial Cr(VI) concentration of 3mg/L. The results from this study showed that enhanced adsorption and retention of Cr(VI) may happen in soils derived from volcanic ash and tuff that contains significant amounts of zeolite with extensive Fe(III) coating. PMID:22542779

  9. Advanced Supersonic Technology Study: Engine Program Summary. Supersonic Propulsion: 1971 to 1976

    NASA Technical Reports Server (NTRS)

    Krebs, J. N.

    1976-01-01

    Sustained supersonic cruise propulsion systems for military applications are studied. The J79-5 in the Mach 2 B-58; YJ93 in the Mach 3.0 B-70 and the current F101 in the B-1, are all examples of military propulsion systems and airplanes operated at sustained supersonic cruise speeds. The Mach 2.7 B2707 transport powered by GE4 turbojet engines was the only non-military, sustained supersonic cruise vehicle intended for commercial passenger service.

  10. Supersonic airplane study and design

    NASA Technical Reports Server (NTRS)

    Cheung, Samson

    1993-01-01

    A supersonic airplane creates shocks which coalesce and form a classical N-wave on the ground, forming a double bang noise termed sonic boom. A recent supersonic commercial transport (the Concorde) has a loud sonic boom (over 100 PLdB) and low aerodynamic performance (cruise lift-drag ratio 7). To enhance the U.S. market share in supersonic transport, an airframer's market risk for a low-boom airplane has to be reduced. Computational fluid dynamics (CFD) is used to design airplanes to meet the dual constraints of low sonic boom and high aerodynamic performance. During the past year, a research effort was focused on three main topics. The first was to use the existing design tools, developed in past years, to design one of the low-boom wind-tunnel configurations (Ames Model 3) for testing at Ames Research Center in April 1993. The second was to use a Navier-Stokes code (Overflow) to support the Oblique-All-Wing (OAW) study at Ames. The third was to study an optimization technique applied on a Haack-Adams body to reduce aerodynamic drag.

  11. Kinetics of Chromium(III) Transport Through a Liquid Membrane Containing DNNSA as a Carrier

    PubMed Central

    Religa, Paweł; Gawroński, Roman; Gierycz, Paweł

    2009-01-01

    Kinetics of Cr(III) ions transport through a bulk liquid membrane containing dinonylnaphthalenesulfonic acid (DNNSA) as a carrier, flowing over aqueous phases, has been examined. Special attention has been paid to the effect of the membrane’s velocity flow on the chromium concentration decrease in a feed phase. For the description of relationships of chromium(III) concentration in particular phases with the time, a model based on the assumption of consecutive first-order reactions was proposed. Satisfactory compatibility of experiments and model results have been obtained both for the membrane flow velocities below 0.0034 m·s−1 when the interfaces begin to fluctuate slightly and for low initial Cr(III) concentration in the feed phase. PMID:19399232

  12. Medical aspects of supersonic travel.

    PubMed

    Preston, F S

    1975-08-01

    During the 1950s, military aircraft in France and the United Kingdom developed along almost identical lines in that supersonic fighters were developed together with delta-plan research aircraft capable of speeds twice the speed of sound (Mach 2). At the end of the decade, discussions between the British Aircraft Corp. (BAC) and Sub-Aviation of France (SUD) resulted in suggested designs for a supersonic transport (SST) aircraft. With official backing from both governments, the Anglo-French Concorde Agreement was signed in 1962. At first, the development costs were estimated to be between 150 and 170 million, the costs to be equally divided between both nations. The total costs for research and development are now expected to exceed 1065 million! PMID:1164343

  13. Overview of Experimental Capabilities - Supersonics

    NASA Technical Reports Server (NTRS)

    Banks, Daniel W.

    2007-01-01

    This viewgraph presentation gives an overview of experimental capabilities applicable to the area of supersonic research. The contents include: 1) EC Objectives; 2) SUP.11: Elements; 3) NRA; 4) Advanced Flight Simulator Flexible Aircraft Simulation Studies; 5) Advanced Flight Simulator Flying Qualities Guideline Development for Flexible Supersonic Transport Aircraft; 6) Advanced Flight Simulator Rigid/Flex Flight Control; 7) Advanced Flight Simulator Rapid Sim Model Exchange; 8) Flight Test Capabilities Advanced In-Flight Infrared (IR) Thermography; 9) Flight Test Capabilities In-Flight Schlieren; 10) Flight Test Capabilities CLIP Flow Calibration; 11) Flight Test Capabilities PFTF Flowfield Survey; 12) Ground Test Capabilities Laser-Induced Thermal Acoustics (LITA); 13) Ground Test Capabilities Doppler Global Velocimetry (DGV); 14) Ground Test Capabilities Doppler Global Velocimetry (DGV); and 15) Ground Test Capabilities EDL Optical Measurement Capability (PIV) for Rigid/Flexible Decelerator Models.

  14. Supersonic through-flow fan engine and aircraft mission performance

    NASA Technical Reports Server (NTRS)

    Franciscus, Leo C.; Maldonado, Jaime J.

    1989-01-01

    A study was made to evaluate potential improvement to a commercial supersonic transport by powering it with supersonic through-flow fan turbofan engines. A Mach 3.2 mission was considered. The three supersonic fan engines considered were designed to operate at bypass ratios of 0.25, 0.5, and 0.75 at supersonic cruise. For comparison a turbine bypass turbojet was included in the study. The engines were evaluated on the basis of aircraft takeoff gross weight with a payload of 250 passengers for a fixed range of 5000 N.MI. The installed specific fuel consumption of the supersonic fan engines was 7 to 8 percent lower than that of the turbine bypass engine. The aircraft powered by the supersonic fan engines had takeoff gross weights 9 to 13 percent lower than aircraft powered by turbine bypass engines.

  15. Visualizing Flutter Mechanism as Traveling Wave Through Animation of Simulation Results for the Semi-Span Super-Sonic Transport Wind-Tunnel Model

    NASA Technical Reports Server (NTRS)

    Christhilf, David M.

    2014-01-01

    It has long been recognized that frequency and phasing of structural modes in the presence of airflow play a fundamental role in the occurrence of flutter. Animation of simulation results for the long, slender Semi-Span Super-Sonic Transport (S4T) wind-tunnel model demonstrates that, for the case of mass-ballasted nacelles, the flutter mode can be described as a traveling wave propagating downstream. Such a characterization provides certain insights, such as (1) describing the means by which energy is transferred from the airflow to the structure, (2) identifying airspeed as an upper limit for speed of wave propagation, (3) providing an interpretation for a companion mode that coalesces in frequency with the flutter mode but becomes very well damped, (4) providing an explanation for bursts of response to uniform turbulence, and (5) providing an explanation for loss of low frequency (lead) phase margin with increases in dynamic pressure (at constant Mach number) for feedback systems that use sensors located upstream from active control surfaces. Results from simulation animation, simplified modeling, and wind-tunnel testing are presented for comparison. The simulation animation was generated using double time-integration in Simulink of vertical accelerometer signals distributed over wing and fuselage, along with time histories for actuated control surfaces. Crossing points for a zero-elevation reference plane were tracked along a network of lines connecting the accelerometer locations. Accelerometer signals were used in preference to modal displacement state variables in anticipation that the technique could be used to animate motion of the actual wind-tunnel model using data acquired during testing. Double integration of wind-tunnel accelerometer signals introduced severe drift even with removal of both position and rate biases such that the technique does not currently work. Using wind-tunnel data to drive a Kalman filter based upon fitting coefficients to

  16. Modification of the Ames 40- by 80-foot wind tunnel for component acoustic testing for the second generation supersonic transport

    NASA Technical Reports Server (NTRS)

    Schmitz, F. H.; Allmen, J. R.; Soderman, P. T.

    1994-01-01

    The development of a large-scale anechoic test facility where large models of engine/airframe/high-lift systems can be tested for both improved noise reduction and minimum performance degradation is described. The facility development is part of the effort to investigate economically viable methods of reducing second generation high speed civil transport noise during takeoff and climb-out that is now under way in the United States. This new capability will be achieved through acoustic modifications of NASA's second largest subsonic wind tunnel: the 40-by 80-Foot Wind Tunnel at the NASA Ames Research Center. Three major items are addressed in the design of this large anechoic and quiet wind tunnel: a new deep (42 inch (107 cm)) test section liner, expansion of the wind tunnel drive operating envelope at low rpm to reduce background noise, and other promising methods of improving signal-to-noise levels of inflow microphones. Current testing plans supporting the U.S. high speed civil transport program are also outlined.

  17. Supersonic biplane—A review

    NASA Astrophysics Data System (ADS)

    Kusunose, Kazuhiro; Matsushima, Kisa; Maruyama, Daigo

    2011-01-01

    One of the fundamental problems preventing commercial transport aircraft from supersonic flight is the generation of strong sonic booms. Sonic booms are the ground-level manifestation of shock waves created by airplanes flying at supersonic speeds. The strength of the shock waves generated by an aircraft flying at supersonic speed is a direct function of both the aircraft’s weight and its occupying volume; it has been very difficult to sufficiently reduce the shock waves generated by the heavier and larger conventional supersonic transport (SST) configuration to meet acceptable at-ground sonic-boom levels. It is our dream to develop a quiet SST aircraft that can carry more than 100 passengers while meeting acceptable at-ground sonic-boom levels. We have started a supersonic-biplane project at Tohoku University since 2004. We meet the challenge of quiet SST flight by extending the classic two-dimensional (2-D) Busemann biplane concept to a 3-D supersonic-biplane wing that effectively reduces the shock waves generated by the aircraft. A lifted airfoil at supersonic speeds, in general, generates shock waves (therefore, wave drag) through two fundamentally different mechanisms. One is due to the airfoil’s lift, and the other is due to its thickness. Multi-airfoil configurations can reduce wave drag by redistributing the system’s total lift among the individual airfoil elements, knowing that wave drag of an airfoil element is proportional to the square of its lift. Likewise, the wave drag due to airfoil thickness can also be nearly eliminated using the Busemann biplane concept, which promotes favorable wave interactions between two neighboring airfoil elements. One of the main objectives of our supersonic-biplane study is, with the help of modern computational fluid dynamics (CFD) tools, to find biplane configurations that simultaneously exhibit both traits. We first re-analyzed using CFD tools, the classic Busemann biplane configurations to understand its basic

  18. Heptachlor induced mitochondria-mediated cell death via impairing electron transport chain complex III

    SciTech Connect

    Hong, Seokheon; Kim, Joo Yeon; Hwang, Joohyun; Shin, Ki Soon; Kang, Shin Jung

    2013-08-09

    Highlights: •Heptachlor inhibited mitochondrial electron transport chain complex III activity. •Heptachlor promoted generation of reactive oxygen species. •Heptachlor induced Bax activation. •Heptachlor induced mitochondria-mediated and caspase-dependent apoptosis. -- Abstract: Environmental toxins like pesticides have been implicated in the pathogenesis of Parkinson’s disease (PD). Epidemiological studies suggested that exposures to organochlorine pesticides have an association with an increased PD risk. In the present study, we examined the mechanism of toxicity induced by an organochlorine pesticide heptachlor. In a human dopaminergic neuroblastoma SH-SY5Y cells, heptachlor induced both morphological and functional damages in mitochondria. Interestingly, the compound inhibited mitochondrial electron transport chain complex III activity. Rapid generation of reactive oxygen species and the activation of Bax were then detected. Subsequently, mitochondria-mediated, caspase-dependent apoptosis followed. Our results raise a possibility that an organochlorine pesticide heptachlor can act as a neurotoxicant associated with PD.

  19. Potassium transport of Salmonella is important for type III secretion and pathogenesis.

    PubMed

    Liu, Yehao; Ho, Katharina Kim; Su, Jing; Gong, Hao; Chang, Alexander C; Lu, Sangwei

    2013-08-01

    Intracellular cations are essential for the physiology of all living organisms including bacteria. Cations such as potassium ion (K(+)), sodium ion (Na(+)) and proton (H(+)) are involved in nearly all aspects of bacterial growth and survival. K(+) is the most abundant cation and its homeostasis in Escherichia coli and Salmonella is regulated by three major K(+) transporters: high affinity transporter Kdp and low affinity transporters Kup and Trk. Previous studies have demonstrated the roles of cations and cation transport in the physiology of Escherichia coli; their roles in the virulence and physiology of pathogenic bacteria are not well characterized. We have previously reported that the Salmonella K(+) transporter Trk is important for the secretion of effector proteins of the type III secretion system (TTSS) of Salmonella pathogenicity island 1 (SPI-1). Here we further explore the role of Salmonella cation transport in virulence in vitro and pathogenesis in animal models. Impairment of K(+) transport through deletion of K(+) transporters or exposure to the chemical modulators of cation transport, gramicidin and valinomycin, results in a severe defect in the TTSS of SPI-1, and this defect in the TTSS was not due to a failure to regulate intrabacterial pH or ATP. Our results also show that K(+) transporters are critical to the pathogenesis of Salmonella in mice and chicks and are involved in multiple growth and virulence characteristics in vitro, including protein secretion, motility and invasion of epithelial cells. These results suggest that cation transport of the pathogenic bacterium Salmonella, especially K(+) transport, contributes to its virulence in addition to previously characterized roles in maintaining homeostasis of bacteria. PMID:23728623

  20. Reaction-Based Reactive Transport Modeling of Fe(III) and U(V) Reduction

    SciTech Connect

    Burgos, William D.; Roden, Eric E.; Yeh, Gour-Tsyh

    2005-06-01

    Our new research project (started Fall 2004) was funded by a grant to The Pennsylvania State University, University of Central Florida, and The University of Alabama in the Integrative Studies Element of the NABIR Program (DE-FG04-ER63914/63915/63196). Our previous NABIR project (DE-FG02-01ER63180/63181/63182, funded within the Biotransformation Element) focused on (1) microbial reduction of Fe(III) and U(VI) individually, and concomitantly in natural sediments, (2) Fe(III) oxide surface chemistry, specifically with respect to reactions with Fe(II) and U(VI), (3) the influence of humic substances on Fe(III) and U(VI) bioreduction, and on U(VI) complexation, and (4) the development of reaction-based reactive transport biogeochemical models to numerically simulate our experimental results. The new project focuses on the development of a mechanistic understanding and quantitative models of coupled Fe(III)/U(VI) reduction in FRC Area 2 sediments. This work builds on our previous studies of microbial Fe(III) and U(VI) reduction, and is directly aligned with the Scheibe et al. NABIR FRC Field Project at Area 2.

  1. Conditions for supersonic bent Marshak waves

    SciTech Connect

    Xu, Qiang Ren, Xiao-dong; Li, Jing; Dan, Jia-kun; Wang, Kun-lun; Zhou, Shao-tong

    2015-03-15

    Supersonic radiation diffusion approximation is an useful method to study the radiation transportation. Considering the 2-d Marshak theory, and an invariable source temperature, conditions for supersonic radiation diffusion are proved to be coincident with that for radiant flux domination in the early time when √(ε)x{sub f}/L≪1. However, they are even tighter than conditions for radiant flux domination in the late time when √(ε)x{sub f}/L≫1, and can be expressed as M>4(1+ε/3)/3 and τ>1. A large Mach number requires the high temperature, while the large optical depth requires the low temperature. Only when the source temperature is in a proper region the supersonic diffusion conditions can be satisfied. Assuming a power-low (in temperature and density) opacity and internal energy, for a given density, the supersonic diffusion regions are given theoretically. The 2-d Marshak theory is proved to be able to bound the supersonic diffusion conditions in both high and low temperature regions, however, the 1-d theory only bounds it in low temperature region. Taking SiO{sub 2} and the Au, for example, these supersonic regions are shown numerically.

  2. Binding of Chromium(III) to Transferrin Could Be Involved in Detoxification of Dietary Chromium(III) Rather than Transport of an Essential Trace Element.

    PubMed

    Levina, Aviva; Pham, T H Nguyen; Lay, Peter A

    2016-07-01

    Cr(III) binding to transferrin (Tf; the main Fe(III) transport protein) has been postulated to mediate cellular uptake of Cr(III) to facilitate a purported essential role for this element. Experiments using HepG2 (human hepatoma) cells, which were chosen because of high levels of the transferrin receptor, showed that Cr(III) binding to vacant Fe(III) -binding sites of human Tf effectively blocks cellular Cr(III) uptake. Through bio-layer interferometry studies of the Tf cycle, it was found that both exclusion and efflux of Cr2 (III) Tf from cells was caused by 1) relatively low Cr2 Tf affinity to cell-surface Tf receptors compared to Fe2 Tf, and 2) disruption of metal release under endosomal conditions and post-endosomal Tf dissociation from the receptor. These data support mounting evidence that Cr(III) is not essential and that Tf binding is likely to be a natural protective mechanism against the toxicity and potential genotoxicity of dietary Cr through blocking Cr(III) cellular accumulation. PMID:27197571

  3. An experimental investigation of a Mach 3.0 high-speed civil transport at supersonic speeds

    NASA Technical Reports Server (NTRS)

    Hernandez, Gloria; Covell, Peter F.; Mcgraw, Marvin E., Jr.

    1993-01-01

    An experimental study was conducted to determine the aerodynamic characteristics of a proposed high speed civil transport. This configuration was designed to cruise at Mach 3.0 and sized to carry 250 passengers for 6500 n.mi. The configuration consists of a highly blended wing body and features a blunt parabolic nose planform, a highly swept inboard wing panel, a moderately swept outboard wing panel, and a curved wingtip. Wind tunnel tests were conducted in the Langley Unitary Plan Wind Tunnel on a 0.0098-scale model. Force, moment, and pressure data were obtained for Mach numbers ranging from 1.6 to 3.6 and at angles of attack ranging from -4 to 10 deg. Extensive flow visualization studies (vapor screen and oil flow) were obtained in the experimental program. Both linear and advanced computational fluid dynamics (CFD) theoretical comparisons are shown to assess the ability to predict forces, moments, and pressures on configurations of this type. In addition, an extrapolation of the wind tunnel data, based on empirical principles, to full-scale conditions is compared with the theoretical aerodynamic predictions.

  4. Spectroscopy with Supersonic Jets.

    ERIC Educational Resources Information Center

    Skinner, Anne R.; Chandler, Dean W.

    1980-01-01

    Discusses a new technique that enables spectroscopists to study gas phase molecules at temperatures below 1 K, without traditional cryogenic apparatus. This technique uses supersonic jets as samples for gas molecular spectroscopy. Highlighted are points in the theory of supersonic flow which are important for applications in molecular…

  5. Transportation Facilitation Education Program: A Handbook for Transportation and Distribution. Part III. Final Report.

    ERIC Educational Resources Information Center

    Oregon Univ., Eugene. Coll. of Business Administration.

    The handbook accents the nature of transportation and related domestic and international business activities. Its objective is to provide basic information for the newcomer to the field. Chapters 2 and 3 describe assistance available from public and private agencies, as well as regulatory requirements for foreign traders and a resume of the…

  6. Carrier transport in dichromatic color-coded semipolar (2021) and (2021) III-N LEDs

    NASA Astrophysics Data System (ADS)

    Kisin, Mikhail V.; Huang, Chih-Li; El-Ghoroury, Hussein S.

    2014-03-01

    Simulation of III-nitride color-coded multiple quantum well (MQW) LED structures was performed using as an experimental benchmark dichromatic semipolar LEDs grown in Ga-polar and N-polar crystallographic orientations (Y. Kawaguchi et.al, APL 100, 231110, 2012). Different QW depths in the color-coded LEDs and opposite interface polarization charges in Ga-polar and N-polar structures provide different conditions for carrier transport across the LED active regions. Combination of several effects was crucial for adequate reproduction of the emission spectra experimentally observed in color-coded structures with violet-aquamarine and aquamarine-violet active region layouts. A standard drift-diffusion transport model wascompleted with rate equations for nonequilibrium QW populations and several high-energy transport features, including the effects of QW carrier overshoot and Auger-assisted QW depopulation. COMSOL-based Optoelectronic Device Modeling Software (ODMS) developed at Ostendo Technologies Inc. was utilized for device simulation.

  7. Supersonic laser propulsion.

    PubMed

    Rezunkov, Yurii; Schmidt, Alexander

    2014-11-01

    To produce supersonic laser propulsion, a new technique based on the interaction of a laser-ablated jet with supersonic gas flow in a nozzle is proposed. It is shown that such parameters of the jet, such as gas-plasma pressure and temperature in the ablation region as well as the mass consumption rate of the ablated solid propellant, are characteristic in this respect. The results of numerical simulations of the supersonic laser propulsion are presented for two types of nozzle configuration. The feasibility to achieve the momentum coupling coefficient of C(m)∼10(-3) N/W is shown. PMID:25402938

  8. Supersonic Cruise Technology

    NASA Technical Reports Server (NTRS)

    Mclean, F. Edward

    1985-01-01

    The history and status of supersonic cruise research is covered. The early research efforts of the National Advisory Committee for Aeronautics and efforts during the B-70 and SST phase are included. Technological progress made during the NASA Supersonic Cruise Research and Variable Cycle Engine programs are presented. While emphasis is on NASA's contributions to supersonic cruise research in the U.S., also noted are developments in England, France, and Russia. Written in nontechnical language, this book presents the most critical technology issues and research findings.

  9. Transonic and supersonic ground effect aerodynamics

    NASA Astrophysics Data System (ADS)

    Doig, G.

    2014-08-01

    A review of recent and historical work in the field of transonic and supersonic ground effect aerodynamics has been conducted, focussing on applied research on wings and aircraft, present and future ground transportation, projectiles, rocket sleds and other related bodies which travel in close ground proximity in the compressible regime. Methods for ground testing are described and evaluated, noting that wind tunnel testing is best performed with a symmetry model in the absence of a moving ground; sled or rail testing is ultimately preferable, though considerably more expensive. Findings are reported on shock-related ground influence on aerodynamic forces and moments in and accelerating through the transonic regime - where force reversals and the early onset of local supersonic flow is prevalent - as well as more predictable behaviours in fully supersonic to hypersonic ground effect flows.

  10. Aerodynamic design and analysis of the AST-204, AST-205, and AST-206 blended wing-fuse large supersonic transport configuration concepts

    NASA Technical Reports Server (NTRS)

    Martin, G. L.; Walkley, K. B.

    1980-01-01

    The aerodynamic design and analysis of three blended wing-fuselage supersonic cruise configurations providing four, five, and six abreast seating was conducted using a previously designed supersonic cruise configuration as the baseline. The five abreast configuration was optimized for wave drag at a Mach number of 2.7. The four and six abreast configurations were also optimized at Mach 2.7, but with the added constraint that the majority of their structure be common with the five abreast configuration. Analysis of the three configurations indicated an improvement of 6.0, 7.5, and 7.7 percent in cruise lift-to-drag ratio over the baseline configuration for the four, five, and six abreast configurations, respectively.

  11. Recent progress in III-V based ferromagnetic semiconductors: Band structure, Fermi level, and tunneling transport

    SciTech Connect

    Tanaka, Masaaki; Ohya, Shinobu Nam Hai, Pham

    2014-03-15

    Spin-based electronics or spintronics is an emerging field, in which we try to utilize spin degrees of freedom as well as charge transport in materials and devices. While metal-based spin-devices, such as magnetic-field sensors and magnetoresistive random access memory using giant magnetoresistance and tunneling magnetoresistance, are already put to practical use, semiconductor-based spintronics has greater potential for expansion because of good compatibility with existing semiconductor technology. Many semiconductor-based spintronics devices with useful functionalities have been proposed and explored so far. To realize those devices and functionalities, we definitely need appropriate materials which have both the properties of semiconductors and ferromagnets. Ferromagnetic semiconductors (FMSs), which are alloy semiconductors containing magnetic atoms such as Mn and Fe, are one of the most promising classes of materials for this purpose and thus have been intensively studied for the past two decades. Here, we review the recent progress in the studies of the most prototypical III-V based FMS, p-type (GaMn)As and its heterostructures with focus on tunneling transport, Fermi level, and bandstructure. Furthermore, we cover the properties of a new n-type FMS, (In,Fe)As, which shows electron-induced ferromagnetism. These FMS materials having zinc-blende crystal structure show excellent compatibility with well-developed III-V heterostructures and devices.

  12. Recent progress in III-V based ferromagnetic semiconductors: Band structure, Fermi level, and tunneling transport

    NASA Astrophysics Data System (ADS)

    Tanaka, Masaaki; Ohya, Shinobu; Nam Hai, Pham

    2014-03-01

    Spin-based electronics or spintronics is an emerging field, in which we try to utilize spin degrees of freedom as well as charge transport in materials and devices. While metal-based spin-devices, such as magnetic-field sensors and magnetoresistive random access memory using giant magnetoresistance and tunneling magnetoresistance, are already put to practical use, semiconductor-based spintronics has greater potential for expansion because of good compatibility with existing semiconductor technology. Many semiconductor-based spintronics devices with useful functionalities have been proposed and explored so far. To realize those devices and functionalities, we definitely need appropriate materials which have both the properties of semiconductors and ferromagnets. Ferromagnetic semiconductors (FMSs), which are alloy semiconductors containing magnetic atoms such as Mn and Fe, are one of the most promising classes of materials for this purpose and thus have been intensively studied for the past two decades. Here, we review the recent progress in the studies of the most prototypical III-V based FMS, p-type (GaMn)As and its heterostructures with focus on tunneling transport, Fermi level, and bandstructure. Furthermore, we cover the properties of a new n-type FMS, (In,Fe)As, which shows electron-induced ferromagnetism. These FMS materials having zinc-blende crystal structure show excellent compatibility with well-developed III-V heterostructures and devices.

  13. [Anaerobic reduction of humus/Fe (III) and electron transport mechanism of Fontibacter sp. SgZ-2].

    PubMed

    Ma, Chen; Yang, Gui-qin; Lu, Qin; Zhou, Shun-gui

    2014-09-01

    Humus and Fe(III) respiration are important extracellular respiration metabolism. Electron transport pathway is the key issue of extracellular respiration. To understand the electron transport properties and the environmental behavior of a novel Fe(III)- reducing bacterium, Fontibacter sp. SgZ-2, capacities of anaerobic humus/Fe(III) reduction and electron transport mechanisms with four electron acceptors were investigated in this study. The results of anaerobic batch experiments indicated that strain SgZ-2 had the ability to reduce humus analog [ 9,10-anthraquinone-2,6-disulfonic acid (AQDS) and 9,10-anthraquinone-2-sulfonic acid (AQS)], humic acids (HA), soluble Fe(III) (Fe-EDTA and Fe-citrate) and Fe(III) oxides [hydrous ferric oxide (HFO)]. Fermentative sugars (glucose and sucrose) were the most effective electron donors in the humus/Fe(III) reduction by strain SgZ-2. Additionally, differences of electron carrier participating in the process of electron transport with different electron acceptors (i. e. , oxygen, AQS, Fe-EDTA and HFO) were investigated using respiratory inhibitors. The results suggested that similar respiratory chain components were involved in the reducing process of oxygen and Fe-EDTA, including dehydrogenase, quinones and cytochromes b-c. In comparison, only dehydrogenase was found to participate in the reduction of AQS and HFO. In conclusion, different electron transport pathways may be employed by strain SgZ-2 between insoluble and soluble electron acceptors or among soluble electron acceptors. Preliminary models of electron transport pathway with four electron acceptors were proposed for strain SgZ-2, and the study of electron transport mechanism was explored to the genus Fontibacter. All the results from this study are expected to help understand the electron transport properties and the environmental behavior of the genus Fontibacter. PMID:25518675

  14. Transgenic petunia with the iron(III)-phytosiderophore transporter gene acquires tolerance to iron deficiency in alkaline environments.

    PubMed

    Murata, Yoshiko; Itoh, Yoshiyuki; Iwashita, Takashi; Namba, Kosuke

    2015-01-01

    Iron is an essential nutrient for all plants. However, terrestrial plants often suffer from iron deficiency in alkaline soil due to its extremely low solubility. Alkaline soil accounts for about 30% of all cultivated ground in the world. Plants have evolved two distinct strategies, I and II, for iron uptake from the soil. Dicots and non-graminaceous monocots use Strategy I, which is primarily based on the reduction of iron(III) to iron(II) and the uptake of iron(II) by the iron-regulated transporter, IRT1. In contrast, graminaceous plants use Strategy II to efficiently acquire insoluble iron(III). Strategy II comprises the synthesis and secretion of iron-chelating phytosiderophores, such as mugineic acids and the Yellow Stripe 1 transporter proteins of the iron(III)-phytosiderophore complex. Barley, which exhibits the highest tolerance to iron deficiency in alkaline soil among graminaceous plants, utilizes mugineic acids and the specific iron(III)-mugineic acids transporter, HvYS1. In this study, we established the transgenic plant Petunia hybrida, which originally had only Strategy I, by introducing the HvYS1 transporter gene derived from barley. When the transgenic plants were grown hydroponically in media containing the iron(III)-2'-deoxymugineic acid complex, free 2'-deoxymugineic acid and its iron(III) complex were detected in the root extract of the transgenic plant by electrospray ionization-Fourier transform-ion cyclotron resonance mass spectrometry. The growth of the transgenic petunia was significantly better than that of the control host in alkaline conditions. Consequently, the transgenic plant acquired a significantly enhanced tolerance to alkaline hydroponic media in the presence of the iron(III)-2'-deoxymugineic acid complex. Furthermore, the flower color of the transgenic plant deepened. The results showed that iron-phytosiderophore complexes and their transporters can potentially be utilized to overcome the worldwide iron uptake problems to diverse

  15. Negative membrane curvature catalyzes nucleation of endosomal sorting complex required for transport (ESCRT)-III assembly.

    PubMed

    Lee, Il-Hyung; Kai, Hiroyuki; Carlson, Lars-Anders; Groves, Jay T; Hurley, James H

    2015-12-29

    The endosomal sorting complexes required for transport (ESCRT) machinery functions in HIV-1 budding, cytokinesis, multivesicular body biogenesis, and other pathways, in the course of which it interacts with concave membrane necks and bud rims. To test the role of membrane shape in regulating ESCRT assembly, we nanofabricated templates for invaginated supported lipid bilayers. The assembly of the core ESCRT-III subunit CHMP4B/Snf7 is preferentially nucleated in the resulting 100-nm-deep membrane concavities. ESCRT-II and CHMP6 accelerate CHMP4B assembly by increasing the concentration of nucleation seeds. Superresolution imaging was used to visualize CHMP4B/Snf7 concentration in a negatively curved annulus at the rim of the invagination. Although Snf7 assemblies nucleate slowly on flat membranes, outward growth onto the flat membrane is efficiently nucleated at invaginations. The nucleation behavior provides a biophysical explanation for the timing of ESCRT-III recruitment and membrane scission in HIV-1 budding. PMID:26668364

  16. Supersonic gas compressor

    DOEpatents

    Lawlor, Shawn P.; Novaresi, Mark A.; Cornelius, Charles C.

    2007-11-13

    A gas compressor based on the use of a driven rotor having a compression ramp traveling at a local supersonic inlet velocity (based on the combination of inlet gas velocity and tangential speed of the ramp) which compresses inlet gas against a stationary sidewall. In using this method to compress inlet gas, the supersonic compressor efficiently achieves high compression ratios while utilizing a compact, stabilized gasdynamic flow path. Operated at supersonic speeds, the inlet stabilizes an oblique/normal shock system in the gasdyanamic flow path formed between the rim of the rotor, the strakes, and a stationary external housing. Part load efficiency is enhanced by the use of a pre-swirl compressor, and using a bypass stream to bleed a portion of the intermediate pressure gas after passing through the pre-swirl compressor back to the inlet of the pre-swirl compressor. Inlet guide vanes to the compression ramp enhance overall efficiency.

  17. Supersonic nonlinear potential analysis

    NASA Technical Reports Server (NTRS)

    Siclari, M. J.

    1984-01-01

    The NCOREL computer code was established to compute supersonic flow fields of wings and bodies. The method encompasses an implicit finite difference transonic relaxation method to solve the full potential equation in a spherical coordinate system. Two basic topic to broaden the applicability and usefulness of the present method which is encompassed within the computer code NCOREL for the treatment of supersonic flow problems were studied. The first topic is that of computing efficiency. Accelerated schemes are in use for transonic flow problems. One such scheme is the approximate factorization (AF) method and an AF scheme to the supersonic flow problem is developed. The second topic is the computation of wake flows. The proper modeling of wake flows is important for multicomponent configurations such as wing-body and multiple lifting surfaces where the wake of one lifting surface has a pronounced effect on a downstream body or other lifting surfaces.

  18. Supersonic through-flow fan engines for supersonic cruise aircraft

    NASA Technical Reports Server (NTRS)

    Franciscus, L. C.

    1978-01-01

    Engine performance, weight and mission studies were carried out for supersonic through flow fan engine concepts. The mission used was a Mach 2.32 cruise mission. The advantages of supersonic through flow fan engines were evaluated in terms of mission range comparisons between the supersonic through flow fan engines and a more conventional turbofan engine. The specific fuel consumption of the supersonic through flow fan engines was 12 percent lower than the more conventional turbofan. The aircraft mission range was increased by 20 percent with the supersonic fan engines compared to the conventional turbofan.

  19. Vortex Flows at Supersonic Speeds

    NASA Technical Reports Server (NTRS)

    Wood, Richard M.; Wilcox, Floyd J., Jr.; Bauer, Steven X. S.; Allen, Jerry M.

    2003-01-01

    A review of research conducted at the National Aeronautics and Space Administration (NASA) Langley Research Center (LaRC) into high-speed vortex flows during the 1970s, 1980s, and 1990s is presented. The data are for flat plates, cavities, bodies, missiles, wings, and aircraft with Mach numbers of 1.5 to 4.6. Data are presented to show the types of vortex structures that occur at supersonic speeds and the impact of these flow structures on vehicle performance and control. The data show the presence of both small- and large-scale vortex structures for a variety of vehicles, from missiles to transports. For cavities, the data show very complex multiple vortex structures exist at all combinations of cavity depth to length ratios and Mach number. The data for missiles show the existence of very strong interference effects between body and/or fin vortices. Data are shown that highlight the effect of leading-edge sweep, leading-edge bluntness, wing thickness, location of maximum thickness, and camber on the aerodynamics of and flow over delta wings. Finally, a discussion of a design approach for wings that use vortex flows for improved aerodynamic performance at supersonic speeds is presented.

  20. Combustion in supersonic flow

    NASA Technical Reports Server (NTRS)

    Northam, G. B.

    1985-01-01

    A workshop on combustion in supersonic flow was held in conjunction with the 21st JANNAF Combustion Meeting at Laurel, Maryland on October 3 to 4 1984. The objective of the workshop was to establish the level of current understanding of supersonic combustion. The workshop was attended by approximately fifty representatives from government laboratories, engine companies, and universities. Twenty different speakers made presentations in their area of expertise during the first day of the workshop. On the second day, the presentations were discussed, deficiencies in the current understanding defined, and a list of recommended programs generated to address these deficiencies. The agenda for the workshop is given.

  1. Shocks in supersonic sand.

    PubMed

    Rericha, Erin C; Bizon, Chris; Shattuck, Mark D; Swinney, Harry L

    2002-01-01

    We measure time-averaged velocity, density, and temperature fields for steady granular flow past a wedge. We find the flow to be supersonic with a speed of granular pressure disturbances (sound speed) equal to about 10% of the flow speed, and we observe shocks nearly identical to those in a supersonic gas. Molecular dynamics simulations of Newton's laws yield fields in quantitative agreement with experiment. A numerical solution of Navier-Stokes-like equations agrees with a molecular dynamics simulation for experimental conditions excluding wall friction. PMID:11800951

  2. Low-speed wind-tunnel tests of a one-tenth-scale model of a blended-arrow advanced supersonic transport. [conducted in Langley full-scale tunnel

    NASA Technical Reports Server (NTRS)

    Lemore, H. C.; Parett, L. P.

    1975-01-01

    Tests were conducted in the Langley full scale tunnel to determine the low-speed aerodynamic characteristics of a 1/10 scale model of a blended-arrow advanced supersonic transport. Tests were made for the clean configuration and a high-lift configuration with several combinations of leading- and trailing-edge flaps deflected for providing improved lift and longitudinal stability in the landing and takeoff modes. The tests were conducted for a range of angles of attack from about -6 deg to 30 deg, sideslip angles from -5 deg to 10 deg, and for Reynolds numbers from 6.78 x 1,000,000 to 13.85 x 1,000,000 corresponding to test velocities of 41 knots to 85 knots, respectively.

  3. Supersonic-combustion rocket

    NASA Technical Reports Server (NTRS)

    Weber, R. J.; Franciscus, L. C. (Inventor)

    1973-01-01

    A supersonic combustion rocket is provided in which a small rocket motor is substituted for heavy turbo pumps in a conventional rocket engine. The substitution results in a substantial reduction in rocket engine weight. The flame emanating from the small rocket motor can act to ignite non-hypergolic fuels.

  4. Infinitesimal Conical Supersonic Flow

    NASA Technical Reports Server (NTRS)

    Busemann, Adolf

    1947-01-01

    The calculation of infinitesimal conical supersonic flow has been applied first to the simplest examples that have also been calculated in another way. Except for the discovery of a miscalculation in an older report, there was found the expected conformity. The new method of calculation is limited more definitely to the conical case.

  5. Supersonic Leading Edge Receptivity

    NASA Technical Reports Server (NTRS)

    Maslov, Anatoly A.

    1998-01-01

    This paper describes experimental studies of leading edge boundary layer receptivity for imposed stream disturbances. Studies were conducted in the supersonic T-325 facility at ITAM and include data for both sharp and blunt leading edges. The data are in agreement with existing theory and should provide guidance for the development of more complete theories and numerical computations of this phenomena.

  6. SUPERSONIC SHEAR INSTABILITIES IN ASTROPHYSICAL BOUNDARY LAYERS

    SciTech Connect

    Belyaev, Mikhail A.; Rafikov, Roman R.

    2012-06-20

    Disk accretion onto weakly magnetized astrophysical objects often proceeds via a boundary layer (BL) that forms near the object's surface, in which the rotation speed of the accreted gas changes rapidly. Here, we study the initial stages of formation for such a BL around a white dwarf or a young star by examining the hydrodynamical shear instabilities that may initiate mixing and momentum transport between the two fluids of different densities moving supersonically with respect to each other. We find that an initially laminar BL is unstable to two different kinds of instabilities. One is an instability of a supersonic vortex sheet (implying a discontinuous initial profile of the angular speed of the gas) in the presence of gravity, which we find to have a growth rate of order (but less than) the orbital frequency. The other is a sonic instability of a finite width, supersonic shear layer, which is similar to the Papaloizou-Pringle instability. It has a growth rate proportional to the shear inside the transition layer, which is of order the orbital frequency times the ratio of stellar radius to the BL thickness. For a BL that is thin compared to the radius of the star, the shear rate is much larger than the orbital frequency. Thus, we conclude that sonic instabilities play a dominant role in the initial stages of nonmagnetic BL formation and give rise to very fast mixing between disk gas and stellar fluid in the supersonic regime.

  7. Aerodynamic Design Opportunities for Future Supersonic Aircraft

    NASA Technical Reports Server (NTRS)

    Wood, Richard M.; Bauer, Steven X. S.; Flamm, Jeffrey D.

    2002-01-01

    A discussion of a diverse set of aerodynamic opportunities to improve the aerodynamic performance of future supersonic aircraft has been presented and discussed. These ideas are offered to the community in a hope that future supersonic vehicle development activities will not be hindered by past efforts. A number of nonlinear flow based drag reduction technologies are presented and discussed. The subject technologies are related to the areas of interference flows, vehicle concepts, vortex flows, wing design, advanced control effectors, and planform design. The authors also discussed the importance of improving the aerodynamic design environment to allow creativity and knowledge greater influence. A review of all of the data presented show that pressure drag reductions on the order of 50 to 60 counts are achievable, compared to a conventional supersonic cruise vehicle, with the application of several of the discussed technologies. These drag reductions would correlate to a 30 to 40% increase in cruise L/D (lift-to-drag ratio) for a commercial supersonic transport.

  8. Growth and Carrier Transport Studies of III-Nitride Alloys by Ammonia Molecular Beam Epitaxy

    NASA Astrophysics Data System (ADS)

    Browne, David Alan

    The III-Nitride alloys span the entire visible spectrum and offer applications to LEDs, lasers, solar cells and power electronics. A detailed understanding of heterojunction growth is required for achieving high performance devices especially due to the large lattice mismatch in this alloy system. The wurtzite crystal system also lacks an inversion center which provides a polarization-induced electric field along the c direction that can be exploited in device design or reduced by growth on other substrate orientations. We present results on the growth of InGaN films by Ammonia MBE on polar gallium nitride substrates as well as on nonpolar and semipolar orientations. We show results from coloaded growth conditions and investigate the effect of substrate temperature, growth rate, and ammonia flow on indium incorporation and impurity uptake. We then present solar cell results from a high indium uptake semipolar orientation with fields in a favorable direction for a p-i-n device. We also investigate and understand the effect of relaxation via basal plane slip and unintentional impurity incorporation on device performance. Results are then be presented on electron transport through c plane InGaN/GaN multiple quantum well (MQW) active regions grown by NH3 MBE which have direct relevance to transport in MQW solar cells and LEDs. The presence of indium fluctuations in InGaN has been suspected and debated in the literature for some time, but there is still much that is not well understood. We present Atom Probe Tomography (APT) analysis of the quantum wells to explicitly examine the magnitude and length scale of these observed local alloy fluctuations. The discrepancy in current-voltage behavior between experiment and modeling using traditional 1D simulation software will be discussed. A 2D/3D drift-diffusion Schrodinger-Poisson solver developed by collaborators was used to input alloy fluctuation parameters to elucidate their direct effect on barrier heights and on

  9. Supersonic Flying Qualities Experience Using the SR-71

    NASA Technical Reports Server (NTRS)

    Cox, Timothy H.; Jackson, Dante

    1997-01-01

    Approximately 25 years ago NASA Dryden Flight Research Center, Edwards, California, initiated the evaluation of supersonic handling qualities issues using the XB-70 and the YF-12. Comparison of pilot comments and ratings with some of the classical handling qualities criteria for transport aircraft provided information on the usefulness of these criteria and insight into supersonic flying qualities issues. A second research study has recently been completed which again addressed supersonic flying qualities issues through evaluations of the SR-71 in flight at Mach 3. Additional insight into supersonic flying qualities issues was obtained through pilot ratings and comments. These ratings were compared with existing military specifications and proposed criteria for the High Speed Civil Transport. This paper investigates the disparity between pilot comments and the Neal/Smith criteria through a modification of the technique using vertical speed at the pilot station. The paper specifically addresses the pilot ability to control flightpath and pitch attitude in supersonic flight and pilot displays typical of supersonic maneuvering.

  10. Unitary Plan Supersonic Tunnel

    NASA Technical Reports Server (NTRS)

    1953-01-01

    Unitary Plan Supersonic Tunnel: In this aerial photograph of construction in the early 1950s, the return air passages are shown in the rear, center. This area was later covered with walls and a roof so that upon completion of the facility, it was not visible from the exterior. Three air storage spheres and the cooling tower are at the extreme right of the building. The spheres store dry air at 150 pounds per square inch. The cooling tower dissipates heat from coolers that control the test air temperature. One of many research facilities at NASA Langley Research Center in Hampton, Virginia, the Unitary Plan Wind Tunnel is used for experimental investigations at supersonic speeds.

  11. Modeling the influence of exopolymeric substances (EPS) extracted from Pseudomonas bacteria on chromium (III) sorption and transport in heterogeneous subsurface soils

    NASA Astrophysics Data System (ADS)

    Kantar, C.; Demiray, H.; Koleli, N.; Mercan, N.

    2009-04-01

    In situ remediation of soils contaminated with Cr(VI) is usually accomplished through microbial reduction of Cr(VI) to Cr(III) by soil microorganisms including Pseudomonas bacteria. Cr(VI) is a toxic substance that may stimulate the production of exopolymeric substances (EPS) by soil bacteria. Natural organic ligands such as EPS may have a pronounced impact on Cr(III) solubility, sorption, transport and bioavailability in subsurface systems. In this study, laboratory sorption and column experiments were performed to investigate the influence of exopolymeric substances (EPS) extracted from Pseudomonas aeruginosa P16, Pseudomonas putida P18 and Pseudomonas stutzeri P40 on chromium (III) sorption and transport in heterogeneous subsurface soils. The results from laboratory experiments indicate that microbial EPS enhanced Cr(III) solubility, which, in turn, led to an increase in Cr(III) transport through columns packed with subsurface soils under slightly acidic to alkaline pH conditions. A reactive transport code that includes a semi-empirical surface complexation model (SCM) to describe chemical processes e.g., sorption was used to simulate bench-scale column data for Cr(III) transport in the presence of EPS. Our transport simulations suggest that for an accurate simulation of Cr(III) transport in the presence of microbial EPS, the following processes and/or interactions need to be explicitly considered: 1) Cr(III)-EPS interactions; 2) binary soil/Cr and soil/EPS surface complexes; and 3) ternary soil/Cr/EPS complexes.

  12. The aerodynamics of supersonic parachutes

    SciTech Connect

    Peterson, C.W.

    1987-06-01

    A discussion of the aerodynamics and performance of parachutes flying at supersonic speeds is the focus of this paper. Typical performance requirements for supersonic parachute systems are presented, followed by a review of the literature on supersonic parachute configurations and their drag characteristics. Data from a recent supersonic wind tunnel test series is summarized. The value and limitations of supersonic wind tunnel data on hemisflo and 20-degree conical ribbon parachutes behind several forebody shapes and diameters are discussed. Test techniques were derived which avoided many of the opportunities to obtain erroneous supersonic parachute drag data in wind tunnels. Preliminary correlations of supersonic parachute drag with Mach number, forebody shape and diameter, canopy porosity, inflated canopy diameter and stability are presented. Supersonic parachute design considerations are discussed and applied to a M = 2 parachute system designed and tested at Sandia. It is shown that the performance of parachutes in supersonic flows is a strong function of parachute design parameters and their interactions with the payload wake.

  13. Bibliography of Supersonic Cruise Research (SCR) program from 1980 to 1983

    NASA Technical Reports Server (NTRS)

    Hoffman, S.

    1984-01-01

    A bibliography for the Supersonic Cruise Research (SCR) and Variable Cycle Engine (VCE) Programs is presented. An annotated bibliography for the last 123 formal reports and a listing of titles for 44 articles and presentations is included. The studies identifies technologies for producing efficient supersonic commercial jet transports for cruise Mach numbers from 2.0 to 2.7.

  14. Advanced supersonic technology concept study: Hydrogen fueled configuration

    NASA Technical Reports Server (NTRS)

    Brewer, G. D.

    1974-01-01

    Conceptual designs of hydrogen fueled supersonic transport configurations for the 1990 time period were developed and compared with equivalent technology Jet A-1 fueled vehicles to determine the economic and performance potential of liquid hydrogen as an alternate fuel. Parametric evaluations of supersonic cruise vehicles with varying design and transport mission characteristics established the basis for selecting a preferred configuration which was then studied in greater detail. An assessment was made of the general viability of the selected concept including an evaluation of costs and environmental considerations, i.e., exhaust emissions and sonic boom characteristics. Technology development requirements and suggested implementation schedules are presented.

  15. Arrangement of electron transport chain components in bovine mitochondrial supercomplex I1III2IV1

    PubMed Central

    Althoff, Thorsten; Mills, Deryck J; Popot, Jean-Luc; Kühlbrandt, Werner

    2011-01-01

    The respiratory chain in the inner mitochondrial membrane contains three large multi-enzyme complexes that together establish the proton gradient for ATP synthesis, and assemble into a supercomplex. A 19-Å 3D map of the 1.7-MDa amphipol-solubilized supercomplex I1III2IV1 from bovine heart obtained by single-particle electron cryo-microscopy reveals an amphipol belt replacing the membrane lipid bilayer. A precise fit of the X-ray structures of complex I, the complex III dimer, and monomeric complex IV indicates distances of 13 nm between the ubiquinol-binding sites of complexes I and III, and of 10–11 nm between the cytochrome c binding sites of complexes III and IV. The arrangement of respiratory chain complexes suggests two possible pathways for efficient electron transfer through the supercomplex, of which the shorter branch through the complex III monomer proximal to complex I may be preferred. PMID:21909073

  16. Geared-elevator flutter study. [wind tunnel tests of transonic flutter effects on control surfaces of supersonic transport tail assemblies, conducted in a NASA-Langley transonic wind tunnel

    NASA Technical Reports Server (NTRS)

    Ruhlin, C. L.; Doggett, R. V., Jr.; Gregory, R. A.

    1976-01-01

    An experimental and analytical study was made of the transonic flutter characteristics of a supersonic transport tail assembly model having an all-movable, horizontal tail with a geared elevator. Two model configurations, namely, one with a gear-elevator (2.8 to 1.0 gear ratio) and one with locked-elevator (1.0 to 1.0 gear ratio), were flutter tested in the Langley transonic dynamics tunnel with an empennage cantilever-mounted on a sting. The geared-elevator configuration fluttered experimentally at about 20% higher dynamic pressures than the locked-elevator configuration. The experimental flutter dynamic pressure boundaries for both configurations were nearly flat over a Mach number range from 0.9 to 1.1. Flutter calculations (mathematical models) were made for the geared-elevator configuration using three subsonic lifting-surface methods. In one method, the elevator was treated as a discrete surface, and in the other two methods, the stabilizer and elevator were treated as a single warped-surface with the primary difference between these two methods being in the mathematical implementation used. A comparison of the experimental and analytical results shows that the discrete-elevator method predicted best the experimental flutter dynamic pressure level. However, the single warped-surface methods predicts more closely the experimental flutter frequencies and Mach number trends.

  17. OLIGOPEPTIDE TRANSPORTERS AND THEIR ROLE IN FE(II)- AND FE(III)-NICOTIANAMINE TRANSPORT IN RICE (ORYZA SATIVA L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ability of organisms to transport small peptides (two to five amino acids) is wide-ranging, and is present in humans, bacteria, fungi, archaea, and plants. There are three major groups of peptide transporters, divided by their substrate specificity: the ATP binding cassette (ABC), the peptide tr...

  18. Determination of thermooptical and transport parameters of ε iron(III) oxide-based nanocomposites by beam deflection spectroscopy

    NASA Astrophysics Data System (ADS)

    Korte, Dorota; Carraro, Giorgio; Maccato, Chiara; Franko, Mladen

    2015-04-01

    In this work, photothermal beam deflection (PBD) experiments have been used to characterize the thermooptical and transport properties of ε-Fe2O3-based nanocomposites. In particular, iron(III) nanostructures have been functionalized with Au, Ag and Cu nanoparticles, tailoring both their nano-organization and their chemical state. In order to elucidate the correlation between the thermooptical and transport parameters, the structural, compositional and morphological properties of Fe2O3-based systems were studied by field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). It was observed that the optothermal and transport parameters were influenced by the nature and oxidation state of the nanoparticles, which can serve as a key tool to master the material properties for their application in light-assisted processes.

  19. Quiet Supersonic Wind Tunnel Development

    NASA Technical Reports Server (NTRS)

    King, Lyndell S.; Kutler, Paul (Technical Monitor)

    1994-01-01

    The ability to control the extent of laminar flow on swept wings at supersonic speeds may be a critical element in developing the enabling technology for a High Speed Civil Transport (HSCT). Laminar boundary layers are less resistive to forward flight than their turbulent counterparts, thus the farther downstream that transition from laminar to turbulent flow in the wing boundary layer is extended can be of significant economic impact. Due to the complex processes involved experimental studies of boundary layer stability and transition are needed, and these are performed in "quiet" wind tunnels capable of simulating the low-disturbance environment of free flight. At Ames, a wind tunnel has been built to operate at flow conditions which match those of the HSCT laminar flow flight demonstration 'aircraft, the F-16XL, i.e. at a Mach number of 1.6 and a Reynolds number range of 1 to 3 million per foot. This will allow detailed studies of the attachment line and crossflow on the leading edge area of the highly swept wing. Also, use of suction as a means of control of transition due to crossflow and attachment line instabilities can be studied. Topics covered include: test operating conditions required; design requirements to efficiently make use of the existing infrastructure; development of an injector drive system using a small pilot facility; plenum chamber design; use of computational tools for tunnel and model design; and early operational results.

  20. Titanium honeycomb structure. [for supersonic aircraft wing structure

    NASA Technical Reports Server (NTRS)

    Davis, R. A.; Elrod, S. D.; Lovell, D. T.

    1972-01-01

    A brazed titanium honeycomb sandwich system for supersonic transport wing cover panels provides the most efficient structure spanwise, chordwise, and loadwise. Flutter testing shows that high wing stiffness is most efficient in a sandwich structure. This structure also provides good thermal insulation if liquid fuel is carried in direct contact with the wing structure in integral fuel tanks.

  1. 76 FR 34124 - Civil Supersonic Aircraft Panel Discussion

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-10

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Civil Supersonic Aircraft Panel Discussion Correction In notice document 2011-12742 appearing on page 30231 in the issue of Tuesday, May 24, 2011, make the following...

  2. Low-Cost Growth of III-V Layers on Si Using Close-Spaced Vapor Transport

    SciTech Connect

    Boucher, Jason W.; Greenaway, Ann L.; Ritenour, Andrew J.; Davis, Allison L.; Bachman, Benjamin F.; Aloni, Shaul; Boettcher, Shannon W.

    2015-06-14

    Close-spaced vapor transport (CSVT) uses solid precursors to deposit material at high rates and with high precursor utilization. The use of solid precursors could significantly reduce the costs associated with III-V photovoltaics, particularly if growth on Si substrates can be demonstrated. We present preliminary results of the growth of GaAs1-xPx with x ≈ 0.3 and 0.6, showing that CSVT can be used to produce III-V-V’ alloys with band gaps suitable for tandem devices. Additionally, we have grown GaAs on Si by first thermally depositing films of Ge and subsequently depositing GaAs by CSVT. Patterning the Ge into islands prevents cracking due to thermal mismatch and is useful for potential tandem structures.

  3. Supersonic-Spray Cleaner

    NASA Technical Reports Server (NTRS)

    Caimi, Raoul E. B.; Lin, Feng-Nan; Thaxton, Eric A.

    1995-01-01

    Spraying system for cleaning mechanical components uses less liquid and operates at pressures significantly lower. Liquid currently used is water. Designed to replace chlorofluorocarbon (CFC) solvent-based cleaning and cleanliness verification methods. Consists of spray head containing supersonic converging/diverging nozzles, source of gas at regulated pressure, pressurized liquid tank, and various hoses, fittings, valves, and gauges. Parameters of nozzles set so any of large variety of liquids and gases combined in desired ratio and rate of flow. Size and number of nozzles varied so system built in configurations ranging from small hand-held spray heads to large multinozzle cleaners. Also used to verify part adequately cleaned. Runoff liquid from spray directed at part collected. Liquid analyzed for presence of contaminants, and part recleaned if necessary.

  4. Supersonic Pulsed Injection

    NASA Technical Reports Server (NTRS)

    Cutler, A. D.; Harding, G. C.; Diskin, G. S.

    2001-01-01

    An injector has been developed to provide high-speed high-frequency (order 10 kHz) pulsed a supersonic crossflow. The injector nozzle is formed between the fixed internal surface of the nozzle and a freely rotating three- or four-sided wheel embedded within the device. Flow-induced rotation of the wheel causes the nozzle throat to open and close at a frequency proportional to the speed of sound of the injected gas. Measurements of frequency and mass flow rate as a function of supply pressure are discussed for various injector designs. Preliminary results are presented for wall-normal injection of helium into a Mach-2 ducted airflow. The data include schlieren images in the injectant plume in a plane normal to the flow, downstream of injection.

  5. Supersonics--Airport Noise

    NASA Technical Reports Server (NTRS)

    Bridges, James

    2007-01-01

    At this, the first year-end meeting of the Fundamental Aeronautics Program, an overview of the Airport Noise discipline of the Supersonics Project leads the presentation of technical plans and achievements in this area of the Project. The overview starts by defining the Technical Challenges targeted by Airport Noise efforts, and the Approaches planned to meet these challenges. These are fleshed out in Elements, namely Prediction, Diagnostics, and Engineering, and broken down into Tasks. The Tasks level is where individual researchers' work is defined and from whence the technical presentations to follow this presentation come. This overview also presents the Milestones accomplished to date and to be completed in the next year. Finally, the NASA Research Announcement cooperative agreement activities are covered and tied to the Tasks and Milestones.

  6. Supersonic reacting internal flow fields

    NASA Technical Reports Server (NTRS)

    Drummond, J. Philip

    1989-01-01

    The national program to develop a trans-atmospheric vehicle has kindled a renewed interest in the modeling of supersonic reacting flows. A supersonic combustion ramjet, or scramjet, has been proposed to provide the propulsion system for this vehicle. The development of computational techniques for modeling supersonic reacting flow fields, and the application of these techniques to an increasingly difficult set of combustion problems are studied. Since the scramjet problem has been largely responsible for motivating this computational work, a brief history is given of hypersonic vehicles and their propulsion systems. A discussion is also given of some early modeling efforts applied to high speed reacting flows. Current activities to develop accurate and efficient algorithms and improved physical models for modeling supersonic combustion is then discussed. Some new problems where computer codes based on these algorithms and models are being applied are described.

  7. Study of the supersonic propeller

    NASA Technical Reports Server (NTRS)

    Fabri, Jean; Siestrunck, Raymond

    1953-01-01

    In this paper a propeller having all sections operating at supersonic speeds is designated a supersonic propeller regardless of flight speed. Analyses assume subsonic flight speeds but very high rotational speeds. A very elementary analysis of the efficiency of a jet-propeller system is presented. A propeller analysis based on conventional vortex blade element theory is presented and reduced to a single point method which leads to an expression for optimum advance ratio in terms of hub-tip diameter ratio and airfoil fineness ratio. An expression for propeller efficiency in terms of advance ratio, hub-tip diameter ratio, and airfoil thickness ratio is also presented. Use is made of theoretical airfoil characteristics at supersonic speeds. A study of blade section interference, blade shock and expansion fields, at supersonic section speeds is presented. An example taken indicates that an efficiency of seventy percent can be obtained with a propeller having a tip Mach number of 2.3.

  8. Cg/Stability Map for the Reference H Cycle 3 Supersonic Transport Concept Along the High Speed Research Baseline Mission Profile

    NASA Technical Reports Server (NTRS)

    Giesy, Daniel P.; Christhilf, David M.

    1999-01-01

    A comparison is made between the results of trimming a High Speed Civil Transport (HSCT) concept along a reference mission profile using two trim modes. One mode uses the stabilator. The other mode uses fore and aft placement of the center of gravity. A comparison is make of the throttle settings (cruise segments) or the total acceleration (ascent and descent segments) and of the drag coefficient. The comparative stability of trimming using the two modes is also assessed by comparing the stability margins and the placement of the lateral and longitudinal eigenvalues.

  9. Advanced supersonic propulsion study. [with emphasis on noise level reduction

    NASA Technical Reports Server (NTRS)

    Sabatella, J. A. (Editor)

    1974-01-01

    A study was conducted to determine the promising propulsion systems for advanced supersonic transport application, and to identify the critical propulsion technology requirements. It is shown that noise constraints have a major effect on the selection of the various engine types and cycle parameters. Several promising advanced propulsion systems were identified which show the potential of achieving lower levels of sideline jet noise than the first generation supersonic transport systems. The non-afterburning turbojet engine, utilizing a very high level of jet suppression, shows the potential to achieve FAR 36 noise level. The duct-heating turbofan with a low level of jet suppression is the most attractive engine for noise levels from FAR 36 to FAR 36 minus 5 EPNdb, and some series/parallel variable cycle engines show the potential of achieving noise levels down to FAR 36 minus 10 EPNdb with moderate additional penalty. The study also shows that an advanced supersonic commercial transport would benefit appreciably from advanced propulsion technology. The critical propulsion technology needed for a viable supersonic propulsion system, and the required specific propulsion technology programs are outlined.

  10. Gene expression of transporters and phase I/II metabolic enzymes in murine small intestine during fasting

    PubMed Central

    van den Bosch, Heleen M; Bünger, Meike; de Groot, Philip J; van der Meijde, Jolanda; Hooiveld, Guido JEJ; Müller, Michael

    2007-01-01

    Background Fasting has dramatic effects on small intestinal transport function. However, little is known on expression of intestinal transport and phase I/II metabolism genes during fasting and the role the fatty acid-activated transcription factor PPARα may play herein. We therefore investigated the effects of fasting on expression of these genes using Affymetrix GeneChip MOE430A arrays and quantitative RT-PCR. Results After 24 hours of fasting, expression levels of 33 of the 253 analyzed transporter and phase I/II metabolism genes were changed. Upregulated genes were involved in transport of energy-yielding molecules in processes such as glycogenolysis (G6pt1) and mitochondrial and peroxisomal oxidation of fatty acids (Cact, Mrs3/4, Fatp2, Cyp4a10, Cyp4b1). Other induced genes were responsible for the inactivation of the neurotransmitter serotonin (Sert, Sult1d1, Dtd, Papst2), formation of eicosanoids (Cyp2j6, Cyp4a10, Cyp4b1), or for secretion of cholesterol (Abca1 and Abcg8). Cyp3a11, typically known because of its drug metabolizing capacity, was also increased. Fasting had no pronounced effect on expression of phase II metabolic enzymes, except for glutathione S-transferases which were down-regulated. Time course studies revealed that some genes were acutely regulated, whereas expression of other genes was only affected after prolonged fasting. Finally, we identified 8 genes that were PPARα-dependently upregulated upon fasting. Conclusion We have characterized the response to fasting on expression of transporters and phase I/II metabolic enzymes in murine small intestine. Differentially expressed genes are involved in a variety of processes, which functionally can be summarized as a) increased oxidation of fat and xenobiotics, b) increased cholesterol secretion, c) increased susceptibility to electrophilic stressors, and d) reduced intestinal motility. This knowledge increases our understanding of gut physiology, and may be of relevance for e.g. pre

  11. ESCRT-III-Associated Protein ALIX Mediates High-Affinity Phosphate Transporter Trafficking to Maintain Phosphate Homeostasis in Arabidopsis

    PubMed Central

    Cardona-López, Ximena; Cuyas, Laura; Marín, Elena; Irigoyen, María Luisa; Gil, Erica; Puga, María Isabel; Bligny, Richard; Nussaume, Laurent; Geldner, Niko; Paz-Ares, Javier

    2015-01-01

    Prior to the release of their cargoes into the vacuolar lumen, sorting endosomes mature into multivesicular bodies (MVBs) through the action of ENDOSOMAL COMPLEX REQUIRED FOR TRANSPORT (ESCRT) protein complexes. MVB-mediated sorting of high-affinity phosphate transporters (PHT1) to the vacuole limits their plasma membrane levels under phosphate-sufficient conditions, a process that allows plants to maintain phosphate homeostasis. Here, we describe ALIX, a cytosolic protein that associates with MVB by interacting with ESCRT-III subunit SNF7 and mediates PHT1;1 trafficking to the vacuole in Arabidopsis thaliana. We show that the partial loss-of-function mutant alix-1 displays reduced vacuolar degradation of PHT1;1. ALIX derivatives containing the alix-1 mutation showed reduced interaction with SNF7, providing a simple molecular explanation for impaired cargo trafficking in alix-1 mutants. In fact, the alix-1 mutation also hampered vacuolar sorting of the brassinosteroid receptor BRI1. We also show that alix-1 displays altered vacuole morphogenesis, implying a new role for ALIX proteins in vacuolar biogenesis, likely acting as part of ESCRT-III complexes. In line with a presumed broad target spectrum, the alix-1 mutation is pleiotropic, leading to reduced plant growth and late flowering, with stronger alix mutations being lethal, indicating that ALIX participates in diverse processes in plants essential for their life. PMID:26342016

  12. O{sub 3} and stratospheric H{sub 2}O radiative forcing resulting from a supersonic jet transport emission scenario

    SciTech Connect

    Grossman, A.S.; Kinnison, D.E.; Penner, J.E.; Grant, K.E.; Tamaresis, J.; Connell, P.S.

    1996-01-01

    The tropospheric radiative forcing has been calculated for ozone and water vapor perturbations caused by a realistic High Speed Civil Transport (HSCT) aircraft emission scenario. Atmospheric profiles of water vapor and ozone were obtained using the LLNL 2-D chemical-radiative-transport model (CRT) of the global troposphere and stratosphere. IR radiative forcing calculations were made with the LLNL correlated k-distribution radiative transfer model. UV-Visible-Near IR radiative forcing calculations were made with the LLNL two stream solar radiation model. For the case of water vapor the IR and Near IR radiative forcing was determined at five different latitudes and then averaged using an appropriate latitudinal average to obtain the global average value. Global average values of radiative forcing were approximately 1.2--2.6 10{sup {minus}3} W/m{sup 2}, depending on the background atmospheric water vapor profile. This result is consistent with prior published values for a similar aircraft scenario and supports the conclusion that the water vapor climate forcing effect is very small. The radiative forcing in the IR and UV-Visible spectral ranges, due to the ozone perturbation, was calculated for the globally averaged atmosphere. Global average values of the radiative forcing were 0.034 W/m{sup 2} for the UV-Visible spectral range and 0.006 W/m{sup 2} for the IR spectral range (0.04 W/m{sup 2} total). This result is also consistent with the range of published values obtained for a similar HSCT scenario. As was the case for water vapor, the ozone forcing is too small to be of major consequence.

  13. Experimental and Numerical Optimization of a High-Lift System to Improve Low-Speed Performance, Stability, and Control of an Arrow-Wing Supersonic Transport

    NASA Technical Reports Server (NTRS)

    Hahne, David E.; Glaab, Louis J.

    1999-01-01

    An investigation was performed to evaluate leading-and trailing-edge flap deflections for optimal aerodynamic performance of a High-Speed Civil Transport concept during takeoff and approach-to-landing conditions. The configuration used for this study was designed by the Douglas Aircraft Company during the 1970's. A 0.1-scale model of this configuration was tested in the Langley 30- by 60-Foot Tunnel with both the original leading-edge flap system and a new leading-edge flap system, which was designed with modem computational flow analysis and optimization tools. Leading-and trailing-edge flap deflections were generated for the original and modified leading-edge flap systems with the computational flow analysis and optimization tools. Although wind tunnel data indicated improvements in aerodynamic performance for the analytically derived flap deflections for both leading-edge flap systems, perturbations of the analytically derived leading-edge flap deflections yielded significant additional improvements in aerodynamic performance. In addition to the aerodynamic performance optimization testing, stability and control data were also obtained. An evaluation of the crosswind landing capability of the aircraft configuration revealed that insufficient lateral control existed as a result of high levels of lateral stability. Deflection of the leading-and trailing-edge flaps improved the crosswind landing capability of the vehicle considerably; however, additional improvements are required.

  14. Second-order closure models for supersonic turbulent flows

    NASA Technical Reports Server (NTRS)

    Speziale, Charles G.; Sarkar, Sutanu

    1991-01-01

    Recent work on the development of a second-order closure model for high-speed compressible flows is reviewed. This turbulent closure is based on the solution of modeled transport equations for the Favre-averaged Reynolds stress tensor and the solenoidal part of the turbulent dissipation rate. A new model for the compressible dissipation is used along with traditional gradient transport models for the Reynolds heat flux and mass flux terms. Consistent with simple asymptotic analyses, the deviatoric part of the remaining higher-order correlations in the Reynolds stress transport equations are modeled by a variable density extension of the newest incompressible models. The resulting second-order closure model is tested in a variety of compressible turbulent flows which include the decay of isotropic turbulence, homogeneous shear flow, the supersonic mixing layer, and the supersonic flat-plate turbulent boundary layer. Comparisons between the model predictions and the results of physical and numerical experiments are quite encouraging.

  15. Passive Ca transport in human red blood cell ghosts measured with entrapped arsenazo III

    PubMed Central

    1984-01-01

    The rate of Ca influx into ghosts containing arsenazo III changes with time, being most rapid during the first 5 min after Ca is added to the outside and declining thereafter. The rate of Ca influx is a nonlinear function of extracellular Ca and plateaus as the latter is increased above 1 mM. The rate of Ca influx was measured as a function of the transmembrane gradients of Na and K and changes in the permeability of the membrane to K and Cl produced by valinomycin and SITS (4-acetamido- 4'-isothiocyano-stilbene-2-2'-disulfonic acid), respectively. Changes in the rate of Ca influx are consistent with expected effects of these treatments on the membrane potential. Oligomycin (10 micrograms/ml) and quinidine (1 mM) inhibit the rate of Ca uptake by inhibiting Ca-induced changes in the K permeability. At constant membrane potential, furosemide produced a slight (15%) consistent increase in Ca uptake. Other experiments show that resealed ghosts are heterogeneous in their passive permeability to Ca and that A23187 can be used to effectively eliminate such differences. The results of this paper show that resealed human red cell ghosts containing arsenazo III can be used to continuously monitor intracellular free Ca and to study the factors that influence the permeability of the red cell membrane to Ca. PMID:6319541

  16. Offshore transport and dispersion in the California coastal region - BLM III. NPS data summary. Technical report

    SciTech Connect

    Schacher, G.E.; Spiel, D.E.; Leonard, C.A.

    1982-05-01

    The third in a series of tracer measurements of overwater transport and diffusion has been completed. This report includes the meteorological data obtained aboard the RV/Acania. Analyses of radiosonde data to yield mixed layer parameters for mixed layer assessment is also included.

  17. Road Transportable Analytical Laboratory (RTAL) system: Volume III, Appendices C through J. Final report

    SciTech Connect

    Finger, S.M.; De Avila, J.C.; Keith, V.F.

    1996-08-01

    The Road Transportable Analytical Laboratory (RTAL) provides a portabler laboratory for the analysis of soils, ground water, and surface water. This report presents data from a soils sample TCLP VOA and SVOA report, aqueous sample RCRA metals report, soils sample total and isotopic uranium report, SVOA sample analytical performance report, and and RCRA metal sample analytical performance report.

  18. Regulation of glomerulotubular balance. III. Implication of cytosolic calcium in flow-dependent proximal tubule transport.

    PubMed

    Du, Zhaopeng; Weinbaum, Sheldon; Weinstein, Alan M; Wang, Tong

    2015-04-15

    In the proximal tubule, axial flow (drag on brush-border microvilli) stimulates Na(+) and HCO3 (-) reabsorption by modulating both Na/H exchanger 3 (NHE3) and H-ATPase activity, a process critical to glomerulotubular balance. We have also demonstrated that blocking the angiotensin II receptor decreases baseline transport, but preserves the flow effect; dopamine leaves baseline fluxes intact, but abrogates the flow effect. In the current work, we provide evidence implicating cytosolic calcium in flow-dependent transport. Mouse proximal tubules were microperfused in vitro at perfusion rates of 5 and 20 nl/min, and reabsorption of fluid (Jv) and HCO3 (-) (JHCO3) were measured. We examined the effect of high luminal Ca(2+) (5 mM), 0 mM Ca(2+), the Ca(2+) chelator BAPTA-AM, the inositol 1,4,5-trisphosphate (IP3) receptor antagonist 2-aminoethoxydiphenyl borate (2-APB), and the Ca-ATPase inhibitor thapsigargin. In control tubules, increasing perfusion rate from 5 to 20 nl/min increased Jv by 62% and JHCO3 by 104%. With respect to Na(+) reabsorption, high luminal Ca(2+) decreased transport at low flow, but preserved the flow-induced increase; low luminal Ca(2+) had little impact; both BAPTA and 2-APB had no effect on baseline flux, but abrogated the flow effect; thapsigargin decreased baseline flow, leaving the flow effect intact. With respect to HCO3 (-) reabsorption, high luminal Ca(2+) decreased transport at low flow and mildly diminished the flow-induced increase; low luminal Ca(2+) had little impact; both BAPTA and 2-APB had no effect on baseline flux, but abrogated the flow effect. These data implicate IP3 receptor-mediated intracellular Ca(2+) signaling as a critical step in transduction of microvillous drag to modulate Na(+) and HCO3 (-) transport. PMID:25651568

  19. Supersonic Laminar Flow Control Research

    NASA Technical Reports Server (NTRS)

    Lo, Ching F.; Wiberg, Clark G.

    1996-01-01

    The objective of this research is to understand supersonic laminar flow stability, transition and active control. Some prediction techniques will be developed or modified to analyze laminar flow stability. The effects of distributed heating and cooling as an active boundary layer control technique will be studied. The primary tasks of the research apply to the NASA/Ames PoC and LFSWT's nozzle design with laminar flow control and are listed as follows: Predictions of supersonic laminar boundary layer stability and transition; Effects of wall heating and cooling on supersonic laminar flow control on a flat plate; Performance evaluation of the PoC and LFSWT nozzle designs with wall heating and cooling applied at different locations and various lengths; Effects of a conducted-vs-pulse wall temperature distribution for the LFSWT; and Application of wall heating and/or cooling to laminar boundary layer and flow separation control of airfoils and investigation of related active control techniques.

  20. Supersonic LFC: Challenges and opportunities

    NASA Technical Reports Server (NTRS)

    Powell, Arthur G.

    1992-01-01

    The discussion and viewgraphs on supersonic laminar control are provided. The high fuel fractions required for long range supersonic airplanes give significant leverage to technologies for cruise drag reduction such as laminar flow control (LFC). Fuel burn benefits are further enhanced when sizing effects are considered. These effects may even be powerful enough to reduce airplane production cost over a turbulent baseline. This is an important goal for LFC technology development. The results of aerodynamics studies on the application of LFC technology to the highly swept wings of supersonic airplanes are presented. Important questions of applicability, realistic benefit, and critical application issues, addressed in a NASA-sponsored study conducted by McDonnell Douglas Corporation in 1987-88 are reviewed. Efforts aimed at establishing the feasibility of demonstrating extensive laminarization on the F-16XL-2 airplane are summarized.

  1. Supersonic Dislocation Bursts in Silicon

    PubMed Central

    Hahn, E. N.; Zhao, S.; Bringa, E. M.; Meyers, M. A.

    2016-01-01

    Dislocations are the primary agents of permanent deformation in crystalline solids. Since the theoretical prediction of supersonic dislocations over half a century ago, there is a dearth of experimental evidence supporting their existence. Here we use non-equilibrium molecular dynamics simulations of shocked silicon to reveal transient supersonic partial dislocation motion at approximately 15 km/s, faster than any previous in-silico observation. Homogeneous dislocation nucleation occurs near the shock front and supersonic dislocation motion lasts just fractions of picoseconds before the dislocations catch the shock front and decelerate back to the elastic wave speed. Applying a modified analytical equation for dislocation evolution we successfully predict a dislocation density of 1.5 × 1012 cm−2 within the shocked volume, in agreement with the present simulations and realistic in regards to prior and on-going recovery experiments in silicon. PMID:27264746

  2. Supersonic Dislocation Bursts in Silicon

    DOE PAGESBeta

    Hahn, E. N.; Zhao, S.; Bringa, E. M.; Meyers, M. A.

    2016-06-06

    Dislocations are the primary agents of permanent deformation in crystalline solids. Since the theoretical prediction of supersonic dislocations over half a century ago, there is a dearth of experimental evidence supporting their existence. Here we use non-equilibrium molecular dynamics simulations of shocked silicon to reveal transient supersonic partial dislocation motion at approximately 15 km/s, faster than any previous in-silico observation. Homogeneous dislocation nucleation occurs near the shock front and supersonic dislocation motion lasts just fractions of picoseconds before the dislocations catch the shock front and decelerate back to the elastic wave speed. Applying a modified analytical equation for dislocation evolutionmore » we successfully predict a dislocation density of 1.5 x 10(12) cm(-2) within the shocked volume, in agreement with the present simulations and realistic in regards to prior and on-going recovery experiments in silicon.« less

  3. Supersonic Dislocation Bursts in Silicon.

    PubMed

    Hahn, E N; Zhao, S; Bringa, E M; Meyers, M A

    2016-01-01

    Dislocations are the primary agents of permanent deformation in crystalline solids. Since the theoretical prediction of supersonic dislocations over half a century ago, there is a dearth of experimental evidence supporting their existence. Here we use non-equilibrium molecular dynamics simulations of shocked silicon to reveal transient supersonic partial dislocation motion at approximately 15 km/s, faster than any previous in-silico observation. Homogeneous dislocation nucleation occurs near the shock front and supersonic dislocation motion lasts just fractions of picoseconds before the dislocations catch the shock front and decelerate back to the elastic wave speed. Applying a modified analytical equation for dislocation evolution we successfully predict a dislocation density of 1.5 × 10(12) cm(-2) within the shocked volume, in agreement with the present simulations and realistic in regards to prior and on-going recovery experiments in silicon. PMID:27264746

  4. Supersonic Dislocation Bursts in Silicon

    NASA Astrophysics Data System (ADS)

    Hahn, E. N.; Zhao, S.; Bringa, E. M.; Meyers, M. A.

    2016-06-01

    Dislocations are the primary agents of permanent deformation in crystalline solids. Since the theoretical prediction of supersonic dislocations over half a century ago, there is a dearth of experimental evidence supporting their existence. Here we use non-equilibrium molecular dynamics simulations of shocked silicon to reveal transient supersonic partial dislocation motion at approximately 15 km/s, faster than any previous in-silico observation. Homogeneous dislocation nucleation occurs near the shock front and supersonic dislocation motion lasts just fractions of picoseconds before the dislocations catch the shock front and decelerate back to the elastic wave speed. Applying a modified analytical equation for dislocation evolution we successfully predict a dislocation density of 1.5 × 1012 cm‑2 within the shocked volume, in agreement with the present simulations and realistic in regards to prior and on-going recovery experiments in silicon.

  5. Diagnostic experiments on supersonic jet noise

    NASA Technical Reports Server (NTRS)

    Mclaughlin, D. K.

    1981-01-01

    Experiments and computations on the flowfield and radiated noise of supersonic model jets are discussed. The shock associated noise produced by large scale instabilities in underexpanded supersonic jets, the nonlinear propagation distortion phenomenon in the noise radiated by supersonic model jets, and computations of instability evolution and radiated noise using the LSNOIS computer code are addressed.

  6. Supersonic coal water slurry fuel atomizer

    DOEpatents

    Becker, Frederick E.; Smolensky, Leo A.; Balsavich, John

    1991-01-01

    A supersonic coal water slurry atomizer utilizing supersonic gas velocities to atomize coal water slurry is provided wherein atomization occurs externally of the atomizer. The atomizer has a central tube defining a coal water slurry passageway surrounded by an annular sleeve defining an annular passageway for gas. A converging/diverging section is provided for accelerating gas in the annular passageway to supersonic velocities.

  7. Feasibility and benefits of laminar flow control on supersonic cruise airplanes

    NASA Technical Reports Server (NTRS)

    Powell, A. G.; Agrawal, S.; Lacey, T. R.

    1989-01-01

    An evaluation was made of the applicability and benefits of laminar flow control (LFC) technology to supersonic cruise airplanes. Ancillary objectives were to identify the technical issues critical to supersonic LFC application, and to determine how those issues can be addressed through flight and wind-tunnel testing. Vehicle types studied include a Mach 2.2 supersonic transport configuration, a Mach 4.0 transport, and two Mach 2-class fighter concepts. Laminar flow control methodologies developed for subsonic and transonic wing laminarization were extended and applied. No intractible aerodynamic problems were found in applying LFC to airplanes of the Mach 2 class, even ones of large size. Improvements of 12 to 17 percent in lift-drag ratios were found. Several key technical issues, such as contamination avoidance and excresence criteria were identified. Recommendations are made for their resolution. A need for an inverse supersonic wing design methodology is indicated.

  8. The type III transporters (PiT-1 and PiT-2) are the major sodium-dependent phosphate transporters in the mice and human brains.

    PubMed

    Inden, Masatoshi; Iriyama, Masaki; Zennami, Miho; Sekine, Shin-Ichiro; Hara, Akira; Yamada, Mitsunori; Hozumi, Isao

    2016-04-15

    PiT-1/SLC20A1 and PiT-2/SLC20A2 are members of the mammalian type-III inorganic phosphate (Pi) transporters encoded by the SLC20 genes. The broad distribution of SLC20A1 and SLC20A2 mRNAs in mammalian tissues is compatible with housekeeping maintenace of intracellular Pi homeostasis by transporting Pi from intrastitial fluid for normal cellular functions. Recently, mutations of SLC20A2 have been found in patients with idiopathic basal ganglia calcification (IBGC), also known as Fahr's disease. However, the localization of PiT-1 and PiT-2 in the normal brain has not been clarified yet. The aim of this study was to reveal the distribution of PiT-1 and PiT-2 in the mouse and human brains. As results, gene expressing analysis showed that SLC20A1 and SLC20A2 mRNAs were widely expressed throughout the mouse and human brains, although other Pi transporters encoded by SLC17 and SLC34 mRNAs were hardly detected. The region of cerebellum contained a higher level of SLC20A1 and SLC20A2 mRNAs than the other brain regions. Additionally, the cerebellum in the mouse brain contained higher levels of PiT-1 and PiT-2 than those in the other regions in the brain, respectively. The immonohistochemical studies showed that PiT-1 was recognized in neuron, astrocytes and vascular endothelial cells. Similarly to PiT-1 immunopositivity, PiT-2 was clearly recognized in these cells. These results suggest that SLC20 family plays a pivotal role in the maintenance of cellular Pi homeostasis particullary in the brain. The viewpoint is compatible with the finding that calcification in IBGC is recognized only in the brain. This provides us with a novel viewpoint to understand the basic pathophysiology of IBGC through type-III Pi transporters. PMID:26923164

  9. Heteroleptic cyclometalated Ir(III) complexes with charge transporting groups: A theoretical study

    SciTech Connect

    Padmaperuma, Asanga B.; Fernandez, Carlos A.

    2012-09-13

    Efficient and stable high energy organic light emitting devices (OLEDs) are a vital component of new generation general illumination solutions. However, large charge imbalances in the emissive layer of OLEDs lead to charge accumulation and subsequent side reactions which lowers the device efficiency and dramatically shortens operational lifetime. Radical changes in the way emitter materials are designed are needed to address this problem. Conventional approaches have only focused on color tuning; however, multi-functional emitter materials are needed to assist the transport of charge in the emissive layer. We propose to design and synthesize new organometallic iridium phosphorescent materials with bipolar charge transport properties to be used in high energy OLEDs and white light configurations

  10. Supersonic laminar-flow control

    NASA Technical Reports Server (NTRS)

    Bushnell, Dennis M.; Malik, Mujeeb R.

    1987-01-01

    Detailed, up to date systems studies of the application of laminar flow control (LFC) to various supersonic missions and/or vehicles, both civilian and military, are not yet available. However, various first order looks at the benefits are summarized. The bottom line is that laminar flow control may allow development of a viable second generation SST. This follows from a combination of reduced fuel, structure, and insulation weight permitting operation at higher altitudes, thereby lowering sonic boom along with improving performance. The long stage lengths associated with the emerging economic importance of the Pacific Basin are creating a serious and renewed requirement for such a vehicle. Supersonic LFC techniques are discussed.

  11. The aeroacoustics of supersonic jets

    NASA Technical Reports Server (NTRS)

    Morris, Philip J.; McLaughlin, Dennis K.

    1995-01-01

    This research project was a joint experimental/computational study of noise in supersonic jets. The experiments were performed in a low to moderate Reynolds number anechoic supersonic jet facility. Computations have focused on the modeling of the effect of an external shroud on the generation and radiation of jet noise. This report summarizes the results of the research program in the form of the Masters and Doctoral theses of those students who obtained their degrees with the assistance of this research grant. In addition, the presentations and publications made by the principal investigators and the research students is appended.

  12. Anaerobic Fe(III) reduction by Shewanella putrefaciens: Analysis of the electron transport chain

    SciTech Connect

    Daad Saffarini

    2004-01-20

    The goals of the project were to isolate mutants that are deficient in metal reduction, identify components of the electron transport chain that are involved in this process, and purify some of these proteins for biochemical analyses. In the 3-year period since the start of the project, we have accomplished many of these goals. We have isolated several new S. oneidensis mutants that are deficient in metal reduction, and have initiated the development of vectors for the overexpression of cytochromes and other proteins in S. oneidensis. We have also overexpressed CymA, one of the c cytochromes that are involved in metal reduction.

  13. Application of Doppler Global Velocimetry to Supersonic Flows

    NASA Technical Reports Server (NTRS)

    Meyers, James F.

    1996-01-01

    The design and implementation of Doppler Global Velocimetry (DGV) for testing in the Langley Unitary Plan Wind Tunnel is presented. The discussion begins by outlining the characteristics of the tunnel and the test environment, with potential problem areas highlighted. Modifications to the optical system design to implement solutions for these problems are described. Since this tunnel entry was the first ever use of DGV in a supersonic wind tunnel, the test series was divided into three phases, each with its own goal. Phase I determined if condensation provided sufficient scattered light for DGV applications. Phase II studied particle lag by measuring the flow about an oblique shock above an inclined flat plate. Phase III investigated the supersonic vortical flow field above a 75-degree delta wing at 24-degrees angle of attack. Example results from these tests are presented.

  14. Optical properties and electrical transport of thin films of terbium(III) bis(phthalocyanine) on cobalt

    PubMed Central

    Robaschik, Peter; Siles, Pablo F; Bülz, Daniel; Richter, Peter; Monecke, Manuel; Fronk, Michael; Klyatskaya, Svetlana; Grimm, Daniel; Schmidt, Oliver G; Ruben, Mario; Zahn, Dietrich R T

    2014-01-01

    Summary The optical and electrical properties of terbium(III) bis(phthalocyanine) (TbPc2) films on cobalt substrates were studied using variable angle spectroscopic ellipsometry (VASE) and current sensing atomic force microscopy (cs-AFM). Thin films of TbPc2 with a thickness between 18 nm and 87 nm were prepared by organic molecular beam deposition onto a cobalt layer grown by electron beam evaporation. The molecular orientation of the molecules on the metallic film was estimated from the analysis of the spectroscopic ellipsometry data. A detailed analysis of the AFM topography shows that the TbPc2 films consist of islands which increase in size with the thickness of the organic film. Furthermore, the cs-AFM technique allows local variations of the organic film topography to be correlated with electrical transport properties. Local current mapping as well as local I–V spectroscopy shows that despite the granular structure of the films, the electrical transport is uniform through the organic films on the microscale. The AFM-based electrical measurements allow the local charge carrier mobility of the TbPc2 thin films to be quantified with nanoscale resolution. PMID:25551034

  15. Supersonic jet shock noise reduction

    NASA Technical Reports Server (NTRS)

    Stone, J. R.

    1984-01-01

    Shock-cell noise is identified to be a potentially significant problem for advanced supersonic aircraft at takeoff. Therefore NASA conducted fundamental studies of the phenomena involved and model-scale experiments aimed at developing means of noise reduction. The results of a series of studies conducted to determine means by which supersonic jet shock noise can be reduced to acceptable levels for advanced supersonic cruise aircraft are reviewed. Theoretical studies were conducted on the shock associated noise of supersonic jets from convergent-divergent (C-D) nozzles. Laboratory studies were conducted on the influence of narrowband shock screech on broadband noise and on means of screech reduction. The usefulness of C-D nozzle passages was investigated at model scale for single-stream and dual-stream nozzles. The effect of off-design pressure ratio was determined under static and simulated flight conditions for jet temperatures up to 960 K. Annular and coannular flow passages with center plugs and multi-element suppressor nozzles were evaluated, and the effect of plug tip geometry was established. In addition to the far-field acoustic data, mean and turbulent velocity distributions were measured with a laser velocimeter, and shadowgraph images of the flow field were obtained.

  16. Supersonic Laminar Flow Control Research

    NASA Technical Reports Server (NTRS)

    Lo, C. F.; Wiberg, Clark G.

    1996-01-01

    The objective of this research is to understand supersonic laminar flow stability, transition and active control. Some prediction techniques are developed or modified to analyze laminar flow stability. The effects of distributed heating and cooling as an active boundary layer control technique are studied. The primary tasks of the research apply to the NASA/Ames Proof-of-Concept (PoC) and the Laminar Flow Supersonic Wind Tunnel's (LFSWT's) nozzle design with laminar flow control and are listed as follows: (1) Predictions of supersonic laminar boundary layer stability and transition; (2) Effects of wall heating and cooling on supersonic laminar flow control on a flat plate; (3) Performance evaluation of the PoC and LFSWT nozzle designs with wall heating and cooling applied at different locations and various lengths; (4) Effects of a conducted -vs- pulse wall temperature distribution for the LFSWT; and (5) Application of wall heating and/or cooling to laminar boundary layer and flow separation control of airfoils and investigation of related active control techniques.

  17. Supersonic Wave Interference Affecting Stability

    NASA Technical Reports Server (NTRS)

    Love, Eugene S.

    1958-01-01

    Some of the significant interference fields that may affect stability of aircraft at supersonic speeds are briefly summarized. Illustrations and calculations are presented to indicate the importance of interference fields created by wings, bodies, wing-body combinations, jets, and nacelles.

  18. Structure-Independent Proton Transport in Cerium(III) Phosphate Nanowires.

    PubMed

    Pusztai, Péter; Haspel, Henrik; Tóth, Ildikó Y; Tombácz, Etelka; László, Krisztina; Kukovecz, Ákos; Kónya, Zoltán

    2015-05-13

    Understanding of water-related electrical conduction is of utmost importance in applications that utilize solid-state proton conductors. However, in spite of the vast amount of theoretical and experimental work published in the literature, thus far its mechanism remained unsolved. In this study, the structure-related ambient temperature electrical conduction of one-dimensional hydrophilic nanostructures was investigated. Cerium phosphate nanowires with monoclinic and hexagonal crystal structures were synthesized via the hydrothermal and ambient temperature precipitation routes, and their structural and surface properties were examined by using high-resolution transmission electron microscopy, X-ray diffractometry, nitrogen and water sorption, temperature-programmed ammonia desorption, and potentiometric titration techniques. The relative humidity (RH)-dependent charge-transport processes of hexagonal and monoclinic nanowires were investigated by means of impedance spectroscopy and transient ionic current measurement techniques to gain insight into their atomistic level mechanism. Although considerable differences in RH-dependent conductivity were first found, the distinct characteristics collapsed into a master curve when specific surface area and acidity were taken into account, implying structure-independent proton conduction mechanism in both types of nanowires. PMID:25859883

  19. Particle simulation of supersonic convection in the protostellar nebula

    NASA Astrophysics Data System (ADS)

    Riegger, J. M.

    1995-02-01

    For the simulation of compressible convection and a possible description of inner processes in meteorites a new algorithm for particle-in-cell methods in particle simulation is developed, which allows a direct description of the inner pressure by use of individual particle temperatures and therefore a description of gas dynamics without the approximations of perturbation theory. The simulation of nonadiabatic processes in superadiabatic stratified atmospheres leads to the self-organization of convection cells and to supersonic convection and instationary shock front systems for high Rayleigh numbers Ra > 5 × 10 5 as they are received by other numerical methods. The transport of material through shock fronts yields much faster temperature and pressure changes than ordinary convective transport in the subsonic range. Tracing the values of state along the pathlines shows that fast entropy increases occur either within shock fronts or due to local dissipation in turbulences. Transport through shock front systems results in multiple rapid temperature changes per cycle. Investigations on the local convective structure of the protostellar nebula with a simple radiative transfer and standard opacities and accretion rates indicate supersonic convection and multiple shock front systems in the outer layers of the solar nebula due to radiative cooling. Supersonic convection provides a very effective mechanism of dissipation for the protostellar nebula and makes a contribution to the discussion on the turbulent structure of the protostellar nebula and to the formation of chrondrules.

  20. Experimental Investigation of Laser-sustained Plasma in Supersonic Argon Flow

    NASA Astrophysics Data System (ADS)

    Sperber, David; Eckel, Hans-Albert; Moessinger, Peter; Fasoulas, Stefanos

    2011-11-01

    Laser-induced energy deposition is widely discussed as a flow control technique in supersonic transportation. In case of thermal laser-plasma upstream of a blunt body, a substantial adaptation of shock wave geometry and magnitude of wave drag is predicted. Related to the research on laser supported detonation, the paper describes the implementation of laser-sustained plasma in a supersonic Argon jet. The stable plasma state is generated by the intersection of a Q-switched Nd:YAG-laser and a continuous wave CO2-laser beams, for ignition and maintenance of the plasma respectively. A miniature supersonic Ludwieg tube test facility generates a supersonic jet at velocities of Mach 2.1. Modifications of the flow and plasma conditions are investigated and characterized by Schlieren flow visualisation, laser energy transmission and plasma radiation measurements. The results include the discussions of the flow field as well as the required laser and gas parameters.

  1. Experimental Investigation of Laser-sustained Plasma in Supersonic Argon Flow

    SciTech Connect

    Sperber, David; Eckel, Hans-Albert; Moessinger, Peter; Fasoulas, Stefanos

    2011-11-10

    Laser-induced energy deposition is widely discussed as a flow control technique in supersonic transportation. In case of thermal laser-plasma upstream of a blunt body, a substantial adaptation of shock wave geometry and magnitude of wave drag is predicted. Related to the research on laser supported detonation, the paper describes the implementation of laser-sustained plasma in a supersonic Argon jet. The stable plasma state is generated by the intersection of a Q-switched Nd:YAG-laser and a continuous wave CO{sub 2}-laser beams, for ignition and maintenance of the plasma respectively. A miniature supersonic Ludwieg tube test facility generates a supersonic jet at velocities of Mach 2.1. Modifications of the flow and plasma conditions are investigated and characterized by Schlieren flow visualisation, laser energy transmission and plasma radiation measurements. The results include the discussions of the flow field as well as the required laser and gas parameters.

  2. Exhaust Nozzles for Propulsion Systems with Emphasis on Supersonic Cruise Aircraft

    NASA Technical Reports Server (NTRS)

    Stitt, Leonard E.

    1990-01-01

    This compendium summarizes the contributions of the NASA-Lewis and its contractors to supersonic exhaust nozzle research from 1963 to 1985. Two major research and technology efforts sponsored this nozzle research work; the U.S. Supersonic Transport (SST) Program and the follow-on Supersonic Cruise Research (SCR) Program. They account for two generations of nozzle technology: the first from 1963 to 1971, and the second from 1971 to 1985. First, the equations used to calculate nozzle thrust are introduced. Then the general types of nozzles are presented, followed by a discussion of those types proposed for supersonic aircraft. Next, the first-generation nozzles designed specifically for the Boeing SST and the second-generation nozzles designed under the SCR program are separately reviewed and then compared. A chapter on throttle-dependent afterbody drag is included, since drag has a major effect on the off-design performance of supersonic nozzles. A chapter on the performance of supersonic dash nozzles follows, since these nozzles have similar design problems, Finally, the nozzle test facilities used at NASA-Lewis during this nozzle research effort are identified and discussed. These facilities include static test stands, a transonic wind tunnel, and a flying testbed aircraft. A concluding section points to the future: a third generation of nozzles designed for a new era of high speed civil transports to produce even greater advances in performance, to meet new noise rules, and to ensure the continuity of over two decades of NASA research.

  3. LANDVIEW III

    EPA Science Inventory

    LandView III is a desktop mapping system that includes database extracts from the Environmental Protection Agency, the Bureau of the Census, The U.S. Geological Survey, the Nuclear Regulatory Commission, the Department of Transportation, and the Federal Emergency Management Agenc...

  4. A Novel Mechanism of Regulating the ATPase VPS4 by Its Cofactor LIP5 and the Endosomal Sorting Complex Required for Transport (ESCRT)-III Protein CHMP5*

    PubMed Central

    Vild, Cody J.; Li, Yan; Guo, Emily Z.; Liu, Yuan; Xu, Zhaohui

    2015-01-01

    Disassembly of the endosomal sorting complex required for transport (ESCRT) machinery from biological membranes is a critical final step in cellular processes that require the ESCRT function. This reaction is catalyzed by VPS4, an AAA-ATPase whose activity is tightly regulated by a host of proteins, including LIP5 and the ESCRT-III proteins. Here, we present structural and functional analyses of molecular interactions between human VPS4, LIP5, and the ESCRT-III proteins. The N-terminal domain of LIP5 (LIP5NTD) is required for LIP5-mediated stimulation of VPS4, and the ESCRT-III protein CHMP5 strongly inhibits the stimulation. Both of these observations are distinct from what was previously described for homologous yeast proteins. The crystal structure of LIP5NTD in complex with the MIT (microtubule-interacting and transport)-interacting motifs of CHMP5 and a second ESCRT-III protein, CHMP1B, was determined at 1 Å resolution. It reveals an ESCRT-III binding induced moderate conformational change in LIP5NTD, which results from insertion of a conserved CHMP5 tyrosine residue (Tyr182) at the core of LIP5NTD structure. Mutation of Tyr182 partially relieves the inhibition displayed by CHMP5. Together, these results suggest a novel mechanism of VPS4 regulation in metazoans, where CHMP5 functions as a negative allosteric switch to control LIP5-mediated stimulation of VPS4. PMID:25637630

  5. Supersonic jet screech tone cancellation

    NASA Technical Reports Server (NTRS)

    Nagel, R. T.; Denham, J. W.; Papathanasiou, A. G.

    1983-01-01

    A new method of supersonic jet screech tone reduction is presented. The method utilizes a sound reflecting surface positioned upstream of the nozzle exit a distance of one-quarter wavelength of the fundamental screech tone. The reflector establishes a standing wave pattern of acoustic waves with a node at the nozzle exit plane. The pressure minimum at the exit halts the screech tone feedback mechanism. Experimental results indicate that the method eliminates supersonic jet screech as effectively as the currently accepted technique using an intrusive tab, but without distortion of the jet flow. The change in shock cell spacing, which occurs with an intrusive tab, does not occur when screech is cancelled with the new technique. The broadband shock-associated noise is also influenced much less when the jet screech tones are eliminated by the new method.

  6. Supersonic aerodynamics of delta wings

    NASA Technical Reports Server (NTRS)

    Wood, Richard M.

    1988-01-01

    Through the empirical correlation of experimental data and theoretical analysis, a set of graphs has been developed which summarize the inviscid aerodynamics of delta wings at supersonic speeds. The various graphs which detail the aerodynamic performance of delta wings at both zero-lift and lifting conditions were then employed to define a preliminary wing design approach in which both the low-lift and high-lift design criteria were combined to define a feasible design space.

  7. Propulsion challenges and opportunities for high-speed transport aircraft

    NASA Technical Reports Server (NTRS)

    Strack, William C.

    1990-01-01

    The major challenges confronting the propulsion community for supersonic transport applications are identified. Both past progress and future opportunities are discussed in relation to perceived technology shortfalls for an economically successful SST that satisfies environmental constraint. A very large improvement in propulsion system efficiency is needed both at supersonic cruise and subsonic cruise conditions. Toward this end, several advanced engine concepts are being considered that promise up to 25 pct. better efficiency than the Concorde engine. The quest for high productivity through higher speed is also thwarted by the lack of a conventional, low priced fuel that is thermally stable at the higher temperatures associated with faster flight. Extending Jet A type fuel to higher temperatures and the adoption of liquid natural gas or methane are two possibilities requiring further study. Airport noise remains a tough challenge because previously researched concepts fall short of achieving FAR 36 Stage III noise levels. Innovative solutions may be necessary to reach acceptably low noise.

  8. Advanced supersonic propulsion study, phase 3

    NASA Technical Reports Server (NTRS)

    Howlett, R. A.; Johnson, J.; Sabatella, J.; Sewall, T.

    1976-01-01

    The variable stream control engine is determined to be the most promising propulsion system concept for advanced supersonic cruise aircraft. This concept uses variable geometry components and a unique throttle schedule for independent control of two flow streams to provide low jet noise at takeoff and high performance at both subsonic and supersonic cruise. The advanced technology offers a 25% improvement in airplane range and an 8 decibel reduction in takeoff noise, relative to first generation supersonic turbojet engines.

  9. Supersonic Wing Optimization Using SpaRibs

    NASA Technical Reports Server (NTRS)

    Locatelli, David; Mulani, Sameer B.; Liu, Qiang; Tamijani, Ali Y.; Kapania, Rakesh K.

    2014-01-01

    This research investigates the advantages of using curvilinear spars and ribs, termed SpaRibs, to design a supersonic aircraft wing-box in comparison to the use of classic design concepts that employ straight spars and ribs. The objective is to achieve a more efficient load-bearing mechanism and to passively control the deformation of the structure under the flight loads. Moreover, the use of SpaRibs broadens the design space and allows for natural frequencies and natural mode shape tailoring. The SpaRibs concept is implemented in a new optimization MATLAB-based framework referred to as EBF3SSWingOpt. This optimization scheme performs both the sizing and the shaping of the internal structural elements, connecting the optimizer with the analysis software. The shape of the SpaRibs is parametrically defined using the so called Linked Shape method. Each set of SpaRibs is placed in a one by one square domain of the natural space. The set of curves is subsequently transformed in the physical space for creating the wing structure geometry layout. The shape of each curve of each set is unique; however, mathematical relations link the curvature in an effort to reduce the number of design variables. The internal structure of a High Speed Commercial Transport aircraft concept developed by Boeing is optimized subjected to stress, subsonic flutter and supersonic flutter constraints. The results show that the use of the SpaRibs allows for the reduction of the aircraft's primary structure weight without violating the constraints. A weight reduction of about 15 percent is observed.

  10. Supersonic Cruise Research 1979, part 1

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Aerodynamics, stability and control, propulsion, and environmental factors of the supersonic cruise aircraft are discussed. Other topics include airframe structures and materials, systems integration, and economics.

  11. Wing-section optimization for supersonic viscous flows

    NASA Technical Reports Server (NTRS)

    Item, Cem C.

    1995-01-01

    The recent interest in High Speed Civil Transport (HSCT) has resulted in renewed research studies of optimized supersonic cruise transport configurations. Incorporation of flow viscosity effects in the design process of such a supersonic wing is currently under investigation. This may lead to more accurate problem formulations and, in turn, greater aerodynamic efficiency than can be obtained by the traditional, inviscid, linear theories. In this context, for a design code to be a candidate for a complex optimization problem, such as three-dimensional viscous supersonic wing design, it should be validated using simpler building-block shapes. To optimize the shape of a supersonic wing, an automated method that also includes higher fidelity to the flow physics is desirable. With this impetus, an aerodynamic optimization methodology incorporating Navier-Stokes equations and sensitivity analysis had been previously developed. Prior to embarking upon the wing design task, the present investigation concentrated on testing the flexibility of the methodology, and the identification of adequate problem formulations, by defining two-dimensional, cost-effective test cases. Starting with two distinctly different initial airfoils, two independent shape optimizations resulted in shapes with very similar features. Secondly, the normal section to the subsonic portion of the leading edge, which had a high normal angle-of-attack, was considered. The optimization resulted in a shape with twist and camber, which eliminated the adverse pressure gradient, hence, exploiting the leading-edge thrust. The wing section shapes obtained in all the test cases had the features predicted by previous studies. Therefore, it was concluded that the flowfield analyses and the sensitivity coefficients were computed and fed to the present gradient-based optimizer correctly. Also, as a result of the present two-dimensional study, suggestions were made for problem formulations which should contribute to an

  12. Validation of OVERFLOW for Supersonic Retropropulsion

    NASA Technical Reports Server (NTRS)

    Schauerhamer, Guy

    2012-01-01

    The goal is to softly land high mass vehicles (10s of metric tons) on Mars. Supersonic Retropropulsion (SRP) is a potential method of deceleration. Current method of supersonic parachutes does not scale past 1 metric ton. CFD is of increasing importance since flight and experimental data at these conditions is difficult to obtain. CFD must first be validated at these conditions.

  13. Multifidelity Analysis and Optimization for Supersonic Design

    NASA Technical Reports Server (NTRS)

    Kroo, Ilan; Willcox, Karen; March, Andrew; Haas, Alex; Rajnarayan, Dev; Kays, Cory

    2010-01-01

    Supersonic aircraft design is a computationally expensive optimization problem and multifidelity approaches over a significant opportunity to reduce design time and computational cost. This report presents tools developed to improve supersonic aircraft design capabilities including: aerodynamic tools for supersonic aircraft configurations; a systematic way to manage model uncertainty; and multifidelity model management concepts that incorporate uncertainty. The aerodynamic analysis tools developed are appropriate for use in a multifidelity optimization framework, and include four analysis routines to estimate the lift and drag of a supersonic airfoil, a multifidelity supersonic drag code that estimates the drag of aircraft configurations with three different methods: an area rule method, a panel method, and an Euler solver. In addition, five multifidelity optimization methods are developed, which include local and global methods as well as gradient-based and gradient-free techniques.

  14. Supersonic HLFC: Potential benefits and technology development requirements

    NASA Technical Reports Server (NTRS)

    Neumann, Frank

    1992-01-01

    The viewgraphs and discussion of the potential benefits and technology development requirements of supersonic Hybrid Laminar Flow Control (HLFC) are reviewed. For the last three years, Boeing has performed studies on the application of laminar flow control to High Speed Civil Transport (HSCT) configurations. Large potential net benefits were identified for laminar flow control, even after accounting for the significant implementation penalties. However, the technical risks are high at this time, and an early, aggressive technology development program is required if laminar flow control (LFC) is to be incorporated in a year 2005 HSCT program. The benefits and required development effort are addressed. Of all the aerodynamic advances that are being considered for the HSCT, LFC has the largest potential for improving the supersonic lift drag ratio of a given configuration. The work accomplished to date, sponsored by NASA Langley, is summarized. This work includes studies on HLFC application to HSCT, cruise HLFC/low speed boundary layer control (BLC) compatibility, and impact of M 0.9 HLFC and high lift BLC. Requirements for production committments are listed. The need for a HSCT-HLFC Risk Reduction Program is addressed. Supersonic HLFC development planning and future applications are addressed. Laminar flow/high-lift integration is addressed.

  15. Supersonic Jet Exhaust Noise at High Subsonic Flight Speed

    NASA Technical Reports Server (NTRS)

    Norum, Thomas D.; Garber, Donald P.; Golub, Robert A.; Santa Maria, Odilyn L.; Orme, John S.

    2004-01-01

    An empirical model to predict the effects of flight on the noise from a supersonic transport is developed. This model is based on an analysis of the exhaust jet noise from high subsonic flights of the F-15 ACTIVE Aircraft. Acoustic comparisons previously attainable only in a wind tunnel were accomplished through the control of both flight operations and exhaust nozzle exit diameter. Independent parametric variations of both flight and exhaust jet Mach numbers at given supersonic nozzle pressure ratios enabled excellent correlations to be made for both jet broadband shock noise and jet mixing noise at flight speeds up to Mach 0.8. Shock noise correlated with flight speed and emission angle through a Doppler factor exponent of about 2.6. Mixing noise at all downstream angles was found to correlate well with a jet relative velocity exponent of about 7.3, with deviations from this behavior only at supersonic eddy convection speeds and at very high flight Mach numbers. The acoustic database from the flight test is also provided.

  16. Multiscale turbulence effects in supersonic jets exhausting into still air

    NASA Technical Reports Server (NTRS)

    Abdol-Hamid, Khaled S.; Wilmoth, Richard G.

    1987-01-01

    A modified version of the multiscale turbulence model of Hanjalic has been applied to the problem of supersonic jets exhausting into still air. In particular, the problem of shock-cell decay through turbulent interaction with the mixing layer has been studied for both mildly interacting and strongly resonant jet conditions. The modified Hanjalic model takes into account the nonequilibrium energy transfer between two different turbulent spectral scales. The turbulence model was incorporated into an existing shock-capturing, parabolized Navier-Stokes computational model in order to perform numerical experiments. The results show that the two-scale turbulence model provides significant improvement over one-scale models in the prediction of plume shock structure for underexpanded supersonic (Mach 2) and sonic (Mach 1) jets. For the supersonic jet, excellent agreement with experiment was obtained for the centerline shock-cell pressure decay up to 40 jet radii. For the sonic jet, the agreement with experiment was not so good, but the two-scale model still showed significant improvement over the one-scale model. It is shown that by relating some of the coefficients in the turbulent-transport equations to the relative time scale for transfer of energy between scales the two-scale model can provide predictions that bound the measured shock-cell decay rate for the sonic jet.

  17. Role of microbial exopolymeric substances (EPS) on chromium sorption and transport in heterogeneous subsurface soils: I. Cr(III) complexation with EPS in aqueous solution

    SciTech Connect

    Kantar, C.; Dodge, C.; Demiray, H.; Dogan, N.M.

    2011-01-26

    Chromium (III) binding by exopolymeric substances (EPS) isolated from Pseudomonas putida P18, Pseudomonas aeruginosa P16 and Pseudomonas stutzeri P40 strains were investigated by the determination of conditional stability constants and the concentration of functional groups using the ion-exchange experiments and potentiometric titrations. Spectroscopic (EXAFS) analysis was also used to obtain information on the nature of Cr(III) binding with EPS functional groups. The data from ion-exchange experiments and potentiometric titrations were evaluated using a non-electrostatic discrete ligand approach. The modeling results show that the acid/base properties of EPSs can be best characterized by invoking four different types of acid functional groups with arbitrarily assigned pK{sub a} values of 4, 6, 8 and 10. The analysis of ion-exchange data using the discrete ligand approach suggests that while the Cr binding by EPS from P. aeruginosa can be successfully described based on a reaction stoichiometry of 1:2 between Cr(III) and HL{sub 2} monoprotic ligands, the accurate description of Cr binding by EPSs extracted from P. putida and P. stutzeri requires postulation of 1:1 Cr(III)-ligand complexes with HL{sub 2} and HL{sub 3} monoprotic ligands, respectively. These results indicate that the carboxyl and/or phosphoric acid sites contribute to Cr(III) binding by microbial EPS, as also confirmed by EXAFS analysis performed in the current study. Overall, this study highlights the need for incorporation of Cr-EPS interactions into transport and speciation models to more accurately assess microbial Cr(VI) reduction and chromium transport in subsurface systems, including microbial reactive treatment barriers.

  18. Role of Microbial Exopolymeric Substances (EPS) on Chromium Sorption and Transport in Heterogeneous Subsurface Soils: I. Cr(III) Complexation with EPS in Aqueous Solution

    SciTech Connect

    C Kantar; H Demiray; N Dogan; C Dodge

    2011-12-31

    Chromium (III) binding by exopolymeric substances (EPS) isolated from Pseudomonas putida P18, Pseudomonas aeruginosa P16 and Pseudomonas stutzeri P40 strains were investigated by the determination of conditional stability constants and the concentration of functional groups using the ion-exchange experiments and potentiometric titrations. Spectroscopic (EXAFS) analysis was also used to obtain information on the nature of Cr(III) binding with EPS functional groups. The data from ion-exchange experiments and potentiometric titrations were evaluated using a non-electrostatic discrete ligand approach. The modeling results show that the acid/base properties of EPSs can be best characterized by invoking four different types of acid functional groups with arbitrarily assigned pK{sub a} values of 4, 6, 8 and 10. The analysis of ion-exchange data using the discrete ligand approach suggests that while the Cr binding by EPS from P. aeruginosa can be successfully described based on a reaction stoichiometry of 1:2 between Cr(III) and HL{sub 2} monoprotic ligands, the accurate description of Cr binding by EPSs extracted from P. putida and P. stutzeri requires postulation of 1:1 Cr(III)-ligand complexes with HL{sub 2} and HL{sub 3} monoprotic ligands, respectively. These results indicate that the carboxyl and/or phosphoric acid sites contribute to Cr(III) binding by microbial EPS, as also confirmed by EXAFS analysis performed in the current study. Overall, this study highlights the need for incorporation of Cr-EPS interactions into transport and speciation models to more accurately assess microbial Cr(VI) reduction and chromium transport in subsurface systems, including microbial reactive treatment barriers.

  19. A New Model for Mixing by Double-diffusive Convection (Semi-convection). III. Thermal and Compositional Transport through Non-layered ODDC

    NASA Astrophysics Data System (ADS)

    Moll, Ryan; Garaud, Pascale; Stellmach, Stephan

    2016-05-01

    Oscillatory double-diffusive convection (ODDC; also known as semi-convection) refers to a type of double-diffusive instability that occurs in regions of planetary and stellar interiors that have a destabilizing thermal stratification and a stabilizing mean molecular weight stratification. In this series of papers, we use an extensive suite of three-dimensional (3D) numerical simulations to quantify the transport of heat and chemical species by ODDC. Rosenblum et al. first showed that ODDC can either spontaneously form layers that significantly enhance the transport of heat and chemical species compared to microscopic transport or remain in a state dominated by large-scale gravity waves, in which there is a more modest enhancement of the turbulent transport rates. Subsequent studies in this series focused on identifying under what conditions layers form and quantifying transport through layered systems. Here we proceed to characterize transport through systems that are unstable to ODDC, but do not undergo spontaneous layer formation. We measure the thermal and compositional fluxes in non-layered ODDC from both two-dimensional (2D) and 3D numerical simulations, and show that 3D simulations are well approximated by similar simulations in a 2D domain. We find that the turbulent mixing rate in this regime is weak and can, to a first-level approximation, be neglected. We conclude by summarizing the findings of papers I through III into a single prescription for transport systems unstable to ODDC.

  20. Calculation of Supersonic Combustion Using Implicit Schemes

    NASA Technical Reports Server (NTRS)

    Yoon, Seokkwan; Kwak, Dochan (Technical Monitor)

    2003-01-01

    One of the technology goals of NASA for advanced space transportation is to develop highly efficient propulsion systems to reduce the cost of payload for space missions. Developments of rockets for the second generation Reusable Launch Vehicle (RLV) in the past several years have been focused on low-cost versions of conventional engines. However, recent changes in the Integrated Space Transportation Program to build a crew transportation vehicle to extend the life of the Space Shuttle fleet might suggest that air-breathing rockets could reemerge as a possible propulsion system for the third generation RLV to replace the Space Shuttle after 2015. The weight of the oxygen tank exceeds thirty percent of the total weight of the Space Shuttle at launch while the payload is only one percent of the total weight. The air-breathing rocket propulsion systems, which consume oxygen in the air, offer clear advantages by making vehicles lighter and more efficient. Experience in the National Aerospace Plane Program in the late 1980s indicates that scramjet engines can achieve high specific impulse for low hypersonic vehicle speeds. Whether taking a form of Rocket Based Combined Cycle (RBCC) or Turbine Based Combined Cycle (TBCC), the scramjet is an essential mode of operation for air-breathing rockets. It is well known that fuel-air mixing and rapid combustion are of crucial importance for the success of scramjet engines since the spreading rate of the supersonic mixing layer decreases as the Mach number increases. A factored form of the Gauss-Seidel relaxation method has been widely used in hypersonic flow research since its first application to non-equilibrium flows. However, difficulties in stability and convergence have been encountered when there is strong interaction between fluid motion and chemical reaction, such as multiple fuel injection problems. The present paper reports the results from investigation of the effect of modifications to the original algorithm on the

  1. Advanced supersonic technology propulsion system study

    NASA Technical Reports Server (NTRS)

    Szeliga, R.; Allan, R. D.

    1974-01-01

    This study had the objectives of determining the most promising conventional and variable cycle engine types; the effect of design cruise Mach number (2.2, 2.7 and 3.2) on a commercial supersonic transport; effect of advanced engine technology on the choice of engine cycle; and effect of utilizing hydrogen as the engine fuel. The technology required for the engines was defined, and the levels of development to ensure availability of this technology in advanced aircraft propulsion systems were assessed. No clearcut best conventional or variable cycle engine was identified. The dry bypass turbojet and the duct burning turbofans were initially selected as the best conventional engines, but later results, utilizing augmentation at takeoff, added the mixed-flow augmented turbofan as a promising contender. The modulating air flow, three-rotor variable cycle engine identified the performance features desired from VCE concepts (elimination of inlet drag and reduction in afterbody drag), but was a very heavy and complex engine.

  2. Microwave plasma assisted supersonic gas jet deposition of thin film materials

    DOEpatents

    Schmitt, III, Jerome J.; Halpern, Bret L.

    1993-01-01

    An apparatus for fabricating thin film materials utilizing high speed gas dynamics relies on supersonic free jets of carrier gas to transport depositing vapor species generated in a microwave discharge to the surface of a prepared substrate where the vapor deposits to form a thin film. The present invention generates high rates of deposition and thin films of unforeseen high quality at low temperatures.

  3. Method and apparatus for starting supersonic compressors

    DOEpatents

    Lawlor, Shawn P.

    2012-04-10

    A supersonic gas compressor. The compressor includes aerodynamic duct(s) situated on a rotor journaled in a casing. The aerodynamic duct(s) generate a plurality of oblique shock waves for efficiently compressing a gas at supersonic conditions. The convergent inlet is adjacent to a bleed air collector, and during acceleration of the rotor, bypass gas is removed from the convergent inlet via a collector to enable supersonic shock stabilization. Once the oblique shocks are stabilized at a selected inlet relative Mach number and pressure ratio, the bleed of bypass gas from the convergent inlet via the bypass gas collectors is eliminated.

  4. Pdf prediction of supersonic hydrogen flames

    NASA Technical Reports Server (NTRS)

    Eifler, P.; Kollmann, W.

    1993-01-01

    A hybrid method for the prediction of supersonic turbulent flows with combustion is developed consisting of a second order closure for the velocity field and a multi-scalar pdf method for the local thermodynamic state. It is shown that for non-premixed flames and chemical equilibrium mixture fraction, the logarithm of the (dimensionless) density, internal energy per unit mass and the divergence of the velocity have several advantages over other sets of scalars. The closure model is applied to a supersonic non-premixed flame burning hydrogen with air supplied by a supersonic coflow and the results are compared with a limited set of experimental data.

  5. Theoretical aspects of supersonic jet noise

    NASA Technical Reports Server (NTRS)

    Tam, Christopher K. W.

    1992-01-01

    The topics covered include the following: the three components of supersonic jet noise; shock cell structure of imperfectly expanded jets; large turbulence structures/instability waves; supersonic jet noise theory; generation of turbulent mixing noise; comparisons between predicted peak noise frequency and direction of radiation with measurements; Strouhal number of maximum SPL of hot supersonic jets; near field sound pressure level contours; generation of broadband shock associated noise; calculated and measured far field shock noise spectra; generation of screech tones; and calculated and measured Strouhal number of screech tones.

  6. Nonlinear stability of supersonic jets

    NASA Technical Reports Server (NTRS)

    Tiwari, S. N. (Principal Investigator); Bhat, T. R. S. (Principal Investigator)

    1996-01-01

    The stability calculations made for a shock-free supersonic jet using the model based on parabolized stability equations are presented. In this analysis the large scale structures, which play a dominant role in the mixing as well as the noise radiated, are modeled as instability waves. This model takes into consideration non-parallel flow effects and also nonlinear interaction of the instability waves. The stability calculations have been performed for different frequencies and mode numbers over a range of jet operating temperatures. Comparisons are made, where appropriate, with the solutions to Rayleigh's equation (linear, inviscid analysis with the assumption of parallel flow). The comparison of the solutions obtained using the two approaches show very good agreement.

  7. Nonlinear Stability of Supersonic Jets

    NASA Technical Reports Server (NTRS)

    Bhat, T. R. S.; Seiner, J. M.; Tiwari, S. N.

    1995-01-01

    This paper presents stability calculations made for a shock-free supersonic jet using the model based on parabolized stability equations. In this analysis the large-scale structures, which play a dominant role in the mixing as well as the noise radiated, are modeled as instability waves. This model takes into consideration non-parallel flow effects and also nonlinear interaction of the instability waves. The stability calculations have been performed for different frequencies and mode numbers over a range of jet operating temperatures. Comparisons are made, where appropriate, with the solutions to Rayleigh's equation (linear, inviscid analysis with the assumption of parallel flow). The comparison of the solutions obtained using the two approaches show very good agreement.

  8. Modeling Combustion in Supersonic Flows

    NASA Technical Reports Server (NTRS)

    Drummond, J. Philip; Danehy, Paul M.; Bivolaru, Daniel; Gaffney, Richard L.; Tedder, Sarah A.; Cutler, Andrew D.

    2007-01-01

    This paper discusses the progress of work to model high-speed supersonic reacting flow. The purpose of the work is to improve the state of the art of CFD capabilities for predicting the flow in high-speed propulsion systems, particularly combustor flow-paths. The program has several components including the development of advanced algorithms and models for simulating engine flowpaths as well as a fundamental experimental and diagnostic development effort to support the formulation and validation of the mathematical models. The paper will provide details of current work on experiments that will provide data for the modeling efforts along with with the associated nonintrusive diagnostics used to collect the data from the experimental flowfield. Simulation of a recent experiment to partially validate the accuracy of a combustion code is also described.

  9. Supersonic Combustion Research at NASA

    NASA Technical Reports Server (NTRS)

    Drummond, J. P.; Danehy, Paul M.; Gaffney, Richard L., Jr.; Tedder, Sarah A.; Cutler, Andrew D.; Bivolaru, Daniel

    2007-01-01

    This paper discusses the progress of work to model high-speed supersonic reacting flow. The purpose of the work is to improve the state of the art of CFD capabilities for predicting the flow in high-speed propulsion systems, particularly combustor flowpaths. The program has several components including the development of advanced algorithms and models for simulating engine flowpaths as well as a fundamental experimental and diagnostic development effort to support the formulation and validation of the mathematical models. The paper will provide details of current work on experiments that will provide data for the modeling efforts along with the associated nonintrusive diagnostics used to collect the data from the experimental flowfield. Simulation of a recent experiment to partially validate the accuracy of a combustion code is also described.

  10. FLOW FIELDS IN SUPERSONIC INLETS

    NASA Technical Reports Server (NTRS)

    Sorenson, R. L.

    1994-01-01

    This computer program is designed to calculate the flow fields in two-dimensional and three-dimensional axisymmetric supersonic inlets. The method of characteristics is used to compute arrays of points in the flow field. At each point the total pressure, local Mach number, local flow angle, and static pressure are calculated. This program can be used to design and analyze supersonic inlets by determining the surface compression rates and throat flow properties. The program employs the method of characteristics for a perfect gas. The basic equation used in the program is the compatibility equation which relates the change in stream angle to the change in entropy and the change in velocity. In order to facilitate the computation, the flow field behind the bow shock wave is broken into regions bounded by shock waves. In each region successive rays are computed from a surface to a shock wave until the shock wave intersects a surface or falls outside the cowl lip. As soon as the intersection occurs a new region is started and the previous region continued only in the area in which it is needed, thus eliminating unnecessary calculations. The maximum number of regions possible in the program is ten, which allows for the simultaneous calculations of up to nine shock waves. Input to this program consists of surface contours, free-stream Mach number, and various calculation control parameters. Output consists of printed and/or plotted results. For plotted results an SC-4020 or similar plotting device is required. This program is written in FORTRAN IV to be executed in the batch mode and has been implemented on a CDC 7600 with a central memory requirement of approximately 27k (octal) of 60 bit words.