High Velocity Jet Noise Source Location and Reduction. Task 3 - Experimental Investigation of Suppression Principles. Volume I. Suppressor Concepts Optimization

DTIC Science & Technology

1978-12-01

multinational corporation in the 1960’s placed extreme emphasis on the need for effective and efficient noise suppression devices. Phase I of work...through model and engine testing applicable to an afterburning turbojet engine. Suppressor designs were based primarily on empirical methods. Phase II...using "ray" acoustics. This method is in contrast to the purely empirical method which consists of the curve -fitting of normalized data. In order to

Flight investigation of an air-cooled plug nozzle with afterburning turbojet

NASA Technical Reports Server (NTRS)

Samanich, N. E.

1972-01-01

A convectively cooled plug nozzle, using 4 percent of the engine air as the coolant, was tested in 1967 K (3540 R) temperature exhaust gas. No significant differences in cooling characteristics existed between flight and static results. At flight speeds above Mach 1.1, nozzle performance was improved by extending the outer shroud. Increasing engine power improved nozzle efficiency considerably more at Mach 1.2 than at 0.9. The effect of nozzle pressure ratio and secondary weight flow on nozzle performance are also presented.

An Extended Combustion Model for the Aircraft Turbojet Engine

NASA Astrophysics Data System (ADS)

Rotaru, Constantin; Andres-Mihăilă, Mihai; Matei, Pericle Gabriel

2014-08-01

The paper consists in modelling and simulation of the combustion in a turbojet engine in order to find optimal characteristics of the burning process and the optimal shape of combustion chambers. The main focus of this paper is to find a new configuration of the aircraft engine combustion chambers, namely an engine with two main combustion chambers, one on the same position like in classical configuration, between compressor and turbine and the other, placed behind the turbine but not performing the role of the afterburning. This constructive solution could allow a lower engine rotational speed, a lower temperature in front of the first stage of the turbine and the possibility to increase the turbine pressure ratio by extracting the flow stream after turbine in the inner nozzle. Also, a higher thermodynamic cycle efficiency and thrust in comparison to traditional constant-pressure combustion gas turbine engines could be obtained.

Preliminary Performance Data on Westinghouse Electronic Power Regulator Operating on J34-WE-32 Turbojet Engine in Altitude Wind Tunnel

NASA Technical Reports Server (NTRS)

Ketchum, James R.; Blivas, Darnold; Pack, George J.

1950-01-01

The behavior of the Westinghouse electronic power regulator operating on a J34-WE-32 turbojet engine was investigated in the NACA Lewis altitude wind tunnel at the request of the Bureau of Aeronautics, Department of the Navy. The object of the program was to determine the, steady-state stability and transient characteristics of the engine under control at various altitudes and ram pressure ratios, without afterburning. Recordings of the response of the following parameters to step changes in power lever position throughout the available operating range of the engine were obtained; ram pressure ratio, compressor-discharge pressure, exhaust-nozzle area, engine speed, turbine-outlet temperature, fuel-valve position, jet thrust, air flow, turbine-discharge pressure, fuel flow, throttle position, and boost-pump pressure. Representative preliminary data showing the actual time response of these variables are presented. These data are presented in the form of reproductions of oscillographic traces.

Evaluation of a simplified gross thrust calculation method for a J85-21 afterburning turbojet engine in an altitude facility

NASA Technical Reports Server (NTRS)

Baer-Riedhart, J. L.

1982-01-01

A simplified gross thrust calculation method was evaluated on its ability to predict the gross thrust of a modified J85-21 engine. The method used tailpipe pressure data and ambient pressure data to predict the gross thrust. The method's algorithm is based on a one-dimensional analysis of the flow in the afterburner and nozzle. The test results showed that the method was notably accurate over the engine operating envelope using the altitude facility measured thrust for comparison. A summary of these results, the simplified gross thrust method and requirements, and the test techniques used are discussed in this paper.

Comparison of parametric duct-burning turbofan and non-afterburning turbojet engines in a Mach 2.7 transport

NASA Technical Reports Server (NTRS)

Whitlow, J. B., Jr.

1975-01-01

A parametric study was made of duct-burning turbofan and suppressed dry turbojet engines installed in a supersonic transport. A range of fan pressure ratios was considered for the separate-flow-fan engines. The turbofan engines were studied both with and without jet noise suppressors. Single- as well as dual-stream suppression was considered. Attention was concentrated on designs yielding sideline noises of FAR 36 (108 EPNdB) and below. Trades were made between thrust and wing area for a constant takeoff field length. The turbofans produced lower airplane gross weights than the turbojets at FAR 36 and below. The advantage for the turbofans increased as the sideline noise limit was reduced. Jet noise suppression, especially for the duct stream, was very beneficial for the turbofan engines as long as duct burning was permitted during takeoff. The maximum dry unsuppressed takeoff mode, however, yielded better results at extremely low noise levels. Noise levels as low as FAR 36-11 EPNdB were obtained with a turbofan in this takeoff mode, but at a considerable gross weight penalty relative to the best FAR 36 results.

NACA Conference on Turbojet Engines for Supersonic Propulsion. A Compilation of Technical Material Presented

DTIC Science & Technology

1953-10-01

turbojet Pngine with a turbine cooled by compressor air involves several design pruilems that do not e~ist in an uncooled turbo - jet engine . Careful...facilitate testing the sheet-metal blades in the turbojet engine , bases were formed by removing the solid airfoil portion from the standard turbine blade ...OF TURBINE BLADES by J. C. Freche 6. APPLICATION AND OPERATION OF AIR-COOLED TURBINES IN TURBOJET ENGINES

Interactive Educational Tool for Turbofan and Afterburning Turbojet Engines

NASA Technical Reports Server (NTRS)

Benson, Thomas J.

1997-01-01

A workstation-based, interactive educational computer program has been developed at the NASA Lewis Research Center to aid in the teaching and understanding of turbine engine design and analysis. This tool has recently been extended to model the performance of two-spool turbofans and afterburning turbojets. The program solves for the flow conditions through the engine by using classical one-dimensional thermodynamic analysis found in various propulsion textbooks. Either an approximately thermally perfect or calorically perfect gas can be used in the thermodynamic analysis. Students can vary the design conditions through a graphical user interface; engine performance is calculated immediately. A variety of graphical formats are used to present results, including numerical results, moving bar charts, and student-generated temperature versus entropy (Ts), pressure versus specific volume (pv), and engine performance plots. The package includes user-controlled printed output, restart capability, online help screens, and a browser that displays teacher-prepared lessons in turbomachinery. The program runs on a variety of workstations or a personal computer using the UNIX operating system and X-based graphics. It is being tested at several universities in the midwestern United States; the source and executables are available free from the author.

On the leading edge; Combining maturity and advanced technology on the F404 turbofan engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Powel, S.F. IV

1991-01-01

In this paper the overall design concept of the F404 afterburning turbofan engine is reviewed together with some of the lessons learned from over 2 million flight hours in service. GE Aircraft Engines' derivative and growth plans for the F404 family are then reviewed including the Building Block component development approach. Examples of advanced technologies under development for introduction into new F404 derivative engine models are presented in the areas of materials, digital and fiber optic controls systems, and vectoring exhaust nozzles. The design concept and details of the F404-GE-402, F412-GE-400, and other derivative engines under full-scale development are described.more » Studies for future growth variants and the benefits of the F404 derivative approach to development of afterburning engines in the 18,000-24,000 lb (80--107 kN) thrust class and non- afterburning engines in the 12,000--19,000 lb (53--85 kN) class are discussed.« less

Integrated Turbine-Based Combined Cycle Dynamic Simulation Model

NASA Technical Reports Server (NTRS)

Haid, Daniel A.; Gamble, Eric J.

2011-01-01

A Turbine-Based Combined Cycle (TBCC) dynamic simulation model has been developed to demonstrate all modes of operation, including mode transition, for a turbine-based combined cycle propulsion system. The High Mach Transient Engine Cycle Code (HiTECC) is a highly integrated tool comprised of modules for modeling each of the TBCC systems whose interactions and controllability affect the TBCC propulsion system thrust and operability during its modes of operation. By structuring the simulation modeling tools around the major TBCC functional modes of operation (Dry Turbojet, Afterburning Turbojet, Transition, and Dual Mode Scramjet) the TBCC mode transition and all necessary intermediate events over its entire mission may be developed, modeled, and validated. The reported work details the use of the completed model to simulate a TBCC propulsion system as it accelerates from Mach 2.5, through mode transition, to Mach 7. The completion of this model and its subsequent use to simulate TBCC mode transition significantly extends the state-of-the-art for all TBCC modes of operation by providing a numerical simulation of the systems, interactions, and transient responses affecting the ability of the propulsion system to transition from turbine-based to ramjet/scramjet-based propulsion while maintaining constant thrust.

Development of Emissions Measurement Techniques for Afterburning Turbine Engines

DTIC Science & Technology

1975-10-01

are most reactive in the plume, with significant de - creases observed at all afterburning power levels. Cnrhon monoxide call either increas~ e or...Plane) Part B. Near Plume Method (Measurement I’rfc(diLr 3•rC for Sampling at Nozzle Exit Plane) viit ! o E . . LIST uO ILLUSrRATIUNS F igure I1.8.t...36. 1lC Concentration Radial Protile, J79-15 Enghine’ at Mid. :•3 AM B Power Level. 37 (𔃺 \\s. C ( O ) (’onv(ent rat io I m .j 7 4 1- E ngtine aI Mmn. A

Preliminary MIPCC Enhanced F-4 and F-15 Preformance Characteristics for a First Stage Reusable Launch Vehicle

NASA Technical Reports Server (NTRS)

Kloesel, Kurt J.; Clark, Casie M.

2013-01-01

Performance increases in turbojet engines can theoretically be achieved through Mass Injection Pre-Compressor Cooling (MIPCC), a process involving injecting water or oxidizer or both into an afterburning turbojet engine. The injection of water results in pre-compressor cooling, allowing the propulsion system to operate at high altitudes and Mach numbers. In this way, a MIPCC-enhanced turbojet engine could be used to power the first stage of a reusable launch vehicle or be integrated into an existing aircraft that could launch a 100-lbm payload to a reference 100-nm altitude orbit at 28 deg inclination. The two possible candidates for MIPCC flight demonstration that are evaluated in this study are the F-4 Phantom II airplane and the F-15 Eagle airplane (both of McDonnell Douglas, now The Boeing Company, Chicago, Illinois), powered by two General Electric Company (Fairfield, Connecticut) J79 engines and two Pratt & Whitney (East Hartford, Connecticut) F100-PW-100 engines, respectively. This paper presents a conceptual discussion of the theoretical performance of each of these aircraft using MIPCC propulsion techniques. Trajectory studies were completed with the Optimal Trajectories by Implicit Simulation (OTIS) software (NASA Glenn Research Center, Cleveland, Ohio) for a standard F-4 airplane and a standard F-15 airplane. Standard aircraft simulation models were constructed, and the thrust in each was altered in accordance with estimated MIPCC performance characteristics. The MIPCC and production aircraft model results were then reviewed to assess the feasibility of a MIPCC-enhanced propulsion system for use as a first-stage reusable launch vehicle; it was determined that the MIPCC-enhanced F-15 model showed a significant performance advantage over the MIPCC-enhanced F-4 model.

Preliminary MIPCC Enhanced F-4 and F-15 Performance Characteristics for a First Stage Reusable Launch Vehicle

NASA Technical Reports Server (NTRS)

Kloesel, Kurt J.

2013-01-01

Performance increases in turbojet engines can theoretically be achieved through Mass Injection Pre-Compressor Cooling (MIPCC), a process involving injecting water or oxidizer or both into an afterburning turbojet engine. The injection of water results in pre-compressor cooling, allowing the propulsion system to operate at high altitudes and Mach numbers. In this way, a MIPCC-enhanced turbojet engine could be used to power the first stage of a reusable launch vehicle or be integrated into an existing aircraft that could launch a 100-lbm payload to a reference 100-nm altitude orbit at 28 deg inclination. The two possible candidates for MIPCC flight demonstration that are evaluated in this study are the F-4 Phantom II airplane and the F-15 Eagle airplane (both of McDonnell Douglas, now The Boeing Company, Chicago, Illinois), powered by two General Electric Company (Fairfield, Connecticut) J79 engines and two Pratt & Whitney (East Hartford, Connecticut) F100-PW-100 engines, respectively. This paper presents a conceptual discussion of the theoretical performance of each of these aircraft using MIPCC propulsion techniques. Trajectory studies were completed with the Optimal Trajectories by Implicit Simulation (OTIS) software (NASA Glenn Research Center, Cleveland, Ohio) for a standard F-4 airplane and a standard F-15 airplane. Standard aircraft simulation models were constructed, and the thrust in each was altered in accordance with estimated MIPCC performance characteristics. The MIPCC and production aircraft model results were then reviewed to assess the feasibility of a MIPCC-enhanced propulsion system for use as a first-stage reusable launch vehicle; it was determined that the MIPCC-enhanced F-15 model showed a significant performance advantage over the MIPCC-enhanced F-4 model.

Foamed-metal-based catalytic afterburners in automotive exhaust systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pestryakov, A.N.; Ametov, V.A.

1994-08-10

Properties of exhaust afterburning catalysts based on porous cellular materials (foamed metals) have been investigated. Catalysts containing oxides of base metals provide a two-to-threefold reduction of CO emission. Platinum-containing foamed catalysts lower the toxicity of exhaust by 85-90%. A favorable effect is demonstrated by the combined use of afterburners and a motor oil additive based on ultradispersed copper.

Thermal imaging of afterburning plumes

NASA Astrophysics Data System (ADS)

Ajdari, E.; Gutmark, E.; Parr, T. P.; Wilson, K. J.; Schadow, K. C.

1989-01-01

Afterburning and nonafterburning exhaust plumes were studied experimentally for underexpanded sonic and supersonic conical circular nozzles. The plume structure was visualized using thermal imaging camera and regular photography. IR emission by the plume is mainly dependent on the presence of afterburning. Temperature and reducing power of the exhaust gases, in addition to the nozzle configuration, determine the structure of the plume core, the location where the afterburning is initiated, its size and intensity. Comparison between single shot and average thermal images of the plume show that afterburning is a highly turbulent combustion process.

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.

J-85 jet engine noise measured in the ONERA S1 wind tunnel and extrapolated to far field

NASA Technical Reports Server (NTRS)

Soderman, Paul T.; Julienne, Alain; Atencio, Adolph, Jr.

1991-01-01

Noise from a J-85 turbojet with a conical, convergent nozzle was measured in simulated flight in the ONERA S1 Wind Tunnel. Data are presented for several flight speeds up to 130 m/sec and for radiation angles of 40 to 160 degrees relative to the upstream direction. The jet was operated with subsonic and sonic exhaust speeds. A moving microphone on a 2 m sideline was used to survey the radiated sound field in the acoustically treated, closed test section. The data were extrapolated to a 122 m sideline by means of a multiple-sideline source-location method, which was used to identify the acoustic source regions, directivity patterns, and near field effects. The source-location method is described along with its advantages and disadvantages. Results indicate that the effects of simulated flight on J-85 noise are significant. At the maximum forward speed of 130 m/sec, the peak overall sound levels in the aft quadrant were attentuated approximately 10 dB relative to sound levels of the engine operated statically. As expected, the simulated flight and static data tended to merge in the forward quadrant as the radiation angle approached 40 degrees. There is evidence that internal engine or shock noise was important in the forward quadrant. The data are compared with published predictions for flight effects on pure jet noise and internal engine noise. A new empirical prediction is presented that relates the variation of internally generated engine noise or broadband shock noise to forward speed. Measured near field noise extrapolated to far field agrees reasonably well with data from similar engines tested statically outdoors, in flyover, in a wind tunnel, and on the Bertin Aerotrain. Anomalies in the results for the forward quadrant and for angles above 140 degrees are discussed. The multiple-sideline method proved to be cumbersome in this application, and it did not resolve all of the uncertainties associated with measurements of jet noise close to the jet. The simulation was complicated by wind-tunnel background noise and the propagation of low frequency sound around the circuit.

Flow Quality for Turbine Engine Loads Simulator (TELS) Facility

DTIC Science & Technology

1980-06-01

2.2 GAS INGESTION A mathematical simulation of the turbojet engine and jet deflector was formulated to estimate the severity of the recirculating...3. Swain. R. L. and Mitchell, J. G. "’Smlulatlon of Turbine Engine Operational Loads." Journal of Aircraft Vol. 15, No. 6, June 1978• 4. Ryan, J...3 AEDC-TR-79-83 ~...~ i ,i g - Flow Quality for Turbine Engine Loads Simulator (TELS) Facility R..I. Schulz ARO, Inc. June 1980

Numerical models for afterburning of TNT detonation products in air

NASA Astrophysics Data System (ADS)

Donahue, L.; Zhang, F.; Ripley, R. C.

2013-11-01

Afterburning occurs when fuel-rich explosive detonation products react with oxygen in the surrounding atmosphere. This energy release can further contribute to the air blast, resulting in a more severe explosion hazard particularly in confined scenarios. The primary objective of this study was to investigate the influence of the products equation of state (EOS) on the prediction of the efficiency of trinitrotoluene (TNT) afterburning and the times of arrival of reverberating shock waves in a closed chamber. A new EOS is proposed, denoted the Afterburning (AB) EOS. This EOS employs the JWL EOS in the high pressure regime, transitioning to a Variable-Gamma (VG) EOS at lower pressures. Simulations of three TNT charges suspended in a explosion chamber were performed. When compared to numerical results using existing methods, it was determined that the Afterburning EOS delays the shock arrival times giving better agreement with the experimental measurements in the early to mid time. In the late time, the Afterburning EOS roughly halved the error between the experimental measurements and results obtained using existing methods. Use of the Afterburning EOS for products with the Variable-Gamma EOS for the surrounding air further significantly improved results, both in the transient solution and the quasi-static pressure. This final combination of EOS and mixture model is recommended for future studies involving afterburning explosives, particularly those in partial and full confinement.

Journal of Engineering Thermophysics (Selected Articles),

DTIC Science & Technology

1983-05-20

A SURGE TEST OF A TWIN-SHAFT TURBOJET ENGINE ON GROUND TEST BED* Chiang Feng (Shengyang Aeroengine Company) ABSTRACT Instrument technique for...oscillogram for the static pressure behind the two compressors. This noise was analyzed and believed to have arisen from the vibrations of the rotating blades...booms are heard. The vibrational energy of the surge is enormous, especially in the range of 85-90% of rotational speed. One can feel the vibrations

An Investigation of the McDonnell XP-85 Airplane in the Ames 40- by 80-Foot Wind Tunnel: Pressure-Distribution Tests

NASA Technical Reports Server (NTRS)

Hunton, Lynn W.; James, Harry A.

1948-01-01

Pressure measurements were made during wind-tunnel tests of the McDonnell XP-85 parasite fighter. Static-pressure orifices were located over the fuselage nose, over the canopy, along the wing root, and along the upper and lower stabilizer roots. A total-pressure and static-pressure rake was located in the turbojet engine air-intake duct. It was installed at the station where the compressor face would be located. Pressure data were obtained for two airplane conditions, clean and with skyhook extended, through a range of angle of attack and a range of yaw.

Performance of J-33-A-21 and J-33-A-23 Compressors with and without Water Injection

NASA Technical Reports Server (NTRS)

Beede, William L.

1948-01-01

In an investigation of the J-33-A-21 and the J-33-A-23 compressors with and without water injection, it was discovered that the compressors reacted differently to water injection although they were physically similar. An analysis of the effect of water injection on compressor performance and the consequent effect on matching of the compressor and turbine components in the turbojet engine was made. The analysis of component matching is based on a turbine flow function defined as the product of the equivalent weight flow and the reciprocal of the compressor pressure ratio.

Development of a Noninterference Technique for Measurement of Turbine Engine Compressor Blade Stress

DTIC Science & Technology

1980-06-01

TECHNIQUE FOR MEASUREMENT OF TURBINE ENGINE COMPRESSOR BLADE STRESS 7 A U T H O R ( s ) P . E. M c C a r t y a n d J . W. Thompson , J r...e a e a ~ and tdentJ~ by b|ock numbe~ A noninterference technique for measuring stress in compressor blades of turbine engines is being developed...43 4 AEDC-TR-79-78 1.0 INTRODUCTION 1.1 BACKGROUND Compressor rotor blades in turbojet engines are subjected to

Measurement of Afterburning Effect of Underoxidized Explosives by Underwater Explosion Method

NASA Astrophysics Data System (ADS)

Cao, Wei; He, Zhongqi; Chen, Wanghua

2015-04-01

The afterburning effect of TNT and a desensitized hexogen RDX-Al explosive was studied in a defined gas volume under water. A double-layer container (DLC) filled with different gases (air, oxygen, and nitrogen) was used to control and distinguish the afterburning effect of explosives. After the charges in the DLC were initiated under water, the shock wave signals were collected and analyzed. It is shown that shock wave peak pressures are duly in compliance with explosion similarity law, pressure, and impulse histories for explosions in oxygen and air are greater than those recorded for explosions in nitrogen due to the afterburing reaction. Moreover, the afterburning energy was calculated. Results show that even though there is excess oxygen in the gas volume, the afterburning energy may not reach the theoretically maximum value. This result is different from that in confined explosion, where the presence of excess oxygen in the compressed gas filling a bomb leads to complete combustion of the detonation products.

Concept development of a Mach 4 high-speed civil transport

NASA Technical Reports Server (NTRS)

Domack, Christopher S.; Dollyhigh, Samuel M.; Beissner, Fred L., Jr.; Geiselhart, Karl A.; Mcgraw, Marvin E., Jr.; Shields, Elwood W.; Swanson, Edward E.

1990-01-01

A study was conducted to configure and analyze a 250 passenger, Mach 4 High Speed Civil Transport with a design range of 6500 n.mi. The design mission assumed an all-supersonic cruise segment and no community noise or sonic boom constraints. The study airplane was developed in order to examine the technology requirements for such a vehicle and to provide an unconstrained baseline from which to assess changes in technology levels, sonic boom limits, or community noise constraints in future studies. The propulsion, structure, and materials technologies utilized in the sizing of the study aircraft were assumed to represent a technology availability date of 2015. The study airplane was a derivative of a previously developed Mach 3 concept and utilized advanced afterburning turbojet engines and passive airframe thermal protection. Details of the configuration development, aerodynamic design, propulsion system, mass properties, and mission performance are presented. The study airplane was estimated to weigh approx. 866,000 lbs. Although an aircraft of this size is a marginally acceptable candidate to fit into the world airport infrastructure, it was concluded that the inclusion of community noise or sonic boom constraints would quickly cause the aircraft to grow beyond acceptable limits using the assumed technology levels.

Simulated afterburner performance with hydrogen peroxide injection for thrust augmentation

NASA Technical Reports Server (NTRS)

Metzler, Allen J; Grobman, Jack S

1956-01-01

Combustion performance of three afterburner configurations was evaluated at simulated altitude flight conditions with liquid augmentation to the primary combustor. Afterburner combustion efficiency and stability were better with injection of high-strength hydrogen peroxide than with no injection or with water injection. Improvements were observed in afterburner configurations with and without flameholders and in a short-length afterburner. At a peroxide-air ratio of 0.3, combustion was stable and 85 to 90 percent efficient in all configurations tested. Calculated augmented net-thrust ratios for peroxide injection with afterburning were approximately 60 percent greater than those for water injection.

Exhaust emission survey of an F100 afterburning turbofan engine at simulated altitude flight conditions

NASA Technical Reports Server (NTRS)

Moss, J. E.; Cullom, R. R.

1981-01-01

Emissions of carbon monoxide, total oxides of nitrogen, unburned hydrocarbons, and carbon dioxide from an F100, afterburning, two spool turbofan engine at simulated flight conditions are reported. For each flight condition emission measurements were made for two or three power levels from intermediate power (nonafterburning) through maximum afterburning. The data showed that emissions vary with flight speed, altitude, power level, and radial position across the nozzle. Carbon monoxide emissions were low for intermediate power (nonafterburning) and partial afterburning, but regions of high carbon monoxide were present downstream of the flame holder at maximum afterburning. Unburned hydrocarbon emissions were low for most of the simulated flight conditions. The local NOX concentrations and their variability with power level increased with increasing flight Mach number at constant altitude, and decreased with increasing altitude at constant Mach number. Carbon dioxide emissions were proportional to local fuel air ratio for all conditions.

Determining the maximal capacity of a combined-cycle plant operating with afterburning of fuel in the gas conduit upstream of the heat-recovery boiler

NASA Astrophysics Data System (ADS)

Borovkov, V. M.; Osmanova, N. M.

2011-01-01

The effect gained from afterburning of fuel in the gas conduit upstream of the heat-recovery boiler used as part of a PGU-450T combined-cycle plant is considered. The results obtained from calculations of the electric and thermal power outputs produced by the combined-cycle plant equipped with an afterburning chamber are presented.

The effects of compressor seventh-stage bleed air extraction on performance of the F100-PW-220 afterburning turbofan engine

NASA Technical Reports Server (NTRS)

Evans, Alison B.

1991-01-01

A study was conducted to determine the effects of seventh-stage compressor bleed on the performance of the F100 afterburning turbofan engine. The effects of bleed on thrust, specific fuel consumption, fan turbine inlet temperature, bleed total pressure, and bleed total temperature were obtained from the engine manufacturer's status deck computer simulation. These effects were determined for power settings of intermediate, partial afterburning, and maximum afterburning for Mach numbers between 0.6 and 2.2 and for altitudes of 30,000, 40,000, and 50,000 ft. It was found that thrust loss and specific fuel consumption increase were approximately linear functions of bleed flow and, based on a percent-thrust change basis, were approximately independent of power setting.

Development of burners for afterburning chambers of heat-recovery boilers at cogeneration stations equipped with combined-cycle plants

NASA Astrophysics Data System (ADS)

Khomenok, L. A.

2007-09-01

Problems related to efficient afterburning of fuel in the medium of gas-turbine unit exhaust gases, as well as new design arrangements of gas-jet burners used in the chambers for afterburning fuel in heat-recovery boilers at cogeneration stations equipped with combined-cycle plants, are considered. Results obtained from comparative experimental investigations of different gas-jet flame stabilizers at a test facility are presented, and the advantages of jet-ejector stabilizers are demonstrated.

Measurements and predictions of flyover and static noise of an afterburning turbofan engine in an F-111 airplane

NASA Technical Reports Server (NTRS)

Burcham, F. W., Jr.

1979-01-01

The noise of the TF30 afterburning turbofan engine in an F-111 airplane was determined from static (ground) and flyover tests. Exhaust temperatures and velocity profiles were measured for a range of power settings. Comparisons were made between predicted and measured jet mixing, internal, and shock noise. It was found that the noise produced at static conditions was dominated by jet mixing noise, and was adequately predicted by current methods. The noise produced during flyovers exhibited large contributions from internally generated noise in the forward arc. For flyovers with the engine at nonafterburning power, the internal noise, shock noise, and jet mixing noise were accurately predicted. During flyovers with afterburning power settings, however, additional internal noise believed to be due to the afterburning process was evident; its level was as much as 8 decibels above the nonafterburning internal noise.

Jet Engine Operating and Support Cost Estimating Relationship Development.

DTIC Science & Technology

1985-09-01

0 H COX UCSSFE SEP 85 RFIT/GSM/LSY/85S-S F/G 14/1 M liiiI~ 1.8 2. I...~ 0 1.8 11111 ~ *& 11110 .8 MICR~OCOPY RESOLUTION TEST CHART N AT-N AL BUEA O... testing equipment, and more highly skilled laborers to maintain the engines. Variables indicative of technology and performance are specific fuel...Qualification Test (MlOT) date. October 1942 was slected because it was the date when the first US turbojet- 50 powered aircraft -Flew (26s14. Another time

14 CFR 23.934 - Turbojet and turbofan engine thrust reverser systems tests.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Turbojet and turbofan engine thrust... CATEGORY AIRPLANES Powerplant General § 23.934 Turbojet and turbofan engine thrust reverser systems tests. Thrust reverser systems of turbojet or turbofan engines must meet the requirements of § 33.97 of this...

Effects of plume afterburning on infrared spectroscopy

NASA Astrophysics Data System (ADS)

Zhu, Xijuan; Xu, Ying; Ma, Jing; Duan, Ran; Wu, Jie

2017-10-01

Contains H2, CO and unburned components of high-temperature plume of rocket engine, then injected into the atmosphere, continue to carry out the oxidation reaction in the plume near field region with the volume in the plume of oxygen in the air, two times burning. The afterburning is an important cause of infrared radiation intensification of propellant plume, which increases the temperature of the flame and changes the components of the gas, thus enhancing the infrared radiation intensity of the flame. [1]. Two the combustion numerical using chemical reaction mechanism involving HO2 intermediate reaction, the study confirmed that HO2 is a key intermediate, plays a decisive role to trigger early response, on afterburning temperature and flow concentration distribution effect. A finite rate chemical reaction model is used to describe the two burning phenomenon in high temperature plume[2]. In this paper, a numerical simulation of the flame flow field and radiative transfer is carried out for the afterburning phenomenon. The effects of afterburning on the composition, temperature and infrared radiation of the plume are obtained by comparison.

Installation for the catalytic afterburning of exhaust gases in the exhaust gas system of an internal combustion engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lange, K.

1974-12-06

An installation is described for the catalytic afterburning of exhaust gases in an internal combustion engine. The system includes a line by-passing the installation for the catalytic afterburning, in which is arranged a throttle valve actuated in dependence on the temperature of the installation. The throttle valve also can be actuated independently of the temperature of the installation, but in dependence of the oil pressure which continues to exist for a short period of time after turning off the engine.

14 CFR 25.934 - Turbojet engine thrust reverser system tests.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Turbojet engine thrust reverser system... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant General § 25.934 Turbojet engine thrust reverser system tests. Thrust reversers installed on turbojet engines must meet the...

Investigating ground effects on mixing and afterburning during a TNT explosion

NASA Astrophysics Data System (ADS)

Fedina, E.; Fureby, C.

2013-05-01

In this paper, the unconfined and semi-confined condensed phase explosions of TNT will be studied using large eddy simulations based on the unsteady, compressible, reacting, multi-species Navier-Stokes equations to gain further understanding of the physical processes involved in a condensed phase explosion and the effect of confinement on the physical processes involved. The analysis of the mixing and afterburning of TNT explosions in free air (unconfined) and near the ground (semi-confined) indicates that the combustion region of detonation products and air is determined by the vorticity patterns, which are induced by the Richtmeyer-Meshkov instabilities that arise during the explosion. When the explosive is detonated in the vicinity of a surface, the surface affects the shock propagation by creating complex shock systems, thereby changing the orientation of the vorticity, giving the afterburning a mushroom shape, and increasing performance of an explosive charge by prolonging the existence of the mixing layer and thereby the afterburning.

14 CFR 91.219 - Altitude alerting system or device: Turbojet-powered civil airplanes.

Code of Federal Regulations, 2013 CFR

2013-01-01

...: Turbojet-powered civil airplanes. 91.219 Section 91.219 Aeronautics and Space FEDERAL AVIATION... system or device: Turbojet-powered civil airplanes. (a) Except as provided in paragraph (d) of this section, no person may operate a turbojet-powered U.S.-registered civil airplane unless that airplane is...

14 CFR 91.219 - Altitude alerting system or device: Turbojet-powered civil airplanes.

Code of Federal Regulations, 2014 CFR

2014-01-01

...: Turbojet-powered civil airplanes. 91.219 Section 91.219 Aeronautics and Space FEDERAL AVIATION... system or device: Turbojet-powered civil airplanes. (a) Except as provided in paragraph (d) of this section, no person may operate a turbojet-powered U.S.-registered civil airplane unless that airplane is...

14 CFR 91.219 - Altitude alerting system or device: Turbojet-powered civil airplanes.

Code of Federal Regulations, 2010 CFR

2010-01-01

...: Turbojet-powered civil airplanes. 91.219 Section 91.219 Aeronautics and Space FEDERAL AVIATION... system or device: Turbojet-powered civil airplanes. (a) Except as provided in paragraph (d) of this section, no person may operate a turbojet-powered U.S.-registered civil airplane unless that airplane is...

Steam thermolysis of tire shreds: modernization in afterburning of accompanying gas with waste steam

NASA Astrophysics Data System (ADS)

Kalitko, V. A.

2010-03-01

On the basis of experience in the commercial operation of tire-shred steam thermolysis in EnresTec Inc. (Taiwan) producing high-grade commercial carbon, liquid pyrolysis fuel, and accompanying fuel gas by this method, we have proposed a number of engineering solutions and calculated-analytical substantiations for modernization and intensification of the process by afterburning the accompanying gas with waste steam condensable in the scrubber of water gas cleaning of afterburning products. The condensate is completely freed of the organic pyrolysis impurities and the necessity of separating it from the liquid fuel, as is the case with the active process, is excluded.

75 FR 21161 - Airworthiness Directives; General Electric Company (GE) CJ610 Series Turbojet Engines and CF700...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-23

... Airworthiness Directives; General Electric Company (GE) CJ610 Series Turbojet Engines and CF700 Series Turbofan... adopting a new airworthiness directive (AD) for GE CJ610 series turbojet engines and CF700 turbofan engines... part 39 with a proposed AD. The proposed AD applies to GE CJ610 series turbojet engines and CF700...

Thermodynamic Model of Afterburning in Explosions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuhl, A L; Howard, M; Fried, L

2003-04-23

Thermodynamic states encountered during afterburning of explosion products gases in air were analyzed with the Cheetah code. Results are displayed in the form of Le Chatelier diagrams: the locus of states of specific internal energy versus temperature, for six different condensed explosives charges. Accuracy of the results was confirmed by comparing the fuel and products curves with the heats of detonation and combustion, and species composition as measured in bomb calorimeter experiments. Results were fit with analytic functions u = f ( T ) suitable for specifying the thermodynamic properties required for gas-dynamic models of afterburning in explosions.

Seminar on the Structure of Aeronautical R&D Held in Lisbon, Portugal on 31 May-1 Jun 1990, Patras, Greece on 4-5 June 1990 and Ankara, Turkey on 7-8 June 1990 (La Structure de la Recherche et Developpement en Aeronautique)

DTIC Science & Technology

1990-05-01

comprehension du processus de la R&D a6ronautiquc, mais elles sont loin d𔄀tre exhaustives . Les opinions et les exp6riences pr6sent6es dmanent de lAm6rique...into the exhaust nozzle, possibly with some low level of F Liquid ..... j afterburning during the acceleration phase. Advanced engine technology...hypersonic vehicles show stagnation temperatures much lower, Obviously, advanced cooling methods such as heat pipes will be required. However. at lower

14 CFR 91.219 - Altitude alerting system or device: Turbojet-powered civil airplanes.

Code of Federal Regulations, 2011 CFR

2011-01-01

...: Turbojet-powered civil airplanes. 91.219 Section 91.219 Aeronautics and Space FEDERAL AVIATION... system or device: Turbojet-powered civil airplanes. (a) Except as provided in paragraph (d) of this section, no person may operate a turbojet-powered U.S.-registered civil airplane unless that airplane is...

14 CFR 91.219 - Altitude alerting system or device: Turbojet-powered civil airplanes.

Code of Federal Regulations, 2012 CFR

2012-01-01

...: Turbojet-powered civil airplanes. 91.219 Section 91.219 Aeronautics and Space FEDERAL AVIATION... system or device: Turbojet-powered civil airplanes. (a) Except as provided in paragraph (d) of this section, no person may operate a turbojet-powered U.S.-registered civil airplane unless that airplane is...

Measurements and predictions of flyover and static noise of a TF30 afterburning turbofan engine

NASA Technical Reports Server (NTRS)

Burcham, F. W., Jr.; Lasagna, P. L.; Oas, S. C.

1978-01-01

The noise of the TF30 afterburning turbofan engine in an F-111 airplane was determined from static (ground) and flyover tests. A survey was made to measure the exhaust temperature and velocity profiles for a range of power settings. Comparisons were made between predicted and measured jet mixing, internal, and shock noise. It was found that the noise produced at static conditions was dominated by jet mixing noise, and was adequately predicted by current methods. The noise produced during flyovers exhibited large contributions from internally generated noise in the forward arc. For flyovers with the engine at nonafterburning power, the internal noise, shock noise, and jet mixing noise were accurately predicted. During flyovers with afterburning power settings, however, additional internal noise believed to be due to the afterburning process was evident; its level was as much as 8 decibels above the nonafterburning internal noise. Power settings that produced exhausts with inverted velocity profiles appeared to be slightly less noisy than power settings of equal thrust that produced uniform exhaust velocity profiles both in flight and in static testing.

Installation for burning-out scrap metal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gutschmidt, P.

1982-08-24

Disclosed is an installation for burning-out scrap metal goods for the purpose of reclaiming scrap metal, comprising at least one furnace wagon, which is capable of being loaded with the scrap metal goods to be burned out; at least one burning-out chamber into which the furnace wagon is movable for burning-out the scrap metal goods to produce scrap steel; means for heating the burning-out chamber to a temperature of at least about 600* C.; at least one afterburning chamber communicating with the burning-out chamber for afterburning flue gases produced in the burning-out chamber at a temperature from about 1100* tomore » 1200* C.; a waste gas purifying plant communicating with the afterburning chamber for eliminating the flue gas impurities and for the scrubbing of the flue-gases originating from the afterburning chamber; and at least one cooling chamber arranged adjacent to and in selective communication with the burning-out chamber for cooling the burned-out material.« less

Bibliography of Books and Published Reports on Gas Turbines, Jet Propulsion, and Rocket Power Plants, January 1950 through December 1953

DTIC Science & Technology

1953-12-01

Vt. J. V. Casamassa, Jet aircraft power systems . McGraw-Hill, New York. C. C. Chapel, Jet aircraft simplified. Aero Pubs. Inc., Los Angeles. V. C...combination. NACA Tech. Note No. 1951 (Sept.). A. F. Lietzke and H. M. Henneberry, Evaluation of piston-type gas- generator engine for subsonic transport...Dynamics of a turbojet engine considered as a quasi-static system . NACA Tech. Note No. 2091 (May). A. E. Puckett, Optimum performance of rocket- powered

Performance analysis and dynamic modeling of a single-spool turbojet engine

NASA Astrophysics Data System (ADS)

Andrei, Irina-Carmen; Toader, Adrian; Stroe, Gabriela; Frunzulica, Florin

2017-01-01

The purposes of modeling and simulation of a turbojet engine are the steady state analysis and transient analysis. From the steady state analysis, which consists in the investigation of the operating, equilibrium regimes and it is based on appropriate modeling describing the operation of a turbojet engine at design and off-design regimes, results the performance analysis, concluded by the engine's operational maps (i.e. the altitude map, velocity map and speed map) and the engine's universal map. The mathematical model that allows the calculation of the design and off-design performances, in case of a single spool turbojet is detailed. An in house code was developed, its calibration was done for the J85 turbojet engine as the test case. The dynamic modeling of the turbojet engine is obtained from the energy balance equations for compressor, combustor and turbine, as the engine's main parts. The transient analysis, which is based on appropriate modeling of engine and its main parts, expresses the dynamic behavior of the turbojet engine, and further, provides details regarding the engine's control. The aim of the dynamic analysis is to determine a control program for the turbojet, based on the results provided by performance analysis. In case of the single-spool turbojet engine, with fixed nozzle geometry, the thrust is controlled by one parameter, which is the fuel flow rate. The design and management of the aircraft engine controls are based on the results of the transient analysis. The construction of the design model is complex, since it is based on both steady-state and transient analysis, further allowing the flight path cycle analysis and optimizations. This paper presents numerical simulations for a single-spool turbojet engine (J85 as test case), with appropriate modeling for steady-state and dynamic analysis.

Thermo-Gas-Dynamic Model of Afterburning in Explosions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuhl, A L; Ferguson, R E; Bell, J B

2003-07-27

A theoretical model of afterburning in explosions created by turbulent mixing of the detonation products from fuel-rich charges with air is described. It contains three key elements: (i) a thermodynamic-equilibrium description of the fluids (fuel, air, and products), (ii) a multi-component gas-dynamic treatment of the flow field, and (iii) a sub-grid model of molecular processes of mixing, combustion and equilibration.

Modeling of chemical reactions in afterburning for the reduction of N{sub 2}O

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gustavsson, L.; Glarborg, P.; Leckner, B.

1996-08-01

Afterburning involves burning a secondary fuel in the flue gases from a fluidized bed combustor to raise the temperature, and thereby decrease the emission of N{sub 2}O. Tests in a 12-MW circulating fluidized bed boiler used the cyclone as an afterburning combustor. The results from these tests are analyzed by chemical kinetic calculations with homogeneous hydrocarbon and nitrogen chemistry. Furthermore, a study is made of the influence on the calculation of particles in the flue gases. The deviation between calculated and measured data is small at high temperatures, but increases at the lower temperatures investigated. The influence of particles ismore » predicted to be small under conditions prevailing in the cyclone.« less

Exhaust emissions survey of a turbofan engine for flame holder swirl type augmentors at simulated altitude flight conditions

NASA Technical Reports Server (NTRS)

Moss, J. E., Jr.

1981-01-01

Emissions of carbon dioxide, total oxides of nitrogen, unburned hydrocarbons, and carbon monoxide from an F100 afterburning two spool turbofan engine at simulated flight conditions are reported. Tests were run at Mach 0.8 at altitudes of 10.97 and 13.71 km (36,000 and 45,000 ft), and at Mach 1.2 at 13.71 km (45,000 ft). Emission measurements were made from intermediate power (nonafterburning) through maximum afterburning, using a single point gas sample probe traversed across the horizontal diameter of the exhaust nozzle. The data show that emissions vary with flight speed, altitude, power level, and radial position across the nozzle. Carbon monoxide emissions were low for intermediate and partial afterburning power. Unburned hydrocarbons were near zero for most of the simulated flight conditions. At maximum afterburning, there were regions of NOx deficiency in regions of high CO. The results suggest that the low NOx levels observed in the tests are a result of interaction with high CO in the thermal converter. CO2 emissions were proportional to local fuel air ratio for all test conditions.

Cavity-actuated supersonic mixing and combustion control

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, K.H.; Schadow, K.C.

1994-11-01

Compressible shear layers in supersonic jets are quite stable and spread very slowly compared with incompressible shear layers. In this paper, a novel use of a cavity-actuated forcing technique is demonstrated for increasing the spreading rate of compressible shear layers. Periodic modulations were applied to Mach 2.0 reacting and nonreacting jets using the cavities that were attached at the exit of a circular supersonic nozzle. The effect of cavity-actuated forcing was studied as a function of the cavity geometry, in particular, the length and the depth of the cavity. When the cavities were tuned to certain frequencies, large-scale highly coherentmore » structures were produced in the shear layers substantially increasing the growth rate. The cavity excitation was successfully applied to both cold and hot supersonic jets. When applied to cold Mach 2.0 air jets. the cavity-actuated forcing increased the spreading rate of the initial shear layers with the convective Mach number (M[sub C]) of 0.85 by a factor of three. For high-temperature Mach 2.0 jets with M[sub C] of 1.4, a 50% increase in the spreading rate was observed with the forcing. Finally, the cavity-actuated forcing was applied to reacting supersonic jets with ethylene-oxygen afterburning. For this case, the forcing caused a 20%--30% reduction in the afterburning flame length and modified the afterburning intensity significantly. The direction of the modification depended on the characteristics of the afterburning flames. The intensity was reduced with forcing for unstable flames with weak afterburning while it was increased for stable flames with strong afterburning.« less

Optical Pressure Measurements of Explosions

DTIC Science & Technology

2013-09-01

near field detonation product gases can have a significant effect upon afterburn ignition times (4). The implication being that afterburning times...can be tuned to bring detonation product afterburning into proximity of the leading shock, influencing brisance, and explosive impulse on target. 3...R. Z.; McAndrew, B. A. Afterburn Ignition Delay and Shock Augmentation in Fuel Rich Solid Explosives. Propellants, Explosives, Pyrotechnics 2010

Core Engine Noise Control Program. Volume III. Prediction Methods

DTIC Science & Technology

1974-08-01

turbofan engines , and Method (C) is based on an analytical description of viscous wake interaction between adjoining blade rows. Turbine Tone/ Jet ...levels for turbojet , turboshaft and turbofan engines . The turbojet data correlate highest and the turbofan data correlate lowest. Turbine Noise Noise...different engines were examined for combustor, jet and fan noise. Tnree turbojet , two turboshaft and two turbofan

An application of modern control theory to jet propulsion systems. [considering onboard computer

NASA Technical Reports Server (NTRS)

Merrill, W. C.

1975-01-01

The control of an airbreathing turbojet engine by an onboard digital computer is studied. The approach taken is to model the turbojet engine as a linear, multivariable system whose parameters vary with engine operating environment. From this model adaptive closed-loop or feedback control laws are designed and applied to the acceleration of the turbojet engine.

Abatement of N{sub 2}O emissions from circulating fluidized bed combustion through afterburning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gustavsson, L.; Leckner, B.

1995-04-01

A method for the abatement of N{sub 2}O emission from fluidized bed combustion has been investigated. The method consists of burning a secondary fuel after the normal circulating fluidized bed combustor. Liquefied petroleum gas (LPG), fuel oil, pulverized coal, and wood, as well as sawdust, were used as the secondary fuel. Experiments showed that the N{sub 2}O emission can be reduced by 90% or more by this technique. The resulting N{sub 2}O emission was principally a function of the gas temperature achieved in the afterburner and independent of afterburning fuel, but the amount of air in the combustion gases frommore » the primary combustion also influences the results. No negative effects on sulfur capture or on NO or CO emissions were recorded. In the experiments, the primary cyclone of the fluidized bed boiler was used for afterburning. If afterburning is implemented in a plant optimized for this purpose, an amount of secondary fuel corresponding to 10% of the total energy input should remove practically all N{sub 2}O. During the present experiments the secondary fuel consumption was greater than 10% of the total energy input due to various losses.« less

Initial Flow Matching Results of MHD Energy Bypass on a Supersonic Turbojet Engine Using the Numerical Propulsion System Simulation (NPSS) Environment

NASA Technical Reports Server (NTRS)

Benyo, Theresa L.

2010-01-01

Preliminary flow matching has been demonstrated for a MHD energy bypass system on a supersonic turbojet engine. The Numerical Propulsion System Simulation (NPSS) environment was used to perform a thermodynamic cycle analysis to properly match the flows from an inlet to a MHD generator and from the exit of a supersonic turbojet to a MHD accelerator. Working with various operating conditions such as the enthalpy extraction ratio and isentropic efficiency of the MHD generator and MHD accelerator, interfacing studies were conducted between the pre-ionizers, the MHD generator, the turbojet engine, and the MHD accelerator. This paper briefly describes the NPSS environment used in this analysis and describes the NPSS analysis of a supersonic turbojet engine with a MHD generator/accelerator energy bypass system. Results from this study have shown that using MHD energy bypass in the flow path of a supersonic turbojet engine increases the useful Mach number operating range from 0 to 3.0 Mach (not using MHD) to an explored and desired range of 0 to 7.0 Mach.

Effects of Altitude on Turbojet Engine Performance

NASA Technical Reports Server (NTRS)

Fleming, William A

1951-01-01

Component and over-all performance characteristics of several turbojet engines investigated in the altitude facilities of the NACA Lewis Laboratory during the last several years are summarized to indicate the effects of altitude on turbojet engine performance. Data presented show that failure of turbojet engine performance to generalize for all altitudes can be traced to reductions in compressor efficiency, corrected air flow, and combustion efficiency at altitude. In addition, it is shown that although engines of different design may have equal thrusts at sea level, the thrusts at altitude may vary widely because of differences in compressor performance characteristics from one engine to another.

Numerical Investigation of Aluminum Burning Behind Blast Waves

DTIC Science & Technology

2010-10-01

Lai, and K.S. Im, “ Afterburning of TNT Explosive Products in Air with Aluminum Particles,” AIAA-2008-1029, 2008 [2] K. Balakrishnan and S. Menon...phase flow was applied. The modeled HE includes a significant percentage of aluminum particles, whose long-time afterburning and energy release must...the physical mechanisms are even more complex. The flow environment is significantly different from bare charge detonation and afterburn . As long

Dioxins and furans formation in pilot incineration tests of sewage sludge spiked with organic chlorine.

PubMed

Mininni, Giuseppe; Sbrilli, Andrea; Guerriero, Ettore; Rotatori, Mauro

2004-03-01

The factors affecting polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) formation were studied in sewage sludge incineration tests carried out on a demonstrative plant. The plant includes a circulating fluidised bed furnace (FBF) and a rotary kiln furnace (RKF), operating alternatively. During the tests sewage sludge was spiked with chlorinated hydrocarbons and the operating parameters of the afterburning chamber were varied. PCDD/F were sampled in each test before the bag filter, thus collecting the above contaminants before abatement systems. From the tests it appeared that PCDD/F were always produced in more abundance in the tests carried out by FBF than by RKF. The higher PCDD/F concentrations in the tests by FBF were reached when sewage sludge was spiked with a high dosage of a surrogate organic mixture of chlorinated hydrocarbons and when the afterburning chamber was used only as transit equipment with the burner off. The distribution of the different PCDD/F homologues was compared. P5CDFs were generally the prevalent fraction, with very few exceptions for the tests by RKF at high temperature of the afterburning chamber. As for FBF tests, it was found that the PCDD/F homologue profile depends on the afterburning chamber temperature.

A Preliminary Study of a Propeller Powered by Gas Jets Issuing from the Blade Tips

DTIC Science & Technology

1946-11-01

ISSUING FROM THE BLADE TIPS By J. C. Sanders and N. D. Sanders Aircraft Engine Research Laboratory Cleveland, Ohio icaflit w<• w &£N •^5$" jm "^o*6w...propeller powered by Jets in the blade tips made by Roy in 1930 (reference 3) showed that this engine would be less efficient than;a reciprocating...development of the turbojet engine , which is .now of outstanding interest. The possibilities of the jet -operated propeller are re-exeroined and the

Performance of Compressor of XJ-41-V Turbojet Engine. 1 - Preliminary Investigation at Equivalent Compressor Speed of 8000 rpm

DTIC Science & Technology

1949-01-01

Aircraft Engine Research Laboratory Cleveland, Ohio Restriction Cancelled ^mmmmmmmm ^Md’^| 5;-;» <^~ k NATIONAL ADVISORY COMMTTErUf0...AEEONAUTICS RESEARCH MEMORANDUM for the Air Materiel Command’, Army Air Forces PERFORMANCE OF COMPRESSOR OF XJ-41-V TURBOJET ENGINE I - PRELIMINARY...of the XJ-41-V turbojet - engine compressor. . .’ The complete compressor was amounted on a collecting chamber having an annular air-flow

Design and Evaluation of a Turbojet Exhaust Simulator, Utilizing a Solid-Propellant Rocket Motor, for use in Free-Flight Aerodynamic Research Models

NASA Technical Reports Server (NTRS)

deMoraes, Carlos A.; Hagginbothom, William K., Jr.; Falanga, Ralph A.

1954-01-01

A method has been developed for modifying a rocket motor so that its exhaust characteristics simulate those of a turbojet engine. The analysis necessary to the design is presented along with tests from which the designs are evaluated. Simulation was found to be best if the exhaust characteristics to be duplicated were those of a turbojet engine at high altitudes and with the afterburner operative.

Hypersonic Flight: Time To Go Operational

DTIC Science & Technology

2013-02-14

and turbojet /turbofan driven aircraft both individually and combined with the latter taking over fighter propulsion in 1945-1948 and quickly...2000 2020 Early Turbojet / Turbofan Piston Aircraft Late Turbojet / Turbofan Year Deployed M ile s pe r H ou 6 ensure the...threaten aircraft , airbases, and naval assets, especially aircraft carrier battle groups. The future is uncertain and the preceding vision of the

Feasibility Study of Laboratory Simulation of Single-Stage-to-Orbit Vehicle Base Heating

NASA Technical Reports Server (NTRS)

Park, Chung Sik; Sharma, Surendra; Edwards, Thomas A. (Technical Monitor)

1995-01-01

The feasibility of simulating in a laboratory the heating environment of the base region of the proposed reusable single-stage-to-orbit vehicle during its ascent is examined. The propellant is assumed to consist of hydrocarbon (RP1), liquid hydrogen (LH2), and liquid oxygen (LO2), which produces CO and H2 as the main combustible components of the exhaust effluent. Since afterburning in the recirculating region can dictate the temperature of the base flowfield and ensuing heating phenomena, laboratory simulation focuses on the thermochemistry of the afterburning. By extrapolating the Saturn V flight data, the Damkohler number, in the base region with afterburning for SSTO vehicle, is estimated to be between 30 and 140. It is shown that a flow with a Damkohler number of 1.8 to 25 can be produced in an impulse ground test facility. Even with such a reduced Damkohler number, the experiment can adequately reproduce the main features of the flight environment.

Alternative fuels for multiple-hearth furnaces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bracken, B.D.; Lawson, T.U.

1980-04-01

A study of alternative procedures for reducing the consumption of No. 2 fuel oil at the Lower Molonglo Water Quality Control Centre near Canberra, Aust., indicated that in comparison with the present system of incineration with heat supplied by burning fuel oil, the installation of a sludge drying operation, consisting of a rotary dryer heated by furnace exhaust gases with the dried sludge used to fuel the furnace, would become economically desirable by 1985 if afterburning is not required, and would be justified immediately if afterburning is required to meet air pollution control regulations. The substitution of any of fourmore » waste fuels (refuse-derived fuel, waste paper, wood waste, or waste oil) or of coal for the No. 2 fuel oil would not be cost-effective through 1989. The furnace system, including afterburning and fuel oil requirements, the envisioned alternative fuel use systems, sludge processing alternatives, heat balance results, and economics are discussed.« less

Feasibility Study of SSTO Base Heating Simulation in Pulsed-Type Facilities

NASA Technical Reports Server (NTRS)

Park, Chung Sik; Sharma, Surendra; Edwards, Thomas A. (Technical Monitor)

1995-01-01

A laboratory simulation of the base heating environment of the proposed reusable Single-Stage-To-Orbit vehicle during its ascent flight was proposed. The rocket engine produces CO2 and H2, which are the main combustible components of the exhaust effluent. The burning of these species, known as afterburning, enhances the base region gas temperature as well as the base heating. To determine the heat flux on the SSTO vehicle, current simulation focuses on the thermochemistry of the afterburning, thermophysical properties of the base region gas, and ensuing radiation from the gas. By extrapolating from the Saturn flight data, the Damkohler number for the afterburning of SSTO vehicle is estimated to be of the order of 10. The limitations on the material strengths limit the laboratory simulation of the flight Damkohler number as well as other flow parameters. A plan is presented in impulse facilities using miniature rocket engines which generate the simulated rocket plume by electric ally-heating a H2/CO2 mixture.

Destructive treatment of waste gas by catalytic afterburning and adsorption

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eppel, S.A.; Kochetkova, R.P.; Kolisnyk, G.P.

1983-07-01

Because of the considerable energy costs involved in the use of catalytic afterburning to clean up waste gases, an alternative method is suggested: adsorption with the use of low-cost adsorbents that are regenerated by destruction of the substances that has been taken up. Activated semicoke (ASK) is proposed as an adsorbent and tested. On the basis of the results, ASK is recommended for the treatment of waste gases to remove oxygen-containing, sulfurcontaining, and tarry compounds.

Increase in the efficiency of electric melting of pellets in an arc furnace with allowance for the energy effect of afterburning of carbon oxide in slag using fuel-oxygen burners

NASA Astrophysics Data System (ADS)

Stepanov, V. A.; Krakht, L. N.; Merker, E. E.; Sazonov, A. V.; Chermenev, E. A.

2015-12-01

The problems of increasing the efficiency of electric steelmaking using fuel-oxygen burners to supply oxygen for the afterburning of effluent gases in an arc furnace are considered. The application of a new energy-saving regime based on a proposed technology of electric melting is shown to intensify the processes of slag formation, heating, and metal decarburization.

Effects of entrained water and strong turbulence on afterburning within solid rocket motor plumes

NASA Technical Reports Server (NTRS)

Gomberg, R. I.; Wilmoth, R. G.

1978-01-01

During the first few seconds of the space shuttle trajectory, the solid rocket boosters will be in the proximity of the launch pad. Because of the launch pad structures and the surface of the earth, the turbulent mixing experienced by the exhaust gases will be greatly increased over that for the free flight situation. In addition, a system will be present, designed to protect the lifting vehicle from launch structure vibrations, which will inject quantities of liquid water into the hot plume. The effects of these two phenomena on the temperatures, chemical composition, and flow field present in the afterburning solid rocket motor exhaust plumes of the space shuttle were studied. Results are included from both a computational model of the afterburning and supporting measurements from Titan 3 exhaust plumes taken at Kennedy Space Center with infrared scanned radiometers.

The Effect of Magnetohydrodynamic (MHD) Energy Bypass on Specific Thrust for a Supersonic Turbojet Engine

NASA Technical Reports Server (NTRS)

Benyo, Theresa L.

2010-01-01

This paper describes the preliminary results of a thermodynamic cycle analysis of a supersonic turbojet engine with a magnetohydrodynamic (MHD) energy bypass system that explores a wide range of MHD enthalpy extraction parameters. Through the analysis described here, it is shown that applying a magnetic field to a flow path in the Mach 2.0 to 3.5 range can increase the specific thrust of the turbojet engine up to as much as 420 N/(kg/s) provided that the magnitude of the magnetic field is in the range of 1 to 5 Tesla. The MHD energy bypass can also increase the operating Mach number range for a supersonic turbojet engine into the hypersonic flight regime. In this case, the Mach number range is shown to be extended to Mach 7.0.

Sustainability Metrics of a Small Scale Turbojet Engine

NASA Astrophysics Data System (ADS)

Ekici, Selcuk; Sohret, Yasin; Coban, Kahraman; Altuntas, Onder; Karakoc, T. Hikmet

2018-05-01

Over the last decade, sustainable energy consumption has attracted the attention of scientists and researchers. The current paper presents sustainability indicators of a small scale turbojet engine, operated on micro-aerial vehicles, for discussion of the sustainable development of the aviation industry from a different perspective. Experimental data was obtained from an engine at full power load and utilized to conduct an exergy-based sustainability analysis. Exergy efficiency, waste exergy ratio, recoverable exergy ratio, environmental effect factor, exergy destruction factor and exergetic sustainability index are evaluated as exergetic sustainability indicators of the turbojet engine under investigation in the current study. The exergy efficiency of the small scale turbojet engine is calculated as 27.25 % whereas the waste exergy ratio, the exergy destruction factor and the sustainability index of the engine are found to be 0.9756, 0.5466 and 0.2793, respectively.

Turbojet-type engines for the airbreathing propulsion of reusable winged launchers

NASA Astrophysics Data System (ADS)

Duparcq, J. L.; Hermant, E.; Scherrer, D.

Combined propulsion systems for hypersonic application have become new challenges for industrial and research organizations. In France, SNECMA and SEP, which have just joined together for a common effort on hypersonics within Hyperspace, and ONERA have been involved, under CNES (French space agency) contracts, in the assessment of new propulsion concepts for reusable winged launchers (SSTO or TSTO). As potential solutions for the airbreathing propulsion, some turbojet-type engines are presented: —the twin spool turbojet or turbofan with reheat —the turbojet with reheat —the twin-duct turbojet ramjet —the precooled turbojet with reheat. All these engines have been sized for a flight Mach number under seven with a cryogenic fuel (liquid hydrogen). Mainly due to total temperature and pressure encountered along the trajectory, the systems will have to withstand severe physical constraints. Coupled with performance and size requirements, like specific thrust and maximum air capture area, these operating conditions have been taken into account in order to select each engine cycle and technical arrangement. Performance and mass criteria make it possible to compare these systems and to emphasize their distinctive features among the propulsion concepts envisioned for the future reusable winged launchers (including airbreathing combined engines under study in France). The first step of the final selection, leading to the best adaptation between the engine and the vehicle, will then be tackled. This will be particularly enhanced by the analysis of potential advantages or technical difficulties, like thrust-to-weight ratio or needs of variable geometry and heat exchangers. The twin-duct turbojet ramjet, for example, is probably one of the best candidates for the first stages of propulsion of a reusable winged launcher.

Self-teaching digital-computer program for fail-operational control of a turbojet engine in a sea-level test stand

NASA Technical Reports Server (NTRS)

Wallhagen, R. E.; Arpasi, D. J.

1974-01-01

The design and evaluation are described of a digital turbojet engine control which is capable of sensing catastrophic failures in either the engine rotor speed or the compressor discharge static-pressure signal and is capable of switching control modes to maintain near normal operation. The control program was developed for and tested on a turbojet engine located in a sea-level test stand. The control program is also capable of acquiring all the data that are necessary for the fail-operational control to function.

Turbo-Electric Compressor/Generator Using Halbach Arrays

NASA Technical Reports Server (NTRS)

Kloesel, Kurt J. (Inventor)

2016-01-01

The present invention is a turbojet design that integrates power generation into the turbojet itself, rather than use separate generators attached to the turbojet for power generation. By integrating the power generation within the jet engine, the weight of the overall system is significantly reduced, increasing system efficiency. Also, by integrating the power generating elements of the system within the air flow of the jet engine, the present invention can use the heat generated by the power generating elements (which is simply expelled waste heat in current designs) to increase the engine performance.

NACA Conference on Turbojet-Engine Thrust Augmentation Research: A Compilation of the Papers Presented by NACA Staff Members

NASA Technical Reports Server (NTRS)

1948-01-01

The conference on Turbojet-Engine Thrust-Augmentation Research was organized by the NACA to present in summarized form the results of the latest experimental and analytical investigations conducted at the Lewis Flight Propulsion Laboratory on methods of augmenting the thrust of turbojet engines. The technical discussions are reproduced herewith in the same form in which they were presented. The original presentation in this record are considered as complementary to, rather than substitutes for, the committee's system of complete and formal reports.

A CFD Study of Turbojet and Single-Throat Ramjet Ejector Interaction

NASA Technical Reports Server (NTRS)

Chang, Ing; Hunter, Louis

1996-01-01

Supersonic ejector-diffuse systems have application in driving an advanced airbreathing propulsion system, consisting of turbojet engines acting as the primary and a single throat ramjet acting as the secondary. The turbojet engines are integrated into the single throat ramjet to minimize variable geometry and eliminate redundant propulsion components. The result is a simple, lightweight system that is operable from takeoff to high Mach numbers. At this high Mach number (approximately Mach 3.0), the turbojets are turned off and the high speed ramjet/scramjet take over and drive the vehicle to Mach 6.0. The turbojet-ejector-ramjet system consists of nonafterburning turbojet engines with ducting canted at 20 degrees to supply supersonic flow (downstream of CD nozzle) to the horizontal ramjet duct at a supply total pressure and temperature. Two conditions were modelled by a 2-D full Navier Stokes code at Mach 2.0. The code modelled the Fabri choke as well as the non-Fabri non critical case, using a computational throat to supply the back pressure. The results, which primarily predict the secondary mass flow rate and the mixed conditions at the ejector exit were in reasonable agreement with the 1-D cycle code (TBCC).

Flow Matching Results of an MHD Energy Bypass System on a Supersonic Turbojet Engine Using the Numerical Propulsion System Simulation (NPSS) Environment

NASA Technical Reports Server (NTRS)

Benyo, Theresa L.

2011-01-01

Flow matching has been successfully achieved for an MHD energy bypass system on a supersonic turbojet engine. The Numerical Propulsion System Simulation (NPSS) environment helped perform a thermodynamic cycle analysis to properly match the flows from an inlet employing a MHD energy bypass system (consisting of an MHD generator and MHD accelerator) on a supersonic turbojet engine. Working with various operating conditions (such as the applied magnetic field, MHD generator length and flow conductivity), interfacing studies were conducted between the MHD generator, the turbojet engine, and the MHD accelerator. This paper briefly describes the NPSS environment used in this analysis. This paper further describes the analysis of a supersonic turbojet engine with an MHD generator/accelerator energy bypass system. Results from this study have shown that using MHD energy bypass in the flow path of a supersonic turbojet engine increases the useful Mach number operating range from 0 to 3.0 Mach (not using MHD) to a range of 0 to 7.0 Mach with specific net thrust range of 740 N-s/kg (at ambient Mach = 3.25) to 70 N-s/kg (at ambient Mach = 7). These results were achieved with an applied magnetic field of 2.5 Tesla and conductivity levels in a range from 2 mhos/m (ambient Mach = 7) to 5.5 mhos/m (ambient Mach = 3.5) for an MHD generator length of 3 m.

Utilizing CFD for Prediction of HD1.3 Pressure Loads in a Cell with Venting

DTIC Science & Technology

2010-07-01

room. The gas load is a result of the heat released during the explosion and afterburning of explosives that was not consumed by the initial...Structural Systems Design Guide HNDED-CS-93-72 specifies that all HD 1.3 in a room will be summed and converted to an equivalent TNT mass (based on...the H2 and CO are shown in Table 5. The Pre- Afterburning quantities are based on the chemical equilibrium calculations performed in the AFCESI code

NACA Conference on Turbojet-Engine Thrust-Augmentation Research - a Compilation of the Papers Presented by NACA Staff Members

DTIC Science & Technology

1948-10-28

N . E. Harvey, Lt. Col. J. A. Hartman, E. P. Hildestad, H. L. Eolbrook, G. E, Hopkins, Lt. Comdr. L. A...velocity and diffuser efficiency on augmentation. 1041A H oo \\=> K H n w E-i O 33 1.6 1.4 E-i co !=> Pi E-i § 1.0 o 1.2 .8...xutm E"H N 1 DO E-i O £3 E-i DO £) E-H o ^ 00 :=> ex E-t Co o Is i.5 i.O .5 :.0 ,5 2 - 750 40G <C < CD-1 T Q lg 3800°

[The post-burn process--a determinant in local surgical treatment of deep burns].

PubMed

Bäumer, F; Henrich, H A

1988-12-01

Afterburning has been studied in the animal experiment by use of intravital dye indicators and by measuring partial oxygen pressure. After third degree burn the oxygen conduction of the damaged skin increased. The afterburning was seen to be finished on the 5th day after the burn trauma. The histological changes in the depth of the afterburn area reaches to the subcutis. The extend of the afterburn area was not related to the applied temperature or the duration of the experimental burn injury.

Process of afterburning combustible constituents of exhaust gases from rotary kilns

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schnabel, W.; Scheu, E.; Serbent, H.

1984-03-13

In order to avoid incrustation and an excessively strong thermal attack on the afterburning chamber, the exhaust gases which contain gaseous and solid constituents which are combustible are afterburned in a plurality of stages, which are connected in series. The rate at which oxygen is supplied to each stage is so controlled that part of the combustible constituents is afterburned in each stage. The gas which is about to enter each succeeding stage is cooled by injected water.

Conceptual Study on Hypersonic Turbojet Experimental Vehicle (HYTEX)

NASA Astrophysics Data System (ADS)

Taguchi, Hideyuki; Murakami, Akira; Sato, Tetsuya; Tsuchiya, Takeshi

Pre-cooled turbojet engines have been investigated aiming at realization of reusable space transportation systems and hypersonic airplanes. Evaluation methods of these engine performances have been established based on ground tests. There are some plans on the demonstration of hypersonic propulsion systems. JAXA focused on hypersonic propulsion systems as a key technology of hypersonic transport airplane. Demonstrations of Mach 5 class hypersonic technologies are stated as a development target at 2025 in the long term vision. In this study, systems analyses of hypersonic turbojet experiment (HYTEX) with Mach 5 flight capability is performed. Aerodynamic coefficients are obtained by CFD analyses and wind tunnel tests. Small Pre-cooled turbojet is fabricated and tested using liquid hydrogen as fuel. As a result, characteristics of the baseline vehicle shape is clarified, . and effects of pre-cooling are confirmed at the firing test.

A 3-D Navier-Stokes CFD study of turbojet/ramjet nozzle plume interactions at Mach 3.0 and comparison with data

NASA Technical Reports Server (NTRS)

Chang, Ing; Hunter, Louis G.

1995-01-01

Advanced airbreathing propulsion systems used in Mach 4-6 mission scenarios, usually consist of a single integrated turboramjet or as in this study, a turbojet housed in an upper bay with a separate ramjet housed in a lower bay. As the engines transition from turbojet to ramjet, there is an operational envelope where both engines operate simultaneously. One nozzle concept under consideration has a common nozzle, where the plumes from the turbojet and ramjet interact with one another as they expand to ambient conditions. In this paper, the two plumes interact at the end of a common 2-D cowl, when they both reach an approximate Mach 3.0 condition and then jointly expand to Mach 3.6 at the common nozzle exit plane. At this condition, the turbojet engine operated at a higher NPR than the ramjet, where the turbojet overpowers the ramjet plume, deflecting it approximately 12 degrees downward and in turn the turbojet plume is deflected 6 degrees upward. In the process, shocks were formed at the deflections and a shear layer formed at the confluence of the two jets. This particular case was experimentally tested and the data used to compare with the PARC3D code with k-kl two equation turbulence model. The 2-D and 3-D centerline CFD solutions are in good agreement, but as the CFD solutions approach the outer sidewall, a slight variance occurs. The outer wall boundary layers are thin and do not present much of an interaction, however, where the confluence interaction shocks interact with the thin boundary layer on the outer wall, strong vortices run down each shock causing substantial disturbances in the boundary layer. These disturbances amplify somewhat as they propagate downstream axially from the confluence point. The nozzle coefficient (CFG) is reduced 1/2 percent as a result of this sidewall interaction, from 0.9850 to 0.9807. This three-dimensional reduction is in better agreement with the experimental value of 0.9790.

Development of Supersonic Vehicle for Demonstration of a Precooled Turbojet Engine

NASA Astrophysics Data System (ADS)

Sawai, Shujiro; Fujita, Kazuhisa; Kobayashi, Hiroaki; Sakai, Shin'ichiro; Bando, Nobutaka; Kadooka, Shouhei; Tsuboi, Nobuyuki; Miyaji, Koji; Uchiyama, Taku; Hashimoto, Tatsuaki

JAXA is developing Mach 5 hypersonic turbojet engine technology that can be applied in a future hypersonic transport. Now, Jet Engine Technology Research Center of JAXA conducts the experimental study using a 1 / 10 scale-model engine. In parallel to engine development activities, a new supersonic flight-testing vehicle for the hypersonic turbojet engine is under development since 2004. In this paper, the system configuration of the flight-testing vehicle is outlined and development status is reported.

Noise emissions and building structural vibration levels from the Supersonic Concorde and subsconic turbojet aircraft

DOT National Transportation Integrated Search

1975-03-01

Noise emissions and building structural vibration levels were measured during landing and take off operations of the Anglo/French supersonic aircraft (Concorde) and from some conventional subsonic turbojet aircraft. Measurements were made at both the...

Net thrust calculation sensitivity of an afterburning turbofan engine to variations in input parameters

NASA Technical Reports Server (NTRS)

Hughes, D. L.; Ray, R. J.; Walton, J. T.

1985-01-01

The calculated value of net thrust of an aircraft powered by a General Electric F404-GE-400 afterburning turbofan engine was evaluated for its sensitivity to various input parameters. The effects of a 1.0-percent change in each input parameter on the calculated value of net thrust with two calculation methods are compared. This paper presents the results of these comparisons and also gives the estimated accuracy of the overall net thrust calculation as determined from the influence coefficients and estimated parameter measurement accuracies.

An Investigation of Landing-Contact Conditions for Two Large Turbojet Transports and a Turboprop Transport During Routine Daylight Operations

NASA Technical Reports Server (NTRS)

Stickle, Joseph W.

1961-01-01

The National Aeronautics and Space Administration has recently completed a statistical investigation of landing-contact conditions for two large turbojet transports and a turboprop transport landing on a dry runway during routine daylight operations at the Los Angeles International Airport. Measurements were made to obtain vertical velocity, airspeed, rolling velocity, bank angle, and distance from the runway threshold, just prior to ground contact. The vertical velocities at touchdown for one of the turbojet airplanes measured in this investigation were essentially the same as those measured on the same type of airplane during a similar investigation (see NASA Technical Note D-527) conducted approximately 8 months earlier. Thus, it appeared that 8 months of additional pilot experience has had no noticeable tendency toward lowering the vertical velocities of this transport. Distributions of vertical velocities for the turbojet transports covered in this investigation were similar and considerably higher than'those for the turboprop transport. The data for the turboprop transport were in good agreement with the data for the piston-engine transports (see NACA Report 1214 and NASA Technical Note D-147) for all the measured parameters. For the turbojet transports, 1 landing in 100 would be expected to equal or exceed a vertical velocity of approximately 4.2 ft/sec; whereas, for the turboprop transport, 1 landing in 100 would be expected to equal or exceed 3.2 ft/sec. The mean airspeeds at touchdown for the three transports ranged from 22.5 percent to 26.6 percent above the stalling speed. Rolling velocities for the turbojet transports were considerably higher than those for the turboprop transport. Distributions of bank angles at contact for the three transports were similar. For each type of airplane, 1 landing in 100 would be expected to equal or exceed a bank angle at touchdown of approximately 3.0 deg. Distributions of touchdown distances for the three transports were also quite similar. Touchdown distances from the threshold for 1 landing in 100 ranged from 2,500 feet for the turboprop transport to 2,800 feet for one of the turbojet transports.

HYDES: A generalized hybrid computer program for studying turbojet or turbofan engine dynamics

NASA Technical Reports Server (NTRS)

Szuch, J. R.

1974-01-01

This report describes HYDES, a hybrid computer program capable of simulating one-spool turbojet, two-spool turbojet, or two-spool turbofan engine dynamics. HYDES is also capable of simulating two- or three-stream turbofans with or without mixing of the exhaust streams. The program is intended to reduce the time required for implementing dynamic engine simulations. HYDES was developed for running on the Lewis Research Center's Electronic Associates (EAI) 690 Hybrid Computing System and satisfies the 16384-word core-size and hybrid-interface limits of that machine. The program could be modified for running on other computing systems. The use of HYDES to simulate a single-spool turbojet and a two-spool, two-stream turbofan engine is demonstrated. The form of the required input data is shown and samples of output listings (teletype) and transient plots (x-y plotter) are provided. HYDES is shown to be capable of performing both steady-state design and off-design analyses and transient analyses.

78 FR 34550 - Airworthiness Directives; Rolls-Royce plc Turbojet Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-10

... Airworthiness Directives; Rolls-Royce plc Turbojet Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: We are adopting a new airworthiness directive (AD) for all Rolls-Royce plc..., contact Defence Aerospace Communications at Rolls-Royce plc, P.O. Box 3, Gypsy Patch Lane, Filton, Bristol...

Comparison of High-Speed Operating Characteristics of Size 215 Cylindrical-Roller Bearings as Determined in Turbojet Engine and in Laboratory Test Rig

NASA Technical Reports Server (NTRS)

Macks, E Fred; Nemeth, Zolton N

1951-01-01

A comparison of the operating characteristics of 75-millimeter-bore (size 215) cylindrical-roller one-piece inner-race-riding cage-type bearings was made using a laboratory test rig and a turbojet engine. Cooling correlation parameters were determined by means of dimensional analysis, and the generalized results for both the inner- and outer-race bearing operating temperatures are compared for the laboratory test rig and the turbojet engine. Inner- and outer-race cooling-correlation curves were obtained for the turbojet-engine turbine-roller bearing with the same inner- and outer-race correlation parameters and exponents as those determined for the laboratory test-rig bearing. The inner- and outer-race turbine roller-bearing temperatures may be predicted from a single curve, regardless of variations in speed, load, oil flow, oil inlet temperature, oil inlet viscosity, oil-jet diameter or any combination of these parameters. The turbojet-engine turbine-roller-bearing inner-race temperatures were 30 to 60 F greater than the outer-race-maximum temperatures, the exact values depending on the operating condition and oil viscosity; these results are in contrast to the laboratory test-rig results where the inner-race temperatures were less than the outer-race-maximum temperatures. The turbojet-engine turbine-roller bearing, maximum outer-race circumferential temperature variation was approximately 30 F for each of the oils used. The effect of oil viscosity on inner- and outer-race turbojet-engine turbine-roller-bearing temperatures was found to be significant. With the lower viscosity oil (6x10(exp -7) reyns (4.9 centistokes) at 100 F; viscosity index, 83), the inner-race temperature was approximately 30 to 35 F less than with the higher viscosity oil (53x10(exp -7) reyns (42.8 centistokes) at 100 F; viscosity index, 150); whereas the outer-race-maximum temperatures were 12 to 28 F lower with the lower viscosity oil over the DN range investigated.

Evaluation of a ducted-fan power plant designed for high output and good cruise fuel economy

NASA Technical Reports Server (NTRS)

Behun, M; Rom, F E; Hensley, R V

1950-01-01

Theoretical analysis of performance of a ducted-fan power plant designed both for high-output, high-altitude operation at low supersonic Mach numbers and for good fuel economy at lower fight speeds is presented. Performance of ducted fan is compared with performance (with and without tail-pipe burner) of two hypothetical turbojet engines. At maximum power, the ducted fan has propulsive thrust per unit of frontal area between thrusts obtained by turbojet engines with and without tail-pipe burners. At cruise, the ducted fan obtains lowest thrust specific fuel consumption. For equal maximum thrusts, the ducted fan obtains cruising flight duration and range appreciably greater than turbojet engines.

A preliminary study of the performance and characteristics of a supersonic executive aircraft

NASA Technical Reports Server (NTRS)

Mascitti, V. R.

1977-01-01

The impact of advanced supersonic technologies on the performance and characteristics of a supersonic executive aircraft was studied in four configurations with different engine locations and wing/body blending and an advanced nonafterburning turbojet or variable cycle engine. An M 2.2 design Douglas scaled arrow-wing was used with Learjet 35 accommodations. All four configurations with turbojet engines meet the performance goals of 5926 km (3200 n.mi.) range, 1981 meters (6500 feet) takeoff field length, and 77 meters per second (150 knots) approach speed. The noise levels of of turbojet configurations studied are excessive. However, a turbojet with mechanical suppressor was not studied. The variable cycle engine configuration is deficient in range by 555 km (300 n.mi) but nearly meets subsonic noise rules (FAR 36 1977 edition), if coannular noise relief is assumed. All configurations are in the 33566 to 36287 kg (74,000 to 80,000 lbm) takeoff gross weight class when incorporating current titanium manufacturing technology.

Proposed regulations submitted by the Environmental Protection Agency to the FAA: moise abatement minimum altitudes for turbojet-powered airplanes in terminal areas; turbojet-powered airplanes. Decision not to prescribe requlations: delayed landing flap procedure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1976-11-29

The Federal Aviation Administration has determined not to prescribe the proposed amendment to the FAA Regulations as submitted by the Environmental Protection Agency (40 F.R. 1072) on January 6, 1975, regarding noise abatement minimum altitudes for civil turbojet-powered airplanes. Instead, an internal directive is being issued aimed at the air traffic control function, which is designed to firmly integrate safety, fuel conservation, and noise abatement objectives into a single national program. It provides the flexibility needed to allow and encourage change with experience. (PCS)

Effect of inlet ingestion of a wing tip vortex on compressor face flow and turbojet stall margin

NASA Technical Reports Server (NTRS)

Mitchell, G. A.

1975-01-01

A two-dimensional inlet was alternately mated to a coldpipe plug assembly and a J85-GE-13 turbojet engine, and placed in a Mach 0.4 stream so as to ingest the tip vortex of a forward mounted wing. Vortex properties were measured just forward of the inlet and at the compressor face. Results show that ingestion of a wing tip vortex by a turbojet engine can cause a large reduction in engine stall margin. The loss in stall compressor pressure ratio was primarily dependent on vortex location and rotational direction and not on total-pressure distortion.

A remote augmentor lift system with a turbine bypass engine

NASA Technical Reports Server (NTRS)

Fishbach, L. H.; Franciscus, L. C.

1982-01-01

Two supersonic vertical takeoff or landing (VTOL) aircraft engine types, a conventional medium bypass ratio turbofan, and a turbine bypass turbojet were studied. The aircraft assumed was a clipped delta wing with canard configuration. A VTOL deck launched intercept, DLI, mission with Mach 1.6 dash and cruise segments was used as the design mission. Several alternate missions requiring extended subsonic capabilities were analyzed. Comparisons were made between the turbofan (TF) and the turbine bypass turbojet (TBE) engines in airplane types using a Remote Augmented Lift Systems, RALS and a Lift plus Lift Cruise system (L+LC). The figure of merit was takeoff gross weight for the VTOL DLI mission. The results of the study show that the turbine bypass turbojet and the conventional turbofan are competitive engines for both type of aircraft in terms of takeoff gross weight and range. However, the turbine bypass turbojet would be a simpler engine and may result in more attractive life cycle costs and reduced maintenance. The RALS and L+LC airplane types with either TBE or TF engines have approximately the same aircraft takeoff gross weight.

Installation for the catalytic afterburning of exhaust gases of a multi-cylinder internal combustion engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lange, K.

1974-04-24

An installation for the catalytic afterburning of exhaust gases of a multi-cylinder internal combustion engine has two cylinder rows with two exhaust gas lines, each of which includes at least one catalyst. A temperature-responsive control is operable during engine start-up to conduct substantially the entire exhaust gas flow from the internal combustion engine during warmup for a predetermined time by way of only one of the two catalyst and then, after a short period of time, to conduct the exhaust gas flow from each row of cylinders by way of its associated gas line and catalyst.

Generalized simulation technique for turbojet engine system analysis

NASA Technical Reports Server (NTRS)

Seldner, K.; Mihaloew, J. R.; Blaha, R. J.

1972-01-01

A nonlinear analog simulation of a turbojet engine was developed. The purpose of the study was to establish simulation techniques applicable to propulsion system dynamics and controls research. A schematic model was derived from a physical description of a J85-13 turbojet engine. Basic conservation equations were applied to each component along with their individual performance characteristics to derive a mathematical representation. The simulation was mechanized on an analog computer. The simulation was verified in both steady-state and dynamic modes by comparing analytical results with experimental data obtained from tests performed at the Lewis Research Center with a J85-13 engine. In addition, comparison was also made with performance data obtained from the engine manufacturer. The comparisons established the validity of the simulation technique.

Quality of Ambulant Measures of Distance, Speed, Load and Energy Consumption During Military Operations

DTIC Science & Technology

2009-10-01

Nutrition 2007, 85, 742-749. [2] Calabro, M. A., Welk, G. J. FACSM, & Eisenmann , J. C. (2007). Measurement Agreemen Between Two Pattern-Recognition Activity...Exercise Energy Expenditure. . Medicine & Science in Sports & Exercise, 36 (6), 1063-1069. [17] McClain, J. J., Welk, G. J., Wickel, E. E., & Eisenmann

Static internal performance including thrust vectoring and reversing of two-dimensional convergent-divergent nozzles

NASA Technical Reports Server (NTRS)

Re, R. J.; Leavitt, L. D.

1984-01-01

The effects of geometric design parameters on two dimensional convergent-divergent nozzles were investigated at nozzle pressure ratios up to 12 in the static test facility. Forward flight (dry and afterburning power settings), vectored-thrust (afterburning power setting), and reverse-thrust (dry power setting) nozzles were investigated. The nozzles had thrust vector angles from 0 deg to 20.26 deg, throat aspect ratios of 3.696 to 7.612, throat radii from sharp to 2.738 cm, expansion ratios from 1.089 to 1.797, and various sidewall lengths. The results indicate that unvectored two dimensional convergent-divergent nozzles have static internal performance comparable to axisymmetric nozzles with similar expansion ratios.

Aircraft/Stores Compatibility, Integration and Separation Testing (Essais de compatibilite, d’integration et de separation des emports sur aeronef)

DTIC Science & Technology

2014-09-01

given mission. There are several different propulsion system choices that can be used in a weapon system, such as turbofan / turbojet, ramjet, ducted...Efficiencies of Propulsion Alternatives Across the Mach Number. Turbojet/ turbofan propulsion alternatives are mature technologies and they are

SST Technology Follow-on Program - Phase I, Performance Evaluation of an SST Noise Suppressor Nozzle System. Volume 1. Suppressed Mode.

DTIC Science & Technology

ACOUSTIC INSULATION, *TURBOJET EXHAUST NOZZLES, *JET ENGINE NOISE, REDUCTION, JET TRANSPORT AIRCRAFT, THRUST AUGMENTATION , SUPERSONIC NOZZLES, DUCT...INLETS, CONVERGENT DIVERGENT NOZZLES, SUBSONIC FLOW, SUPERSONIC FLOW, SUPPRESSORS, TURBOJET INLETS, BAFFLES, JET PUMPS, THRUST , DRAG, TEMPERATURE

Active chlorine and nitric oxide formation from chemical rocket plume afterburning

NASA Astrophysics Data System (ADS)

Leone, D. M.; Turns, S. R.

Chlorine and oxides of nitrogen (NO(x)) released into the atmosphere contribute to acid rain (ground level or low-altitude sources) and ozone depletion from the stratosphere (high-altitude sources). Rocket engines have the potential for forming or activating these pollutants in the rocket plume. For instance, H2/O2 rockets can produce thermal NO(x) in their plumes. Emphasis, in the past, has been placed on determining the impact of chlorine release on the stratosphere. To date, very little, if any, information is available to understand what contribution NO(x) emissions from ground-based engine testing and actual rocket launches have on the atmosphere. The goal of this work is to estimate the afterburning emissions from chemical rocket plumes and determine their local stratospheric impact. Our study focuses on the space shuttle rocket motors, which include both the solid rocket boosters (SRB's) and the liquid propellant main engines (SSME's). Rocket plume afterburning is modeled employing a one-dimensional model incorporating two chemical kinetic systems: chemical and thermal equilibria with overlayed nitric oxide chemical kinetics (semi equilibrium) and full finite-rate chemical kinetics. Additionally, the local atmospheric impact immediately following a launch is modeled as the emissions diffuse and chemically react in the stratosphere.

Active chlorine and nitric oxide formation from chemical rocket plume afterburning

NASA Technical Reports Server (NTRS)

Leone, D. M.; Turns, S. R.

1994-01-01

Chlorine and oxides of nitrogen (NO(x)) released into the atmosphere contribute to acid rain (ground level or low-altitude sources) and ozone depletion from the stratosphere (high-altitude sources). Rocket engines have the potential for forming or activating these pollutants in the rocket plume. For instance, H2/O2 rockets can produce thermal NO(x) in their plumes. Emphasis, in the past, has been placed on determining the impact of chlorine release on the stratosphere. To date, very little, if any, information is available to understand what contribution NO(x) emissions from ground-based engine testing and actual rocket launches have on the atmosphere. The goal of this work is to estimate the afterburning emissions from chemical rocket plumes and determine their local stratospheric impact. Our study focuses on the space shuttle rocket motors, which include both the solid rocket boosters (SRB's) and the liquid propellant main engines (SSME's). Rocket plume afterburning is modeled employing a one-dimensional model incorporating two chemical kinetic systems: chemical and thermal equilibria with overlayed nitric oxide chemical kinetics (semi equilibrium) and full finite-rate chemical kinetics. Additionally, the local atmospheric impact immediately following a launch is modeled as the emissions diffuse and chemically react in the stratosphere.

The development of turbojet aircraft in Germany, Britain, and the United States: A multi-national comparison of aeronautical engineering, 1935--1946

NASA Astrophysics Data System (ADS)

Pavelec, Sterling Michael

In the 1930s aeronautical engineering needed revision. A presumptive anomaly was envisaged as piston-engine aircraft flew higher and faster. Radical alternatives to piston engines were considered in the unending quest for speed. Concurrently, but unwittingly, two turbojet engine programs were undertaken in Europe. The air-breathing three-stage turbojet engine was based on previous turbine technology; the revolutionary idea was the gas turbine as a prime mover for aircraft. In Germany, Dr. Hans von Ohain was the first to complete a flight-worthy turbojet engine for aircraft. Installed in a Heinkel designed aircraft, the Germans began the jet age on 27 August 1939. The Germans led throughout the war and were the first to produce jet aircraft for combat operations. The principal limiting factor for the German jet program was a lack of reliable engines. The continuing myths that Hitler orders, too little fuel, or too few pilots hindered the program are false. In England, Frank Whittle, without substantial support, but with dogged determination, also developed a turbojet engine. The British came second in the jet race when the Whittle engine powered the Gloster Pioneer on 15 May 1941. The Whittle-Gloster relationship continued and produced the only Allied combat jet aircraft during the war, the Meteor, which was confined to Home Defense in Britain. The American turbojet program was built directly from the Whittle engine. General Electric copied the Whittle designs and Bell Aircraft was contracted to build the first American jet plane. The Americans began the jet age on 1 October 1942 with a lackluster performance from their first jet, the Airacomet. But the Americans forged ahead, and had numerous engine and airframe programs in development by the end of the war. But, the Germans did it right and did it first. Partly because of a predisposition towards excellent engineering and physics, partly out of necessity, the Germans were able to produce combat turbojet aircraft during the war. The Allies lagged from a lack of necessity, operational incompatibility, and stringent acceptance requirements. By the end of the war the Germans needed qualitative technological superiority to combat an overwhelming Allied quantitative advantage.

Technical Feasibility of Loitering Lighter-Than-Air Near-Space Maneuvering Vehicles

DTIC Science & Technology

2005-03-01

one year [7]. NASA’s superpressure design consists of a pumpkin shaped balloon (Figure 8) to minimize envelope material stresses. Figure 8: NASA...Figure 12: Turbojet Engine In addition to the pure turbojet engine, the basic gas turbine core is also used to power turboprop and turbofan

14 CFR 61.58 - Pilot-in-command proficiency check: Operation of an aircraft that requires more than one pilot...

Code of Federal Regulations, 2013 CFR

2013-01-01

...-powered; (5) For a pilot authorized by the Administrator to operate an experimental turbojet-powered aircraft that possesses, by original design or through modification, more than a single seat, the required proficiency check for all of the experimental turbojet-powered aircraft for which the pilot holds an...

Performance Evaluation of an Experimental Turbojet Engine

NASA Astrophysics Data System (ADS)

Ekici, Selcuk; Sohret, Yasin; Coban, Kahraman; Altuntas, Onder; Karakoc, T. Hikmet

2017-11-01

An exergy analysis is presented including design parameters and performance assessment, by identifying the losses and efficiency of a gas turbine engine. The aim of this paper is to determine the performance of a small turbojet engine with an exergetic analysis based on test data. Experimental data from testing was collected at full-load of small turbojet engine. The turbojet engine exhaust data contains CO2, CO, CH4, H2, H2O, NO, NO2, N2 and O2 with a relative humidity of 35 % for the ambient air of the performed experiments. The evaluated main components of the turbojet engine are the air compressor, the combustion chamber and the gas turbine. As a result of the thermodynamic analysis, exergy efficiencies (based on product/fuel) of the air compressor, the combustion chamber and the gas turbine are 81.57 %, 50.13 % and 97.81 %, respectively. A major proportion of the total exergy destruction was found for the combustion chamber at 167.33 kW. The exergy destruction rates are 8.20 %, 90.70 % and 1.08 % in the compressor, the combustion chamber and the gas turbine, respectively. The rates of exergy destruction within the system components are compared on the basis of the exergy rate of the fuel provided to the engine. Eventually, the exergy rate of the fuel is calculated to be 4.50 % of unusable due to exergy destruction within the compressor, 49.76 % unusable due to exergy destruction within the combustion chamber and 0.59 % unusable due to exergy destruction within the gas turbine. It can be stated that approximately 55 % of the exergy rate of the fuel provided to the engine can not be used by the engine.

Altitude Performance Characteristics of Tail-pipe Burner with Convergingconical Burner Section on J47 Turbojet Engine

NASA Technical Reports Server (NTRS)

Prince, William R; Mcaulay, John E

1950-01-01

An investigation of turbojet-engine thrust augmentation by means of tail-pipe burning was conducted in the NACA Lewis altitude wind tunnel. Performance data were obtained with a tail-pipe burner having a converging conical burner section installed on an axial-flow-compressor type turbojet engine over a range of simulated flight conditions and tail-pipe fuel-air ratios with a fixed-area exhaust nozzle. A maximum tail-pipe combustion efficiency of 0.86 was obtained at an altitude of 15,000 feet and a flight Mach number of 0.23. Tail-pipe burner operation was possible up to an altitude of 45,000 feet at a flight Mach number of 0.23.

Comparison of Theoretically and Experimentally Determined Effects of Oxide Coatings Supplied by Fuel Additives on Uncooled Turbine-blade Temperature During Transient Turbojet-engine Operation

NASA Technical Reports Server (NTRS)

Schafer, Louis J; Stepka, Francis S; Brown, W Byron

1953-01-01

An analysis was made to permit the calculation of the effectiveness of oxide coatings in retarding the transient heat flow into turbine blades when the combustion gas temperature of a turbojet engine is suddenly changed. The analysis is checked with experimental data obtained from a turbojet engine whose blades were coated with two different coating materials (silicon dioxide and boric oxide) by adding silicone oil and tributyl borate to the engine fuel. The very thin coatings (approximately 0.001 in.) that formed on the blades produced a negligible effect on the turbine-blade transient temperature response. With the analysis discussed here, it was possible to predict the turbine rotor-blade temperature response with a maximum error of 40 F.

Ionic Mechanisms of Carbon Formation in Flames.

DTIC Science & Technology

1981-05-01

EFFECT OF MOLECULAR STRUCTURE ON INCIPIENT SOOT FORMATION, H.F. Calcote and D.M. Manos APPENDIX E: CORRELATION OF SOOT FORMATION IN TURBOJET ENGINES...future use by the Air Force of synfuels derived from coal, tar sands, and shale oil . These fuels are expected to have higher molecular weights, more...emissions and flame radiation from turbojet engines and larger scale combustors simulating practical engine conditions. b. Interpret and correlate the

Community noise sources and noise control issues

NASA Technical Reports Server (NTRS)

Nihart, Gene L.

1992-01-01

The topics covered include the following: community noise sources and noise control issues; noise components for turbine bypass turbojet engine (TBE) turbojet; engine cycle selection and noise; nozzle development schedule; NACA nozzle design; NACA nozzle test results; nearly fully mixed (NFM) nozzle design; noise versus aspiration rate; peak noise test results; nozzle test in the Low Speed Aeroacoustic Facility (LSAF); and Schlieren pictures of NACA nozzle.

Assembly and Initial Analysis of a Database of the Characteristics of Fixed-Wing Unmanned Aircraft Systems

DTIC Science & Technology

2014-11-01

sea level (evaluated for turbojet- and turbofan -powered UAVs and targets only) R range (km) ferryR ferry range (km) radiusR mission radius (km...operating airspeed for manned turbofan -powered aircraft, and a power law for birds derived by Alerstam et al. [22...UAVs in the Database; and ratio of operating to maximum airspeed for turbojet- or turbofan -powered UAVs with mmax > 103 kg

14 CFR 61.58 - Pilot-in-command proficiency check: Operation of an aircraft that requires more than one pilot...

Code of Federal Regulations, 2014 CFR

2014-01-01

...-powered; (5) For a pilot authorized by the Administrator to operate an experimental turbojet-powered aircraft that possesses, by original design or through modification, more than a single seat, the required proficiency check for all of the experimental turbojet-powered aircraft for which the pilot holds an...

Internal combustion engine having a reactor for afterburning of unburned exhaust gas constituents

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maurhoff, G.; Steinwart, J.

1974-08-07

An internal combustion engine is described which has an engine housing and a reactor for afterburning of unburned constituents in the exhaust gas. The reactor has a shell with a periphery and contains a heat-insulated, reactor chamber which is freely movable beyond the point of connection to the shell. The reactor has an inlet nozzle extending freely through the shell and connected to an outlet passage of the engine and has an outlet for escape of the exhaust gases from the reactor chamber. The inlet nozzle protrudes freely into the outlet passage, and the shell has a portion around themore » inlet nozzle in contact with the engine housing.« less

Two-Dimensional Supersonic Nozzle Thrust Vectoring Using Staggered Ramps

NASA Astrophysics Data System (ADS)

Montes, Carlos Fernando

A novel mechanism for vectoring the thrust of a supersonic, air-breathing engine was analyzed numerically using ANSYS Fluent. The mechanism uses two asymmetrically staggered ramps; one placed at the throat, the other positioned at the exit lip of the nozzle. The nozzle was designed using published flow data, isentropic relationships, and piecewise quartic splines. The design was verified numerically and was in fair agreement with the analytical data. Using the steady-state pressure-based solver, along with the realizable kappa - epsilon turbulence model, a total of eighteen simulations were conducted: three ramp lengths at three angles, using two sets of inlet boundary conditions (non-afterburning and afterburning). The vectoring simulations showed that the afterburning flow yields a lower flow deflection distribution, shown by the calculated average deflection angle and area-weighted integrals of the distributions. The data implies that an aircraft can achieve an average thrust vectoring angle of approximately 30° in a given direction with the longest ramp length and largest ramp angle configuration. With increasing ramp angle, the static pressure across the nozzle inlet increased, causing concern for potential negative effects on the engine's turbine. The mechanism, for which a provisional patent application has been filed, will require further work to investigate the maximum possible thrust vectoring angle, including experiments.

Theoretical models for the combustion of alloyable materials

NASA Astrophysics Data System (ADS)

Armstrong, Robert

1992-09-01

The purpose of this work is to extend a theoretical model of layered (laminar) media for SHS combustion presented in an earlier article [1] to explore possible mechanisms for after-burning in SHS ( i.e., gasless) combustion. As before, our particular interest is how the microscopic geometry of the solid reactants is reflected in the combustion wave and in the reaction product. The model is constructed from alternating lamina of two pure reactants that interdiffuse exothermically to form a product. Here, the laminar model is extended to contain layers of differing thicknesses. Using asymptotic theory, it was found that under certain conditions, the combustion wave can become “detached,” and an initial thin flame propagates through the media, leaving a slower, thicker flame following behind ( i.e., afterburning). Thin laminae are consumed in the initial flame and are thick in the secondary. The thin flame has a width determined by the inverse of the activation energy of diffusion, as found previously. The width of the afterburning zone, however, is determined by the absolute time of diffusion for the thicker laminae. Naturally, when the laminae are all the same thickness, there is only one thin flame. The condition for the appearance of afterburning is found to be contingent on the square of the ratio of smallestto-largest thicknesses being considerably less than unity.

Comparison of High-Speed Operating Characteristics of Size 215 Cylindrical-Roller Bearings as Determined in Turbojet Engine and in Laboratory Test Rig

NASA Technical Reports Server (NTRS)

Macks, E Fred; Nemeth, Zolton N

1952-01-01

A comparison of the operating characteristics of 75-millimeter-bore (size 215) cylindrical-roller one-piece inner-race-riding cage-type bearings was made by means of a laboratory test rig and a turbojet engine. Cooling correlation parameters were determined by means of dimensional analysis, and the generalized results for both the inner- and the outer-race bearing operating temperatures are computed for the laboratory test rig and the turbojet engine. A method is given that enables the designer to predict the inner- and outer-race turbine roller-bearing temperatures from single curves, regardless of variations in speed, load, oil flow, oil inlet temperature, oil inlet viscosity, oil-jet diameter, or any combination of these parameters.

A computer simulation of the afterburning processes occurring within solid rocket motor plumes in the troposphere

NASA Technical Reports Server (NTRS)

Gomberg, R. I.; Stewart, R. B.

1976-01-01

As part of a continuing study of the environmental effects of solid rocket motor (SRM) operations in the troposphere, a numerical model was used to simulate the afterburning processes occurring in solid rocket motor plumes and to predict the quantities of potentially harmful chemical species which are created. The calculations include the effects of finite-rate chemistry and turbulent mixing. It is found that the amount of NO produced is much less than the amount of HCl present in the plume, that chlorine will appear predominantly in the form of HCl although some molecular chlorine is present, and that combustion is complete as is evident from the predominance of carbon dioxide over carbon monoxide.

Turbojet engine blade damping

NASA Technical Reports Server (NTRS)

Srinivasan, A. V.; Cutts, D. G.; Sridhar, S.

1981-01-01

The potentials of various sources of nonaerodynamic damping in engine blading are evaluated through a combination of advanced analysis and testing. The sources studied include material hysteresis, dry friction at shroud and root disk interfaces as well as at platform type external dampers. A limited seris of tests was conducted to evaluate damping capacities of composite materials (B/AL, B/AL/Ti) and thermal barrier coatings. Further, basic experiments were performed on titanium specimens to establish the characteristics of sliding friction and to determine material damping constants J and n. All the tests were conducted on single blades. Mathematical models were develthe several mechanisms of damping. Procedures to apply this data to predict damping levels in an assembly of blades are developed and discussed.

Performance and control study of a low-pressure-ratio turbojet engine for a drone aircraft

NASA Technical Reports Server (NTRS)

Seldner, K.; Geyser, L. C.; Gold, H.; Walker, D.; Burgner, G.

1972-01-01

The results of analog and digital computer studies of a low-pressure-ratio turbojet engine system for use in a drone vehicle are presented. The turbojet engine consists of a four-stage axial compressor, single-stage turbine, and a fixed area exhaust nozzle. Three simplified fuel schedules and a generalized parameter fuel control for the engine system are presented and evaluated. The evaluation is based on the performance of each schedule or control during engine acceleration from a windmill start at Mach 0.8 and 6100 meters to 100 percent corrected speed. It was found that, because of the higher acceleration margin permitted by the control, the generalized parameter control exhibited the best dynamic performance.

Calculated and measured stresses in simple panels subject to intense random acoustic loading including the near noise field of a turbojet engine

NASA Technical Reports Server (NTRS)

Lassiter, Leslie W; Hess, Robert W

1958-01-01

Flat 2024-t3 aluminum panels measuring 11 inches by 13 inches were tested in the near noise fields of a 4-inch air jet and turbojet engine. The stresses which were developed in the panels are compared with those calculated by generalized harmonic analysis. The calculated and measured stresses were found to be in good agreement. In order to make the stress calculations, supplementary data relating to the transfer characteristics, damping, and static response of flat and curved panels under periodic loading are necessary and were determined experimentally. In addition, an appendix containing detailed data on the near pressure field of the turbojet engine is included.

Subsonic Performance of Ejector Systems

NASA Astrophysics Data System (ADS)

Weil, Samuel

Combined cycle engines combining scramjets with turbo jets or rockets can provide efficient hypersonic flight. Ejectors have the potential to increase the thrust and efficiency of combined cycle engines near static conditions. A computer code was developed to support the design of a small-scale, turbine-based combined cycle demonstrator with an ejector, built around a commercially available turbojet engine. This code was used to analyze the performance of an ejector system built around a micro-turbojet. With the use of a simple ejector, net thrust increases as large as 20% over the base engine were predicted. Additionally the specific fuel consumption was lowered by 10%. Increasing the secondary to primary area ratio of the ejector lead to significant improvements in static thrust, specific fuel consumption (SFC), and propulsive efficiency. Further ejector performance improvements can be achieved by using a diffuser. Ejector performance drops off rapidly with increasing Mach number. The ejector has lower thrust and higher SFC than the turbojet core at Mach numbers above 0.2. When the nozzle chokes a significant drop in ejector performance is seen. When a diffuser is used, higher Mach numbers lead to choking in the mixer and a shock in the nozzle causing a significant decrease in ejector performance. Evaluation of different turbo jets shows that ejector performance depends significantly on the properties of the turbojet. Static thrust and SFC improvements can be achieved with increasing ejector area for all engines, but size of increase and change in performance at higher Mach numbers depend heavily on the turbojet. The use of an ejector in a turbine based combined cycle configuration also increases performance at static conditions with a thrust increase of 5% and SFC decrease of 5% for the tested configuration.

An Investigation of Landing-Contact Conditions for a Large Turbojet Transport During Routine Daylight Operations

NASA Technical Reports Server (NTRS)

Stickle, Joseph W.; Silsby, Norman S.

1960-01-01

An investigation has been made by the NASA to obtain statistical measurements of landing-contact conditions for a large turbojet transport in commercial airline operations. The investigation was conducted at the Los Angeles International Airport in Los Angeles, California. Measurements were taken photographically during routine daylight operations. The quantities determined were vertical velocity, horizontal velocity, rolling velocity, bank angle, and distance from runway threshold, just prior to ground contact. The results indicated that the mean vertical velocity for the turbojet-transport landings was 1.62 feet per second and that 1 landing out of 100 would be expected to equal or exceed about 4.0 feet per second. The mean airspeed at contact was 132.0 knots, with 1 landing in 100 likely to equal or exceed about 153.0 knots. The mean rolling velocity was about 1.6 deg per second. One lending in 100 would probably equal or exceed a rolling velocity of about 4.0 deg. per second in the direction of the first wheel to touch. The mean bank angle for the turbojet transports was 1.04 deg, and right and left angles of bank were about evenly divided. One lending in 100 would be likely to equal or exceed a bank angle of about 3.5 deg. The mean value of distance to touchdown from the runway threshold was 1,560 feet. One lending in 100 would be expected to touchdown at or beyond about 2,700 feet from the runway threshold. The mean values for vertical velocity, airspeed, and distance t o touch-down for the turbojet transports were somewhat higher than those found previously for piston-engine transports. No significant differences were found for values of rolling velocity and bank angle.

AIRCRAFT REACTOR CONTROL SYSTEM APPLICABLE TO TURBOJET AND TURBOPROP POWER PLANTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gorker, G.E.

1955-07-19

Control systems proposed for direct cycle nuclear powered aircraft commonly involve control of engine speed, nuclear energy input, and chcmical energy input. A system in which these parameters are controlled by controlling the total energy input, the ratio of nuclear and chemical energy input, and the engine speed is proposed. The system is equally applicable to turbojet or turboprop applications. (auth)

High frequency-heated air turbojet

NASA Technical Reports Server (NTRS)

Miron, J. H. D.

1986-01-01

A description is given of a method to heat air coming from a turbojet compressor to a temperature necessary to produce required expansion without requiring fuel. This is done by high frequency heating, which heats the walls corresponding to the combustion chamber in existing jets, by mounting high frequency coils in them. The current transformer and high frequency generator to be used are discussed.

Performance of the Components of the XJ34-WE-32 Turbojet Engine over a Range of Engine and Flight Conditions

NASA Technical Reports Server (NTRS)

Mcaulay, John E; Sobolewski, Adam E; Smith, Ivan D

1952-01-01

Performance of the compressor, combustor, and turbine operating as integral parts of the XJ34-WE-32 turbojet engine was determined in the Lewis altitude wind tunnel over a range of altitudes from 5000 to 55,000 feet and flight Mach numbers from 0.28 to 1.05. Data were obtained for each of four exhaust-nozzle areas and are presented in graphical and tabular form.

The Use of Ion Implantation for Materials Processing.

DTIC Science & Technology

1982-07-02

corrosion studies. i this application main shaft bearings for turbojet engirps are being implanted to impart corrosion resistance to the rolling element...following discussion. Steels of this composition can be deep harened to Rockwell C-65 when quenched from the austenitizing temperature of 1230 C. An oil ...lubricant was a synthetic polyester lubricant used for turbojet engine bearings. As can be seen in Fig. 16 the wear rate after running-in is a factor

Liquid Chromatographic Analysis of Nitrocellulose-Base Propellants

DTIC Science & Technology

1983-03-28

18 radial PkC column using 10 micron silica coated with octadecyl silane. The detector was a LC 85 variable wavelength UV detector from Perkin-Elmer...Snyder, L. R. J Chrom Scd i6, (1978), 223. i •2 Glatch, J. L., Kirkland, J. J., Squire, K. M., and Miner, J. M.; J. Chromatgography, 199, (1980), 57. 4...assuming non retained peaks elute at 1 minute). This produces 3 solvents of approximately the same strengths bnt greatly differing selectivities. Once

Factors that Affect Operational Reliability of Turbojet Engines

NASA Technical Reports Server (NTRS)

1956-01-01

The problem of improving operational reliability of turbojet engines is studied in a series of papers. Failure statistics for this engine are presented, the theory and experimental evidence on how engine failures occur are described, and the methods available for avoiding failure in operation are discussed. The individual papers of the series are Objectives, Failure Statistics, Foreign-Object Damage, Compressor Blades, Combustor Assembly, Nozzle Diaphrams, Turbine Buckets, Turbine Disks, Rolling Contact Bearings, Engine Fuel Controls, and Summary Discussion.

A Thermodynamic Study of the Turbojet Engine

NASA Technical Reports Server (NTRS)

Pinkel, Benjamin; Karp, Irvin M

1947-01-01

Charts are presented for computing thrust, fuel consumption, and other performance values of a turbojet engine for any given set of operating conditions and component efficiencies. The effects of pressure losses in the inlet duct and the combustion chamber, of variation in physical properties of the gas as it passes through the system, of reheating of the gas due to turbine losses, and of change in mass flow by the addition of fuel are included. The principle performance chart shows the effects of primary variables and correction charts provide the effects of secondary variables and of turbine-loss reheat on the performance of the system. The influence of characteristics of a given compressor and turbine on performance of a turbojet engine containing a matched set of these given components is discussed for cases of an engine with a centrifugal-flow compressor and of an engine with an axial-flow compressor.

Effect of Axially Staged Fuel Introduction on Performance of One-quarter Sector of Annular Turbojet Combustor

NASA Technical Reports Server (NTRS)

Zettle, Eugene V; Mark, Herman

1953-01-01

The design principle of injecting liquid fuel at more than one axial station in an annual turbojet combustor was investigated. Fuel was injected into the combustor as much as 5 inches downstream of the primary fuel injectors. Many fuel-injection configurations were examined and the performance results are presented for 11 configurations that best demonstrate the trends in performance obtained. The performance investigations were made at a constant combustor-inlet pressure of 15 inches of mercury absolute and at air flows up to 70 percent higher than values typical of current design practice. At these higher air flows, staging the fuel introduction improved the combustion efficiency considerably over that obtained in the combustor when no fuel staging was employed. At air flows currently encountered in turbojet engines, fuel staging was of minor value. Radial temperature distribution seemed relatively unaffected by the location of fuel-injection stations.

Preliminary Altitude Performance Data of J71-A2 Turbojet Engine Afterburner

NASA Technical Reports Server (NTRS)

Useller, James W.; Mallett, William E.

1954-01-01

The performance and operational characteristics of the J71-A2 turbojet-engine afterburner were investigated for a range of altitudes from 23,000 to 60,000 feet at a flight Mach number of 0,9 and at flight Mach numbers of 0.6, 0.9, and 1.0 at an altitude of 45,000 feet. The combustion performance and altitude operational limits, as well as the altitude starting characteristics have been determined.

Modeling the Effects of Two Behavior Moderators in ACT-R

DTIC Science & Technology

2002-01-10

11(2), 93-100. Kelsey, R. M., Blascovich , J ., Leitten, C. L., Schneider, T. R., Tomaka , J ., & Wiens, S. (2000). Cardiovascular reactivity and...Computer Studies, 55, 85-107. Tomaka , J ., Blascovich , J ., Kelsey, R. M., & Leitten, C. L. (1993). Subjective, physiological, and behavioral effects of...performance and more solution attempts than neutral situations (Kelsey, Blascovich , Leitten, Schneider, Tomaka , & Wiens, 2000; Quigley, Barret, & Weinstein

Method and apparatus for afterburning flue gases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sikander, A.; Bjorkman, A.; Jonsson, G.

1984-11-13

A method of afterburning flue gases comprises passing impure gases from, for example, an incineration plant such as a destructor, process furnace, crematory furnace or heating boiler, through a burner in an afterburner where through enforced mixture with combustion gas they undergo complete combustion. The combustion gas, depending on the composition of the flue gases, may comprise air or oxygen or either mixed with petroleum gas. In apparatus for implementation of the method, the flue gases and the combustion gas are introduced into a burner which blows the gas mixture into a flame bowl where temperatures in the range ofmore » from 1,500/sup 0/-2,000/sup 0/ C. can be achieved. In one embodiment, the burner produces a conical basket-shaped flame in which the flue gases undergo complete combustion.« less

Aerodynamic tests and analysis of a turbojet-boosted launch vehicle concept (spacejet) over a Mach number range of 1.50 to 2.86. [Langley Unitary Plan Wind Tunnel Tests

NASA Technical Reports Server (NTRS)

Riebe, G. D.; Small, W. J.; Morris, O. A.

1981-01-01

Results from analytical and experimental studies of the aerodynamic characteristics of a turbojet-boosted launch vehicle concept through a Mach number range of 1.50 to 2.86 are presented. The vehicle consists of a winged orbiter utilizing an area-ruled axisymmetric body and two winged turbojet boosters mounted underneath the orbiter wing. Drag characteristics near zero lift were of prime interest. Force measurements and flow visualization techniques were employed. Estimates from wave drag theory, supersonic lifting surface theory, and impact theory are compared with data and indicate the ability of these theories to adequately predict the aerodynamic characteristics of the vehicle. Despite the existence of multiple wings and bodies in close proximity to each other, no large scale effects of boundary layer separation on drag or lift could be discerned. Total drag levels were, however, sensitive to booster locations.

Environmental and High-Strain Rate effects on composites for engine applications

NASA Technical Reports Server (NTRS)

Chamis, C. C.; Smith, G. T.

1982-01-01

The Lewis Research Center is conducting a series of programs intended to investigate and develop the application of composite materials to structural components for turbojet engines. A significant part of that effort is directed to establishing resistance, defect growth, and strain rate characteristics of composite materials over the wide range of environmental and load conditions found in commercial turbojet engine operations. Both analytical and experimental efforts are involved.

Sea-level evaluation of digitally implemented turbojet engine control functions

NASA Technical Reports Server (NTRS)

Arpasi, D. J.; Cwynar, D. S.; Wallhagen, R. E.

1972-01-01

The standard hydromechanical control system of a turbojet engine was replaced with a digital control system that implemented the same control laws. A detailed discussion of the digital control system in use with the engine is presented. The engine was operated in a sea-level test stand. The effects of control update interval are defined, and a method for extending this interval by using digital compensation is discussed.

The Mission Defines the Cycle: Turbojet, Turbofan and Variable Cycle Engines for High Speed Propulsion

DTIC Science & Technology

2010-09-01

RTO-EN-AVT-185 2 - 1 The Mission Defines the Cycle: Turbojet, Turbofan and Variable Cycle Engines for High Speed Propulsion Joachim Kurzke...following turbine parts 1 %. With T4=2000K the amounts of cooling air are 10% and 6% respectively. Burner pressure ratio is taken into account with 0.97 and...Figure 2 . Figure 3 shows specific thrust (i.e. thrust per unit of air flow) and specific fuel consumption SFC for three altitude / Mach number

Laboratory generation of free chlorine from HCl under stratospheric afterburning conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burke, M.L.; Zittel, P.F.

1998-01-01

Experiments have been conducted using a low pressure laboratory flame apparatus to examine the chemistry of solid rocket motor (SRM) afterburning relevant for stratospheric altitudes. It was found that a significant fraction of the HCl injected into H{sub 2}-O{sub 2} and H{sub 2}-CO-O{sub 2} flames can be consumed, with observed losses of up to 40%. The extent of conversion of HCl was found to increase with increasing oxygen:fuel (O/F) ratio and decreasing pressure; the loss at a given O/F was also higher for flames with equal flows of H{sub 2} and CO compared to flames with no CO in themore » fuel. The major product of HCl reaction was found to be Cl{sub 2}, with no other chlorine-contained products observed via mass spectrometry. Distinct Cl{sub 2} B {yields} X emission bands were observed along with very weak CIO A {yields} C bands and a bright, white continuum emission that apparently arose from one or more chlorine-containing compounds. The general findings concerning the magnitude of HCl conversion and the formation of Cl{sub 2} are consistent with published modeling results for SRM stratospheric afterburning. This formation of free chlorine could lead to catalytic destruction of ozone in regions near the path the launch vehicle follows during boost through the stratosphere.« less

Post-Detonation Energy Release from Tnt-Aluminum Explosives

NASA Astrophysics Data System (ADS)

Zhang, Fan; Anderson, John; Yoshinaka, Akio

2007-12-01

TNT and TNT-aluminum composites were experimentally studied in an air-filled 26 m3 chamber for charge masses ranging from 1.1 to 4 kg. Large aluminum mass fractions (35 to 50%wt.) and particle sizes (36 μm) were combined with TNT in two configurations, whereby the aluminum particles were uniformly mixed in cast TNT or arranged into a shell surrounding a cast TNT cylinder. The results show that improved performance is achieved for the shell configuration versus the mixed version during the early afterburning phase (10-40 ms), while both approach the same quasi-static explosion overpressure (QSP) after a long duration. The QSP ratios with respect to TNT in nitrogen are in good agreement with equilibrium predictions. Thus, the large aluminum mass fraction improves spatial mixing of hot fuels with oxidizing gases in the detonation products and chamber air, resulting in more efficient afterburning energy release.

Metabolite Differentiation and Discovery Lab (MeDDL): A New Tool for Biomarker Discovery and Mass Spectral Visualization

DTIC Science & Technology

2010-06-01

Jeremy Nicholson, Elaine Holmes , and John Lindon at the Imperial College in London1 utilizing nuclear magnetic resonance (NMR) based analysis, has...Lindon, J. C.; Holmes , E. Xenobiotica 1999, 29, 1181– 1189. (2) Pham-Tuan, H.; Kaskavelis, L.; Daykin, C.; Janssen, H. J. Chromatogr. B 2003, 789, 283...301. (3) Lindon, J.; Holmes , E.; Nicholson, J. Pharm. Res. 2006, 23, 1075–1088. (4) Robertson, D. Toxicol. Sci. 2005, 85, 809–822. (5) Nicholson, J

A Study on Application of Fuzzy Adaptive Unscented Kalman Filter to Nonlinear Turbojet Engine Control

NASA Astrophysics Data System (ADS)

Han, Dongju

2018-05-01

Safe and efficient flight powered by an aircraft turbojet engine relies on the performance of the engine controller preventing compressor surge with robustness from noises or disturbances. This paper proposes the effective nonlinear controller associated with the nonlinear filter for the real turbojet engine with highly nonlinear dynamics. For the feasible controller study the nonlinearity of the engine dynamics was investigated by comparing the step responses from the linearized model with the original nonlinear dynamics. The fuzzy-based PID control logic is introduced to control the engine efficiently and FAUKF is applied for robustness from noises. The simulation results prove the effectiveness of FAUKF applied to the proposed controller such that the control performances are superior over the conventional controller and the filer performance using FAUKF indicates the satisfactory results such as clearing the defects by reducing the distortions without compressor surge, whereas the conventional UKF is not fully effective as occurring some distortions with compressor surge due to a process noise.

Preliminary Transient Performance Data on the J73 Turbojet Engine. 3; Altitude, 45,000 Feet

NASA Technical Reports Server (NTRS)

McAulay, John E.; Wallner, Lewis E.

1953-01-01

A program was undertaken to determine the J73 turbojet engine compressor stall and surge characteristics and combustor blow-out limits enc ountered during transient engine operation. Data were obtained in the form of oscillograph traces showing the time history of several engi ne parameters with changes in engine fuel flow. The data presented in this report are for step and ramp changes in fuel flow at an altitude of 45,000 feet and flight Mach numbers of 0 and 0.8.

Performance Charts for the Turbojet Engine

NASA Technical Reports Server (NTRS)

Pinkel, Benjamin; Karp, Irving M.

1947-01-01

Charts are presented for computing the thrust, fuel consumption, and other performance values of a turbojet engine for any given set of operating conditions and component efficiencies. The effects of the pressure losses in the inlet duct and combustion chamber, the variation in the physical properties of the gas as it passes through the cycle, and the change in mass flow by the addition of fuel are included. The principle performance charts show the effects of the primary variables and correction charts provide the effects of the secondary variables.

A simplified gross thrust computing technique for an afterburning turbofan engine

NASA Technical Reports Server (NTRS)

Hamer, M. J.; Kurtenbach, F. J.

1978-01-01

A simplified gross thrust computing technique extended to the F100-PW-100 afterburning turbofan engine is described. The technique uses measured total and static pressures in the engine tailpipe and ambient static pressure to compute gross thrust. Empirically evaluated calibration factors account for three-dimensional effects, the effects of friction and mass transfer, and the effects of simplifying assumptions for solving the equations. Instrumentation requirements and the sensitivity of computed thrust to transducer errors are presented. NASA altitude facility tests on F100 engines (computed thrust versus measured thrust) are presented, and calibration factors obtained on one engine are shown to be applicable to the second engine by comparing the computed gross thrust. It is concluded that this thrust method is potentially suitable for flight test application and engine maintenance on production engines with a minimum amount of instrumentation.

Solid Propellant Reclamation Study

DTIC Science & Technology

1982-11-01

8217 Jovember 1982 > D J J Authors: M. P. Coover L. W. Poulter Thiokol Corporation Wasatch Division P. O. Box 524 Brigham City, Utah 84202 TWR-31084...William R. and Thun, Wayne E.. . 12 2.1.1.2 Mclntosh, M. J. et al 20 1.3 Sinclair, J. E. et al 27 1.4 Tomna, A. S 28 1.5 Tompa, A. S., French, D . M...Technology 81 2 Nitrate Ester Extraction Process 85 3 Nitramine/Inorganic Oxidizer Extraction Process 96 4 Process Definition 103 5 Process Model 108

An Intelligent Tool for the Design of Presentations: A System Identification Study

DTIC Science & Technology

1989-10-01

translated by W. J . Berg), University of Wisconson Press: Madison,WI, 1983. Betts, W., Burlingame, D ., Fischer, G., Foley, j ., Green, M., Kasik, D ., Kerr, S...T., Olsen, D ., and J . Thomas, "Goals and Objectives for User Interface Software." Computer Graphics, Vol. 21, No. 2, 1987, pp.73-78. 89 - . I - i 1...85 Conference on Artificial Intelligence, Warwick UK, April 1985. Buchanan, B., Barstow, D ., Betchtel, R., Bennett, J ., Clancey, W., Kulikowski, C

Afterburning control of internal combustion engine exhaust gas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakajima, Y.; Hayashi, Y.; Nagumo, S.I.

1976-08-17

Flow of secondary air into the exhaust system is regulated by diaphragm assembly controlled valves between an air supply and the exhaust system. The diaphragm assemblies respond to vacuum in the intake air system of the engine.

Parametric studies with an atmospheric diffusion model that assesses toxic fuel hazards due to the ground clouds generated by rocket launches

NASA Technical Reports Server (NTRS)

Stewart, R. B.; Grose, W. L.

1975-01-01

Parametric studies were made with a multilayer atmospheric diffusion model to place quantitative limits on the uncertainty of predicting ground-level toxic rocket-fuel concentrations. Exhaust distributions in the ground cloud, cloud stabilized geometry, atmospheric coefficients, the effects of exhaust plume afterburning of carbon monoxide CO, assumed surface mixing-layer division in the model, and model sensitivity to different meteorological regimes were studied. Large-scale differences in ground-level predictions are quantitatively described. Cloud alongwind growth for several meteorological conditions is shown to be in error because of incorrect application of previous diffusion theory. In addition, rocket-plume calculations indicate that almost all of the rocket-motor carbon monoxide is afterburned to carbon dioxide CO2, thus reducing toxic hazards due to CO. The afterburning is also shown to have a significant effect on cloud stabilization height and on ground-level concentrations of exhaust products.

Bullets with Names: The Deadly Dilemma

DTIC Science & Technology

1992-06-01

become dysfuctiona aoi requires reevahmir. w. iSTiuRtlNAVAEU MMMMr O A N5RL 21 ADSTMACrSnLSWC1O X uNCLAssiFIE~tm NumnrID j ] SAMEAs %’r. El uncuswa...Deter? ......................... 85 D. CONCL) J USIONS ......... ........................... 87 V. ASSASSINATION, REALPOLITIK" AND THE DEMOCRATIC IDEAL...Presideg s’ Serret Wars (New York: William Morrow and Company, Inc., 1986). 34-9. ’See George J . Church, ’ýGoing to the Source," Ijj 28 April 1986, 17

Magnetotransport in Two Dimensional Electron Systems Under Microwave Excitation and in Highly Oriented Pyrolytic Graphite

DTIC Science & Technology

2012-01-01

Phys. Rev. Lett. 82, 2147 (1999). [89] Y. Zhang, Y. Tan, H. L. Stormer and P. Kim, Nature 438, 10 (2005). [90] J. W. McClure, Phys. Rev. 108, 612 (1957...Phys. 2, 595 (2006). [97] H. L. Stormer , J. P. Eisenstein, A. C. Gossard, W. Wiegmann, and K. Baldwin, Phys. Rev. Lett. 56, 85 (1985). [98] B. A...Sadowski, J. M. Schneider, and M. Potemski, J. Phys.: Cond. Matter 20, 454223 (2008). [108] W. Pan, J. S. Xia, H. L. Stormer , D. C. Tsui, C. L

Dynamic Ring-on-Ring Equibiaxial Flexural Strength of Borosilicate Glass

DTIC Science & Technology

2010-01-01

Flexure Strength and Dynamic Fatigue of Soda – Lime – Silica Float Glass ,’’ J. Am. Ceram. Soc., 85 [7] 1777–1782 (2002). 9. A. Borger, R. Danzer, and P...on the Strength and Fatigue Behavior of Indented Soda – Lime Glass ,’’ Glass Technol., 32 [2] 51– 54 (1991). 16. J. J. Jr. Mecholsky, S. W. Freiman, and... Soda – Lime Glass Rods by a Statistical Approach,’’ J. Eur. Ceram. Soc., 11 341–346 (1993). 28. S. R. Choi and J. A. Salem, ‘‘Ultra-fast Fracture

Annular MHD Physics for Turbojet Energy Bypass

NASA Technical Reports Server (NTRS)

Schneider, Steven J.

2011-01-01

The use of annular Hall type MHD generator/accelerator ducts for turbojet energy bypass is evaluated assuming weakly ionized flows obtained from pulsed nanosecond discharges. The equations for a 1-D, axisymmetric MHD generator/accelerator are derived and numerically integrated to determine the generator/accelerator performance characteristics. The concept offers a shockless means of interacting with high speed inlet flows and potentially offers variable inlet geometry performance without the complexity of moving parts simply by varying the generator loading parameter. The cycle analysis conducted iteratively with a spike inlet and turbojet flying at M = 7 at 30 km altitude is estimated to have a positive thrust per unit mass flow of 185 N-s/kg. The turbojet allowable combustor temperature is set at an aggressive 2200 deg K. The annular MHD Hall generator/accelerator is L = 3 m in length with a B(sub r) = 5 Tesla magnetic field and a conductivity of sigma = 5 mho/m for the generator and sigma= 1.0 mho/m for the accelerator. The calculated isentropic efficiency for the generator is eta(sub sg) = 84 percent at an enthalpy extraction ratio, eta(sub Ng) = 0.63. The calculated isentropic efficiency for the accelerator is eta(sub sa) = 81 percent at an enthalpy addition ratio, eta(sub Na) = 0.62. An assessment of the ionization fraction necessary to achieve a conductivity of sigma = 1.0 mho/m is n(sub e)/n = 1.90 X 10(exp -6), and for sigma = 5.0 mho/m is n(sub e)/n = 9.52 X 10(exp -6).

DYNGEN: A program for calculating steady-state and transient performance of turbojet and turbofan engines

NASA Technical Reports Server (NTRS)

Sellers, J. F.; Daniele, C. J.

1975-01-01

The DYNGEN, a digital computer program for analyzing the steady state and transient performance of turbojet and turbofan engines, is described. The DYNGEN is based on earlier computer codes (SMOTE, GENENG, and GENENG 2) which are capable of calculating the steady state performance of turbojet and turbofan engines at design and off-design operating conditions. The DYNGEN has the combined capabilities of GENENG and GENENG 2 for calculating steady state performance; to these the further capability for calculating transient performance was added. The DYNGEN can be used to analyze one- and two-spool turbojet engines or two- and three-spool turbofan engines without modification to the basic program. A modified Euler method is used by DYNGEN to solve the differential equations which model the dynamics of the engine. This new method frees the programmer from having to minimize the number of equations which require iterative solution. As a result, some of the approximations normally used in transient engine simulations can be eliminated. This tends to produce better agreement when answers are compared with those from purely steady state simulations. The modified Euler method also permits the user to specify large time steps (about 0.10 sec) to be used in the solution of the differential equations. This saves computer execution time when long transients are run. Examples of the use of the program are included, and program results are compared with those from an existing hybrid-computer simulation of a two-spool turbofan.

Census of U.S. Civil Aircraft for Calendar Year 1983.

DTIC Science & Technology

1983-12-31

8217JR r~0 b W ~ .- 4b im~ (’ jb C, .t b 𔄁 j% 𔃾t m0 * -apt4 Uco~ -W(4(.et uO cy(’ (’- 0 0 0 ’-V ’) Wg ’ .4a 0LOc0,).444 O ) 0 % - r-o 0’U ko 4t 0 0 0s...61 1 0 1 1 JONESIE 4248 1 64 2 0 1 1 ROTOR REC ENGINE 61 0 1 1 ROTOR TURBOJET 84 0 1 1 TOTAL 0 2 2 KAMAN H-43A 2 61 1 0 2 2 H-43B 2 61 1 0 2 2 HH -43F...1 ’ORMER 1 41 1 0 1 1 :UDA 2 41 1 0 15 15 ’UDA300 2 41 10 1 1 "T SKYBOLT 2 41 1 0 1 1 "SKYDTE 1 41 1 0 1 1 JB MK REPLICA 1 41 1 0 1 1 I-HEATH 1 41 1

Engine environmental effects on composite behavior

NASA Technical Reports Server (NTRS)

Chamis, C. C.; Smith, G. T.

1980-01-01

A series of programs were conducted to investigate and develop the application of composite materials to turbojet engines. A significant part of that effort was directed to establishing the impact resistance and defect growth chracteristics of composite materials over the wide range of environmental conditions found in commercial turbojet engine operations. Both analytical and empirical efforts were involved. The experimental programs and the analytical methodology development as well as an evaluation program for the use of composite materials as fan exit guide vanes are summarized.

Effect of Fuel on Performance of a Single Combustor of an I-16 Turbojet Engine at Simulated Altitude Conditions

NASA Technical Reports Server (NTRS)

Zettle, Eugene V; Bolz, Ray E; Dittrich, R T

1947-01-01

As part of a study of the effects of fuel composition on the combustor performance of a turbojet engine, an investigation was made in a single I-16 combustor with the standard I-16 injection nozzle, supplied by the engine manufacturer, at simulated altitude conditions. The 10 fuels investigated included hydrocarbons of the paraffin olefin, naphthene, and aromatic classes having a boiling range from 113 degrees to 655 degrees F. They were hot-acid octane, diisobutylene, methylcyclohexane, benzene, xylene, 62-octane gasoline, kerosene, solvent 2, and Diesel fuel oil. The fuels were tested at combustor conditions simulating I-16 turbojet operation at an altitude of 45,000 feet and at a rotor speed of 12,200 rpm. At these conditions the combustor-inlet air temperature, static pressure, and velocity were 60 degrees F., 12.3 inches of mercury absolute, and 112 feet per second respectively, and were held approximately constant for the investigation. The reproducibility of the data is shown by check runs taken each day during the investigation. The combustion in the exhaust elbow was visually observed for each fuel investigated.

Optimum flight paths of turbojet aircraft

NASA Technical Reports Server (NTRS)

Miele, Angelo

1955-01-01

The climb of turbojet aircraft is analyzed and discussed including the accelerations. Three particular flight performances are examined: minimum time of climb, climb with minimum fuel consumption, and steepest climb. The theoretical results obtained from a previous study are put in a form that is suitable for application on the following simplifying assumptions: the Mach number is considered an independent variable instead of the velocity; the variations of the airplane mass due to fuel consumption are disregarded; the airplane polar is assumed to be parabolic; the path curvatures and the squares of the path angles are disregarded in the projection of the equation of motion on the normal to the path; lastly, an ideal turbojet with performance independent of the velocity is involved. The optimum Mach number for each flight condition is obtained from the solution of a sixth order equation in which the coefficients are functions of two fundamental parameters: the ratio of minimum drag in level flight to the thrust and the Mach number which represents the flight at constant altitude and maximum lift-drag ratio.

Small, low-cost, expendable turbojet engine. 1: Design, fabrication, and preliminary testing

NASA Technical Reports Server (NTRS)

Dengler, R. P.; Macioce, L. E.

1976-01-01

A small experimental axial-flow turbojet engine in the 2,669-Newton (600-lbf) thrust class was designed, fabricated, and tested to demonstrate the feasibility of several low-cost concepts. Design simplicity was stressed in order to reduce the number of components and machining operations. Four engines were built and tested for a total of 157 hours. Engine testing was conducted at both sea-level static and simulated flight conditions for engine speeds as high as 38,000 rpm and turbine-inlet temperatures as high as 1,255 K (1,800 F).

Perioperative Clinical Nurse Specialist Role Delineation: A Systematic Review

DTIC Science & Technology

2006-06-01

care plans for psychosocial nursing diagnoses. Ostomy Wound Manage, 40(3), 18-22, 24-16. Heath, J., Andrews, J., & Balkstra, C. R. Potential reduction...the clinical nurse specialist. Clin Nurse Spec, 17(2), 83-85. O’Malley, P. (2004). New hope for patients with pulmonary hypertension: endothelin

Atomic Tailoring of the Solid State Materials for Laser Cryogenic Coolers

DTIC Science & Technology

2010-04-01

Opt. 24, 1041 (1999) [15] C. W. Hoyt, M. Sheik- Bahae , R. I . Epstein, B. C. Edwards, and J. E. Anderson, Phys. Rev. Lett. 85, 3600 (2000) [16] J...21] M. Sheik- Bahae and R. I . Epstein, Nature Photonics, 1, 693 (2007) [22] M. Sheik- Bahae (Private Communications) [23] J. Fernandez, A. J...introduced and initiated by the Air Force Office of Scientific Research. It was made possible by a grant from them. I greatly appreciate their

Biohazard Detoxification Method Utilizing Magnetic Particles

DTIC Science & Technology

2007-05-01

configurations (noted by the yellow in the flow tube region). These data highlight the importance of the magnetic field gradient in particle capture...Weyhers, F. Specht , J.S. Lucks, Int. J. Pharm. 138(1996) 85. [9] Z.L. Liu, Z.H. Ding, K.L. Yao, J. Magn. Magn. Mater. 265(2003) 98. [10] P.A. Dresco

CFD Study of Turbo-Ramjet Interactions in Hypersonic Airbreathing Propulsion System

NASA Technical Reports Server (NTRS)

Chang, Ing; Hunter, Louis G.

1996-01-01

Advanced airbreathing propulsion systems used in Mach 4-6 mission scenarios, usually involve turbo-ramjet configurations. As the engines transition from turbojet to ramjet, there is an operational envelope where both engines operate simultaneously. In the first phase of our study, an over/under nozzle configuration was analyzed. The two plumes from the turbojet and ramjet interact at the end of a common 2-D cowl, where they both reach an approximate Mach 3.0 condition and then jointly expand to Mach 3.6 at the common nozzle exit plane. For the problem analyzed, the turbojet engine operates at a higher nozzle pressure ratio than the ramjet, causes the turbojet plume overpowers the ramjet plume, deflecting it approximately 12 degrees downward and in turn the turbojet plume is deflected 6 degrees upward. In the process, shocks were formed at the deflections and a shear layer formed at the confluence of the two jets. This particular case was experimentally tested and the data were used to compare with a computational fluid dynamics (CFD) study using the PARC2D code. The CFD results were in good agreement with both static pressure distributions on the cowl separator and on nozzle walls. The thrust coefficients were also in reasonable agreement. In addition, inviscid relationships were developed around the confluence point, where the two exhaust jets meet, and these results compared favorably with the CFD results. In the second phase of our study, a 3-D CFD solution was generated to compare with the 2-D solution. The major difference between the 2-D and 3-D solutions was the interaction of the shock waves, generated by the plume interactions, on the sidewall. When a shock wave interacts with a sidewall and sidewall boundary layer, it is called a glancing shock sidewall interaction. These interactions entrain boundary layer flow down the shockline into a vortical flow pattern. The 3-D plots show the streamlines being entrained down the shockline. The pressure of the flow also decreases slightly as the sidewall is approached. Other difference between the 2-D and 3-D solutions were a lowering of the nozzle thrust coefficient value from 0.9850 (2-D) to 0.9807 (3-D), where the experimental value was 0.9790. In the third phase of our study, a different turbo-ramjet configuration was analyzed. The confluence of a supersonic turbojet and a subsonic ramjet in the turbine based combined-cycle (TBCC) propulsion system was studied by a 2-D CFD code. In the analysis, Mach 1.4 primary turbojet was mixed with the subsonic ramjet secondary flow in an ejector mode operation. Reasonable agreements were obtained with the supplied I-D TBCC solutions. For low downstream backpressure, the Fabri choke condition (Break-Point condition) was observed in the secondary flow within mixing zone. For sufficient high downstream backpressure, the Fabri choke no longer exist, the ramjet flow was reduced and the ejector flow became backpressure dependent. Highly non-uniform flow at ejector exit were observed, indicated that for smooth downstream combustion, the mixing of the two streams probably required some physical devices.

Study and Evaluation of Current and Future Aircraft Loaders

DTIC Science & Technology

1986-08-01

Tigers Airlines JFK Airport , NY 10 Feb 86 Boeing Military Airplane Co. Boeing Commercial Airplane Co. Seattle, WA 11 Feb 86 Korean Airlines LAX, CA 12...Nash Boeing Aircraft Co., Seattle, WA Mr. J. Nelson JFK Airport , NY Mr. P. O’Brien ASD/ENCA Wright-Patterson AFB, OH Mr. C. Outran HQ AFLC/DSTMA...Locations 15 Oct 85 TWA Freight Terminal Laimbert Int’l Airport , St. Louis, mO 22 Nov 85 Lockheed - Georgia Aircraft Co. Marietta, GA 13 Dec 85 Flying

Prediction of the production of nitrogen oxide (NOx) in turbojet engines

NASA Astrophysics Data System (ADS)

Tsague, Louis; Tsogo, Joseph; Tatietse, Thomas Tamo

Gaseous nitrogen oxides (NO+NO2=NOx) are known as atmospheric trace constituent. These gases remain a big concern despite the advances in low NOx emission technology because they play a critical role in regulating the oxidization capacity of the atmosphere according to Crutzen [1995. My life with O 3, NO x and other YZO x S; Nobel Lecture; Chemistry 1995; pp 195; December 8, 1995] . Aircraft emissions of nitrogen oxides ( NOx) are regulated by the International Civil Aviation Organization. The prediction of NOx emission in turbojet engines by combining combustion operational data produced information showing correlation between the analytical and empirical results. There is close similarity between the calculated emission index and experimental data. The correlation shows improved accuracy when the 2124 experimental data from 11 gas turbine engines are evaluated than a previous semi empirical correlation approach proposed by Pearce et al. [1993. The prediction of thermal NOx in gas turbine exhausts. Eleventh International Symposium on Air Breathing Engines, Tokyo, 1993, pp. 6-9]. The new method we propose predict the production of NOx with far more improved accuracy than previous methods. Since a turbojet engine works in an atmosphere where temperature, pressure and humidity change frequently, a correction factor is developed with standard atmospheric laws and some correlations taken from scientific literature [Swartwelder, M., 2000. Aerospace engineering 410 Term Project performance analysis, November 17, 2000, pp. 2-5; Reed, J.A. Java Gas Turbine Simulator Documentation. pp. 4-5]. The new correction factor is validated with experimental observations from 19 turbojet engines cruising at altitudes of 9 and 13 km given in the ICAO repertory [Middleton, D., 1992. Appendix K (FAA/SETA). Section 1: Boeing Method Two Indices, 1992, pp. 2-3]. This correction factor will enable the prediction of cruise NOx emissions of turbojet engines at cruising speeds. The ICAO database [Goehlich, R.A., 2000. Investigation into the applicability of pollutant emission models for computer aided preliminary aircraft design, Book number 175654, 4.2.2000, pp. 57-79] can now be completed using the approach we propose to complete the whole mission flight NOx emissions.

J-2 Engine ready to go into test stand

NASA Technical Reports Server (NTRS)

1965-01-01

Two technicians watch carefully as cables prepare to lift a J-2 engine into a test stand. The J-2 powered the second stage and the third stage of the Saturn V moon rocket. The towering 363-foot Saturn V was a multi-stage, multi-engine launch vehicle standing taller than the Statue of Liberty. Altogether, the Saturn V engines produced as much power as 85 Hoover Dams.

Performance potential of an advanced technology Mach 3 turbojet engine installed on a conceptual high-speed civil transport

NASA Technical Reports Server (NTRS)

Morris, Shelby J., Jr.; Geiselhart, Karl A.; Coen, Peter G.

1989-01-01

The performance of an advanced technology conceptual turbojet optimized for a high-speed civil aircraft is presented. This information represents an estimate of performance of a Mach 3 Brayton (gas turbine) cycle engine optimized for minimum fuel burned at supersonic cruise. This conceptual engine had no noise or environmental constraints imposed upon it. The purpose of this data is to define an upper boundary on the propulsion performance for a conceptual commercial Mach 3 transport design. A comparison is presented demonstrating the impact of the technology proposed for this conceptual engine on the weight and other characteristics of a proposed high-speed civil transport. This comparison indicates that the advanced technology turbojet described could reduce the gross weight of a hypothetical Mach 3 high-speed civil transport design from about 714,000 pounds to about 545,000 pounds. The aircraft with the baseline engine and the aircraft with the advanced technology engine are described.

Experience with integrally-cast compressor and turbine components for a small, low-cost, expendable-type turbojet engine

NASA Technical Reports Server (NTRS)

Dengler, R. P.

1975-01-01

Experiences with integrally-cast compressor and turbine components during fabrication and testing of four engine assemblies of a small (29 cm (11 1/2 in.) maximum diameter) experimental turbojet engine design for an expendable application are discussed. Various operations such as metal removal, welding, and re-shaping of these components were performed in preparation of full-scale engine tests. Engines with these components were operated for a total of 157 hours at engine speeds as high as 38,000 rpm and at turbine inlet temperatures as high as 1256 K (1800 F).

Performance of 4600-pound-thrust centrifugal-flow-type turbojet engine with water-alcohol injection at inlet

NASA Technical Reports Server (NTRS)

Glasser, Philip W

1950-01-01

An experimental investigation of the effects of injecting a water-alcohol mixture of 2:1 at the compressor inlet of a centrifugal-flow type turbojet engine was conducted in an altitude test chamber at static sea-level conditions and at an altitude of 20,000 feet with a flight Mach number of 0.78 with an engine operating at rated speed. The net thrust was augmented by 0.16 for both flight conditions with a ratio of injected liquid to air flow of 0.05. Further increases in the liquid-air ratio did not give comparable increases in thrust.

Operational procedure for computer program for design point characteristics of a gas generator or a turbojet lift engine for V/STOL applications

NASA Technical Reports Server (NTRS)

Krebs, R. P.

1972-01-01

The computer program described calculates the design-point characteristics of a gas generator or a turbojet lift engine for V/STOL applications. The program computes the dimensions and mass, as well as the thermodynamic performance of the model engine and its components. The program was written in FORTRAN 4 language. Provision has been made so that the program accepts input values in either SI Units or U.S. Customary Units. Each engine design-point calculation requires less than 0.5 second of 7094 computer time.

Internal performance of a hybrid axisymmetric/nonaxisymmetric convergent-divergent nozzle

NASA Technical Reports Server (NTRS)

Taylor, John G.

1991-01-01

An investigation was conducted in the static test facility of the Langley 16-foot transonic tunnel to determine the internal performance of a hybrid axisymmetric/nonaxisymmetric nozzle in forward-thrust mode. Nozzle cross-sections in the spherical convergent section were axisymmetric whereas cross-sections in the divergent flap area nonaxisymmetric (two-dimensional). Nozzle concepts simulating dry and afterburning power settings were investigated. Both subsonic cruise and supersonic cruise expansion ratios were tested for the dry power nozzle concepts. Afterburning power configurations were tested at an expansion ratio typical for subsonic acceleration. The spherical convergent flaps were designed in such a way that the transition from axisymmetric to nonaxisymmetric cross-section occurred in the region of the nozzle throat. Three different nozzle throat geometries were tested for each nozzle power setting. High-pressure air was used to simulate jet exhaust at nozzle pressure ratios up to 12.0.

Delta Clipper-Experimental In-Ground Effect on Base-Heating Environment

NASA Technical Reports Server (NTRS)

Wang, Ten-See

1998-01-01

A quasitransient in-ground effect method is developed to study the effect of vertical landing on a launch vehicle base-heating environment. This computational methodology is based on a three-dimensional, pressure-based, viscous flow, chemically reacting, computational fluid dynamics formulation. Important in-ground base-flow physics such as the fountain-jet formation, plume growth, air entrainment, and plume afterburning are captured with the present methodology. Convective and radiative base-heat fluxes are computed for comparison with those of a flight test. The influence of the laminar Prandtl number on the convective heat flux is included in this study. A radiative direction-dependency test is conducted using both the discrete ordinate and finite volume methods. Treatment of the plume afterburning is found to be very important for accurate prediction of the base-heat fluxes. Convective and radiative base-heat fluxes predicted by the model using a finite rate chemistry option compared reasonably well with flight-test data.

Mechanism(s) of Electricity Production by Shewanella and other Microbes: Understanding and Optimization

DTIC Science & Technology

2013-08-23

oxidation of propionate in a microbial fuel cell. Biotechnol. Lett. 32:79-85 32. Kan, J. B. Flood, J.P. McCrow, J.S. Kim, L. Tan , and K.H. Nealson. 2011...Y., A. Obraztsova, G. Rosen, J. Leather , K.G. Scheckel, K.H. Nealson, and Y.M. Arias-Thode. 2011. Marine microbial community response to inorganic

Investigation of Altitude Starting and Acceleration Characteristics of J47 Turbojet Engine

NASA Technical Reports Server (NTRS)

Golladay, Richard L; Bloomer, Harry E

1951-01-01

An investigation was conducted on an axial-flow-compressor type turbojet engine in the NACA Lewis altitude wind tunnel to determine the operational characteristics of several ignition systems, cross-fire tube configurations and fuel systems over a range of simulated flight conditions. The opposite-polarity-type spark plug provided the most satisfactory ignition. Increasing the cross-fire-tube diameter improved intercombustor flame propagation. At high windmilling speeds, accelerations to approximately 6200 rpm could be made at a preset constant throttle position. The use of a variable-area nozzle reduced acceleration time.

Results of turbojet engine operation tests using a 50-50 mixture of JP-4 and tributyl borate as the fuel

NASA Technical Reports Server (NTRS)

Schafer, Louis J , Jr; Stepka, Francis S

1957-01-01

An experimental investigation was conducted on a centrifugal-type turbojet engine using a 50-50 mixture of tributyl borate and JP-4 as the fuel to determine the magnitude and the location of the boric oxide deposits in the engine as well as the effect of these deposits on the engine performance. Large deposits of boric acid formed in the combustor walls and on the turbine rotor and stator blades. The deposits had no effect on the engine thrust.

Performance Charts for a Turbojet System

NASA Technical Reports Server (NTRS)

Karp, Irving M.

1947-01-01

Convenient charts are presented for computing the thrust, fuel consumption, and other performance values of a turbojet system. These charts take into account the effects of ram pressure, compressor pressure ratio, ratio of combustion-chamber-outlet temperature to atmospheric temperature, compressor efficiency, turbine efficiency, combustion efficiency, discharge-nozzle coefficient, losses in total pressure in the inlet to the jet-propulsion unit and in the combustion chamber, and variation in specific heats with temperature. The principal performance charts show clearly the effects of the primary variables and correction charts provide the effects of the secondary variables. The performance of illustrative cases of turbojet systems is given. It is shown that maximum thrust per unit mass rate of air flow occurs at a lower compressor pressure ratio than minimum specific fuel consumption. The thrust per unit mass rate of air flow increases as the combustion-chamber discharge temperature increases. For minimum specific fuel consumption, however, an optimum combustion-chamber discharge temperature exists, which in some cases may be less than the limiting temperature imposed by the strength temperature characteristics of present materials.

Ocean Drilling Program: Completed Legs

Science.gov Websites

. Austin Leg summary Repository Wolfgang Schlager 102 14-Mar-85 25-Apr-85 Miami, Florida 418 Bermuda Rise Lisbon, Portugal 902-906 New Jersey Sea-Level Transect Peter Blum Gregory Mountain Leg summary Repository , Nova Scotia 1071-1073 Continuing the New Jersey Sea-Level Transect Mitchell J. Malone James A. Austin

Anti-Cyanide Drugs

DTIC Science & Technology

1988-05-01

Fort Detrick, Frederick, Maryland 21701-S012 * Contract No. DAMD7-85-C-5OS6 Department of Chemistry Howard University Washington, D. C. 20059 ED TIC...REPORT NUMBER(S) 68. NAME OF PERFORMING ORGANIZATION 6b. OFFICE SYMBOL 7a. NAME OF MONITORING ORGANIZATION Howard University (If appicabie) Department...pr&i Contract No. DAMD17-85-C-5086 D TAB J’utificat Ion - Department of Chemistry Howard University Washington, D. C. 20059 By.Dlstribution

Odor intensity and characterization studies of exhaust from a turbojet engine combustor

NASA Technical Reports Server (NTRS)

Butze, H. F.; Kendall, D. A.

1973-01-01

Sensory odor tests of the exhaust from a turbojet combustor operating at simulated idle conditions were made by a human panel sniffing diluted exhaust gas. Simultaneously, samples of undiluted exhaust gas were collected on adsorbent substrates, subsequently removed by solvent flushing, and analyzed chemically by liquid chromatographic methods. The concentrations of the principal malodorous species, the aromatic (unburned fuel-related) and the oxygenated (partially burned fuel) fractions, as determined chromatographically, correlated well with the intensity of the odor as determined by sniffing. Odor intensity increased as combustion efficiency decreased. Combustor modifications which increased combustion efficiency decreased odor intensity.

Minimum fuel trajectory for the aerospace-plane

NASA Technical Reports Server (NTRS)

Breakwell, John V.; Golan, Oded; Sauvageot, Anne

1990-01-01

An overall trajectory for a single-stage-to-orbit vehicle with an initial weight of 234 tons is calculated, and four different propulsion models including turbojet, ramjet, scramjet, and rocket are considered. First, the atmospheric flight in the thicker atmosphere is discussed with emphasis on trajectory optimization, optimization problem, aerodynamic problem, propulsion model, and initial conditions. The performance of turbojet and ramjet-scramjet engines is analyzed; and then the flight to orbit is assessed from the optimization point of view. It is shown that roll modulation saves little during the trajectory, and the combined application of airbreathing propulsion and aerodynamic lift is suggested.

Investigation of Thrust Augmentation of a 1600-pound Thrust Centrifugal-flow-type Turbojet Engine by Injection of Refrigerants at Compressor Inlets

NASA Technical Reports Server (NTRS)

Jones, William L.; Dowman, Harry W.

1947-01-01

Investigations were conducted to determine effectiveness of refrigerants in increasing thrust of turbojet engines. Mixtures of water an alcohol were injected for a range of total flows up to 2.2 lb/sec. Kerosene was injected into inlets covering a range of injected flows up to approximately 30% of normal engine fuel flow. Injection of 2.0 lb/sec of water alone produced an increase in thrust of 35.8% of rate engine conditions and kerosene produced a negligible increase in thrust. Carbon dioxide increased thrust 23.5 percent.

Flow Measurements Using Particle Image Velocimetry in the Ultra Compact Combustor

DTIC Science & Technology

2009-12-01

addition effectively increases the flow velocity resulting in increased thrust. The afterburning cycle is much less efficient than the Brayton cycle used...31. Rekab, K., & Shaikh, M., Statistical Design of Experiments with Engineering Applications, Florida: CRC Press, Taylor & Francis Group, 2005

Military Forces in Urban Antiterrorism

DTIC Science & Technology

1989-10-01

not constitule an official eodorýemtnt oi apprcvai of the use of’ s3ch commercial products. UNCLASSIFIED ýEUAITY CLAS .’A71ON; 01 - ~’PAGE J FIorm...Continue on reverse if necessary and identify by block number) ýIFLD GROUP SU1R- AU P urban wlrfare; MOUT, 15 6 ____ ,.rban terrorism LIC J terrorism (see...onclusions and address-ez their impl ic~ati ons for U.S. military forces in future urban aril itrror int operat2.on:?.k 20DiSTRiBUITION /AVAILABILTY OF j .,85

Recognizing 3 D Objects from 2D Images Using Structural Knowledge Base of Genetic Views

DTIC Science & Technology

1988-08-31

technical report. [BIE85] I. Biederman , "Human image understanding: Recent research and a theory", Computer Vision, Graphics, and Image Processing, vol...model bases", Technical Report 87-85, COINS Dept, University of Massachusetts, Amherst, MA 01003, August 1987 . [BUR87b) Burns, J. B. and L. J. Kitchen...34Recognition in 2D images of 3D objects from large model bases using prediction hierarchies", Proc. IJCAI-10, 1987 . [BUR891 J. B. Burns, forthcoming

Simulations of Heterogeneous Detonations and Post Detonation Turbulent Mixing and Afterburning

NASA Astrophysics Data System (ADS)

Menon, Suresh; Gottiparthi, Kalyana

2011-06-01

Most metal-loaded explosives and thermobaric explosives exploit the afterburning of metals to maintain pressure and temperature conditions.The use of such explosives in complex environment can result in post detonation flow containing many scales of vortical motion, flow jetting and shear, as well as plume-surface interactions due to flow impingement and wall flows. In general, all these interactions can lead to highly turbulent flow fields even if the initial ambient conditions were quiescent. Thus, turbulent mixing can dominate initial mixing and impact the final afterburn. We conduct three-dimensional numerical simulations of the propagation of detonation resulting from metal-loaded (inert or reacting) explosives and analyze the afterburn process as well as the generation of multiple scales of mixing in the post detonation flow field. Impact of the detonation and post-detonation flow field on solid surface is also considered for a variety of initial conditions. Comparison with available data is carried out to demonstrate validity of the simulation method. Supported by Defense Threat Reduction Agency

Apparatus for afterburning the exhaust gases of an internal combustion engine to remove pollutants therefrom

DOE Office of Scientific and Technical Information (OSTI.GOV)

Laurent, P.A.

1976-09-28

An apparatus is described for afterburning the combustible pollutants from the exhaust gases of an internal combustion engine in a reactor, in which secondary air is introduced. Upstream of the reactor, a chamber in the form of a torus is provided, through which the exhaust gases from a maximum number of cylinders flow before entering the reactor. A first obstacle, acting as a flame holder is disposed inside the torus. The reactor comprises a chamber whose inner surface is approximately a surface of revolution, and mounted inside of which is a second obstacle, acting as flame holder, substantially along themore » axis of revolution. The second flame holder has a diameter large enough to provide a contact time of 1 to 3 x 10/sup -3/ seconds of the gas flow in a recirculation zone surrounding the second flame holder, the diameter of the second flame holder being 15 to 40 percent of the reactor diameter.« less

Comparison of combustion characteristics of ASTM A-1, propane, and natural-gas fuels in an annular turbojet combustor

NASA Technical Reports Server (NTRS)

Wear, J. D.; Jones, R. E.

1973-01-01

The performance of an annular turbojet combustor using natural-gas fuel is compared with that obtained using ASTM A-1 and propane fuels. Propane gas was used to simulate operation with vaporized kerosene fuels. The results obtained at severe operating conditions and altitude relight conditions show that natural gas is inferior to both ASTM A-1 and propane fuels. Combustion efficiencies were significantly lower and combustor pressures for relight were higher with natural-gas fuel than with the other fuels. The inferior performance of natural gas is shown to be caused by the chemical stability of the methane molecule.

A First Cut at Doctrine for Automation of Division Command and Control.

DTIC Science & Technology

1985-12-02

34MSE: Mobile Subscriber Equipmentd," Arm-Y Communicator (Fall 1984), pp. 6-22. 20. Anthony L. Borelli and LTC Raymond J. Leopold, "Enhanced JTIDS: High...three, 1985. I’- pp. 85-8,. Berceau, CPT Stan. "ASAS." C2MUG Bulletin. September 1965, pp. 1-2. Borelli , Anthony L. and Leopold, LTC Raymond J

Reliable Real-time Calculation of Heart-rate Complexity in Critically Ill Patients Using Multiple Noisy Waveform Sources

DTIC Science & Technology

2014-01-01

systems Machine learning Automatic data processing 1 Introduction Heart-rate complexity (HRC) is a method of quantifying the amount of complex...5. Batchinsky AI, Skinner J, Necsoiu C, et al. New measures of heart-rate complexity: effect of chest trauma and hemorrhage. J Trauma. 2010;68:1178–85

Automated Design of a High-Velocity Channel

DTIC Science & Technology

2006-05-01

using Newton’s method. 2.2.2 Groundwater Applications Optimization methods are also very useful for solving groundwater problems. Townley et al... Townley 85] apply present computational algorithms to steady and transient models for groundwater °ow. The aquifer storage coe±cients, transmissivities...Reliability Analysis", Water Resources Research, Vol. 28, No. 12, December 1992, pp. 3269-3280. [ Townley 85] Townley , L. R. and Wilson, J. L

Process and apparatus for afterburning of combustible pollutants from an internal combustion engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Laurent, P.A.

1978-07-04

In a process for the afterburning of the combustible pollutants from an internal combustion engine, in order to automatically reduce the secondary induction rate when power increases without using a controlling valve actuatd by the carburetor venturi depression, there is provided a volumetric efficiency of the secondary air pump linked to and activated by the engine and a volumetric efficiency which decreases when the ratio between its back pressure and suction pressure increases, this reduction being achieved through the proper selection of the pump volumetric compression ratio r: between 0.6 c and 1.3 c when a steeply decreasing trend ismore » required, and above 1.3 c if a slower and slower decreasing trend is required. To perform this process an afterburner apparatus has a nitrogen oxide reducing catalyst placed inside the afterburner reactor on the gas stream immediately at the outlet of a torus, in which the gases are homogenized and their reaction with preinjection air is terminated.« less

Micro turbine engines for drones propulsion

NASA Astrophysics Data System (ADS)

Dutczak, J.

2016-09-01

Development of micro turbine engines began from attempts of application of that propulsion source by group of enthusiasts of aviation model making. Nowadays, the domain of micro turbojet engines is treated on a par with “full size” aviation constructions. The dynamic development of these engines is caused not only by aviation modellers, but also by use of micro turbojet engines by army to propulsion of contemporary drones, i.e. Unmanned Aerial Vehicles (UAV) or Unmanned Aerial Systems (UAS). On the base of selected examples the state of art in the mentioned group of engines has been presented in the article.

A Coherent Fused Silica Fiberoptic Array.

DTIC Science & Technology

1986-07-01

7 AD-R I? 09 3 COHERENT FUSED SILIC FIBEROPTIC ARR AY(U) O ALILED / ELECTRa-OPTICS CORP STURBRIDGE MR J E ROURKE ET AL. JUL 86 ORL-CR-557 DAAIKiS...7. AUTHOR(a) 6. CONTRACT OR GRANT NUMUER(a) J. Edward Rourke * Dean J. Geraci Mark L. DeLong DAAA15-85- C -Olll 9. PERFORMING ORGANIZATION NAME AND...3r.4 c Le o COL 0) * EE >0 a) LL 141 opposite end. A variation of light intensity vs. angular position was approximately Gaussian. The NA is

The Red Blood Cell Transfusion Trigger: Has the Sin of Commission Now Become a Sin of Omission?.

DTIC Science & Technology

1997-05-01

disease. N . Engl. J. Med. 1995;333:251-253. 85. Ignarro LJ, Buga GM, Wood KS, et al. Endothelium -derived relaxing factor produced and released from...George D, Loscalzo J. Inhibition of fibrinogen binding to human platelets by S-nitroso- N - acetylcysteine . J. Biol. Chem. 1990;265:19028-19034. 28 92...attributable primarily to shear stress-induced nitric oxide release from the endothelium , it would seem logical that transfusing red blood cells to the 30

Infrared-Terahertz Double-Resonance Spectroscopy of CH3F and CH3Cl at Atmospheric Pressure

DTIC Science & Technology

2012-05-16

coincidence with the RQ3(6) rovibrational transition in CH3 35Cl [Fig. 4(b)]. At atmospheric pressure, nine more P -, Q-, and R-branch rovibrational...the double-resonance signatures of all IR-THz pump-probe coincidences at atmospheric pressure for 12CH3F and CH3 35Cl 052507-11050-2947/2012/85(5...were calculated using the rotational constants listed in Tables I and II. For CH3F, the standard P - type (J = − 1), Q-type (J = 0), and R-type (J

Size Effects in Epitaxial Films of Magnetite

DTIC Science & Technology

2002-06-03

van Eemeren , J. aan de Stegge, 1727. WJ.M. de Jonge, Surf. Sci. 373 (1997) 85. [38] J.L. Dormann, T. Merceron, P. Renaudin, VA.M. Brabers, J. [20] S.A...Metals and Semiconductors, Trans Tech, Switzerland, 1994, p. __221. [4] G.A. Prinz, Phys. Today 48 (1995) 58. 100 - [5] P.J. van der Zaag. P.J.H...Bloemen. J.M. Gaines, R.M. Wolf, -10 -8 -6 -4 -2 0 2 4 6 8 10 P.A.A. van der Heijden, R.J.M. van de Veerdonk, W.J.M. velocity [mm/s] de Jonge, J. Magn. Magn

Summary of NACA Research on Afterburners for Turbojet Engines

NASA Technical Reports Server (NTRS)

Lundin, Bruce T; Gabriel, David S; Fleming, William A

1956-01-01

NACA research on afterburners for turbojet engines during the past 5 years is summarized. Although most of this work has been directed toward the development of specific afterburners for various engines rather than toward the accumulation of systematic data, it has, nevertheless, provided a large fund of experimental data and experience in the field. The references cited present over 1000 afterburner configurations and some 3500 hours of operation. In the treatment of the material of this summary, the principal effort has been to convey to the reader the "know-how" acquired by research engineers in the course of the work rather than to formulate a set of design rules.

Wind Tunnel Test of Mach 5 Class Hypersonic Airplane

NASA Astrophysics Data System (ADS)

Nakatani, Hiroki; Taguchi, Hideyuki; Fujita, Kazuhisa; Shindo, Shigemi; Honami, Shinji

JAXA is currently performing studies on a Hypersonic Turbojet Experimental Vehicle, which involve a hypersonic flight test of a Small Pre-cooled Turbojet Engine. The aerodynamic performance of this airplane was examined at the JAXA hypersonic, supersonic, and transonic wind tunnel facilities. The 6-degrees-of-freedom forces and pressure distribution around the model were measured and evaluated. This airplane satisfies the lift-to-drag ratio requirement for a flight test at Mach 5. In addition, the results indicate that this airplane has longitudinal and directional static stability if the moment reference point is x/l smaller than 0.35. A separation occurs at the external expanding nozzle. Therefore, a redesign is necessary to solve these problems.

Metabolic syndrome

MedlinePlus

... to or higher than 130/85 mm Hg Fasting blood sugar (glucose) equal to or higher than ... Dietetics: interventions for the treatment of overweight and obesity in adults. J Acad Nutr Diet . 2016;116( ...

Saturn Apollo Program

NASA Image and Video Library

1965-04-26

Two technicians watch carefully as cables prepare to lift a J-2 engine into a test stand. The J-2 powered the second stage and the third stage of the Saturn V moon rocket. The towering 363-foot Saturn V was a multi-stage, multi-engine launch vehicle standing taller than the Statue of Liberty. Altogether, the Saturn V engines produced as much power as 85 Hoover Dams.

Packaging of single DNA molecules by the yeast mitochondrial protein Abf2p: reinterpretation of recent single molecule experiments.

PubMed

Stigter, Dirk

2004-07-01

Brewer et al. (Biophys. J. 85 (2003) 2519-2524) have studied the compaction of dsDNA in a double flow cell by observing the extension of stained DNA tethered in buffer solutions with or without Abf2p. They use a Langmuir adsorption model in which one Abf2p molecule adsorbs on one site on the DNA, and the binding constant, K, is given as the ratio of the experimental rates of adsorption and desorption. This paper presents an improved interpretation. Instead of Langmuir adsorption we use the more appropriate McGhee-von Hippel (J. Mol. Biol. 86 (1974) 469-489) theory for the adsorption of large ligands to a one-dimensional lattice. We assume that each adsorbed molecule shortens the effective contour length of DNA by the foot print of Abf2p of 27 base pairs. When Abf2p adsorbs to DNA stretched in the flowing buffer solution, we account for a tension effect that decreases the adsorption rate and the binding constant by a factor of 2 to 4. The data suggest that the accessibility to Abf2p decreases significantly with increasing compaction of DNA, resulting in a lower adsorption rate and a lower binding constant. The kinetics reported by Brewer et al. (Biophys. J. 85 (2003) 2519-2524) lead to a binding constant K=3.6 x 10(6) M(-1) at the beginning, and to K=5 x 10(5) M(-1) near the end of a compaction run, more than an order of magnitude lower than the value K=2.57 x 10(7) M(-1) calculated by Brewer et al. (Biophys. J. 85 (2003) 2519-2524).

NASA Research Bearing on Jet Engine Reliability

NASA Technical Reports Server (NTRS)

Mason, S. S.; Ault, G. M.; Pinkel, B.

1959-01-01

Turbojet engine reliability has long been an intense interest to the military users of this type of aircraft propulsion. With the recent inauguration of commercial jet transport this subject has assumed a new dimension of importance. In January l96 the Lewis Research Center of the NASA (then the MACA) published the results of an extensive study on the factors that affect the opera- center dot tional reliability of turbojet engines (ref. 1). At that time the report was classified Confidential. In July l98 this report was declassified. It is thus appropriate at this time to present some of the highlights of the studies described in the NASA report. In no way is it intended to outline the complete contents of the report; rather it is hoped to direct attention to it among those who are center dot directly concerned with this problem. Since the publication of our study over three years ago, the NASA has completed a number of additional investigations that bear significantly on this center dot subject. A second object of this paper, therefore, is to summarize the results of these recent studies and to interpret their significance in relation to turbojet operational reliability.

Vertical Structure of Shadow Zone Arrivals: Comparison of Parabolic Equation Simulations and Acoustic Data

DTIC Science & Technology

2011-01-01

676 677 Travel Time (sec) 678 45 95 £ 85 ? 75 £ 65 3 55 *§ 85 75 65 55 85 75 65 55 45’— 673 dB re 1 uPa A :,. 1.. i b , u . k , AL...1. u * .1 t., J. .1. 674 675 676 677 Travel Time (sec) 678 673 674 675 676 677 Travel Time (sec) 678 Range...hydrophone data at the 3892 -meter depth (Figure 2(d)). A more quantitative measure of the vertical extension of the cusp is the energy profile of the cusp

Online Performance-Improvement Algorithms

DTIC Science & Technology

1994-08-01

fault rate as the request sequence length approaches infinity. Their algorithms are based on an innovative use of the classical Ziv - Lempel [85] data ...Report CS-TR-348-91. [85] J. Ziv and A. Lempel . Compression of individual sequences via variable-rate coding. IEEE Trans. Inf. Theory, 24:530-53`, 1978. 94...Deferred Data Structuring Recall that our incremental multi-trip algorithm spreads the building of the fence-tree over several trips in order to

Performance gains by using heated natural-gas fuel in an annular turbojet combustor

NASA Technical Reports Server (NTRS)

Marchionna, N. R.

1973-01-01

A full-scale annular turbojet combustor was tested with natural gas fuel heated from ambient temperature to 800 K (980 F). In all tests, heating the fuel improved combustion efficiency. Two sets of gaseous fuel nozzles were tested. Combustion instabilities occurred with one set of nozzles at two conditions: one where the efficiency approached 100 percent with the heated fuel; the other where the efficiency was very poor with the unheated fuel. The second set of nozzles exhibited no combustion instability. Altitude relight tests with the second set showed that relight was improved and was achievable at essentially the same condition as blowout when the fuel temperature was 800 K (980 F).

Radiant heat transfer from flames in a single tubular turbojet combustor / Leonard Topper

NASA Technical Reports Server (NTRS)

Topper, Leonard

1952-01-01

An experimental investigation of thermal radiation from the flame of a single tubular turbojet-engine combustor to the combustor liner is presented. The effects of combustor inlet-air pressure, air mass flow, and fuel-air ratio on the radiant intensity and the temperature and emissivity of the flame are reported. The total radiation of the "luminous" flames (containing incandescent soot particles) was much greater (4 to 21 times) than the "nonluminous" molecular radiation. The intensity of radiation from the flame increased rapidly with an increase in combustor inlet-air pressure; it was affected to a lesser degree by variations in fuel-air ratio and air mass flow.

Observation of Flame Stabilized at a Hydrogen-Turbojet-Engine Injector Installed into a Lab-Scale Combustion Wind Tunnel

NASA Astrophysics Data System (ADS)

Michishita, Kazutaka; Nomura, Hiroshi; Ujiie, Yasushige; Okai, Keiichi

A lab-scale combustion wind tunnel was developed for investigation of low-pressure ignition and flame holding in a sub-scale pre-cooled turbojet engine with hydrogen fuel in order to make engine start at high altitudes sure. The combustion wind tunnel is a blow-down type. A fuel injector of the sub-scale pre-cooled turbojet engine was installed into the combustion wind tunnel. Conditions in which a flame can be stabilized at the fuel injector were examined. The combustor pressure and equivalence ratio were varied from 10 to 40 kPa and from 0.4 to 0.8, respectively. The mean inlet air velocity was varied from 2 to 48 m/s. Flames stabilized at 20 kPa in pressure and 0.6 in equivalence ratio were observed. It was found that the decrease in the combustor pressure narrows the mean inlet air velocity range for successful flame holdings. Flame holding at lower combustor pressures is realized at the equivalence ratio of 0.4 in the low mean inlet air velocity range, and at the equivalence ratio of 0.6 in the high mean inlet air velocity range. Flame luminosity is the largest near the fuel injector. The flame luminosity distribution becomes flatter as the increase in the mean inlet air velocity.

Cylindrical Explosive Dispersal of Metal Particles: Predictive Calculations in SUpport of Experimental Trials

DTIC Science & Technology

2007-12-11

motivated by an experimental effort at the High Explosives R&D facility at Eglin AFB that aims to simulate dispersal and afterburning effects using dense...3] Ripley, R.C., Donahue, L., Dunbar, T.E., and Zhang, F., Explosion performance of aluminized TNT in a chamber, Proc. 19th Military Aspects of

Investigations of Air-cooled Turbine Rotors for Turbojet Engines II : Mechanical Design, Stress Analysis, and Burst Test of Modified J33 Split-disk Rotor / Richard H. Kemp and Merland L. Moseson

NASA Technical Reports Server (NTRS)

Kemp, Richard H; Moseson, Merland L

1952-01-01

A full-scale J33 air-cooled split turbine rotor was designed and spin-pit tested to destruction. Stress analysis and spin-pit results indicated that the rotor in a J33 turbojet engine, however, showed that the rear disk of the rotor operated at temperatures substantially higher than the forward disk. An extension of the stress analysis to include the temperature difference between the two disks indicated that engine modifications are required to permit operation of the two disks at more nearly the same temperature level.

Turbojet Performance and Operation at High Altitudes with Hydrogen and Jp-4 Fuels

NASA Technical Reports Server (NTRS)

Fleming, W A; Kaufman, H R; Harp, J L , Jr; Chelko, L J

1956-01-01

Two current turbojet engines were operated with gaseous-hydrogen and JP-4 fuels at very high altitudes and a simulated Mach number of 0.8. With gaseous hydrogen as the fuel stable operation was obtained at altitudes up to the facility limit of about 90,000 feet and the specific fuel consumption was only 40 percent of that with JP-4 fuel. With JP-4 as the fuel combustion was unstable at altitudes above 60,000 to 65,000 feet and blowout limits were reached at 75,000 to 80,000 feet. Over-all performance, component efficiencies, and operating range were reduced considerable at very high altitudes with both fuels.

Extended Operation of Turbojet Engine with Pentaborane

NASA Technical Reports Server (NTRS)

Useller, James W; Jones, William L

1957-01-01

A full-scale turbojet engine was operated with pentaborane fuel continuously for 22 minutes at conditions simulating flight at a Mach number of 0.8 at an altitude of 50,000 feet. This period of operation is approximately three times longer than previously reported operation times. Although the specific fuel consumption was reduced from 1.3 with JP-4 fuel to 0.98 with pentaborane, a 13.2-percent reduction in net thrust was also encountered. A portion of this thrust loss is potentially recoverable with proper design of the engine components. The boron oxide deposition and erosion processes within the engine approached an equilibrium condition after approximately 22 minutes of operation with pentaborane.

Development of a Fuel Spill/Vapor Migration Modeling System.

DTIC Science & Technology

1985-12-01

transforms resulting in a direct solution of the differential equation. A second order finite * difference approximation to the Poisson equation A2*j is...7 O-A64 043 DEVELOPMENT OF A FUEL SPILL/VPOR MIGRATION MODELING 1/2 SYSTEM(U) TRACER TECHNOLOGIES ESCONDIDO Cflo IL 0 ENGLAND ET AL. DEC 85 RFURL...AFWAL-TR-85-2089 DEVELOPMENT OF A FUEL SPILL/VAPOR MIGRATION MODELING SYSTEM W.G. England * L.H. Teuscher TRACER TECHNOLOGIES DTIC *2120 WEST MISSION

Dental Electric Handengines: Test and Evaluation.

DTIC Science & Technology

1985-04-01

ADRD5 066 A DENTAL ELECTRIC HANDENGINES: TEST AND EVALUATION(U) j/ij SCHOOL OF AEROSPACE MEDICINE BROOKS AFB TX C D FOSTER ET AL. APR 85 USAFSAM-TR... DENTAL ELECTRIC HANDENGINES o Test and Evaluation In -- I Cad D. Foster, Major, USAF, DC Paul M. Callison, Master Sergeant, USAF Gerald F. McKinley...AFSC) Brooks Air Force Base, TX 78235-5301 85 7 15 057 NOTICES This final report was submitted by personnel of the Dental Investigation Service

Comparative Macro-Structure of Armor Plate Ingots

DTIC Science & Technology

1932-05-12

Inoluded) Bur Stock (C J4.O; Mn ,^1 3l .1251 S .0^7; P .016) l|.08 lb«. Armoo Iron{C .05) 85 " Perro -Molybdenum (C »Ol+j SI 6.I4ÜI...Mo b5.9Ü) 5.7 " perro -VBtiBdlum (c *33i Si 1.1ÖJ V« 57.68) 5 Atf " perro -Chrowlum (c .18; Cr 68.82) Ü.75 " Perro -Man^B-ieae (Mn...97.5) ^55) ^M-) 1*56) 0.55 lb. l|J+5) 1.15 n ^57) perro -Slllcon (^l 95.0) O.k w They «ere the 6th 1 7th» iith, 9th, 10th

New Methodology for First Principle Calculations of Electrical Levels for Radiation Induced Defects in Silicates

DTIC Science & Technology

2005-02-22

1993). 72 U. Itoh, Y. Toyoshima, H . Onuki , N. Washida, and T. Ibuki, J. Chem. Phys. 85, 4867 (1986). 73 M. J. Field, P. A. Bash, and M. Karplus, J...the following publi- cations: 1. V. B. Sulimov, P. V. Sushko, A. H . Edwards, A. L. Shluger, and A. M. Stoneham, ”Asymmetry and log-range character of...lattice deformation by neu- tral oxygen vacancy in alpha-quartz”, Physical Re- view B, 66, p. 024108, (2002). 2. A. H . Edwards, P. V. Sushko, A. L

Molar heat capacity and entropy of calcium metal

USGS Publications Warehouse

Hemingway, B.S.; Robie, R.A.; Chase, M.W.

1997-01-01

The heat capacity of calcium has been measured at 85 mean temperatures between T ??? 8 K and T ??? 369 K using an adiabatically-shielded calorimeter in an intermittent heating mode. At T = 298.15 K, the recommended values for the molar heat capacity, molar entropy, and molar enthalpy increment referred to T = 0 are (25.77 ?? 0.08) J??K-1??mol-1, (42.90 ?? 0.11) J??K-1??mol-1, and (5811 ?? 12) J??mol-1, respectively. The uncertainties are twice the standard deviation of the mean. ?? 1997 Academic Press Limited.

Using Underwater Explosion and Cylinder Expansion Tests to Calibrate Afterburn Models for Aluminized Explosives

NASA Astrophysics Data System (ADS)

Wedberg, Rasmus

2017-06-01

The study explores the combined use of underwater performance tests and cylinder expansion tests in order to parameterize detonation models for aluminized explosives which exhibit afterburning. The approach is suggested to be used in conjunction with thermochemical computation. A formulation containing RDX and aluminum powder is considered and several charges with varying masses are submerged and detonated. Pressure gauges are employed at horizontal distances scaling with the charge diameter, and the specific shock wave energy is shown to increase with charge mass. This is attributed to the combustion of aluminum particles after the Chapman-Jouguet plane. Cylinder expansion tests are carried out using Photon Doppler Velocimetry to register the wall expansion velocity. The tests are modeled using a multi-material arbitrary Lagrangian-Eulerian approach with the Guirguis-Miller model describing detonation with afterburning. The equation of state and afterburn rate law parameters are adjusted such that the model reproduces the results from the cylinder expansion and underwater tests. The approach seems promising, and might be valuable for aluminized explosive formulations intended to be used in a variety of confinement conditions. Swedish Armed Forces.

Post-Detonation Energy Release from TNT-Aluminum Explosives

NASA Astrophysics Data System (ADS)

Zhang, Fan; Anderson, John; Yoshinaka, Akio

2007-06-01

Detonation and post-detonation energy release from TNT and TNT-aluminum composite have been experimentally studied in an air-filled chamber, 26 m^3 in volume and 3 m in diameter. While TNT has a high oxygen deficiency, experiments with 1.1 kg to 4 kg charges yield energy releases reaching only 86% of theoretical equilibrium values, possibly due to the non-uniform mixing between the detonation products and air. In order to improve mixing and further increase afterburning energy, large mass fractions of large aluminum particles are combined with TNT. The effect of particle distribution is also investigated in two composite configurations, whereby the aluminum particles are uniformly mixed in cast TNT or arranged in a shell surrounding a TNT cylinder. It is shown that the TNT-aluminum composite outperforms pure TNT, while improved performance is achieved for the shell configuration due to enhanced spatial mixing of hot fuels with oxidizing gases. Comparisons with the equilibrium theory and a liquid-based aluminized composite explosive (with an oxygen deficiency less than that of TNT) are conducted to further explore the mixing and afterburning mechanism.

A Hydrogen Peroxide Hot-Jet Simulator for Wind-Tunnel Tests of Turbojet-Exit Models

NASA Technical Reports Server (NTRS)

Runckel, Jack F.; Swihart, John M.

1959-01-01

A turbojet-engine-exhaust simulator which utilizes a hydrogen peroxide gas generator has been developed for powered-model testing in wind tunnels with air exchange. Catalytic decomposition of concentrated hydrogen peroxide provides a convenient and easily controlled method of providing a hot jet with characteristics that correspond closely to the jet of a gas turbine engine. The problems associated with simulation of jet exhausts in a transonic wind tunnel which led to the selection of a liquid monopropellant are discussed. The operation of the jet simulator consisting of a thrust balance, gas generator, exit nozzle, and auxiliary control system is described. Static-test data obtained with convergent nozzles are presented and shown to be in good agreement with ideal calculated values.

Thrust performance of a variable-geometry, divergent exhaust nozzle on a turbojet engine at altitude

NASA Technical Reports Server (NTRS)

Straight, D. M.; Collom, R. R.

1983-01-01

A variable geometry, low aspect ratio, nonaxisymmetric, two dimensional, convergent-divergent exhaust nozzle was tested at simulated altitude on a turbojet engine to obtain baseline axial, dry thrust performance over wide ranges of operating nozzle pressure ratios, throat areas, and internal expansion area ratios. The thrust data showed good agreement with theory and scale model test results after the data were corrected for seal leakage and coolant losses. Wall static pressure profile data were also obtained and compared with one dimensional theory and scale model data. The pressure data indicate greater three dimensional flow effects in the full scale tests than with models. The leakage and coolant penalties were substantial, and the method to determine them is included.

Explicit Finite Element Method for Transparency Impact Analysis

DTIC Science & Technology

1991-06-01

investigators have employed a similar concept for fiber-reinforced composite laminates (Chow 1971, 1975; Noor 1975, 1989; Chatterjee, 1979). Consider...Intense Impulsive Loads, It. J. Nuon. Meth. Engng. 14, 1865- 1871. Jones, R. M. (1975), Mechanics of Composite Materials, Scripta Book Co., Washington, D...Structural Dynamics, J. Eng. Mech. Div. 85, 67-94. Noor, A. K. (1975), Stability of Multilayered Composite Plates, Fibre Sci. Tech. 8, 81-89. Noor, A. K

J C Nalle Elementary School, Washington, D.C. Schools on the Move: Stories of Urban Schools Engaged in Inclusive Journeys of Change.

ERIC Educational Resources Information Center

Ferguson, Phil; Blumberg, Richard

This paper describes one urban school in the midst of change and renewal. J C Nalle Elementary School, Washington, DC, is a full-service community school that supports children and families. It is one of 85 schools with which the National Institute for Urban School Improvement is involved in partnerships for change. It is located in an…

In-flight thrust determination

NASA Technical Reports Server (NTRS)

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

1986-01-01

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

Drugs of Abuse in Aviation Fatalities. 1. Marijuana

DTIC Science & Technology

1985-08-01

h. DOT/FAA-:AM-85-8 V DRUGS OF ABUSE IN AVIATION FATALITIES: 1. MARIJUANA Delbert J. Lacefield Patricia A. Roberts Paula M. Grape Civil Aeromedical...Catalog No. DOT/FAA-AM-85-8 4. T.tle and Subtorle 5. Report Date Drugs of Abuse in Aviation Fatalities: 1. Marijuana AUGUST 1985 6. Performing Organization...47. 16. Abstract Isopropyl alcohol swabs taken from the oral cavities of pilots killed in general aviation accidents were analyzed for marijuana by

Site Investigation Report Groups 3,5, and 6 Fort Devens, Massachusetts. Volume 2 of 2: Appendices

DTIC Science & Technology

1996-01-01

Invertebrates: A Synoptic Review" U.S. Fish and Wildlife Service Biological Report 85 (1.6), 60 pp. Eisler , R., 1987 . "Mercury Hazards to Fish, Wildlife, and...Invertebrates: A Synoptic Review" U.S. Fish and Wildlife Service Biological Report 85 (1.10), 90 pp. Eisler , R., 1987 . "Polycyclic Aromatic...1983). [f] From Eisler ( 1987 ). [g] Value from Hansch and Leo (1979). [h] Plant value from Eisler (1988). [i] Mammal value from USEPA (1985). [j

Numerical simulation of long-duration blast wave evolution in confined facilities

NASA Astrophysics Data System (ADS)

Togashi, F.; Baum, J. D.; Mestreau, E.; Löhner, R.; Sunshine, D.

2010-10-01

The objective of this research effort was to investigate the quasi-steady flow field produced by explosives in confined facilities. In this effort we modeled tests in which a high explosive (HE) cylindrical charge was hung in the center of a room and detonated. The HEs used for the tests were C-4 and AFX 757. While C-4 is just slightly under-oxidized and is typically modeled as an ideal explosive, AFX 757 includes a significant percentage of aluminum particles, so long-time afterburning and energy release must be considered. The Lawrence Livermore National Laboratory (LLNL)-produced thermo-chemical equilibrium algorithm, “Cheetah”, was used to estimate the remaining burnable detonation products. From these remaining species, the afterburning energy was computed and added to the flow field. Computations of the detonation and afterburn of two HEs in the confined multi-room facility were performed. The results demonstrate excellent agreement with available experimental data in terms of blast wave time of arrival, peak shock amplitude, reverberation, and total impulse (and hence, total energy release, via either the detonation or afterburn processes.

Investigating alternative solutions for adsorption-contact drying when burning vegetable wastes

NASA Astrophysics Data System (ADS)

Golubkovich, A. V.

2007-06-01

Results are presented from investigation of three alternative solutions for adsorption-contact drying: combined (with cooling by means of outdoor air), with afterburning of combustible matters, and with limited adsorption of moisture using solid products of fuel combustion. Mathematical models and simplified expressions for calculating the time taken for the fuel drying to proceed are proposed.

Hurtful Emotions: Understanding Self-Harm

MedlinePlus

... criteria for NSSI disorder in adolescent inpatients. Muehlenkamp JJ, Brausch AM, Washburn JJ. J Consult Clin Psychol . 2017 Jun;85(6): ... high school and college students. Taliaferro LA, Muehlenkamp JJ. Suicide Life Threat Behav. 2015 Feb;45(1): ...

Trial Run of a Junction-Box Attachment Test for Use in Photovoltaic Module Qualification (Presentation)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, D.; Deibert, S.; Wohlgemuth, J.

Engineering robust adhesion of the junction-box (j-box) is a hurdle typically encountered by photovoltaic (PV) module manufacturers during product development and manufacturing process control. There are historical incidences of adverse effects (e.g., fires), caused when the j-box/adhesive/module system has failed in the field. The addition of a weight to the j-box during the 'damp-heat', 'thermal-cycle', or 'creep' tests within the IEC qualification protocol is proposed to verify the basic robustness of the adhesion system. The details of the proposed test are described, in addition to a trial run of the test procedure. The described experiments examine 4 moisture-cured silicones, 4more » foam tapes, and a hot-melt adhesive used in conjunction with glass, KPE, THV, and TPE substrates. For the purpose of validating the experiment, j-boxes were adhered to a substrate, loaded with a prescribed weight, and then subjected to aging. The replicate mock-modules were aged in an environmental chamber (at 85 deg C/85% relative humidity for 1000 hours; then 100 degrees C/<10% relative humidity for 200 hours) or fielded in Golden, Miami, and Phoenix for 1 year. Attachment strength tests, including pluck and shear test geometries, were also performed on smaller component specimens.« less

Trial-Run of a Junction-Box Attachment Test for Use in Photovoltaic Module Qualification: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, D. C.; Deibert, S. L.; Wohlgemuth, J. H.

Engineering robust adhesion of the junction box (j-box) is a hurdle typically encountered by photovoltaic module manufacturers during product development and manufacturing process control. There are historical incidences of adverse effects (e.g., fires) caused when the j-box/adhesive/module system has failed in the field. The addition of a weight to the j-box during the 'damp-heat,' 'thermal-cycle,' or 'creep' tests within the IEC qualification protocol is proposed to verify the basic robustness of the adhesion system. The details of the proposed test are described, in addition to a trial-run of the test procedure. The described experiments examine four moisture-cured silicones, four foammore » tapes, and a hot-melt adhesive used in conjunction with glass, KPE, THV, and TPE substrates. For the purpose of validating the experiment, j-boxes were adhered to a substrate, loaded with a prescribed weight, and then subjected to aging. The replicate mock-modules were aged in an environmental chamber (at 85 degrees C/85% relative humidity for 1000 hours; then 100 degrees C/<10% relative humidity for 200 hours) or fielded in Golden (CO), Miami (FL), and Phoenix (AZ) for one year. Attachment strength tests, including pluck and shear test geometries, were also performed on smaller component specimens.« less

Preliminary Results of Altitude-Wind-Tunnel Investigation of X24C-4B Turbojet Engine. IV - Performance of Modified Compressor. Part 4; Performance of Modified Compressor

NASA Technical Reports Server (NTRS)

Thorman, H. Carl; Dupree, David T.

1947-01-01

The performance of the 11-stage axial-flow compressor, modified to improve the compressor-outlet velocity, in a revised X24C-4B turbojet engine is presented and compared with the performance of the compressor in the original engine. Performance data were obtained from an investigation of the revised engine in the MACA Cleveland altitude wind tunnel. Compressor performance data were obtained for engine operation with four exhaust nozzles of different outlet area at simulated altitudes from 15,OOO to 45,000 feet, simulated flight Mach numbers from 0.24 to 1.07, and engine speeds from 4000 to 12,500 rpm. The data cover a range of corrected engine speeds from 4100 to 13,500 rpm, which correspond to compressor Mach numbers from 0.30 to 1.00.

Generalization of turbojet and turbine-propeller engine performance in windmilling condition

NASA Technical Reports Server (NTRS)

Wallner, Ewis E; Welna, Henry J

1951-01-01

Windmilling characteristics of several turbojet and turbine-propeller engines were investigated individually over a wide range of flight conditions in the NACA Lewis altitude wind tunnel. A study was made of all these data and windmilling performance of gas turbine engines was generalized. Although internal-drag, air-flow, and total-pressure-drop parameters were generalized to a single curve for both the axial-flow type engines and another for the centrifugal-flow engine. The engine speed, component pressure changes, and windmilling-propeller drag were generalized to single curves for the two turbine-propeller-type engines investigated. By the use of these curves the windmilling performance can be estimated for axial-flow type gas turbine engines similar to the types investigated over a wide range of flight conditions.

Process for detoxicating exhaust gases from Otto-combustion engines and apparatus for carrying out such process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klaue, H.J.; Reisacher, J.

1974-03-12

An afterburning process for reducing motor vehicle emissions of carbon monoxide and hydrocarbons is described which precludes extensive equipment for feeding the required air into the exhaust gases by means of exhaust gas expansion so that combustion air is sucked in by a partial vacuum formed. A twist generator is used to impart a swirl to the exhaust gases, resulting in their expansion. Air is aspirated into the expanded exhaust gases to provide a combustible gas-air mixture which is delivered to a diffusor for afterburning. The exhaust gases flowing to the twist generator pass through a heat exchanger which servesmore » to preheat the combustion air. The twist generator may be a set of stationary whirl-imparting vanes or may be the rotor of an exhaust gas turbo charger directly driving an air compressor which delivers the air through the heat exchanger to the turbocharger, with some of the compressed air being delivered back to the engine. The flow area of the outlet of the twist generator is adjustable to control the quantity of air aspirated into the exhaust gases supplied to the diffusor.« less

Propulsion

ERIC Educational Resources Information Center

Air and Space, 1978

1978-01-01

An introductory discussion of aircraft propulsion is included along with diagrams and pictures of piston, turbojet, turboprop, turbofan, and jet engines. Also, a table on chemical propulsion is included. (MDR)

Nuclear Data Sheets for A=85

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singh, Balraj; Chen, Jun

2014-02-01

Evaluated experimental data are presented for 13 known nuclides of mass 85 (Zn, Ga, Ge, As, Se, Br, Kr, Rb, Sr, Y, Zr, Nb, Mo). Since the previous 1990 evaluation of A=85, {sup 85}Zn, {sup 85}Ga, {sup 85}Ge and {sup 85}nuclides are newly added here. Excited state data for {sup 85}Se, {sup 85}Zr have become available from radioactive decay and in–beam γ–ray studies. New and improved high–spin data are available for {sup 85}Br, {sup 85}Kr, {sup 85}Rb, {sup 85}Y, {sup 85}Nb and {sup 85}Mo. New direct and precise measurement of atomic masses of {sup 85}Ge, {sup 85}As, {sup 85}Se, {supmore » 85}Br, {sup 85}Rb, {sup 85}Zr, {sup 85}Nb and {sup 85}Mo have greatly improved the landscape of β decay–Q values and separation energies in this mass region. In spite of extensive experimental work on the isobaric nuclei of this mass chain several deficiencies remain. No excited states are known in {sup 85}Zn, {sup 85}Ga, {sup 85}As. Only a few excited state are assigned in {sup 85}Ge from {sup 85}Ga β– decay. From radioactivity studies, the decay schemes of {sup 85}Zn and {sup 85}Mo are not known, and those for {sup 85}Ga, {sup 85}Ge, {sup 85}As and 10.9–s isomer of {sup 85}Zr are incomplete. Level lifetimes are not known for excited states in {sup 85}Se, {sup 85}Br, {sup 85}Nb and {sup 85}Mo. The {sup 85}Tc nuclide has not been detected in fragmentation experiments at GANIL, alluding to its unbound nature for proton emission. The {sup 85}Kr, {sup 85}Rb, {sup 85}Sr, and {sup 85}Y nuclides remain the most extensively studied from many different reactions and decays. The evaluation of A=85 nuclides has been done after a span of 23 years, thus includes an extensive amount of new data for almost each nuclide. This work supersedes the data for A=85 nuclides presented in earlier full NDS publication by J. Tepel in 1980Te04 and a later one published in an update mode by H. Sievers in 1991Si01.« less

Combustion Limits and Efficiency of Turbojet Engines

NASA Technical Reports Server (NTRS)

Barnett, H. C.; Jonash, E. R.

1956-01-01

Combustion must be maintained in the turbojet-engine combustor over a wide range of operating conditions resulting from variations in required engine thrust, flight altitude, and flight speed. Furthermore, combustion must be efficient in order to provide the maximum aircraft range. Thus, two major performance criteria of the turbojet-engine combustor are (1) operatable range, or combustion limits, and (2) combustion efficiency. Several fundamental requirements for efficient, high-speed combustion are evident from the discussions presented in chapters III to V. The fuel-air ratio and pressure in the burning zone must lie within specific limits of flammability (fig. 111-16(b)) in order to have the mixture ignite and burn satisfactorily. Increases in mixture temperature will favor the flammability characteristics (ch. III). A second requirement in maintaining a stable flame -is that low local flow velocities exist in the combustion zone (ch. VI). Finally, even with these requirements satisfied, a flame needs a certain minimum space in which to release a desired amount of heat, the necessary space increasing with a decrease in pressure (ref. 1). It is apparent, then, that combustor design and operation must provide for (1) proper control of vapor fuel-air ratios in the combustion zone at or near stoichiometric, (2) mixture pressures above the minimum flammability pressures, (3) low flow velocities in the combustion zone, and (4) adequate space for the flame.

Calpain-Dependent Proteolysis of the Androgen Receptor

DTIC Science & Technology

2009-11-01

Cancer 1999;84:6–9. 17. Lakshmikuttyamma A, Selvakumar P, Kanthan R , Kanthan SC, Sharma RK. Overexpression of m-calpain in human colorectal...determinants of calpain cleavage. J Biol Chem 2004;279:20775–85. 10. Rios-Doria J, Day KC, Kuefer R , et al. The role of calpain in the proteolytic...prostate carcinoma cell line, 22Rv1. In vitro Cell Dev Biol 1999;35:403–9. 15. Gupta AK, Cerniglia GJ, Mick R , McKenna WG, Muschel RJ. HIV protease

Target Patterns in Reaction-Diffusion Systems,

DTIC Science & Technology

1981-01-01

Riol. 37 (1974), 225-235. 8. M. H. COHEN AND S. A. ROBERTSON, Wave propagation in the early stages of aggregation of cellular slime molds . J. Theoret...the Zaikin-Zhabotinskii-Winfree reagent, Chem. Educ. 56 (1979), 574. 5. F. ALCANTARA AND M. MONK, Signal propagation during aggregation in the slime ... mold Dit’resteltu n discoideum. J. Gen. Microbiol. 85 (1974). 321-334. 6. M. S. COHEN AND P. S. HAGAN, Diffusion induced morphogenesis in the

Prenatal Effects of Exposure to High-Level Noise,

DTIC Science & Technology

1982-03-01

R.J. (1968). Sound transmission to the human foetus through the maternal abdominal wall. J. Genet. Psychol., 113:85-87. Bench, R.J., and Hittler, M.A...1967). Changes of heart rate in re- sponse to auditory stimulation in the human foetus (abstract). Bull. Brit. Psychol. Soc., 20:14A. Bench, R.J...Aust. J. Ment. Ret., 2:63-64. Johansson, B., Wedenberg, E., and Westin, B. (1964). Measurement of tone response by the human foetus . Acta Otolaryngol

Checkpoint Kinase-Dependent Regulation of DNA Repair and Genome Instability in Breast Cancer

DTIC Science & Technology

2007-06-01

cells reduces radiosensitivity. Cancer J 9:277-85. 15. Lehmann, A. R. 2003. DNA repair-deficient diseases, xeroderma pigmentosum , Cockayne syndrome...in NER give rise to the autosomal recessive disorder xeroderma pigmentosum (XP), which is characterized by ex- treme sun sensitivity, premature aging...mediated ubiquitination and deg- radation. J. Biol. Chem. 276:48175–48182. 14. Chu, G., and E. Chang. 1988. Xeroderma pigmentosum group E cells lack a

Airsickness During Naval Flight Officer Training: Advanced Squadron VT86-AJN.

DTIC Science & Technology

1980-05-06

85 -.05 -. e6 -. 15 .60 -. 06 -. 85 -. 96 -. 19 23 TMSI-MS HISTORY, PART 1 .31* .28# .16 -.81 .23 .31* . 281 .17 -. 68 .9 24 THSQ2-NS HISTORY PART... ZWI I 4LZ to W wwoc I w 0~r CU aQ 1 .4 . ’ .’ . . CO.. .C . . im a *rwol. 1011Y 1W 1.- 1 0 1M e E-4 Ai Ř -0 4 ,u g : I’ ItI W . ).4U J M I W t X 4

Genetics Home Reference: cerebral folate transport deficiency

MedlinePlus

... a treatable neurodegenerative disorder associated with disturbed myelin metabolism. Am J Hum Genet. 2009 Sep;85(3):354-63. doi: 10.1016/j.ajhg.2009.08.005. Citation on PubMed or Free article on PubMed Central Toelle SP, Wille D, Schmitt ...

Deterministic Parsing and Linguistic Explanation. Revision,

DTIC Science & Technology

1985-06-01

near the town can have any of the following intepretations : 2"See Zubizarretta (1082) wrod StoweU (1081). 17...Department of Linguistics and Philosophy. 43 ... FILMED " ൒-85 D I’ DTIC " , S . I * -J’ . p -#-

Optimization of light dosimetry for photodynamic therapy of Barrett's esophagus

NASA Astrophysics Data System (ADS)

Panjehpour, Masoud; Phan, Mary N.; Overholt, Bergein F.; Haydek, John M.

2004-06-01

Background and Objective: Photodynamic therapy (PDT) may be used for ablation of high grade dysplasia and/or early cancer (HGD/T1) in Barrett's esophagus. A complication of PDT is esophageal stricture. The objective of this study was to find the lowest light dose to potentially reduce the incidence of strictures while effectively ablating HGD/T1. Materials and Methods: Patients (n=113) with HGD/T1 received an intravenous injection of porfimer sodium (2 mg/kg). Three days later, laser light (630 nm) was delivered using a cylindrical diffuser inserted in a 20 mm.diameter PDT balloon. Patients were treated at light doses of 115 J/cm, 105 J/cm, 95 J/cm and 85 J/cm. The efficacy was determined by four quadrant biopsies of the treated area three months after PDT. The formation of stricture was determined by the incidence of dysphagia and the need for esophageal dilation. Strictures were considered mild if they required less than 6 dilations, and severe if 6 or more dilations were required. Efficacy and incidence of strictures were tabulated as a function of light dose. Results: Using 115 J/cm, there were 17% of patients with residual HGD/T1 after one treatment. However, when the light doses of 105 J/cm, 95 J/cm and 85 J/cm were used, the residual HGD/T1 after one PDT session was increased to 33%, 30%, and 32% respectively. The overall incidence of strictures (mild and severe) was not correlated to the light dose. However, the incidence of severe strictures was directly proportional to the light dose. Using the light dose of 115 J/cm, 15.3% of patients developed severe strictures compared to about 5% in the groups of patients who received the lower light doses. Conclusions: Decreasing the light dose below 115 J/cm doubled the rate of residual HGD/T1 after one treatment while reducing the incidence of severe strictures to one-third of cases from 115 J/cm. The results may be used to evaluate the risks and benefits of different light doses.

Adhesion of Antireflective Coatings in Multijunction Photovoltaics: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brock, Ryan; Dauskardt, Reinhold H.; Miller, David C.

2016-06-16

The development of a new composite dual cantilever beam (cDCB) thin-film adhesion testing method is reported, which allows the measurement of adhesion on the fragile thin substrates used in multijunction photovoltaics. We address the adhesion of several antireflective coating systems on multijunction cells. By varying interface chemistry and morphology, we demonstrate the ensuing effects on adhesion and help to develop an understanding of how high adhesion can be achieved, as adhesion values ranging from 0.5 J/m2 to 10 J/m2 were measured. Damp Heat (85 degrees C/85% RH) was used to invoke degradation of interfacial adhesion. We show that even withmore » germanium substrates that fracture easily, quantitative measurements of adhesion can still be made at high test yield. The cDCB test is discussed as an important new methodology, which can be broadly applied to any system that makes use of thin, brittle, or otherwise fragile substrates.« less

Adhesion of Antireflective Coatings in Multijunction Photovoltaics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brock, Ryan; Miller, David C.; Dauskardt, Reinhold H.

2016-11-21

The development of a new composite dual cantilever beam (cDCB) thin-film adhesion testing method is reported, which allows the measurement of adhesion on the fragile thin substrates used in multijunction photovoltaics. We address the adhesion of several antireflective coating systems on multijunction cells. By varying interface chemistry and morphology, we demonstrate the ensuing effects on adhesion and help to develop an understanding of how high adhesion can be achieved, as adhesion values ranging from 0.5 J/m2 to 10 J/m2 were measured. Damp Heat (85 degrees C/85% RH) was used to invoke degradation of interfacial adhesion. We show that even withmore » germanium substrates that fracture easily, quantitative measurements of adhesion can still be made at high test yield. The cDCB test is discussed as an important new methodology, which can be broadly applied to any system that makes use of thin, brittle, or otherwise fragile substrates.« less

Altitude Performance of Annular Combustor Type Turbojet Engine with JFC-2 Fuel /james W. Useller, James L. Harp, Jr. and Zelmar Barson

NASA Technical Reports Server (NTRS)

Useller, James W; Harp, James L JR; Barson, Zelmar

1952-01-01

An investigation was made comparing the performance of JFC-2 fuel and unleaded, clear gasoline in a 3000-pound-thrust turbojet engine. The JFC-2 fuel was a blend of percent diesel fuel and 25 percent aviation gasoline. Engine combustion efficiency was equal to that obtained with gasoline at rated engine speed and altitudes up to 35,000 feet, but at lower engine speeds or at higher altitudes the JFC-2 fuel gave lower combustion efficiency. No discernible difference was obtained in starting or low-speed combustiion blow-out characteristics of the two fuels. Turbine-discharge radial temperature profiles were nearly the same at altitudes up to 35,000 feet.

A Meta System for Generating Software Engineering Environments.

DTIC Science & Technology

1985-01-01

CI/NR-85-710 UNCLSSIFIED F/ G 9/2 NL 1.0 2-8! j~j~ 1s 3-15 jjll !2 __ L__ ILlh 1121 ,.., - - NATIONAL BUREAU OF STANDARDS MSCRCOPY RESOLUMIN TEST CHART...34 ". " ....-.... .......-... . . - ...-............’. . -...... -.--..-..-.. : 23 H4eta Dt: t-o (Knowled&e Base) Attributed G raoonr form ___ lepresenta tion of a Kethod...implements a programming environment on a relational database. The IDEOSY system 38’ is a graph-oriented language programming environment. I l t . G = o

Distance Metric between 3D Models and 2D Images for Recognition and Classification

DTIC Science & Technology

1992-07-01

and 2D Image__ for Recognition and Classification D TIC Ronen Basri and Daphna Weinshall ELECTE JAN2 91993’ Abstract C Similarity measurements...Research Projects Agency of the Department of Defense under Office of Naval Research contract N00014-19-J-4038. Ronen Basri is supported by the...Distance Metric Between 3D Models and 2D Images for N00014-85-K-0124 Recognition and Classification N00014-91-J-4038 6. AUTHOR(S) Ronen Basri and

Performance of a small annular turbojet combustor designed for low cost

NASA Technical Reports Server (NTRS)

Fear, J. S.

1972-01-01

Performance investigations were conducted on a combustor utilizing several cost-reducing innovations and designed for use in a low-cost 4448-N thrust turbojet engine for commercial light aircraft. Low-cost features included simple, air-atomizing fuel injectors; combustor liners of perforated sheet; and the use of inexpensive type 304 stainless-steel material. Combustion efficiencies at the cruise and sea-level-takeoff design points were approximately 97 and 98 percent, respectively. The combustor isothermal pressure loss was 6.3 percent at the cruise-condition diffuser inlet Mach number of 0.34. The combustor exit temperature pattern factor was less than 0.24 at both the cruise and sea-level-takeoff design points. The combustor exit average radial temperature profiles at all conditions were in very good agreement with the design profile.

DYGABCD: A program for calculating linear A, B, C, and D matrices from a nonlinear dynamic engine simulation

NASA Technical Reports Server (NTRS)

Geyser, L. C.

1978-01-01

A digital computer program, DYGABCD, was developed that generates linearized, dynamic models of simulated turbofan and turbojet engines. DYGABCD is based on an earlier computer program, DYNGEN, that is capable of calculating simulated nonlinear steady-state and transient performance of one- and two-spool turbojet engines or two- and three-spool turbofan engines. Most control design techniques require linear system descriptions. For multiple-input/multiple-output systems such as turbine engines, state space matrix descriptions of the system are often desirable. DYGABCD computes the state space matrices commonly referred to as the A, B, C, and D matrices required for a linear system description. The report discusses the analytical approach and provides a users manual, FORTRAN listings, and a sample case.

Transient Two-Dimensional Analysis of Side Load in Liquid Rocket Engine Nozzles

NASA Technical Reports Server (NTRS)

Wang, Ten-See

2004-01-01

Two-dimensional planar and axisymmetric numerical investigations on the nozzle start-up side load physics were performed. The objective of this study is to develop a computational methodology to identify nozzle side load physics using simplified two-dimensional geometries, in order to come up with a computational strategy to eventually predict the three-dimensional side loads. The computational methodology is based on a multidimensional, finite-volume, viscous, chemically reacting, unstructured-grid, and pressure-based computational fluid dynamics formulation, and a transient inlet condition based on an engine system modeling. The side load physics captured in the low aspect-ratio, two-dimensional planar nozzle include the Coanda effect, afterburning wave, and the associated lip free-shock oscillation. Results of parametric studies indicate that equivalence ratio, combustion and ramp rate affect the side load physics. The side load physics inferred in the high aspect-ratio, axisymmetric nozzle study include the afterburning wave; transition from free-shock to restricted-shock separation, reverting back to free-shock separation, and transforming to restricted-shock separation again; and lip restricted-shock oscillation. The Mach disk loci and wall pressure history studies reconfirm that combustion and the associated thermodynamic properties affect the formation and duration of the asymmetric flow.

Process and apparatus, mainly for burning agricultural plant refuse

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bela, B.; Geza, G.; Istvan, C.

1984-05-22

Freshly harvested agricultural materials having a moisture content no greater than 45% by weight are burned in a furnace in which the housing thereof is divided into preburning and afterburning spaces by a baffle wall. The preburning space contains a horizontally arranged first grating adjacent the baffle wall and a second grating adjacent the first and inclined upwardly therefrom and juxtaposed with an inlet in the housing for the introduction at a constant rate of the materials onto the inclined grating, the upper portion of which is fed by a first portion of primary air for the removal of moisturemore » from the materials, while a lower portion of the inclined grating is fed with a second portion of primary air for the air-deficient burning of the dried materials and the production of combustible gases. The horizontal grating is fed with a third portion of primary air for driving the combustible gases along the baffle wall, which acts to deflect the gases in a counterflow to the flow of the materials, the gases mixing with secondary air introduced through at least one air inlet formed in the baffle wall, the mixture being burned completely in the afterburning space.« less

Afterburning in spherical premixed turbulent explosions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bradley, D.; Lawes, M.; Scott, M.J.

1994-12-01

During the early stages of spherical turbulent flame propagation, more than half of the gas behind the visible flame front may be unburned. Previous models of the afterburning of the gas behind the apparent flame front have been extended in the present work, to include the effects of flame quenching, consequent upon localized flame stretch. The predictions of the model cover, the spatial and temporal variations of the fraction burned, the flame propagation rate, and the mass burning rate. They are all in dimensionless form and are well supported by associated experimental measurements in a fan-stirred bomb with controlled turbulence.more » The proportion of the gas that is unburned decreases with time and increases with the product of the Karlovitz stretch factor and the Lewis number. Simultaneous photographs were taken of the spherical schlieren image and of that due to Mie scattering from small seed particles in a thin laser sheet that sectioned the spherical flame. These clearly showed the amount of unburned gas within the sphere and, along with other evidence suggest laminar flamelet burning across a scale of distance which is close to the Taylor confirm the predictions of the fraction of gas unburned and of the rate at which it is burning.« less

J-PET: A New Technology for the Whole-body PET Imaging

NASA Astrophysics Data System (ADS)

Niedźwiecki, S.; Białas, P.; Curceanu, C.; Czerwiński, E.; Dulski, K.; Gajos, A.; Głowacz, B.; Gorgol, M.; Hiesmayr, B. C.; Jasińska, B.; Kapłon, Ł.; Kisielewska-Kamińska, D.; Korcyl, G.; Kowalski, P.; Kozik, T.; Krawczyk, N.; Krzemień, W.; Kubicz, E.; Mohammed, M.; Pawlik-Niedźwiecka, M.; Pałka, M.; Raczyński, L.; Rudy, Z.; Sharma, N. G.; Sharma, S.; Shopa, R. Y.; Silarski, M.; Skurzok, M.; Wieczorek, A.; Wiślicki, W.; Zgardzińska, B.; Zieliński, M.; Moskal, P.

The Jagiellonian Positron Emission Tomograph (J-PET) is the first PET built from plastic scintillators. J-PET prototype consists of 192 detection modules arranged axially in three layers forming a cylindrical diagnostic chamber with the inner diameter of 85 cm and the axial field-of-view of 50 cm. An axial arrangement of long strips of plastic scintillators, their small light attenuation, superior timing properties, and relative ease of the increase of the axial field-of-view opens promising perspectives for the cost effective construction of the whole-body PET scanner, as well as construction of MR and CT compatible PET inserts. Present status of the development of the J-PET tomograph will be presented and discussed.

Comparison of Performance of AN-F-58 Fuel and Gasoline in J34-WE-22 Turbojet Engine

NASA Technical Reports Server (NTRS)

Dowman, Harry W; Younger, George G

1949-01-01

As part of an investigation of the performance of AN-F-58 fuel in various types of turbojet engine, the performance of this fuel in a 3000-pound-thrust turbojet engine has been investigated in an altitude test chamber together with the comparative performance of 62-octane gasoline. The investigation of normal engine performance, which covered a range of engine speeds at altitudes from 5000 to 50,000 feet and flight Mach numbers up to 1.00, showed that both the net thrust and average turbine-outlet temperatures were approximately the same for both fuels. The specific fuel consumption and the combustion efficiency at the maximum engine speeds investigated were approximately the same for both fuels at altitudes up to 35,000 feet, but at an altitude of 50,000 feet the specific fuel consumption was about 9 percent higher and the combustion efficiency was correspondingly lower with the AN-F-58 fuel than with gasoline. The low-engine-speed blow-out limits were about the same for both fuels. Ignition of AN-F-58 fuel with the standard spark plug was possible only with the spark plug in a clean condition; ignition was impossible at all flight conditions investigated when the plug was fouled by an accumulation of liquid fuel from a preceding false start. Use of an extended-electrode spark plug provided satisfactory ignition over a slightly smaller range of altitudes and flight Mach numbers than for gasoline with the standard spark plug.

Evaluation of pressure and thermal data from a wind tunnel test of a large-scale, powered, STOL fighter model

NASA Technical Reports Server (NTRS)

Howell, G. A.; Crosthwait, E. L.; Witte, M. C.

1981-01-01

A STOL fighter model employing the vectored-engine-over wing concept was tested at low speeds in the NASA/Ames 40 by 80-foot wind tunnel. The model, approximately 0.75 scale of an operational fighter, was powered by two General Electric J-97 turbojet engines. Limited pressure and thermal instrumentation were provided to measure power effects (chordwise and spanwise blowing) and control-surface-deflection effects. An indepth study of the pressure and temperature data revealed many flow field features - the foremost being wing and canard leading-edge vortices. These vortices delineated regions of attached and separated flow, and their movements were often keys to an understanding of flow field changes caused by power and control-surface variations. Chordwise blowing increased wing lift and caused a modest aft shift in the center of pressure. The induced effects of chordwise blowing extended forward to the canard and significantly increased the canard lift when the surface was stalled. Spanwise blowing effectively enhanced the wing leading-edge vortex, thereby increasing lift and causing a forward shift in the center of pressure.

A Microprocessor-Based Real-Time Simulator of a Turbofan Engine

DTIC Science & Technology

1988-01-01

NASA AVSCOM Technical Memorandum 100889 Technical Report 88-C-011 Lfl A Microprocessor-Based Real-Time Simulator of a Turbofan Engine CD I Jonathan S...Accession For NTIS GRA&I A MICROPROCESSOR-BASED REAL-TIME SIMULATOR DTIC TABUnannounced OF A TURBOFAN ENGINE Justifiaation, Jonathan S. Litt Propulsion...the F100 engine without augmentation (without afterburning). HYTESS is a simplified simulation written in FORTRAN of a generalized turbofan engine . To

14 CFR 34.23 - Exhaust Emission Standards for Engines Manufactured on and after July 18, 2012.

Code of Federal Regulations, 2013 CFR

2013-01-01

... output less than 26.7 kN (6,000 lb) manufactured on and after July 18, 2012: SN = 83.6(rO) −0.274 or 50.0... Engines Class Rated pressure ratio—rPR Rated output rO (kN) NOX (g/kN) TF, T3, T8 rPR ≤ 30 26.7 89.0 16.72...(g/kN) TSS All 36 + 2.42 (rPR) 4,550 (rPR) −1.03 1 rO is the rated output with afterburning applied...

ANALYTICAL AND EXPERIMENTAL INVESTIGATION OF ROTATING STALL PHENOMENA IN TURBINE ENGINE COMPRESSORS.

DTIC Science & Technology

AXIAL FLOW COMPRESSORS, STALLING), TURBOJET ENGINES , AXIAL FLOW COMPRESSOR BLADES , LIFT, HYSTERESIS, TURBULENCE, INLET GUIDE VANES , RINGS, STABILITY, THREE DIMENSIONAL FLOW, VISCOSITY, VORTICES, FLUIDICS.

The Appearance of a Boric Oxide Exhaust Cloud from a Turbojet Engine Operating on Trimethylborate Fuel

NASA Technical Reports Server (NTRS)

Lord, Albert M; Kaufman, Warner B

1956-01-01

An investigation was conducted on the size and density of the boric oxide exhaust cloud from a J47-25 turbojet engine operating on trimethylborate fuel at sea-level static condition. Movies and still photographs were taken from the ground and from a helicopter. Objects could not be perceived through the main body of the cloud at distances up to 800 feet from the engine. Data are included on the amount of fallout from the cloud and the concentration of boric oxide in the cloud. A radiation detection device was set up to determine whether the glowing oxide particles would be more susceptible than hydrocarbon exhaust gases to this type of tracking device. The device showed an increase in radiation by a factor of 3 for trimethylborate over that for JP-4.

Computer model predictions of the local effects of large, solid-fuel rocket motors on stratospheric ozone. Technical report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zittel, P.F.

1994-09-10

The solid-fuel rocket motors of large space launch vehicles release gases and particles that may significantly affect stratospheric ozone densities along the vehicle's path. In this study, standard rocket nozzle and flowfield computer codes have been used to characterize the exhaust gases and particles through the afterburning region of the solid-fuel motors of the Titan IV launch vehicle. The models predict that a large fraction of the HCl gas exhausted by the motors is converted to Cl and Cl2 in the plume afterburning region. Estimates of the subsequent chemistry suggest that on expansion into the ambient daytime stratosphere, the highlymore » reactive chlorine may significantly deplete ozone in a cylinder around the vehicle track that ranges from 1 to 5 km in diameter over the altitude range of 15 to 40 km. The initial ozone depletion is estimated to occur on a time scale of less than 1 hour. After the initial effects, the dominant chemistry of the problem changes, and new models are needed to follow the further expansion, or closure, of the ozone hole on a longer time scale.« less

A detailed numerical simulation of a liquid-propellant rocket engine ground test experiment

NASA Astrophysics Data System (ADS)

Lankford, D. W.; Simmons, M. A.; Heikkinen, B. D.

1992-07-01

A computational simulation of a Liquid Rocket Engine (LRE) ground test experiment was performed using two modeling approaches. The results of the models were compared with selected data to assess the validity of state-of-the-art computational tools for predicting the flowfield and radiative transfer in complex flow environments. The data used for comparison consisted of in-band station radiation measurements obtained in the near-field portion of the plume exhaust. The test article was a subscale LRE with an afterbody, resulting in a large base region. The flight conditions were such that afterburning regions were observed in the plume flowfield. A conventional standard modeling approach underpredicted the extent of afterburning and the associated radiation levels. These results were attributed to the absence of the base flow region which is not accounted for in this model. To assess the effects of the base region a Navier-Stokes model was applied. The results of this calculation indicate that the base recirculation effects are dominant features in the immediate expansion region and resulted in a much improved comparison. However, the downstream in-band station radiation data remained underpredicted by this model.

An Assessment of Technology for Turbojet Engine Rotor Failures

NASA Technical Reports Server (NTRS)

Witmer, E. A. (Editor)

1977-01-01

Design considerations, objectives, and approaches used in containing rotor burst debris are discussed. Methods are given for determining the fracture resistance of various materials used in providing lightweight shielding from fragment impact.

Low cost high temperature, duplex coating for superalloys

NASA Technical Reports Server (NTRS)

Young, S. G.; Deadmore, D. L.

1981-01-01

Duplex silicon-slurry/aluminide coating substantially improves high temperature resistance to oxidation and corrosion of nickel base alloys. Coating used in critical sections of power systems like turbojet engines extends their operating capabilities.

Minutes of the HUSKY PUP Prefielding Instrumentation Meeting Held on 28- 29 April 1975 at Kirtland AFB, New Mexico

DTIC Science & Technology

1976-02-26

D£? E ;-:: E NUCLEAR ( y AGENCY „ v—TECHNICAL LIBRARY GU^ 28-29 APRIL 1975 DEFENSE NUCLEAR AGENCY TEST DIRECTORATE KIRTLAND AFB, NEW...HENRY J. THAYER ’^LTC, USA CHIEF, ENGINEERING BRANCH Q\\W\\0N ^ e .-igi«3 /^A i,nmiiJiiJMii y M MU«umwjm$iBKv^^ ■■. DISTRIBUTION: Director, Defense...ATTN: Mr. E . Sumner, Mr. T. Maguire, Mr. F. Moyer, Dept. 85-85, Bldg. 10?, P.O. Box 50^, Sunnyvale, CA 9^088 Lockheed Missiles and Space Company, ATTN

Optimized Hyperthermia Treatment of Prostate Cancer Using a Novel Intracavitary Ultrasound Array

DTIC Science & Technology

2006-01-01

Overgaard J, Gonzalez GD, Hulshof MC, Arcangeli G, Dahl O, Mella O, et al. 1995. Randomised trial of hyperthermia as adjuvant to radiotherapy for...Gonzalez, G. D., Hulshof , M. C., Arcangeli, G., Dahl, O., Mella, O., and Bentzen, S. M., "Hyperthermia as an adjuvant to radiation therapy of recurrent or...25 pp. 79-85, 1993. 9. Overgaard, J., Gonzalez, G. D., Hulshof , M. C., Arcangeli, G., Dahl, O., Mella, O., and Bentzen, S. M.: Hyperthermia as an

Oral Administration of N-Acetyl-D Glucosamine Polymer Particles Down-Regulates Airway Allergic Responses

DTIC Science & Technology

2005-03-01

detection with flow cytometry. Cancer . 85:2359-67. 18. Justice JP, Shibata Y, Sur S, Mustafa J, Fan M, Van Scott MR. 2001. IL-10 gene knockout attenuates...primed donors. Regional Immunol., 2, 169-175. 7. Druker, B. J., Wepsic, H. T. (1983) BCG-induced macrophages as suppressor cells. Cancer Investig. 1:151...however, have significantly lower binding affinities to de-acetylated glucosamine sugar residues (31). Dectin-1/[3- glucan CLR, on the other hand

VUV and UV Sources and Spectroscopic Applications

DTIC Science & Technology

1991-12-01

Toyoshima, H . Onuki , N. Washida, and T. Ibuki, J. Chem. Phys. 85, 4867 (1986). 17 J. Heidberg, R. Daghighi-Ruhi. H . von Weyssenhoff. and A. Habekost, Mat...20.0 1Sp r 3r 33867.2±0.39 14.3658 6.37±0.105 13.0±10.09 N.D. 18pa 31: h h h h h 16pm 3T8 33938.4±0.3 15.435 6.30±0.15 N.D. N.D. 19pa 3E 33987.0±0.3...photodissociation often results in the rupture of the weakest bond in the molecule, which may yield, for example, ABC + h -- AB + C (2.3) rather than the desired

Ultrahigh Vacuum Studies of the Fundamental Interactions of Chemical Warfare Agents and Their Simulants with Amorphous Silica

DTIC Science & Technology

2015-07-14

Aldao, C. M. Monte Carlo Study of Thermal Desorption Curves of Water from Zeolite Type A. Langmuir 1996, 12, 36-39. (83) Gorte, R. J. Design Parameters...and Diffusion-Limited TPD of Water from Zeolite Linde 4A. Thermochimica Acta 1998, 319, 177-184. (85) Palmero, A.; Loffler, D. G. Kinetics of Water...Desorption from Pelletized 4A and 5A Zeolites . Thermochimica Acta 1990, 159, 171-176. (86) Dean, J. A. Lange’s Handbook of Chemistry; Fifteenth

Mechanic watches a General Electric I-40 Engine Fire

NASA Image and Video Library

1948-01-21

A mechanic watches the firing of a General Electric I-40 turbojet at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory. The military selected General Electric’s West Lynn facility in 1941 to secretly replicate the centrifugal turbojet engine designed by British engineer Frank Whittle. General Electric’s first attempt, the I-A, was fraught with problems. The design was improved somewhat with the subsequent I-16 engine. It was not until the engine's next reincarnation as the I-40 in 1943 that General Electric’s efforts paid off. The 4000-pound thrust I-40 was incorporated into the Lockheed Shooting Star airframe and successfully flown in June 1944. The Shooting Star became the US’s first successful jet aircraft and the first US aircraft to reach 500 miles per hour. NACA Lewis studied all of General Electric’s centrifugal turbojet models during the 1940s. In 1945 the entire Shooting Star aircraft was investigated in the Altitude Wind Tunnel. Engine compressor performance and augmentation by water injection; comparison of different fuel blends in a single combustor; and air-cooled rotors were studied. The mechanic in this photograph watches the firing of a full-scale I-40 in the Jet Propulsion Static Laboratory. The facility was quickly built in 1943 specifically in order to test the early General Electric turbojets. The I-A was secretly analyzed in the facility during the fall of 1943.

Development of acoustically lined ejector technology for multitube jet noise suppressor nozzles by model and engine tests over a wide range of jet pressure ratios and temperatures

NASA Technical Reports Server (NTRS)

Atvars, J.; Paynter, G. C.; Walker, D. Q.; Wintermeyer, C. F.

1974-01-01

An experimental program comprising model nozzle and full-scale engine tests was undertaken to acquire parametric data for acoustically lined ejectors applied to primary jet noise suppression. Ejector lining design technology and acoustical scaling of lined ejector configurations were the major objectives. Ground static tests were run with a J-75 turbojet engine fitted with a 37-tube, area ratio 3.3 suppressor nozzle and two lengths of ejector shroud (L/D = 1 and 2). Seven ejector lining configurations were tested over the engine pressure ratio range of 1.40 to 2.40 with corresponding jet velocities between 305 and 610 M/sec. One-fourth scale model nozzles were tested over a pressure ratio range of 1.40 to 4.0 with jet total temperatures between ambient and 1088 K. Scaling of multielement nozzle ejector configurations was also studied using a single element of the nozzle array with identical ejector lengths and lining materials. Acoustic far field and near field data together with nozzle thrust performance and jet aerodynamic flow profiles are presented.

Dynamic response of a Mach 2.5 axisymmetric inlet and turbojet engine with a poppet-value controlled inlet stability bypass system when subjected to internal and external airflow transients

NASA Technical Reports Server (NTRS)

Sanders, B. W.

1980-01-01

The throat of a Mach 2.5 inlet that was attached to a turbojet engine was fitted with a poppet-valve-controlled stability bypass system that was designed to provide a large, stable airflow range. Propulsion system response and stability bypass performance were determined for several transient airflow disturbances, both internal and external. Internal airflow disturbances included reductions in overboard bypass airflow, power lever angle, and primary-nozzle area as well as compressor stall. For reference, data are also included for a conventional, fixed-exit bleed system. The poppet valves greatly increased inlet stability and had no adverse effects on propulsion system performance. Limited unstarted-inlet bleed performance data are presented.

The Effect of Altitude Conditions on the Particle Emissions of a J85-GE-5L Turbojet Engine

NASA Technical Reports Server (NTRS)

Rickey, June Elizabeth

1995-01-01

Particles from a J85-GE-5L turbojet engine were measured over a range of engine speeds at simulated altitude conditions ranging from near sea level to 45,000 ft and at flight Mach numbers of 0.5 and 0.8. Samples were collected from the engine by using a specially designed probe positioned several inches behind the exhaust nozzle. A differential mobility particle sizing system was used to determine particle size. Particle data measured at near sea-level conditions were compared with Navy Aircraft Environmental Support Office (AESO) particle data taken from a GE-J85-4A engine at a sea-level static condition. Particle data from the J85 engine were also compared with particle data from a J85 combustor at three different simulated altitudes.

Burnout control at the Albright coal-waste-bank fire. Rept. of investigations/1991

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chaiken, R.F.; Bayles, L.G.

1991-01-01

Burnout Control is a process developed by the U.S. Bureau of Mines for accelerating the burning of wasted coal fires in situ, while at the same time controlling the heat and fumes produced. The Albright fire project is a first field trial of Burnout Control as applied to a coal waste bank. An exhaust ventilation system was designed and constructed and then operated over a 1-year period at the site of an existing abandoned mine land fire near the town of Albright, W.V. While predicted exhaust gas temperatures of 900 C and thermal power levels of 5 MW were achievedmore » at 20- to 30-in H2O vacuum levels, problems were encountered with engineering designs, equipment breakdown, and fuel-rich combustion that curtailed the time period of satisfactory operation. Effective afterburning of the exhaust gases (as they were drawn from the bank) corrected the problems associated with combustion stoichiometry and led to high thermal outputs. It is believed that with (1) improvements in engineering design and construction, (2) better control of the afterburning process, and (3) the use of conventional stack gas air-pollution controls, Burnout Control can be applied successfully to a coal waste bank fire.« less

Calculated effects of turbine rotor-blade cooling-air flow, altitude, and compressor bleed point on performance of a turbojet engine

NASA Technical Reports Server (NTRS)

Arne, Vernon L; Nachtigall, Alfred J

1951-01-01

Effects of air-cooling turbine rotor blades on performance of a turbojet engine were calculated for a range of altitudes from sea level to 40,000 feet and a range of coolant flows up to 3 percent of compressor air flow, for two conditions of coolant bleed from the compressor. Bleeding at required coolant pressure resulted in a sea-level thrust reduction approximately twice the percentage coolant flow and in an increase in specific fuel consumption approximately equal to percentage coolant flow. For any fixed value of coolant flow ratio the percentage thrust reduction and percentage increase in specific fuel consumption decreased with altitude. Bleeding coolant at the compressor discharge resulted in an additional 1 percent loss in performance at sea level and in smaller increase in loss of performance at higher altitudes.

Performance of Axial-Flow Supersonic Compressor of XJ55-FF-1 Turbojet Engine. III; Over-All Performance of Compressor

NASA Technical Reports Server (NTRS)

Hartmann, Melvin J.; Tysl, Edward R.

1949-01-01

An investigation was conducted to determine the performance characteristics of the rotor and inlet guide vanes used in the axial-flow supersonic compressor of the XJ55-FF-1 turbojet engine. Outlet stators used in the engine were omitted to facilitate study of the supersonic rotor. The extent of the deviation from design performance indicates that the design-shock configuration was not obtained. A maximum pressure ratio of 2.26 was obtained at an equivalent tip speed of 1614 feet per second and an adiabatic efficiency of 0.61. The maximum efficiency obtained was 0.79 at an equivalent tip speed of 801 feet per second and a pressure ratio of 1.29. The performance obtained was considerably below design performance. The effective aerodynamic forces encountered appeared to be large enough to cause considerable damage to the thin aluminum leading edges of the rotor blades.

Improved Analytical Potentials for the a ^3Σu+ and X ^1Σg+ States of {Cs_2}

NASA Astrophysics Data System (ADS)

Baldwin, Jesse; Le Roy, Robert J.

2012-06-01

Recent studies of the collisional properties of ultracold Cs atoms have led to a renewed interest in the singlet and triplet ground-state potential energy functions of Cs_2. Coxon and Hajigeorgiou recently determined an analytic potential function for the X ^1Σ_g^+ state that accurately reproduces a large body of spectroscopic data that spanned 99.45% of the potential well. However, their potential explicitly incorporates only the three leading inverse-power terms in the long-range potential, and does not distinguish between the three asymptotes associated with the different Cs atom spin states. Similarly, Xie et al. have reported two versions of an analytic potential energy function for the a ^3Σ_u^+ state that they determined from direct potential fits to emission data that spanned 93 % of its potential energy well. However, the tail of their potential function model was not constrained to have the inverse-power-sum form required by theory. Moreover, a physically correct description of cold atom collision phenomena requires the long-range inverse-power tails of these two potentials to be identical, and they are not. Thus, these functions cannot be expected to describe cold atom collision properties correctly. The present paper describes our efforts to determine improved analytic potential energy functions for these states that have identical long-range tails, and fully represent all of the spectroscopic data used in the earlier worka,b,c as well as photoassociation data that was not considered there and experimental values of the collisional scattering lengths for the two states. J. A. Coxon and P. Hajigeorgiou, J. Chem. Phys. 132, 09105 (2010). F. Xie et al. J. Chem. Phys. 130 051102 (2009). F. Xie et al. J. Chem. Phys. 135, 024303 (2011) J. G. Danzl et al., Science, 321, 1062 (2008). C. Chin, et al., Phys. Rev. Lett. 85, 2717 (2000) P. J. Leo, C. J. Williams, and P. S. Julienne, Phys. Rev. Lett. 85, 2721 (2000)

Turbojet-exhaust-nozzle secondary-airflow pumping as an exit control of an inlet-stability bypass system for a Mach 2.5 axisymmetric mixed-compression inlet. [Lewis 10- by 10-ft. supersonic wind tunnel test

NASA Technical Reports Server (NTRS)

Sanders, B. W.

1980-01-01

The throat of a Mach 2.5 inlet that was attached to a turbojet engine was fitted with large, porous bleed areas to provide a stability bypass system that would allow a large, stable airflow range. Exhaust-nozzle, secondary-airflow pumping was used as the exit control for the stability bypass airflow. Propulsion system response and stability bypass performance were obtained for several transient airflow disturbances, both internal and external. Internal airflow disturbances included reductions in overboard bypass airflow, power lever angle, and primary-nozzle area, as well as compressor stall. Nozzle secondary pumping as a stability bypass exit control can provide the inlet with a large stability margin with no adverse effects on propulsion system performance.

Novel Approach to Conducting Blast Load Analyses Using Abaqus/Explicit-CEL

DTIC Science & Technology

2010-05-01

versus uncased, effects of afterburning , angle of incidence with respect to incoming shock, nearby geometry/barriers interacting with the shock...2. Blast parameters as a function of scaled distance – from TNT air blast data (DOE/TIC-11268, 1981). Due to inertial effects, the volume of air...positive phase duration) can be determined for a particular scaled distance. Figure 2 was generated from TNT air blast data for bare, spherical charges

Section II: Reviews. Antihypertensive Drugs in Aircrew

DTIC Science & Technology

2001-06-01

Sleep 1997;20:806-11. utility in treating hypertensive emergencies. Only hydralazine and minoxidil are suitable for 7. Hampton JR. Comparative efficacy...like trials. European Heart J 1992;13(Suppl G):85- syndrome, the frequency of occurrence depending 91. on dose and duration. 4 Minoxidil causes severe

14 CFR 21.183 - Issue of standard airworthiness certificates for normal, utility, acrobatic, commuter, and...

Code of Federal Regulations, 2014 CFR

2014-01-01

... transport category large airplanes and jet (turbojet powered) airplanes that have not had any flight time... airplane is complete and meets the FAA-approved type design data. (g) Fuel venting and exhaust emission...

14 CFR 34.1 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... series, displacement, and design characteristics and are approved under the same type certificate... engines. Class TF means all turbofan or turbojet aircraft engines or aircraft engines designed for... turbine engines employed for propulsion of aircraft designed to operate at supersonic flight speeds...

U.S. Air Force Bomber Sustainment and Modernization: Background and Issues for Congress

DTIC Science & Technology

2014-06-04

turbofan Thrust: Each engine up to 17,000 pounds Wingspan: 185 feet (56.4 meters) Length: 159 feet, 4 inches (48.5 meters) Height: 40 feet, 8...precision and non-precision weapons. Features The B-1B’s blended wing and body configuration, variable-geometry wings, and turbofan afterburning engines... turbofan engine with afterburner Thrust: 30,000-plus pounds with afterburner, per engine Wingspan: 137 feet (41.8 meters) extended forward, 79 feet

40 CFR 87.1 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... engines. Class TF means all turbofan or turbojet aircraft engines or aircraft engines designed for... turbine engines employed for propulsion of aircraft designed to operate at supersonic flight speeds... Model means all commercial aircraft turbine engines which are of the same general series, displacement...

Compact high-speed MWIR spectrometer applied to monitor CO2 exhaust dynamics from a turbojet engine

NASA Astrophysics Data System (ADS)

Linares-Herrero, R.; Vergara, G.; Gutiérrez Álvarez, R.; Fernández Montojo, C.; Gómez, L. J.; Villamayor, V.; Baldasano Ramírez, A.; Montojo, M. T.; Archilla, V.; Jiménez, A.; Mercader, D.; González, A.; Entero, A.

2013-05-01

Dfgfdg Due to international environmental regulations, aircraft turbojet manufacturers are required to analyze the gases exhausted during engine operation (CO, CO2, NOx, particles, unburned hydrocarbons (aka UHC), among others).Standard procedures, which involve sampling the gases from the exhaust plume and the analysis of the emissions, are usually complex and expensive, making a real need for techniques that allow a more frequent and reliable emissions measurements, and a desire to move from the traditional gas sampling-based methods to real time and non-intrusive gas exhaust analysis, usually spectroscopic. It is expected that the development of more precise and faster optical methods will provide better solutions in terms of performance/cost ratio. In this work the analysis of high-speed infrared emission spectroscopy measurements of plume exhaust are presented. The data was collected during the test trials of commercial engines carried out at Turbojet Testing Center-INTA. The results demonstrate the reliability of the technique for studying and monitoring the dynamics of the exhausted CO2 by the observation of the infrared emission of hot gases. A compact (no moving parts), high-speed, uncooled MWIR spectrometer was used for the data collection. This device is capable to register more than 5000 spectra per second in the infrared band ranging between 3.0 and 4.6 microns. Each spectrum is comprised by 128 spectral subbands with aband width of 60 nm. The spectrometer operated in a passive stand-off mode and the results from the measurements provided information of both the dynamics and the concentration of the CO2 during engine operation.

46 CFR 310.1 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... maritime academies. (j) Deputy means the Deputy Maritime Administrator, Department of Transportation. (k... of this subpart A: (a) The 1958 Act means the Maritime Academy Act of 1958, Pub. L. 85-672. (b) Act means the Maritime Education and Training Act of 1980, Pub. L. 96-453, as amended. (c) Administration...

Quantitative adhesion characterization of antireflective coatings in multijunction photovoltaics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brock, Ryan; Rewari, Raunaq; Novoa, Fernando D.

We discuss the development of a new composite dual cantilever beam (cDCB) thin-film adhesion testing method, which enables the quantitative measurement of adhesion on the thin and fragile substrates used in multijunction photovoltaics. In particular, we address the adhesion of several 2- and 3-layer antireflective coating systems on multijunction cells. By varying interface chemistry and morphology through processing, we demonstrate the marked effects on adhesion and help to develop an understanding of how high adhesion can be achieved, as adhesion values ranging from 0.5 J/m2 to 10 J/m2 were measured. Damp heat (85 degrees C/85% RH) was used to invokemore » degradation of interfacial adhesion. We demonstrate that even with germanium substrates that fracture relatively easily, quantitative measurements of adhesion can be made at high test yield. The cDCB test is discussed as an important new methodology, which can be broadly applied to any system that makes use of thin, brittle, or otherwise fragile substrates.« less

Analysis of mixing in high-explosive fireballs using small-scale pressurised spheres

NASA Astrophysics Data System (ADS)

Courtiaud, S.; Lecysyn, N.; Damamme, G.; Poinsot, T.; Selle, L.

2018-02-01

After the detonation of an oxygen-deficient homogeneous high explosive, a phase of turbulent combustion, called afterburning, takes place at the interface between the rich detonation products and air. Its modelling is instrumental for the accurate prediction of the performance of these explosives. Because of the high temperature of detonation products, the chemical reactions are mixing-driven. Modelling afterburning thus relies on the precise description of the mixing process inside fireballs. This work presents a joint numerical and experimental study of a non-reacting reduced-scale set-up, which uses the compressed balloon analogy and does not involve the detonation of a high explosive. The set-up produces a flow similar to the one caused by a spherical detonation and allows focusing on the mixing process. The numerical work is composed of 2D and 3D LES simulations of the set-up. It is shown that grid independence can be reached by imposing perturbations at the edge of the fireball. The results compare well with the existing literature and give new insights on the mixing process inside fireballs. In particular, they highlight the fact that the mixing layer development follows an energetic scaling law but remains sensitive to the density ratio between the detonation products and air.

Rapid identification of serotypes of Mycobacterium avium-M. intracellulare complex by using infected swine sera and reference antigenic glycolipids.

PubMed

Ikawa, H; Oka, S; Murakami, H; Hayashi, A; Yano, I

1989-11-01

The species of 136 strains of acid-fast bacteria isolated from swine with mycobacteriosis were identified by numerical taxonomy and chemotaxonomy on the basis of mycolic acid subclass composition as members of the Mycobacterium avium-M. intracellulare (MAI) complex. The isolates were further classified by using both thin-layer chromatography of the antigenic glycopeptidolipids (GPL) obtained from the bacteria by the method of Tsang et al. (A. Y. Tsang, I. Drupa, M. Goldberg, J. K. McClatchy, and P. J. Brennan, Int. J. Syst. Bacteriol. 33:285-292, 1983) and the seroagglutination test devised by W. B. Schaefer (Am. Rev. Respir. Dis. 92[Suppl.]:85-93, 1965). For the reference standard, purified antigenic GPL of serotypes 4, 8, and 9 were isolated and their structures were analyzed by negative fast-atom bombardment-mass spectrometry. The fast-atom bombardment-mass spectrometric spectra of the intact GPL antigens of serotypes 4, 8, and 9 agreed with the structures reported earlier by Brennan et al. (P. J. Brennan and M. B. Goren, J. Biol. Chem. 254:4205-4211, 1979; P. J. Brennan, G. O. Aspinall, and J. E. Nam Shin, J. Biol. Chem. 256:6817-6822, 1981). With these antigenic GPL, the thin-layer chromatographic behaviors of the alkali-stable lipids of the above-described isolates were examined. These MAI complex isolates fell into the serotype 8 (85 strains), 4 (33 strains), and 9 (7 strains) and untypeable (11 strains) categories. Furthermore, an enzyme-linked immunosorbent assay (ELISA) based on type-specific glycolipid antigens and infected swine sera was used to diagnose the serological types of the MAI complex isolates. Of 14 cases typed by both the seroagglutination reaction and thin-layer chromatography, 13 showed clear agreement with the ELISA results. The results demonstrated that ELISA using infected sera was especially useful, and it can be recommended on the basis of simplicity, sensitivity, and specificity as an adjunct to the seroaggulutination test and thin-layer chromatography for identification of mycobacteria belonging to the MAI complex.

The Distance Dependence of Regional Phase Discriminants

DTIC Science & Technology

1992-11-09

600. 650. Ranqe fkml 19 RC - fenni obs 110. -rT T 105. 100. 95. 90. 85. 80. 75. 70. 65. S60. 00 55. S 50. 1- 45. 40. 35. 30. 25. 20. 15.L 10. 5. 0...Z -5.r. I...... , I . . I . 1.’ 111111, 111 LIL I J 50. 100. 150. 200. 250. 300. 350. 400. 450. 500. 550 600. 650 Range(kin] 20 TC - fenni obs 110...450. 500. 550. 600. 650. R;nnp fLNer] P&S - fenni 110. 105. 100. 95. 90. 85. 80. 75. 70.2 65. S60. 00 55.L c so 1- 45. 40. 35. 30. 25. 20

14 CFR 21.183 - Issue of standard airworthiness certificates for normal, utility, acrobatic, commuter, and...

Code of Federal Regulations, 2013 CFR

2013-01-01

... transport category large airplanes and jet (turbojet powered) airplanes that have not had any flight time... airplane is complete and meets the FAA-approved type design data. (g) Fuel venting and exhaust emission...

14 CFR 34.1 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... which are of the same general series, displacement, and design characteristics and are approved under... means all turbofan or turbojet aircraft engines or aircraft engines designed for applications that... employed for propulsion of aircraft designed to operate at supersonic flight speeds. Commercial aircraft...

14 CFR 34.1 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... which are of the same general series, displacement, and design characteristics and are approved under... means all turbofan or turbojet aircraft engines or aircraft engines designed for applications that... employed for propulsion of aircraft designed to operate at supersonic flight speeds. Commercial aircraft...

Influence of Thrust Level on the Architecture and Optimal Working Process Parameters of a Small-scale Turbojet for UAV

NASA Astrophysics Data System (ADS)

Kuz`michev, V. S.; Filinov, E. P.; Ostapyuk, Ya A.

2018-01-01

This article describes how the thrust level influences the turbojet architecture (types of turbomachines that provide the maximum efficiency) and its working process parameters (turbine inlet temperature (TIT) and overall pressure ratio (OPR)). Functional gasdynamic and strength constraints were included, total mass of fuel and the engine required for mission and the specific fuel consumption (SFC) were considered optimization criteria. Radial and axial turbines and compressors were considered. The results show that as the engine thrust decreases, optimal values of working process parameters decrease too, and the regions of compromise shrink. Optimal engine architecture and values of working process parameters are suggested for turbojets with thrust varying from 100N to 100kN. The results show that for the thrust below 25kN the engine scale factor should be taken into the account, as the low flow rates begin to influence the efficiency of engine elements substantially.

Effect of Afterbody-Ejector Configurations on the Performance at Transonic Speeds of a Pylon-Supported Nacelle Model having a Hot-Jet Exhaust

NASA Technical Reports Server (NTRS)

Swihart, John M.; Mercer, Charles E.; Norton, Harry T., Jr.

1959-01-01

An investigation of several afterbody-ejector configurations on a pylon-supported nacelle model has been completed in the Langley 16-foot transonic tunnel at Mach numbers from 0.80 to 1.05. The propulsive performance of two nacelle afterbodies with low boattailing and long ejector spacing was compared with a configuration corresponding to a turbojet-engine installation having a highly boattailed afterbody with a short ejector. The jet exhaust was simulated with a hydrogen peroxide turbojet simulator. The angle of attack was maintained at 0 deg, and the average Reynolds number based on body length was 20 x 10(exp 6). The results of the investigation indicated that the configuration with a conical afterbody with smooth transition to a 15 deg boattail angle had large beneficial jet effects on afterbody pressure-drag coefficient and had the best thrust-minus-drag performance of the afterbody-ejector configurations investigated.

The Secret of Guided Missile Re-Entry,

DTIC Science & Technology

1986-06-25

I RD-PAI169 598 THE SECRET OF GUIDED MISSILE RE-ENTRY(U) FOREIGN / I TECHNOLOGY DIV NRIGHT-PATTERSON RFB OH J CHEN ET AL. I 25 JUN 96 FTD-ID(RS)T...TECHNOLOGY DIVISION THE SECRET OF GUIDED MISSILE RE-ENTRY by Chen Jingzhong, An Sehua J L 0 7 ’:;85’ ’ 0 *Approved for public release; Distribution...unlimite t d. :. 86 7 034.. FTD- ID(RS)T-0459-86 HUMAN TRANSLATION FTD-ID(RS)T-0459-86 25 June 1986 MICROFICHE NR: F - - 0Q 9? THE SECRET OF GUIDED

A Review of Approaches to the Study of Turbulence Modification by Means of Non-Newtonian Additives

DTIC Science & Technology

1987-12-10

6a 69 77 80 84 85 JIB-’I REFERENCES ^ c? ■i:’:r>i g.iif:.5,- i6 ’Si " m 104 {!!--7l J- . I .t .<a /".r., i!!j,ivu.-- H ’-’.-^w^TiSvv...1971), Tanner 29 (1976), Onuki (1985) and Dash et al (1985). One very comprehensive structural hypothesis for the mechanism of drag reduction was...of the spring, and the moment of inertia, I , is given by the expression: I=bhVl2 with b being the width and h the thickness of the

Corrosion and Biofouling on the Non-Heat-Exchanger Surfaces of an Ocean Thermal Energy Conversion Power Plant. A Survey

DTIC Science & Technology

1979-05-01

8217• . 5-nitrothia~ol, 1 0 6 pesticides such as DDT1 0 6 and Nopcocide, 1 0 7 and juverile hormones. 1 0 8 Organometallic compounds that have...Technology, Vol. 1, No. 3, pp. 321-327 (1966). 61. Basil . .J. 1., "Report of Test , t Plastic Panels Exoosed in Sea- wate for One Year at Wrightsville Reacli...34 Proceedings of Controlled Release Pesticides Symposium, Wright State UnIv., Dayton, Ohict (1975). 85. Dick, R. J. et al., "Analysis of Buoy Coating

Spontaneous ignition in afterburner segment tests at an inlet temperature of 1240 K and a pressure of 1 atmosphere with ASTM jet-A fuel

NASA Technical Reports Server (NTRS)

Schultz, D. F.; Branstetter, J. R.

1973-01-01

A brief testing program was undertaken to determine if spontaneous ignition and stable combustion could be obtained in a jet engine afterburning operating with an inlet temperature of 1240 K and a pressure of 1 atmosphere with ASTM Jet-A fuel. Spontaneous ignition with 100-percent combustion efficiency and stable burning was obtained using water-cooled fuel spraybars as flameholders.

Turbojet-engine Starting and Acceleration

NASA Technical Reports Server (NTRS)

Mc Cafferty, R. J.; Straight, D. M.

1956-01-01

From considerations of safety and reliability in performance of gas-turbine aircraft, it is clear that engine starting and acceleration are of utmost importance. For this reason extensive efforts have been devoted to the investigation of the factors involved in the starting and acceleration of engines. In chapter III it is shown that certain basic combustion requirements must be met before ignition can occur; consequently, the design and operation of an engine must be tailored to provide these basic requirements in the combustion zone of the engine, particularly in the vicinity of the ignition source. It is pointed out in chapter III that ignition by electrical discharges is aided by high pressure, high temperature, low gas velocity and turbulence, gaseous fuel-air mixture, proper mixture strength, and-an optimum spark. duration. The simultaneous achievement of all these requirements in an actual turbojet-engine combustor is obviously impossible, yet any attempt to satisfy as many requirements as possible will result in lower ignition energies, lower-weight ignition systems, and greater reliability. These factors together with size and cost considerations determine the acceptability of the final ignition system. It is further shown in chapter III that the problem of wall quenching affects engine starting. For example, the dimensions of the volume to be burned must be larger than the quenching distance at the lowest pressure and the most adverse fuel-air ratio encountered. This fact affects the design of cross-fire tubes between adjacent combustion chambers in a tubular-combustor turbojet engine. Only two chambers in these engines contain spark plugs; therefore, the flame must propagate through small connecting tubes between the chambers. The quenching studies indicate that if the cross-fire tubes are too narrow the flame will not propagate from one chamber to another. In order to better understand the role of the basic factors in actual engine operation, many investigations have been conducted in single combustors from gas-turbine engines and in full-scale engines in altitude tanks and in flight. The purpose of the present chapter is to discuss the results of such studies and, where possible, to interpret these results qualitatively in terms of the basic requirements reported in chapter III. The discussion parallels the three phases of turbojet engine starting: (1) Ignition of the fuel-air mixture (2) Propagation of flame throughout the combustion zone (3) Acceleration of the engine to operating speed.

46 CFR 58.25-85 - Special requirements for tank vessels.

Code of Federal Regulations, 2010 CFR

2010-10-01

... (e), (h), (i), and (j); (2) Ensure working access to machinery and controls in the steering-gear compartment (which must include handrails and either gratings or other non-slip surfaces to ensure a safe working environment in case hydraulic fluid leaks); (3) Have two separate and independent steering-gear...

The Industrial Base and National Security: A New Strategy

DTIC Science & Technology

1993-04-01

addresses this issue in her article entitled, " Managing Innovation on the Factory Floor": Manufacturing managers often buy the most advanced...Incentives Program." Government Contract Number MDA903-85-C-0139 Final Report, 1986. 31 11. Tyre, Marcie J. " Managing Innovation On The Factory Floor

Compact Magnetic Antennas for Directional Excitation of Surface Plasmons

DTIC Science & Technology

2012-07-01

Steininger, G.; Koch, M.; von Plessen, G.; Feldmann, J. Launching surface plasmons into nanoholes in metal films. Appl. Phys. Lett. 2000, 76, 140−142...plasmons at single nanoholes in Au films. Appl. Phys. Lett. 2004, 85, 467−469. (14) Baudrion, A.-L.; et al. Coupling efficiency of light to surface

Analysis of Soldier Effectiveness in a Mine Resistant Ambush Protected Ground Vehicle

DTIC Science & Technology

2010-08-17

5% 15% 25% 50% 75% 85% 95% Figure 9: Overall thermal comfort CONCLUSION The effectiveness of Soldiers with varying physiological builds was...Curran, A., Pryor, J., Hepokoski, M. 2010 “Assessment of Various Environmental Thermal Loads on Passenger Thermal Comfort .” SAE Paper 2010-01-1205.

Atomic Energy Levels. As Derived From the Analyses of Optical Spectra. Volume 3

DTIC Science & Technology

1958-05-01

26756.70 0 1.24 1 27362. 55 1.06 10 1 .98626.50 1.443 S S 0 0 0 0 0 0 0 3® Mt --Coaniued Mo 1-Cmedaned Conf. De @al J Level Intera Oba. C;044 Del6 . J... De , 1 Level Inteval Ob, I Conig. Desig. J Level Interval Ob..g W 2 15. P7 L 146 83° 4 5M. 5 0 1.17 46’ S 51808.89 88 84’ 5 55957.80 1. 14 4w 6 51853...41772 --176.14 1.86 1 85&07 -14&.00 1.4041M4 728 10&3& 32 854 $2408. 07 165 4d0( GD)5 a 4D 31 10516. 34 1.44 4d$(a D)5p s ’ De 34 38560. 87 465. 33 L

On high suppression of NO x and CO emissions in gas-turbine plants with combined gas-and-steam cycles

NASA Astrophysics Data System (ADS)

Ivanov, A. A.; Ermakov, A. N.; Shlyakhov, R. A.

2010-12-01

In this work are given results of analyzing processes of production of nitrogen oxides (NO x ) and afterburning of CO when firing natural gas at combined-cycle gas-turbine plants. It is shown that for suppressing emissions of the said microcomponents it is necessary to lower temperature in hot local zones of the flame in which NOx is formed, and, in so doing, to avoid chilling of cold flame zones that prevents afterburning of CO. The required lowering of the combustion temperature can be provided by combustion of mixtures of methane with steam, with high mixing uniformity that ensures the same and optimum fraction of the steam "ballast" in each microvolume of the flame. In addition to chilling, the steam ballast makes it possible to maintain a fairly high concentration of hydroxil radicals in the flame zone as well, and this provides high burning out of fuel and reduction in carbon monoxide emissions (active steam ballast). Due to this fact the fraction of steam when firing its mixtures with methane in a gas-turbine plant can be increased up to the weight ratio 4: 1. In this case, the concentrations of NO x and CO in emissions can be reduced to ultra-low values (less than 3 ppm).

Restriction Fragment Length Polymorphisms of Virulence Plasmids in Rhodococcus equi

PubMed Central

Takai, Shinji; Shoda, Masato; Sasaki, Yukako; Tsubaki, Shiro; Fortier, Guillaume; Pronost, Stephane; Rahal, Karim; Becu, Teotimo; Begg, Angela; Browning, Glenn; Nicholson, Vivian M.; Prescott, John F.

1999-01-01

Virulent Rhodococcus equi, which is a well-known cause of pyogranulomatous pneumonia in foals, possesses a large plasmid encoding virulence-associated 15- to 17-kDa antigens. Foal and soil isolates from five countries—Argentina, Australia, Canada, France, and Japan—were investigated for the presence of 15- to 17-kDa antigens by colony blotting, using the monoclonal antibody 10G5, and the gene coding for 15- to 17-kDa antigens by PCR. Plasmid DNAs extracted from positive isolates were digested with restriction endonucleases BamHI, EcoRI, EcoT22I, and HindIII, and the digestion patterns that resulted divided the plasmids of virulent isolates into five closely related types. Three of the five types had already been reported in Canadian and Japanese isolates, and the two new types had been found in French and Japanese isolates. Therefore, we tentatively designated these five types 85-kb type I (pREAT701), 85-kb type II (a new type), 87-kb type I (EcoRI and BamHI type 2 [V. M. Nicholson and J. F. Prescott, J. Clin. Microbiol. 35:738–740, 1997]), 87-kb type II (a new type), and 90-kb (pREL1) plasmids. The 85-kb type I plasmid was found in isolates from Argentina, Australia, Canada, and France. Plasmid 87-kb type I was isolated in specimens from Argentina, Canada, and France. The 85-kb type II plasmid appeared in isolates from France. On the other hand, plasmids 87-kb type II and 90-kb were found only in isolates from Japan. These results revealed geographic differences in the distribution of the virulence plasmids found in the five countries and suggested that the restriction fragment length polymorphism of virulence plasmids might be useful to elucidate the molecular epidemiology of virulent R. equi in the world. PMID:10488224

14 CFR 21.183 - Issue of standard airworthiness certificates for normal, utility, acrobatic, commuter, and...

Code of Federal Regulations, 2012 CFR

2012-01-01

... transport category large airplanes and jet (turbojet powered) airplanes that have not had any flight time... airplane is complete and meets the FAA-approved type design data. (g) Fuel venting and exhaust emission...

14 CFR 34.1 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... series, displacement, and design characteristics and are approved under the same type certificate... engines. Class TF means all turbofan or turbojet aircraft engines or aircraft engines designed for... turbine engines employed for propulsion of aircraft designed to operate at supersonic flight speeds...

40 CFR 87.1 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR... turboprop engines. Class TF means all turbofan or turbojet aircraft engines or aircraft engines designed for... turbine engines employed for propulsion of aircraft designed to operate at supersonic flight speeds...

Performance of Compressor of XJ-41-V Turbojet Engine. 4; Performance Analysis Over Range of Compressor Speeds from 5000 to 10,000 RPM

NASA Technical Reports Server (NTRS)

Creagh, John W. R.; Ginsburg, Ambrose

1948-01-01

An investigation of the XJ-41-V turbojet-engine compressor was conducted to determine the performance of the compressor and to obtain fundamental information on the aerodynamic problems associated with large centrifugal-type compressors. The results of the research conducted on the original compressor indicated the compressor would not meet the desired engine-design air-flow requirements because of an air-flow restriction in the vaned collector. The compressor air-flow choking point occurred near the entrance to the vaned-collector passage and was instigated by a poor mass-flow distribution at the vane entrance and from relatively large negative angles of attack of the air stream along the entrance edges of the vanes at the outer passage wall and large positive angles of attack at the inner passage wall. As a result of the analysis, a design change of the vaned collector entrance is recommended for improving the maximum flow capacity of the compressor.

Parentocracy Revisited: Still a Relevant Concept for Understanding Middle Class Educational Advantage?

ERIC Educational Resources Information Center

Barrett DeWiele, Corinne E.; Edgerton, Jason D.

2016-01-01

In this paper, we revisit Brown's ("Br J Soc Educ" 14: 65-85, 1990) concept of "parentocracy" which has been informatively applied in educational research in a number of studies in various countries internationally--but almost none in North America. We provide an expanded conceptualization of parentocracy and suggest that it…

Wave Transformation Over Reefs: Evaluation of One-Dimensional Numerical Models

DTIC Science & Technology

2009-01-01

equations on an unstructured grid. Proceedings International Conference on Coastal Engineering ‘06 V1. San Diego, CA, 73-85. Baldock, T. E., P. Holmes , S...equations. Monthly Weather Review 91:99-164. Smith, J. M, A. R. Sherlock , and D. T. Resio. 2001. Steady state spectral wave model user’s manual

Improvements in Dynamic GPS Positions Using Track Averaging

DTIC Science & Technology

1999-08-01

Imagery and Mapping Agency 2 NIMA/SOEMD, Mail Stop D-85 Attn: Larry Kunz Kenneth Croisant 4600 Sangamore Road Bethesda, MD 20816 -5003 6. National...Imagery and Mapping Agency NIMA/ARR, Mail Stop D-82 Attn: William Wooden 4600 Sangamore Road Bethesda, MD 20816 -5003 7. Michael J. Full USAF SMC/CZD 2435

Excited Electronic and Vibrational State Decomposition of Energetic Materials and Model Systems on Both Nanosecond and Femtosecond Time Scales

DTIC Science & Technology

2014-07-22

differences among electronically excited nitro-containing molecules with different X–NO2 (X = C, N, O) bond connections. Nitromethane (NM...Dynamics of Nitromethane at 226 nm and 271 nm at both Nanosecond and Femtosecond Temporal Scales," J. Phys. Chem. A 113, 85 (2009).

46 CFR 58.25-85 - Special requirements for tank vessels.

Code of Federal Regulations, 2012 CFR

2012-10-01

... must meet equivalent standards to the satisfaction of the Commanding Officer, Marine Safety Center. (d... installed are non-duplicated hydraulic and if— (1) The actuators comply with § 58.25-60; and (2) In case of... (e), (h), (i), and (j); (2) Ensure working access to machinery and controls in the steering-gear...

46 CFR 58.25-85 - Special requirements for tank vessels.

Code of Federal Regulations, 2013 CFR

2013-10-01

... must meet equivalent standards to the satisfaction of the Commanding Officer, Marine Safety Center. (d... installed are non-duplicated hydraulic and if— (1) The actuators comply with § 58.25-60; and (2) In case of... (e), (h), (i), and (j); (2) Ensure working access to machinery and controls in the steering-gear...

Simulation of Gas-Surface Dynamical Interactions

DTIC Science & Technology

2007-07-01

the interacting particle on the surface. Trapping probabilities often scale as Ei cosn θi with n < 2. An exponent of n = 0 corresponds to total energy...1996). [85] A. E. Wiskerke, F. H. Geuzebroek, A. W. Kleyn, and B. E. Hayden, Surf. Sci. 272, 256 (1992). [86] J. E. Hurst , L. Wharton, K. C. Janda

Procedures for making gaseous industrial waste safe

NASA Astrophysics Data System (ADS)

Matros, Yu Sh; Noskov, Aleksandr S.

1990-10-01

The application of various methods (adsorption, absorption, thermal afterburning, catalytic purification, and others) for the removal of sulphur and nitrogen oxides, toxic organic compounds, hydrogen sulphide, and carbon monoxide from industrial waste gases is described. Much attention is devoted to the catalytic procedure for making the gases safe using an energy collecting non-stationary method (reversible process). The advantages and limitations of various gas purification methods are considered. The bibliography includes 279 references.

The Effect of Microstructure on the Properties of High Strength Aluminum Alloys

DTIC Science & Technology

1980-02-01

precracked samples were loaded with opposing bolts to constant crack opening displacement (COD) values. The notch with the precrack was sealed with Scotch tape ...Respectfully submitted: Edgar K. Starke, Jr. Principal Investigator Si Il I REFERENCES 1. P. C. Paris and F. Erdogan , J. Basic Eng., Vol. 85, 1963, p. 528

Introduction to Financial Management for Foreign Military Staff Officers

DTIC Science & Technology

1991-06-01

House: New York, 1986. 5. Ishikawa , Kaoru . What is Total Quality Control? The Japanese Way. Prentice-Hall: Englewood Cliffs, NJ., 1985. 6. Juran, J. M...the key to process improvement is the infinite human potential of an organization’s people." 5 [ Ishikawa , 85) 6. Processes, not people, are the root

40 CFR 258.10 - Airport safety.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Airport safety. 258.10 Section 258.10... SOLID WASTE LANDFILLS Location Restrictions § 258.10 Airport safety. (a) Owners or operators of new... meters) of any airport runway end used by turbojet aircraft or within 5,000 feet (1,524 meters) of any...

40 CFR 258.10 - Airport safety.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Airport safety. 258.10 Section 258.10... SOLID WASTE LANDFILLS Location Restrictions § 258.10 Airport safety. (a) Owners or operators of new... meters) of any airport runway end used by turbojet aircraft or within 5,000 feet (1,524 meters) of any...

14 CFR 21.231 - Applicability.

Code of Federal Regulations, 2011 CFR

2011-01-01

... brake horsepower; and (6) Propellers manufactured for use on engines covered by paragraph (a)(4) of this section; and (b) Issuing airworthiness approval tags for engines, propellers, and parts of products... small gliders; (2) Commuter category airplanes; (3) Normal category rotorcraft; (4) Turbojet engines of...

40 CFR 87.1 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... engines. Class TF means all turbofan or turbojet aircraft engines or aircraft engines designed for... turbine engines employed for propulsion of aircraft designed to operate at supersonic flight speeds... Model means all commercial aircraft turbine engines which are of the same general series, displacement...

40 CFR 87.1 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... engines. Class TF means all turbofan or turbojet aircraft engines or aircraft engines designed for... turbine engines employed for propulsion of aircraft designed to operate at supersonic flight speeds... Model means all commercial aircraft turbine engines which are of the same general series, displacement...

Research on hypersonic aircraft using pre-cooled turbojet engines

NASA Astrophysics Data System (ADS)

Taguchi, Hideyuki; Kobayashi, Hiroaki; Kojima, Takayuki; Ueno, Atsushi; Imamura, Shunsuke; Hongoh, Motoyuki; Harada, Kenya

2012-04-01

Systems analysis of a Mach 5 class hypersonic aircraft is performed. The aircraft can fly across the Pacific Ocean in 2 h. A multidisciplinary optimization program for aerodynamics, structure, propulsion, and trajectory is used in the analysis. The result of each element model is improved using higher accuracy analysis tools. The aerodynamic performance of the hypersonic aircraft is examined through hypersonic wind tunnel tests. A thermal management system based on the data of the wind tunnel tests is proposed. A pre-cooled turbojet engine is adopted as the propulsion system for the hypersonic aircraft. The engine can be operated continuously from take-off to Mach 5. This engine uses a pre-cooling cycle using cryogenic liquid hydrogen. The high temperature inlet air of hypersonic flight would be cooled by the same liquid hydrogen used as fuel. The engine is tested under sea level static conditions. The engine is installed on a flight test vehicle. Both liquid hydrogen fuel and gaseous hydrogen fuel are supplied to the engine from a tank and cylinders installed within the vehicle. The designed operation of major components of the engine is confirmed. A large amount of liquid hydrogen is supplied to the pre-cooler in order to make its performance sufficient for Mach 5 flight. Thus, fuel rich combustion is adopted at the afterburner. The experiments are carried out under the conditions that the engine is mounted upon an experimental airframe with both set up either horizontally or vertically. As a result, the operating procedure of the pre-cooled turbojet engine is demonstrated.

14 CFR 135.243 - Pilot in command qualifications.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Pilot in command qualifications. 135.243... Crewmember Requirements § 135.243 Pilot in command qualifications. (a) No certificate holder may use a person, nor may any person serve, as pilot in command in passenger-carrying operations— (1) Of a turbojet...

F-100A on ramp

NASA Technical Reports Server (NTRS)

1957-01-01

North American F-100A Super Sabre on the ramp near the NACA High-Speed Flight Station in 1957. Some airplane characteristics are: Fuselage length, feet 45.64 Wing span, feet Original wing 36.58 Extended wing 38.58 Power Plant: Pratt & Whitney J57-P7 turbojet engine with afterburner Airplane weight, pounds: Basic (without fuel, oil, water, pilot) 19,662

Microwave fidelity studies by varying antenna coupling

NASA Astrophysics Data System (ADS)

Köber, B.; Kuhl, U.; Stöckmann, H.-J.; Gorin, T.; Savin, D. V.; Seligman, T. H.

2010-09-01

The fidelity decay in a microwave billiard is considered, where the coupling to an attached antenna is varied. The resulting quantity, coupling fidelity, is experimentally studied for three different terminators of the varied antenna: a hard-wall reflection, an open wall reflection, and a 50Ω load, corresponding to a totally open channel. The model description in terms of an effective Hamiltonian with a complex coupling constant is given. Quantitative agreement is found with the theory obtained from a modified VWZ approach [J. J. M. Verbaarschot , Phys. Rep. 129, 367 (1985)10.1016/0370-1573(85)90070-5].

Interface Chemistry of Hg(1-x)Cd(x)Te.

DTIC Science & Technology

1985-05-08

ET AL. 08 MARY 85 N@8814-84-K-0545 UNCLASSIFIED F/G 7/4 MEl ’..mmmui V liii - - liii- 71776-97, IL 5 III" j " % 33 Il...II " II1# ’ ;’"" ,- 3.6...eV. The EDC for the clean surface is in good agreement with the results of Silberman et al.8 and Spicer et al.9 and exhibits a Te p-derived density...supported by NSF Grant DMR-20164. F . ............ -8- REFERENCES 1. W.E. Spicer, J.A. Silberman , I. Lindau, A.-B. Chen, A. Sher, and J.A. Wilson, J. Vac

Prime Contract Awards Alphabetically by Contractor, by State or Country, and Place, FY 85. Part 21 (Video Animation Systems Inc - Zytron Corporation).

DTIC Science & Technology

1985-01-01

22202-4302 ; a NAM E 0- FUND’NG ’SPONSORING Bb OFFICE SYMBOL 9 PROCUREMENT INSTRUMENT IDENTIFICATION NUMBER7 0 RGAN IZ A nON (if applicable) ’, fy Stare...CODES 18. SUBJECT TERMS (Continue on reverse if necessary and identify by block number) rIELD GROUP SUB-GROUP 9 ABSTRACT (Continue on reverse if necessary...used untl exhausted. SECURITY CLASSIFICATION OF THIS PAGE 86 3 18 135 ’- . * -’ -" LLJi -- <ZO z. I.D K Z. %.) v 0w 0- a La Z. L.-J. _ju j V) 9 , 1. caZ0 0

14 CFR 21.231 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-01-01

... category rotorcraft; (4) Turbojet engines of not more than 1,000 pounds thrust; (5) Turbopropeller and reciprocating engines of not more than 500 brake horsepower; and (6) Propellers manufactured for use on engines covered by paragraph (a)(4) of this section; and (b) Issuing airworthiness approval tags for engines...

Pricing American Asian options with higher moments in the underlying distribution

NASA Astrophysics Data System (ADS)

Lo, Keng-Hsin; Wang, Kehluh; Hsu, Ming-Feng

2009-01-01

We develop a modified Edgeworth binomial model with higher moment consideration for pricing American Asian options. With lognormal underlying distribution for benchmark comparison, our algorithm is as precise as that of Chalasani et al. [P. Chalasani, S. Jha, F. Egriboyun, A. Varikooty, A refined binomial lattice for pricing American Asian options, Rev. Derivatives Res. 3 (1) (1999) 85-105] if the number of the time steps increases. If the underlying distribution displays negative skewness and leptokurtosis as often observed for stock index returns, our estimates can work better than those in Chalasani et al. [P. Chalasani, S. Jha, F. Egriboyun, A. Varikooty, A refined binomial lattice for pricing American Asian options, Rev. Derivatives Res. 3 (1) (1999) 85-105] and are very similar to the benchmarks in Hull and White [J. Hull, A. White, Efficient procedures for valuing European and American path-dependent options, J. Derivatives 1 (Fall) (1993) 21-31]. The numerical analysis shows that our modified Edgeworth binomial model can value American Asian options with greater accuracy and speed given higher moments in their underlying distribution.

78 FR 63015 - Exhaust Emissions Standards for New Aircraft Gas Turbine Engines and Identification Plate for...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-23

... Turbine Engines and Identification Plate for Aircraft Engines AGENCY: Federal Aviation Administration (FAA... regulatory requirements for aircraft turbofan or turbojet engines with rated thrusts greater than 26.7... standards for certain turbine engine powered airplanes to incorporate the standards promulgated by the...

Jet Engines as High-Capacity Vacuum Pumps

NASA Technical Reports Server (NTRS)

Wojciechowski, C. J.

1983-01-01

Large diffuser operations envelope and long run times possible. Jet engine driven ejector/diffuser system combines two turbojet engines and variable-area-ratio ejector in two stages. Applications in such industrial proesses as handling corrosive fumes, evaporation of milk and fruit juices, petroleum distillation, and dehydration of blood plasma and penicillin.

14 CFR 121.400 - Applicability and terms used.

Code of Federal Regulations, 2010 CFR

2010-01-01

... purpose of this subpart, airplane groups are as follows: (1) Group I. Propeller driven, including— (i) Reciprocating powered; and (ii) Turbopropeller powered. (2) Group II. Turbojet powered. (c) For the purpose of... airplane of the same group. (2) Transition training. The training required for crewmembers and dispatchers...

Air-atomizing splash-cone fuel nozzle reduces pollutant emissions from turbojet engines

NASA Technical Reports Server (NTRS)

Ingebo, R. D.; Norgren, C. T.

1973-01-01

Advantages of fuel nozzle over conventional pressure-atomizing fuel nozzles: simplicity of construction, ability to distribute fuel-air mixture uniformly across full height of combustor without using auxiliary air supply, reliability when using contaminated fuels, and durability of nozzle at high operating temperatures.

Characterization of Influenza Virus-Induced Leukocyte Adherence to Human Umbilical Vein Endothelial Cell Monolayers

DTIC Science & Technology

1993-07-01

Minick. antibodies in infectious mononucleosis . Am. J. Med. 76:85. 1973. Culture of human endothelial cells derived from um- 5I. Friedman. H. M.. E...TCIDs5 ,, 50% tissue culture infectious dose, totoxicity assay using a colorimetric kit (LK-1(X), Proteins • • • •• • • S •112 VIRUS-INDUCED

On Stratified Vortex Motions under Gravity.

DTIC Science & Technology

1985-06-20

always destabi- lizes the flow. 16 The physical intepretation of Eqs. (5.2) can also be reached by similar arguments and will not be repeated here...34 ,= - . .. .. _ ,_. . . . - ’ - ., , • - - .. ’ .. . " 0i 0 N IE / . LU, 0 0 27 ii. 0> z c* L 4-J Ln 2 0 ) A. M L.L > 0 4 ,-0 ToVW FILMED * 8-85 DTIC

ONR Europe Reports. Computer Science/Computer Engineering in Central Europe: A Report on Czechoslovakia, Hungary, and Poland

DTIC Science & Technology

1992-08-01

Rychlik J.: Simulation of distributed control systems. Research report of Institute of Technology in 22 Pilsen no. 209-07-85, Jun. 1985 Kocur P... Kocur P.: Sensitivity analysis of reliability parameters. Proceedings of conf. FTSD, Brno, Jun. 1986, pp. 97-101 Smrha P., Kocur P., Racek S.: A

Constrained and Unconstrained Localization for Automated Inspection of Marine Propellers

DTIC Science & Technology

1991-05-01

associated control polyhedron and hq, (0 < i < m - 1, 0 < j n - 1) are positive weights. B1 v(u) and Bj,’v) are the B-spline basis functions over open...Inspection by Database Matching. Technical Report CMU-RI-TR-85-4, The Robotics Institute, Carnegie Mellon University, March, 1985. Tuohy, S. T., Patrikalakis

76 FR 53301 - Airworthiness Directives; Saab AB, Saab Aerosystems Model SAAB 2000 Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-26

....S. registry. We also estimate that it will take about 12 work-hours per product to comply with the basic requirements of this AD. The average labor rate is $85 per work-hour. Based on these figures, we... 01, dated September 3, 2009. (j) Within 30 days after accomplishing the inspection required by...

78 FR 12255 - Airworthiness Directives; Rolls-Royce (1971) Limited, Bristol Engine Division Turbojet Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-22

...: (202) 493-2251. For service information identified in this AD, contact Rolls-Royce plc, Corporate... received by the closing date and may amend this proposed AD based on those comments. We will post all... this AD, contact Rolls-Royce plc, Corporate Communications, P.O. Box 31, Derby, England, DE248BJ; phone...

14 CFR 135.243 - Pilot in command qualifications.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Pilot in command qualifications. 135.243... Crewmember Requirements § 135.243 Pilot in command qualifications. (a) No certificate holder may use a person, nor may any person serve, as pilot in command in passenger-carrying operations— (1) Of a turbojet...

14 CFR 135.243 - Pilot in command qualifications.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Pilot in command qualifications. 135.243... Crewmember Requirements § 135.243 Pilot in command qualifications. (a) No certificate holder may use a person, nor may any person serve, as pilot in command in passenger-carrying operations— (1) Of a turbojet...

Study on the Treatment of Wastewater Generated at KSC (Kennedy Space Center) STS (Space Transport System) Operations and Projected Effects on the Design of the STS Hazardous Waste Management Facility at Vandenberg AFB, California.

DTIC Science & Technology

1983-10-01

carbon monoxide gas (mostly converted to carbon dioxide during afterburning), alu- minum oxide particles, and hydrogen chloride gas. Additionally, a great...colorimetrically or with an oxidation -reduction probe (ORP). The laboratory tests used a colorimetric indi- cator N.N.-Dimethyl-P-Phenylene Diamine Sulfate...in the composite wastewater sample under both quiescent and dynamic conditions to determine the corrosivity of the fluid . The procedures followed and

Investigation of Noise Field and Velocity Profiles of an Afterburning Engine

NASA Technical Reports Server (NTRS)

North, Warren J.; Callaghan, E. E.; Lanzo, C. D.

1954-01-01

Sound pressure levels, frequency spectrum, and jet velocity profiles are presented for an engine-afterburner combination at various values of afterburner fuel - air ratio. At the high fuel-air ratios, severe low-frequency resonance was encountered which represented more than half the total energy in the sound spectrum. At similar thrust conditions, lower sound pressure levels were obtained from a current fighter air craft with a different afterburner configuration. The lower sound pressure levels are attributed to resonance-free afterburner operation and thereby indicate the importance of acoustic considerations in afterburner design.

Flight Engineer. Question Book. Expires September 1, 1991.

ERIC Educational Resources Information Center

Federal Aviation Administration (DOT), Washington, DC.

This question book was developed by the Federal Aviation Administration (FAA) to be used by FAA testing centers and FAA-designated written test examiners when administering the flight engineer written test. The book can be used to test applicants in the following flight engineer knowledge areas: basic, turbojet powered, turbopropeller powered, and…

Newburyport Harbor, Massachusetts; Report 2. Design for Hydrodynamics, Salinity, and Sedimentation. Hydraulic Model Investigation.

DTIC Science & Technology

1985-03-01

prototype, there was no supplemental provision for the passage of tidal flow at the southern model limits. Since the tidal flow in this area is quite small...iusii tiil ii signi II- t nt to A1 t Iiouil predoinancei~ir valu ofi 12.9) livr ~t n. Std ’M" I It , prt’dliiiiii Ic stA iI2B~ was lit Iihanged by...0) II It 96 S. at 74-1 ?zz K, Os wt C vi 4l Z40 1151 .qt .os *j- 0 QX. 9? r S’S -~ 4wat5 nw j. at ~ 0 > LT 367 I0 FILMED * 8-85 * DTIC

40 CFR 258.10 - Airport safety.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 25 2014-07-01 2014-07-01 false Airport safety. 258.10 Section 258.10... SOLID WASTE LANDFILLS Location Restrictions § 258.10 Airport safety. (a) Owners or operators of new... meters) of any airport runway end used by turbojet aircraft or within 5,000 feet (1,524 meters) of any...

Temperature in a J47-25 Turbojet-engine Combustor and Turbine Sections During Steady-state and Transient Operation in a Sea-level Test Stand

NASA Technical Reports Server (NTRS)

Morse, C R; Johnston, J R

1955-01-01

In order to determine the conditions of engine operation causing the most severe thermal stresses in the hot parts of a turbojet engine, a J47-25 engine was instrumented with thermocouples and operated to obtain engine material temperatures under steady-state and transient conditions. Temperatures measured during rated take-off conditions of nozzle guide vanes downstream of a single combustor differed on the order of 400 degrees F depending on the relation of the blades position to the highest temperature zone of the burner. Under the same operation conditions, measured midspan temperatures in a nozzle guide vane in the highest temperature zone of a combustor wake ranged from approximately 1670 degrees F at leading and trailing edges to 1340 degrees F at midchord on the convex side of the blade. The maximum measured nozzle-guide-vane temperature of 1920degrees at the trailing edge occurred during a rapid acceleration from idle to rated take-off speed following which the tail-pipe gas temperature exceeded maximum allowable temperature by 125 degrees F.

Parametric scramjet analysis

NASA Astrophysics Data System (ADS)

Choi, Jongseong

The performance of a hypersonic flight vehicle will depend on existing materials and fuels; this work presents the performance of the ideal scramjet engine for three different combustion chamber materials and three different candidate fuels. Engine performance is explored by parametric cycle analysis for the ideal scramjet as a function of material maximum service temperature and the lower heating value of jet engine fuels. The thermodynamic analysis is based on the Brayton cycle as similarly employed in describing the performance of the ramjet, turbojet, and fanjet ideal engines. The objective of this work is to explore material operating temperatures and fuel possibilities for the combustion chamber of a scramjet propulsion system to show how they relate to scramjet performance and the seven scramjet engine parameters: specific thrust, fuel-to-air ratio, thrust-specific fuel consumption, thermal efficiency, propulsive efficiency, overall efficiency, and thrust flux. The information presented in this work has not been done by others in the scientific literature. This work yields simple algebraic equations for scramjet performance which are similar to that of the ideal ramjet, ideal turbojet and ideal turbofan engines.

The Performance of a Subsonic Diffuser Designed for High Speed Turbojet-Propelled Flight

NASA Technical Reports Server (NTRS)

Biesiadny, Thomas J. (Technical Monitor); Wendt, Bruce J.

2004-01-01

An initial-phase subsonic diffuser has been designed for the turbojet flowpath of the hypersonic x43B flight demonstrator vehicle. The diffuser fit into a proposed mixed-compression supersonic inlet system and featured a cross-sectional shape transitioning flowpath (high aspect ratio rectangular throat-to-circular engine face) and a centerline offset. This subsonic diffuser has been fabricated and tested at the W1B internal flow facility at NASA Glenn Research Center. At an operating throat Mach number of 0.79, baseline Pitot pressure recovery was found to be just under 0.9, and DH distortion intensity was about 0.4 percent. The diffuser internal flow stagnated, but did not separate on the offset surface of this initial-phase subsonic diffuser. Small improvements in recovery (+0.4 percent) and DH distortion (-32 percent) were obtained from using vane vortex generator flow control applied just downstream of the diffuser throat. The optimum vortex generator array patterns produced inflow boundary layer divergence (local downwash) on the offset surface centerline of the diffuser, and an inflow boundary layer convergence (local upwash) on the centerline of the opposite surface.

Performance of Axial-Flow Supersonic Compressor of the XJ55-FF-1 Turbojet Engine. IV - Analysis of Compressor Operation over a Range of Equivalent Tip Speeds from 801 to 1614 Feet Per Second

NASA Technical Reports Server (NTRS)

Graham, Robert C.; Hartmann, Melvin J.

1949-01-01

An investigation was conducted to determine the performance characteristics of the axial-flow supersonic compressor of the XJ55-FF-1 turbojet engine. An analysis of the performance of the rotor was made based on detailed flow measurements behind the rotor. The compressor apparently did not obtain the design normal-shock configuration in this investigation. A large redistribution of mass occurred toward the root of the rotor over the entire speed range; this condition was so acute at design speed that the tip sections were completely inoperative. The passage pressure recovery at maximum pressure ratio at 1614 feet per second varied from a maximum of 0.81 near the root to 0.53 near the tip, which indicated very poor efficiency of the flow process through the rotor. The results, however, indicated that the desired supersonic operation may be obtained by decreasing the effective contraction ratio of the rotor blade passage.

Investigation of acceleration characteristics of a single-spool turbojet engine

NASA Technical Reports Server (NTRS)

Oppenheimer, Frank L; Pack, George J

1953-01-01

Operation of a single-spool turbojet engine with constant exhaust-nozzle area was investigated at one flight condition. Data were obtained by subjecting the engine to approximate-step changes in fuel flow, and the information necessary to show the relations of acceleration to the sensed engine variables was obtained. These data show that maximum acceleration occurred prior to stall and surge. In the low end of the engine-speed range the margin was appreciable; in the high-speed end the margin was smaller but had not been completely defined by these data. Data involving acceleration as a function of speed, fuel flow, turbine-discharge temperature, compressor-discharge pressure, and thrust have been presented and an effort has been made to show how a basic control system could be improved by addition of an override in which the acceleration characteristic is used not only to prevent the engine from entering the surge region but also to obtain acceleration along the maximum acceleration line during throttle bursts.

The Effect of Atmospheric Pressure and Temperature on Air Shock and Appendixes I and II

DTIC Science & Technology

1950-05-01

other ex- plosives than :sntolite and TNT , for which data are of lower reproduci- bility than for Thntolite, this method should give better results than...the chamber will be extended over a ruch longer time than is possible with pie..age rec crdin-gZ To .nvestigato the aff.ct of afterburning , it is... TNT L S. . Bombs", by Joseph Sperrazza and Elaine Gilinson, March 1948. Ballistic Research Laboratories Report No. 681, "Comparison of the Blast from

Reactive Shear Layer Mixing and Growth Rate Effects on Afterburning Properties for Axisymetric Rocket Engine Plumes

DTIC Science & Technology

2006-09-01

water, carbon monoxide and carbon dioxide . The ratio of specific heats is reduced as the number of atoms in the molecule increases and as the...The flow of the jet is faster than the surrounding air, and since gas turbine engines run fuel lean, the exhaust products have generally fully reacted...previous types by several characteristics. The core of the rocket exhaust flowfield is fuel rich, and unlike gas turbine engines, which burn fuel

Development of Emissions Measurement Techniques for Afterburning Turbine Engines. Supplement 2. Afterburner Plume Computer Program User’s Manual.

DTIC Science & Technology

1975-10-01

AO-AUHb b27 UNCLASSIFIED GENERAL ELECTRIC CO CINCINNATI OHIO AIRCRAFT ENGINE GROUP F/G 2l/5 DEVELOPMENT OF EMISSIONS MEASUREMENT TECHNIQUES FOR...Colley D.R. Ferguson M.A. Smith GENERAL ELECTRIC COMPANY Aircraft Engine Group Cincinnati, Ohio 45215 October 1975 Technical Report AFAPL-TR-7 5-52...Service (NTIS). At NTIS, it will be avail’ able to the general public, including foreign nations. This technical report has been reviewed and is

Proceedings of the Workshop on the Chemical Suppression of Rocket Afterburning and of Gun Muzzle Flash

DTIC Science & Technology

1987-03-01

We report here the first results of this gun simulator used in the study of muzzle flash. The test setup used is shown in Figure 18. Pressure ports...experiments. For the first tests , the exploding wires mentioned above ignited the gas mixture. Later, "soft" ignition by means of a single tungsten...wire, placed axially in the chamber, was also tested . The voltage pulse applied across this hot wire is shown in Figure 19. This "soft" ignition

Operationally efficient propulsion system study (OEPSS) data book. Volume 10; Air Augmented Rocket Afterburning

NASA Technical Reports Server (NTRS)

Farhangi, Shahram; Trent, Donnie (Editor)

1992-01-01

A study was directed towards assessing viability and effectiveness of an air augmented ejector/rocket. Successful thrust augmentation could potentially reduce a multi-stage vehicle to a single stage-to-orbit vehicle (SSTO) and, thereby, eliminate the associated ground support facility infrastructure and ground processing required by the eliminated stage. The results of this preliminary study indicate that an air augmented ejector/rocket propulsion system is viable. However, uncertainties resulting from simplified approach and assumptions must be resolved by further investigations.

VizieR Online Data Catalog: Brown dwarf surface gravities with Keck/NIRSPEC (Martin , 2017)

NASA Astrophysics Data System (ADS)

Martin, E. C.; Mace, G. N.; McLean, I. S.; Logsdon, S. E.; Rice, E. L.; Kirkpatrick, J. D.; Burgasser, A. J.; McGovern, M. R.; Prato, L.

2017-10-01

In this paper, we follow up on prior NIR spectroscopy by our group and use a modified Allers & Liu (A13, 2013ApJ...772...79A) method to determine surface gravities for 228 M, L, and T dwarfs. We present medium-resolution (R~20000) J-band spectra of 85 M dwarfs, 92 L dwarfs, and 51 T dwarfs obtained as part of the Keck NIRSPEC Brown Dwarf Spectroscopic Survey (BDSS). Ninety-seven spectra were published previously in McLean+ (2003ApJ...596..561M), Burgasser+ (2003ApJ...592.1186B), McGovern+ (2004ApJ...600.1020M), Rice+ (2010ApJS..186...63R), Kirkpatrick+ (2010, J/ApJS/190/100), Luhman (2012ARA&A..50...65L), Thompson+ (2013PASP..125..809T), Mace+ (2013, J/ApJS/205/6), Mace+ (2013ApJ...777...36M), and Kirkpatrick+ (2014, J/ApJ/783/122), and the remaining 131 are presented here for the first time. Observation information (spanning 1999 Apr to 2015 Mar) for all of the targets in our sample is listed in Table 1. (4 data files).

77 FR 46684 - In the Matter of: Universal Industries Limited, Inc., 3050 SW 14th Place Unit 3, Boynton Beach...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-06

... export from the United States to Singapore military aircraft parts, that is approximately 200 J-85 Stage... owned, possessed or controlled by the Denied Person, or service any item, of whatever origin, that is... the foreign-produced direct product of U.S.-origin technology. V. This Order is effective immediately...

Military Reengineering Between the World Wars

DTIC Science & Technology

2005-01-01

University. I am also grateful to Tamera Dorland for her much-needed perspectives. Any inaccura- cies remain mine alone. xxiii Abbreviations FFRDC...or shape any motorization opportunities that under- mined their branch’s immediate interests. Infantry chiefs such as Robert Allen, Stephen Fuqua...Warfare, An- napolis, Md.: Naval Institute Press, 1983, p. 187. 85 Kenneth J. Clifford, Amphibious Warfare Development in Britannia and America from

Saturn Apollo Program

NASA Image and Video Library

1960-01-01

The powerful J-2 engine is prominent in this photograph of a Saturn V Third Stage (S-IVB) resting on a transporter in the Manufacturing Facility at Marshall Space Flight Center in Huntsville, Alabama. The towering 363-foot Saturn V was a multi-stage, multi-engine launch vehicle standing taller than the Statue of Liberty. Altogether, the Saturn V engines produced as much power as 85 Hoover Dams.

A Universal Impedance for Soils

DTIC Science & Technology

1975-10-01

Circles are from our universal formulae. .1 󈧰 100 lilt I I I I I11 I I I I I 300 Percent waer - - 10-2 s...1 30 otemn Wolff 43 4L) 0 00 1 10 percent waer ... Kevin McCarthy, 0-85-71 ATTN: Louis Brickmore ATTN- Tech. Lib. ATTN: L-365 Dept. 81-20 National Academy of Sciences ATTN: Philip J. Hart, Dept 81-14

A flow calorimeter for determining combustion efficiency from residual enthalpy of exhaust gases

NASA Technical Reports Server (NTRS)

Evans, Albert; Hibbard, Robert R

1954-01-01

A flow calorimeter for determining the combustion efficiency of turbojet and ram-jet combustors from measurement of the residual enthalpy of combustion of the exhaust gas is described. Briefly, the calorimeter catalytically oxidizes the combustible constituents of exhaust-gas samples, and the resultant temperature rise is measured. This temperature rise is related to the residual enthalpy of combustion of the sample by previous calibration of the calorimeter. Combustion efficiency can be calculated from a knowledge of the residual enthalpy of the exhaust gas and the combustor input enthalpy. An accuracy of +-0.2 Btu per cubic foot was obtained with prepared fuel-air mixtures, and the combustion efficiencies of single turbojet combustors measured by both the flow-calorimeter and heat-balance methods compared within 3 percentage units. Flow calorimetry appears to be a suitable method for determining combustion efficiencies at high combustor temperatures where ordinary thermocouples cannot be used. The method is fundamentally more accurate than heat-balance methods at high combustion efficiencies and can be used to verify near-100-percent efficiency data.

Acceleration of high-pressure-ratio single-spool turbojet engine as determined from component performance characteristics I : effect of air bleed at compressor outlet

NASA Technical Reports Server (NTRS)

Rebeske, John J , Jr; Rohlik, Harold E

1953-01-01

An analytical investigation was made to determine from component performance characteristics the effect of air bleed at the compressor outlet on the acceleration characteristics of a typical high-pressure-ratio single-spool turbojet engine. Consideration of several operating lines on the compressor performance map with two turbine-inlet temperatures showed that for a minimum acceleration time the turbine-inlet temperature should be the maximum allowable, and the operating line on the compressor map should be as close to the surge region as possible throughout the speed range. Operation along such a line would require a continuously varying bleed area. A relatively simple two-step area bleed gives only a small increase in acceleration time over a corresponding variable-area bleed. For the modes of operation considered, over 84 percent of the total acceleration time was required to accelerate through the low-speed range ; therefore, better low-speed compressor performance (higher pressure ratios and efficiencies) would give a significant reduction in acceleration time.

Unmanned Intratheater Airlift

DTIC Science & Technology

2010-12-01

aircraft use a standard forward- thrust turbojet or turbofan engine that provides forward thrust while in forward flight. However, when performing...Afghanistan and Iraq required resupply by ground convoy, airdrop, or verticaltakeoff- and-landing aircraft . Unfortunately, the Department of Defense (DOD...challenges and requirements, the author suggests the use of remotely piloted aircraft (RPA) as a potential solution. Focusing on existing and quickly

77 FR 76842 - Exhaust Emissions Standards for New Aircraft Gas Turbine Engines and Identification Plate for...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-31

... Aircraft Gas Turbine Engines and Identification Plate for Aircraft Engines AGENCY: Federal Aviation... , compliance flexibilities, and other regulatory requirements for aircraft turbofan or turbojet engines with...)(v). 6. Standards for Supersonic Aircraft Turbine Engines This final rule contains carbon monoxide...

78 FR 63017 - Exhaust Emissions Standards for New Aircraft Gas Turbine Engines and Identification Plate for...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-23

... Aircraft Gas Turbine Engines and Identification Plate for Aircraft Engines AGENCY: Federal Aviation... (NO X ), compliance flexibilities, and other regulatory requirements for aircraft turbofan or turbojet... adopting the gas turbine engine test procedures of the International Civil Aviation Organization (ICAO...

General Aviation Pilot and Aircraft Activity Survey.

DTIC Science & Technology

1985-09-01

Balloon 3. Rotorcraft piston 6. Turbojet 4. HOW 010 YOU OBTAIN THE AIRCRAFT FOR THIS FLIGHT’ iCheck only one) 1. Individual owner or partnership 4...you prefer that the destination airport in requirements? (Check all) your cross-country flight have the following facilities ? iCheck ail) Ve wll Ade

14 CFR 135.243 - Pilot in command qualifications.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Pilot in command qualifications. 135.243... Crewmember Requirements § 135.243 Pilot in command qualifications. (a) No certificate holder may use a person, nor may any person serve, as pilot in command in passenger-carrying operations— (1) Of a turbojet...

14 CFR 135.243 - Pilot in command qualifications.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Pilot in command qualifications. 135.243... Crewmember Requirements § 135.243 Pilot in command qualifications. (a) No certificate holder may use a person, nor may any person serve, as pilot in command in passenger-carrying operations— (1) Of a turbojet...

An Experimental Study of a Catalytic Combustor for an Expendable Turbojet Engine

DTIC Science & Technology

1978-03-01

automobiles have catalytic converters in their exhaust systems for oxidizing unburned hydrocarbons, carbon monoxide, etc., to produce a cleaner exhaust. A...1 ratio for automobiles . Other noble metals are sometimes used, in varying ratio and loading (amount of catalyst. per area) configerations (Ref 7). 2

76 FR 75735 - Certification of Part 23 Turbofan- and Turbojet-Powered Airplanes and Miscellaneous Amendments

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-02

... airplanes in air commerce by prescribing minimum standards required in the interest of safety for the design... prescribes new safety standards for the design of normal, utility, acrobatic, and commuter category airplanes... Category To Include Turbojets C. Performance, Flight Characteristics, and Other Design Considerations D...

Analysis of Rocket, Ram-Jet, and Turbojet Engines for Supersonic Propulsion of Long-Range Missles. II - Rocket Missile Performance

NASA Technical Reports Server (NTRS)

Huff, Vearl N.; Kerrebrock, Jack

1954-01-01

The theoretical performance of a two-stage ballistic rocket mis having a centerbody and two parallel boosters was investigated for J oxygen and ammonia-fluorine propellants. Both power-plant and missi parameters were optimized to give minimum cost on-the basis of the analysis for a range of 5500 nautical miles. After optimum values were found, each parameter was varied independently to determine its effect on performance of the missile. The missile using the ammonia-fluorine propellant weighs about one half as much as a missile using JP4-oxygen. Based on an expected unit cost of fluorine in quantity production, the ammonia-fluorine missile has a substantially lower relative cost than a JP4-oxygen missile. Optimum chamber pressures for both propellant systems and for both the centerbody and boosters were between 450 and 600 pounds per square inch. High design altitudes for the exhaust nozzle are desirable for both the centerbody and boosters. For the centerbody, the design altitude should be between 45,000 and 60,000 feet, with the value for ammonia-fluorine lower than that for JP4-oxygen. For the boosters, the design altitude should be 20,000 to 30,000 feet, with the value for the ammonia-fluorine. missile higher.

Pollution reduction technology program for small jet aircraft engines: Class T1

NASA Technical Reports Server (NTRS)

Bruce, T. W.; Davis, F. G.; Mongia, H. C.

1977-01-01

Small jet aircraft engines (EPA class T1, turbojet and turbofan engines of less than 35.6 kN thrust) were evaluated with the objective of attaining emissions reduction consistent with performance constraints. Configurations employing the technological advances were screened and developed through full scale rig testing. The most promising approaches in full-scale engine testing were evaluated.

77 FR 66769 - Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG Turbojet Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-07

.... (5) If any bolt is found broken in the HPT shaft air seal sleeve, inspect the HPT stage 1 disc for...) bearing support assembly and HPT air seal sleeve bolts identified that, before installation, those bolts... assembly, high-pressure turbine (HPT) bearing support assembly, and HPT air seal sleeve. (2) If engine...

Visualization of turbulent combustion of TNT detonation products in a steel vessel

NASA Astrophysics Data System (ADS)

Wolański, P.; Gut, Z.; Trzciński, W. A.; Szymańczyk, L.; Paszula, J.

Mixing and afterburning of TNT detonation products in a steel vessel are recorded by the use of the Schlieren visualization system and high speed photography. The vessel is filled with air or 50% oxygen enriched air. Overpressure histories at the vessel wall are also recorded by using pressure transducers. In these experiments nitrogen, air or 50% oxygen enriched air are used as vessel fillers. The Oppenheim-Kuhl theory of thermodynamics of closed systems is applied to estimate the released energy on the basis of pressure histories.

Preliminary Data on the Effects of Inlet Pressure Distortions on the J57-P-1 Turbojet Engine

NASA Technical Reports Server (NTRS)

Wallner, Lewis E.; Lubick, Robert J.; Einstein, Thomas H.

1954-01-01

An investigation to determine the steady-state and surge characteristics of the J57-P-1 two-spool turbojet engine with various inlet air-flow distortions was conducted in the altitude wind tunnel at the NACA Lewis laboratory. Along with a uniform inlet total-pressure distribution, one circumferential and three radial pressure distortions were investigated. Data were obtained over a complete range of compressor speeds both with and without intercompressor air bleed at a flight Mach number of 0.8 and at altitudes of 35,000 and 50,000 feet. Total-pressure distortions of the magnitudes investigated had very little effect on the steady-state operating line for either the outer or inner compressor. The small radial distortions investigated also had engine over that obtained with the uniform inlet pressure distribution. The circumferential distortion, however, raised the minimum speed at which the engine could operate without encountering surge when the intercompressor bleeds were closed. This increase in minimum speed resulted in a substantial reduction in the operable speed range accompanied by a reduction in the altitude operating limit.

Defining the Ecological Coefficient of Performance for an Aircraft Propulsion System

NASA Astrophysics Data System (ADS)

Şöhret, Yasin

2018-05-01

The aircraft industry, along with other industries, is considered responsible these days regarding environmental issues. Therefore, the performance evaluation of aircraft propulsion systems should be conducted with respect to environmental and ecological considerations. The current paper aims to present the ecological coefficient of performance calculation methodology for aircraft propulsion systems. The ecological coefficient performance is a widely-preferred performance indicator of numerous energy conversion systems. On the basis of thermodynamic laws, the methodology used to determine the ecological coefficient of performance for an aircraft propulsion system is parametrically explained and illustrated in this paper for the first time. For a better understanding, to begin with, the exergy analysis of a turbojet engine is described in detail. Following this, the outputs of the analysis are employed to define the ecological coefficient of performance for a turbojet engine. At the end of the study, the ecological coefficient of performance is evaluated parametrically and discussed depending on selected engine design parameters and performance measures. The author asserts the ecological coefficient of performance to be a beneficial indicator for researchers interested in aircraft propulsion system design and related topics.

Short Forms of the Wechsler Memory Scale--Revised: Cross- Validation and Derivation of a Two-Subtest Form.

ERIC Educational Resources Information Center

van den Broek, Anneke; Golden, Charles J.; Loonstra, Ann; Ghinglia, Katheryne; Goldstein, Diane

1998-01-01

Indicated excellent cross-validations with correlation of 0.99 for past formulas (J. L. Woodard and B. N. Axelrod, 1995; B. N. Axelrod et al, 1996) for estimating the Wechsler Memory Scale- Revised General Memory and Delayed Recall Indexes. Over 85% of the estimated scores were within 10 points of actual scores. Age, education, diagnosis, and IQ…

Second Annual Safar Symposium

DTIC Science & Technology

2005-10-01

the polio epi- ery, and control of infection . Both were ventilation, cardiopulmonary resuscita- demic of 1948 and 1949 in Los Angeles, committed to...School of Medicine dents, fellows, and professional nurses, overwhelming cancer and infection and its division of critical care medicine To his...critically modynamic studies on clinical shock associ- tial cardiorespiratory variables in defining ill. Mod Med 1971; 39:83-85 ated with infection . Am J

Northeast Artificial Intelligence Consortium (NAIC). Volume 2. Discussing, Using, and Recognizing Plans

DTIC Science & Technology

1990-12-01

knowledge and meta-reasoning. In Proceedings of EP14-85 ("Encontro Portugues de Inteligencia Artificial "), pages 138-154, Oporto, Portugal, 1985. [19] N, J...See reverse) 7. PERFORMING ORGANIZATION NAME(S) AND ADORESS(ES) 8. PERFORMING ORGANIZATION Northeast Artificial Intelligence...ABSTRACTM-2.,-- The Northeast Artificial Intelligence Consortium (NAIC) was created by the Air Force Systems Command, Rome Air Development Center, and

LGB and Questioning Students in Schools: The Moderating Effects of Homophobic Bullying and School Climate on Negative Outcomes

ERIC Educational Resources Information Center

Birkett, Michelle; Espelage, Dorothy L.; Koenig, Brian

2009-01-01

Lesbian, gay, and bisexual students (LGB) and those questioning their sexual orientation are often at great risk for negative outcomes like depression, suicidality, drug use, and school difficulties (Elliot and Kilpatrick, How to Stop Bullying, A KIDSCAPE Guide to Training, 1994; Mufoz-Plaza et al., High Sch J 85:52-63, 2002; Treadway and Yoakam,…

The Role of Erythropoietin Signaling in Human Cancer

DTIC Science & Technology

2004-01-01

Semenza GL. Hearts from rodents exposed to intermittent hypoxia or erythropoietin are protected against ischemia - reperfusion injury . Circulation, 2003...against ischemia - reperfusion injury . Circulation, 2003; 108:79-85. 18. Wu H, Lee SH, Gao J, Liu X and Iruela-Arispe ML. Inactivation of... injury of the brain and spinal cord39, 40. It prevents hypoxia/ ischemia -induced DNA fragmentation in an experimental model of perinatal asphyxia41. Epo

A perspective on thirty years of the Webb, Pearman and Leuning density corrections

Treesearch

Xuhui Lee; William J. Massman

2011-01-01

The density correction theory of Webb et al. (1980, Q J Roy Meteorol Soc 106: 85-100, hereafter WPL) is a principle underpinning the experimental investigation of surface fluxes of energy and masses in the atmospheric boundary layer. It has a long-lasting influence in boundary-layer meteorology and micrometeorology, and the year 2010 marks the 30th anniversary of the...

CFD assessment of the pollutant environment from RD-170 propulsion system testing

NASA Technical Reports Server (NTRS)

Wang, Ten-See; Mcconnaughey, Paul; Warsi, Saif; Chen, Yen-Sen

1995-01-01

Computational Fluid Dynamics (CFD) technology has been used to assess the exhaust plume pollutant environment of the RD-170 engine hot-firing on the F1 Test Stand at Marshall Space Flight Center. Researchers know that rocket engine hot-firing has the potential for forming thermal nitric oxides (NO(x)), as well as producing carbon monoxide (CO) when hydrocarbon fuels are used. Because of the complicated physics involved, however, little attempt has been made to predict the pollutant emissions from ground-based engine testing, except for simplified methods which can grossly underpredict and/or overpredict the pollutant formations in a test environment. The objective of this work, therefore, has been to develop a technology using CFD to describe the underlying pollutant emission physics from ground-based rocket engine testing. This resultant technology is based on a three-dimensional (3D), viscous flow, pressure-based CFD formulation, where wet CO and thermal NO finite-rate chemistry mechanisms are solved with a Penalty Function method. A nominal hot-firing of a RD-170 engine on the F1 stand has been computed. Pertinent test stand flow physics such as the multiple-nozzle clustered engine plume interaction, air aspiration from base and aspirator, plume mixing with entrained air that resulted in contaminant dilution and afterburning, counter-afterburning due to flame bucket water-quenching, plume impingement on the flame bucket, and restricted multiple-plume expansion and turning have been captured. The predicted total emission rates compared reasonably well with those of the existing hydrocarbon engine hot-firing test data.

DITERMINAL OXIDATION OF LONG-CHAIN ALKANES BY BACTERIA1

PubMed Central

Kester, A. S.; Foster, J. W.

1963-01-01

Kester, A. S. (The University of Texas, Austin) and J. W. Foster. Diterminal oxidation of long-chain alkanes by bacteria. J. Bacteriol. 85:859–869. 1963.—A corynebacterial organism capable of growing in mineral salts with individual pure alkanes as carbon sources produces a series of acids from the C10-C14 alkanes. They have been isolated in pure form and identified as monoic, ω-hydroxy monoic, and dioic acids containing the same number of carbon atoms as the substrate alkane. Oxidation took place at both terminal methyl groups—“diterminal oxidation.” Appropriate labeling experiments indicate that omega oxidation of fatty acids occurs in this organism and that an oxygenation with O2 occurs. Images PMID:14044955

The kinetic temperature and density of the Sagittarius B2 molecular cloud from observations of methyl cyanide

NASA Technical Reports Server (NTRS)

Cummins, S. E.; Green, S.; Thaddeus, P.; Linke, R. A.

1983-01-01

Observations of the K components of the CH3CN J = 4-to-3 rotational transition at 73.6 GHz, the 6-to-5 transition at 110.4 GHz, and the 7-to-6 transition at 128.7 GHz, yield a mean kinetic temperature value of 85 + or - 10 K and a mean H2 density of 110,000 + or - 50,000/cu cm for the central 2.0 arcmin of the Sgr B2 molecular cloud. Within the K = zero-to-4 ladders of CH3CN in Sgr B2, the populations of the radiatively coupled J levels are relaxed and exhibit a rotational temperature of about 16 K, which is similar to that of several linear molecules.

A Study of the Effects of Sensor Noise and Guidance Laws on SAM Effectiveness Against Cruise Missiles

DTIC Science & Technology

2015-06-01

submarines, or from the ground. Most CMs use air- breathing engines (i.e., pulsejet, ramjet, turbojet, or turbofan ), and some use rocket motors...lateral acceleration for a Turbofan engine–powered Tomahawk [26]. 1. Target Motion Using the same concept as in missile motion, we get the target

The M-15-aircraft (samolot M-15)

NASA Technical Reports Server (NTRS)

Leiiecki, R.

1978-01-01

The M-15 is an all-metal, semimonocoque, twin-tail-boom sesquiplane aircraft designed exclusively for agricultural support operations involving slow low-level flight. It is powered by a single Al-25 bypass turbojet engine used in the Yak-40 aircraft. Tanks for spraying chemicals are mounted between the lower and upper wings. Dimensions, weights, and performance data are tabulated.

Status of NASA full-scale engine aeroelasticity research

NASA Technical Reports Server (NTRS)

Lubomski, J. F.

1980-01-01

Data relevant to several types of aeroelastic instabilities were obtained using several types of turbojet and turbofan engines. In particular, data relative to separated flow (stall) flutter, choke flutter, and system mode instabilities are presented. The unique characteristics of these instabilities are discussed, and a number of correlations are presented that help identify the nature of the phenomena.

Solar thermal rocket engine (STRE) thrust characteristics at the change of engine operation mode and of the flight vehicle attitude in the solar system

NASA Astrophysics Data System (ADS)

Kudrin, O. I.

1993-10-01

Relationships are presented which describe changes in the thrust and specific impulse of a solar thermal rocket engine due to a change in the flow rate of the working fluid (hydrogen). Expressions are also presented which describe the variation of the STRE thrust and specific impulse with the distance between the flight vehicle and the sun. Results of calculations are presented for an STRE with afterburning of the working fluid (hydrogen + oxygen) using hydrogen heating by solar energy to a temperature of 2360 K.

Yield and Blast Analyses with a Unified Theory of Explosions

DTIC Science & Technology

1982-08-01

and afterburning of PBXN 103. The ambient conditions are for the test site at Socorro, NM, altitude -- 5200 feet. The input mass was 1038 pounds...essentially the warhead, most of which is PBXN -103. This was the very first test of the code. The relative yield is plFj.ed as T (time). The TOA yield, .90...YO =YO*1.0 ’Relative yields from earlier runs or fits 52 ’ 1 G = 106 cal = 4pi/3*le6 kg m^2/m^3/sec^2 53 AB=.00 ’Afterburning fraction 56 YO = Y0*(I

Propulsion System for Very High Altitude Subsonic Unmanned Aircraft

NASA Technical Reports Server (NTRS)

Bents, David J.; Mockler, Ted; Maldonado, Jaime; Harp, James L., Jr.; King, Joseph F.; Schmitz, Paul C.

1998-01-01

This paper explains why a spark ignited gasoline engine, intake pressurized with three cascaded stages of turbocharging, was selected to power NASA's contemplated next generation of high altitude atmospheric science aircraft. Beginning with the most urgent science needs (the atmospheric sampling mission) and tracing through the mission requirements which dictate the unique flight regime in which this aircraft has to operate (subsonic flight at greater then 80 kft) we briefly explore the physical problems and constraints, the available technology options and the cost drivers associated with developing a viable propulsion system for this highly specialized aircraft. The paper presents the two available options (the turbojet and the turbocharged spark ignited engine) which are discussed and compared in the context of the flight regime. We then show how the unique nature of the sampling mission, coupled with the economic considerations pursuant to aero engine development, point to the spark ignited engine as the only cost effective solution available. Surprisingly, this solution compares favorably with the turbojet in the flight regime of interest. Finally, some remarks are made about NASA's present state of development, and future plans to flight demonstrate the three stage turbocharged powerplant.

State-to-state collisional interelectronic and intraelectronic energy transfer involving CN A 2Π v=3 and X 2Σ+ v=7 rotational levels

NASA Astrophysics Data System (ADS)

Jihua, Guo; Ali, Ashraf; Dagdigian, Paul J.

1986-12-01

Collisional transfer within the CN A 2Π v=3 vibrational manifold and to the X 2Σ+ v=7 manifold has been studied with initial and final rotational state resolution by an optical-optical double resonance technique. Despite the large energy gap between these two manifolds, the interelectronic cross sections are significant for only a relatively small range of ΔJ, and there is no observable propensity for energy resonant, large ΔJ transitions. The even-odd alternation vs N, observed previously in vA=7 collisions [N. Furio, A. Ali, and P. J. Dagdigian, J. Chem. Phys. 85, 3860 (1986)] and indicative of the near homonuclear form of the CN-Ar interaction potentials, is even more pronounced here for vA=3. The relative rate of intraelectronic and interelectronic energy transfer for the vA=3 N=6 F1f initial level was found to be comparable to that for the corresponding vA=7 level, despite the smaller Franck-Condon factor and larger energy gap to the neighboring vX=vA-4 manifold for the former.

Instabilities of coupled Cu2O5 ladders

NASA Astrophysics Data System (ADS)

Schuetz, Florian; Marston, Brad

2008-03-01

The spin-ladder compound Sr14-xCaxCu24O41 has a complex phase diagram including charge-density-wave order as well as unconventional superconductivity under high pressure. Due to its quasi-one-dimensional natureootnotetextS. Lee, J. B. Marston, J. O. Fjaerestad, Phys. Rev. B 72, 075126. fundamental questions about the high-Tc cuprates might be more easily addressed in this context. However, due to the spatial proximity of neighboring ladders inter-ladder Coulomb repulsion as well as hopping between ladders might still be important. Using the functional renormalization groupootnotetextM. Salmhofer and C. Honerkamp, Prog. Theor. Physics 105, 1 (2001). and an analysis of generalized susceptibilities ootnotetextD. Zanchi and H. J. Schulz, Phys. Rev. B 61, 13609 (2000); C. J. Halboth and W. Metzner, Phys. Rev. Lett. 85, 5162 (2000)., we study a model of coupled Cu2O5 ladders ootnotetextK. Wohlfeld, A. M. Oles, and G. A. Sawatzky, Phys. Rev. B 75, 180501(R) (2007).. We investigate instabilities towards charge, spin, and pairing order as a function of hole doping, inter-ladder hopping, and interaction strength starting from experimentally relevant hopping parametersootnotetextT. F. A. Müller, et al., Phys. Rev. B 57, R12655 (1998)..

CaMn 2Sb 2: Spin waves on a frustrated antiferromagnetic honeycomb lattice

DOE PAGES

McNally, D. E.; Simonson, J. W.; Kistner-Morris, J. J.; ...

2015-05-22

Here we presenmore » t inelastic neutron scattering measurements of the antiferromagnetic insulator CaMn 2 Sb 2 , which consists of corrugated honeycomb layers of Mn. The dispersion of magnetic excitations has been measured along the H and L directions in reciprocal space, with a maximum excitation energy of ≈ 24 meV. These excitations are well described by spin waves in a Heisenberg model, including first-and second-neighbor exchange interactions J 1 and J 2 in the Mn plane and also an exchange interaction between planes. The determined ratio J 2/J 1 ≈ 1/6 suggests that CaMn 2 Sb 2 is an example of a compound that lies very close to the mean field tricritical point, known for the classical Heisenberg model on the honeycomb lattice, where the Néel phase and two different spiral phases coexist. Lastly, the magnitude of the determined exchange interactions reveals a mean field ordering temperature ≈ 4 times larger than the reported Néel temperature T N = 85 K, suggesting significant frustration arising from proximity to the tricritical point.« less

Acquiring Expertise.

DTIC Science & Technology

1983-01-31

LaBerge and Samuels, 1974): The reading process is too complex to operate completely at the declarative processing level. It can only work well when...1978, 85, 363-394. 44 The Acquisition of Expertise Lesgold Laberge , P. , & Samuels, S. J. Toward a theory of automatic information k - processing in...Menlo Park, CA 94025 Box 11A. Yale Station * New Haven, CT 06520 1 William B. Whitten Bell Laboratories 1 Dr. Albert Stevens 2D-610 Bolt Beranek

Low Back Pain: Considerations for Rotary-Wing Aircrew (Reprint)

DTIC Science & Technology

2012-12-01

1985 . Report No: DCIEM-85-R-49 . 8. Bongers PM, Hulshof CTJ, Dukstra L, Boshuizen HC . Back pain and exposure to whole body vibration...in helicopter pilots . Ergonomics 1990 ; 33 : 1007 – 26 . 9. Bovenzi M, Hulshof CT . An updated review of epidemiologic studies on the...injuries. In: LaDou J, ed. Current occupational and environmental medicine, 4th ed. New York: McGraw-Hill, Inc.; 2007 . 42. Hulshof C, van Zanten

Deals Among Rational Agents,

DTIC Science & Technology

1985-03-01

ARD-AI57 966 DEALS AMONG RATIONAL AGENTS(U) STANFORD UNIV CA DEPT OF 1/1lit COMPUTER SCIENCE J S ROSENSCHEIN ET AL. MAR 857 STAN-CS-85-1e42 NOO039-83... Rational Agents by Jeffrey S. Rosenschemn Michael R. Genesereth Contract N00039-83-c-0136 Department of Computer Science Stanford University Stanford, CA... Rational Agents Jeffrey S. Rosenschein Michael R. Genesereth COMPUTER SCIENCE DEPARTME NT Stanford University Sta-;!ord, California 94305 A ~ ,2 TA

Electronic State Decomposition of Energetic Materials and Model Systems

DTIC Science & Technology

2010-11-17

Nitromethane at 226 nm and 271 nm at both Nanosecond and Femtosecond Temporal Scales," J. Phys. Chem. A 113, 85 (2009). Y. Q. Guo, A. Bhattacharya and E...less "energetic". 8. Photodissociation Dynamics of Nitromethane at 226 and 271 nm at Both Nanosecond and Femtosecond Time Scales Photodissociation...of nitromethane has been investigated for decades both theoretically and experimentally; however, as a whole picture, the dissociation dynamics for

47 CFR 15.256 - Operation of level probing radars within the bands 5.925-7.250 GHz, 24.05-29.00 GHz, and 75-85 GHz.

Code of Federal Regulations, 2014 CFR

2014-10-01

... than 8 degrees. (j) Antenna side lobe gain. LPR devices operating under the provisions of this section must limit the side lobe antenna gain relative to the main beam gain for off-axis angles from the main beam of greater than 60 degrees to the levels provided in Table 2. Table 2—Antenna Side Lobe Gain...

Sociocultural Influences on Psychosocial Adjustment in Antarctica

DTIC Science & Technology

1985-12-01

od-; SOCIOCULTURAL INFLUENCES ON PSYCHOSOCIAL ADJUSTMENT IN ANTARCTICA L. A. PALINKAS 00 00 ’n REPORT NO. 85-49 D I MAR ~3 11986 L) L O~flN STAnTEMN...A Apprtoved 6Wz PUbli reIl. NAVAL HEALTH RESEARCH CENTER P.O. BOX 85122 0 SAN DIEGO, CALIFORNIA 92138-9174 --j NAVAL MEDICAL RESEARCH AND DEVELOPMENT ...COMMAND LJ6. BETHESDA, MARYLAND SOCIOCULTURAL INFLUENCES ON PSYCHOSOCIAL ADJUSTMENT IN ANTARCTICA Lawrence A. Palinkas, Ph.D. Manager, Psychiatric

Aft View of Saturn V Third Stage (S-IVB)

NASA Technical Reports Server (NTRS)

1960-01-01

The powerful J-2 engine is prominent in this photograph of a Saturn V Third Stage (S-IVB) resting on a transporter in the Manufacturing Facility at Marshall Space Flight Center in Huntsville, Alabama. The towering 363-foot Saturn V was a multi-stage, multi-engine launch vehicle standing taller than the Statue of Liberty. Altogether, the Saturn V engines produced as much power as 85 Hoover Dams.

Second Stage (S-II) Plays Key Role in Apollo missions

NASA Technical Reports Server (NTRS)

1970-01-01

This photograph of the Saturn V Second Stage (S-II) clearly shows the cluster of five powerful J-2 engines needed to boost the Apollo spacecraft into earth orbit following first stage separation. The towering 363-foot Saturn V was a multi-stage, multi-engine launch vehicle standing taller than the Statue of Liberty. Altogether, the Saturn V engines produced as much power as 85 Hoover Dams.

Analysis of a Turbine Blade Failure in a Military Turbojet Engine

NASA Astrophysics Data System (ADS)

Sahoo, Benudhar; Satpathy, R. K.; Panigrahi, S. K.

2016-06-01

This paper deals with failure analysis of a low-pressure turbine blade of a straight flow turbojet engine. The blade is made of a wrought precipitation hardened Nickel base superalloy with oxidation-resistant diffusion aluminizing coating. The failure mode is found to be fatigue with multiple cracks inside the blade having crack origin at metal carbides. In addition to the damage in the coating, carbide banding has been observed in few blades. Carbide banding may be defined as inclusions in the form of highly elongated along deformation direction. The size, shape and banding of carbides and their location critically affect the failure of blades. Carbon content needs to be optimized to reduce interdendritic segregation and thereby provide improved fatigue and stress rupture life. Hence, optimization of size, shape and distribution of carbides in the billet and forging parameters during manufacturing of blade play a vital role to eliminate/reduce extent of banding. Reference micrographs as acceptance criteria are essential for evaluation of raw material and blade. There is a need to define the acceptance criteria for carbide bandings and introduce more sensitive ultrasonic check during billet and on finished blade inspection.

Altitude-wind-tunnel investigation of tail-pipe burning with a Westinghouse X24C-4B axial-flow turbojet engine

NASA Technical Reports Server (NTRS)

Fleming, William A; Wallner, Lewis E

1948-01-01

Thrust augmentation of an axial-flow type turbojet engine by burning fuel in the tail pipe has been investigated in the NACA Cleveland altitude wind tunnel. The performance was determined over a range of simulated flight conditions and tail-pipe fuel flows. The engine tail pipe was modified for the investigation to reduce the gas velocity at the inlet of the tail-pipe combustion chamber and to provide an adequate seat for the flame; four such modifications were investigated. The highest net-thrust increase obtained in the investigation was 86 percent with a net thrust specific fuel consumption of 2.91 and a total fuel-air ratio of 0.0523. The highest combustion efficiencies obtained with the four configurations ranged from 0.71 to 0.96. With three of the tail-pipe burners, for which no external cooling was provided, the exhaust nozzle and the rear part of the burner section were bright red during operation at high tail-pipe fuel-air ratios. With the tail-pipe burner for which fuel and water cooling were provided, the outer shell of the tail-pipe burner showed no evidence of elevated temperatures at any operating condition.

78 FR 17082 - Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG Turbojet Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-20

... flight. (5) If you find any broken bolt in the HPT shaft air seal sleeve, visually inspect the HPT stage... assembly, high pressure turbine (HPT) bearing support assembly and HPT air seal sleeve bolts identified... turbine (HPT) bearing support assembly, and HPT air seal sleeve within 100 engine cycles-in-service. (2...

Aircraft noise source and computer programs - User's guide

NASA Technical Reports Server (NTRS)

Crowley, K. C.; Jaeger, M. A.; Meldrum, D. F.

1973-01-01

The application of computer programs for predicting the noise-time histories and noise contours for five types of aircraft is reported. The aircraft considered are: (1) turbojet, (2) turbofan, (3) turboprop, (4) V/STOL, and (5) helicopter. Three principle considerations incorporated in the design of the noise prediction program are core effectiveness, limited input, and variable output reporting.

The determination of potential energy curve and dipole moment of the (5)0{sup +} electronic state of {sup 85}Rb{sup 133}Cs molecule by high resolution photoassociation spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuan, Jinpeng; Zhao, Yanting, E-mail: zhaoyt@sxu.edu.cn; Ji, Zhonghua

2015-12-14

We present the formation of ultracold {sup 85}Rb{sup 133}Cs molecules in the (5)0{sup +} electronic state by photoassociation and their detection via resonance-enhanced two-photon ionization. Up to v = 47 vibrational levels including the lowest v = 0 vibrational and lowest J = 0 levels are identified with rotationally resolved high resolution photoassociation spectra. Precise Dunham coefficients are determined for the (5)0{sup +} state with high accuracy, then the Rydberg-Klein-Rees potential energy curve is derived. The electric dipole moments with respect to the vibrational numbers of the (5)0{sup +} electronic state of {sup 85}Rb{sup 133}Cs molecule are also measured inmore » the range between 1.9 and 4.8 D. These comprehensive studies on previously unobserved rovibrational levels of the (5)0{sup +} state are helpful to understand the molecular structure and discover suitable transition pathways for transferring ultracold atoms to deeply bound rovibrational levels of the electronic ground state.« less

Research and Development of the Aeroturbine Engine,

DTIC Science & Technology

1981-04-15

whether the selection of a turbojet or turbofan carries increased power. Afterwards, the engine cycle parameters (such as the pressurized ratio of the gns...into production. Conclusion The emergence of a new model aviation turbine engine is the achievement of the collective labors of a multitude of people...under unified organiza- tional leadership. Each organization and individual engaged in aviation turbine engine research and development resemble each

Military Jet Engine Acquisition: Technology Basics and Cost-Estimating Methodology

DTIC Science & Technology

2002-01-01

aircraft , rather than by these forms of jet engines . Like the turbofan or turbojet , these engines have a nozzle down- stream of the low-pressure...2.5 illustrates the process of turbine blade cooling. Figure 2.6 illustrates the steady and rapid increase in RIT for turbo - jets , turbofans , and...87 B. AN OVERVIEW OF MILITARY JET ENGINE HISTORY ... 97 C. AIRCRAFT TURBINE ENGINE DEVELOPMENT ...... 121 D.

Dioxins, furans and polycyclic aromatic hydrocarbons emissions from a hospital and cemetery waste incinerator

NASA Astrophysics Data System (ADS)

Mininni, Giuseppe; Sbrilli, Andrea; Maria Braguglia, Camilla; Guerriero, Ettore; Marani, Dario; Rotatori, Mauro

An experimental campaign was carried out on a hospital and cemetery waste incineration plant in order to assess the emissions of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polycyclic aromatic hydrocarbons (PAHs). Raw gases were sampled in the afterburning chamber, using a specifically designed device, after the heat recovery section and at the stack. Samples of slags from the combustion chamber and fly ashes from the bag filter were also collected and analyzed. PCDD/Fs and PAHs concentrations in exhaust gas after the heat exchanger (200-350 °C) decreased in comparison with the values detected in the afterburning chamber. Pollutant mass balance regarding the heat exchanger did not confirm literature findings about the de novo synthesis of PCDD/Fs in the heat exchange process. In spite of a consistent reduction of PCDD/Fs in the flue gas treatment system (from 77% up to 98%), the limit of 0.1 ng ITEQ Nm -3 at the stack was not accomplished. PCDD/Fs emission factors for air spanned from 2.3 up to 44 μg ITEQ t -1 of burned waste, whereas those through solid residues (mainly fly ashes) were in the range 41-3700 μg ITEQ t -1. Tests run with cemetery wastes generally showed lower PCDD/F emission factors than those with hospital wastes. PAH total emission factors (91-414 μg kg -1 of burned waste) were in the range of values reported for incineration of municipal and industrial wastes. In spite of the observed release from the scrubber, carcinogenic PAHs concentrations at the stack (0.018-0.5 μg Nm -3) were below the Italian limit of 10 μg Nm -3.

Convair XF-102 Model in the 8- by 6-Foot Supersonic Wind Tunnel

NASA Image and Video Library

1953-08-21

A .10-scale model of Convair’s XF-102 in the 8- by 6-Foot Supersonic Wind Tunnel at the National Advisory Committee for Aeronautics (NACA) Lewis Flight Propulsion Laboratory for jet exit studies. The XF-102 was a prototype of the F-102 Delta Dagger. The F-102 served as an interceptor against long range bombers from the Soviet Union. The aircraft was powered by a Pratt and Whitney J57 turbojet. The first prototype crashed two weeks after is first flight on October 24, 1953, just months after this photograph. Engineers then incorporated the fixed-wing design to reduce drag at supersonic speeds. The production model F-102 became the first delta-wing supersonic aircraft in operation. The 8- by 6-Foot Supersonic Wind Tunnel is used to study propulsion systems, including inlets and exit nozzles, combustion fuel injectors, flame holders, exit nozzles, and controls on ramjet and turbojet engines. Flexible sidewalls alter the tunnel’s nozzle shape to vary the Mach number during operation. A seven-stage axial compressor, driven by three electric motors that yield a total of 87,000 horsepower, generates air speeds from Mach 0.36 to 2.0.

Small Engine Component Technology (SECT)

NASA Technical Reports Server (NTRS)

Early, M.; Dawson, R.; Zeiner, P.; Turk, M.; Benn, K.

1986-01-01

A study of small gas turbine engines was conducted to identify high payoff technologies for year-2000 engines and to define companion technology plans. The study addressed engines in the 186 to 746 KW (250 to 1000 shp) or equivalent thrust range for rotorcraft, commuter (turboprop), cruise missile (turbojet), and APU applications. The results show that aggressive advancement of high payoff technologies can produce significant benefits, including reduced SFC, weight, and cost for year-2000 engines. Mission studies for these engines show potential fuel burn reductions of 22 to 71 percent. These engine benefits translate into reductions in rotorcraft and commuter aircraft direct operating costs (DOC) of 7 to 11 percent, and in APU-related DOCs of 37 to 47 percent. The study further shows that cruise missile range can be increased by as much as 200 percent (320 percent with slurry fuels) for a year-2000 missile-turbojet system compared to a current rocket-powered system. The high payoff technologies were identified and the benefits quantified. Based on this, technology plans were defined for each of the four engine applications as recommended guidelines for further NASA research and technology efforts to establish technological readiness for the year 2000.

Performance of J33 turbojet engine with shaft-power extraction III : turbine performance

NASA Technical Reports Server (NTRS)

Huppert, M C; Nettles, J C

1949-01-01

The performance of the turbine component of a J33 turbojet engine was determined over a range of turbine speeds from 8000 to 11,500 rpm.Turbine-inlet temperature was varied from the minimum required to drive the compressor to a maximum of approximately 2000 degrees R at each of several intermediate turbine speeds. Data are presented that show the horsepower developed by the turbine per pound of gas flow. The relation between turbine-inlet stagnation pressure, turbine-outlet stagnation pressure, and turbine-outlet static pressure was established. The turbine-weight-flow parameter varied from 39.2 to 43.6. The maximum turbine efficiency measured was 0.86 at a pressure ratio of 3.5 and a ratio of blade speed to theoretical nozzle velocity of 0.39. A generalized performance map of the turbine-horsepower parameter plotted against the turbine-speed parameter indicated that the best turbine efficiency is obtained when the turbine power is 10 percent greater than the compressor horsepower. The variation of efficiency with the ratio of blade speed to nozzle velocity indicated that the turbine operates at a speed above that for maximum efficiency when the engine is operated normally with the 19-inch-diameter jet nozzle.

STREPTOMYCES NODOSUS SP. N., THE AMPHOTERICIN-PRODUCING ORGANISM

PubMed Central

Trejo, William H.; Bennett, R. E.

1963-01-01

Trejo, William (Squibb Institute for Medical Research, New Brunswick, N.J.) and Ralph E. Bennett. Streptomyces nodosus sp. n., the amphotericin-producing organism. J. Bacteriol. 85:436–439. 1963.—Streptomyces nodosus, the amphotericin-producing organism, is described as a new species in conformity with the rules of nomenclature as applied to streptomycetes. The relationship between S. nodosus and S. rutgersensis is discussed, and the basis for separation of the species is presented. Images PMID:13994057

Motor Cortex Stimulation Reverses Maladaptive Plasticity Following Spinal Cord Injury

DTIC Science & Technology

2012-09-01

pp 74–85. Austin: Landes Biosciences. 3. Abstracts o Mechanisms of Pain Relief Following Motor Cortex Stimulation: An fMRI Study. Society for...Neuroscience Meeting. Washington, DC. 2012. o Resting State fMRI in a Rat Model of Spinal Cord Injury Neuropathic Pain: A Longitudinal Study. Society...2601–2610. 16. Stefanacci L, Reber P, Costanza J, Wong E, Buxton R, Zola S, Squire L, Albright T. fMRI of monkey visual cortex. Neuron 1998;20:1051

Establishment of Production Cleanliness Criteria and Processes for Printed Wiring Boards and Assemblies.

DTIC Science & Technology

1981-12-01

H (hydrogen) and He (helium) are excluded since they have no outer shell electrons to eject. If the thin film analysis capability of Auger is...comtaminant profiling (C/P) system instrumentation will detect and intepret the amounts of contaminant species in an extract in terms of parts-per-billion...Nadas, and P. Fennell Evans, J. Phys. Chem;, 74 (1970), 4572. 215 4’. FILMED 7 4-85 DTIC

A Simulation of High Latitude F-Layer Instabilities in the Presence of Magnetosphere-Ionosphere Coupling.

DTIC Science & Technology

1985-07-08

Equatorial spread F: recent observations and a new intepretation , J. Geophys. Res., 77, 5625, 1972. Basu, S., S. Basu, E. MacKenzie, W.R. Coley, W.B. Hanson...HOPKINS ROAD LAUREL, MD 20810 DR. R. GREENWALD DR. C. MENG UNIVERSITY OF PITTSBURGH PITTSBURGH, PA 15213 DR. N. ZABUSKY DR. M. BIONDI DR. E. OVERMAN 26 FILMED 9-85 DTIC RJa. I - rlt -6 ,I, a~l O -3

The Top Three Valor Awards and the United States Marine Corps: A Study from World War I to Present Day Iraq and Afghanistan

DTIC Science & Technology

2014-06-13

the Medal of Honor.85 “The process by which the MOH is awarded has become flawed, and the DOD must strive to bring an end to an era of overprotection ...later in the literature review. 84Ibid., 37. 85Wes J. Deaver, “The Medal of Honor, An Era of Overprotection ,” Marine Corps Gazette 94, no. 9

Overcoming the Practical Barriers to Spinal Cord Cell Transplantation for ALS

DTIC Science & Technology

2015-12-01

Nashold BS, Jr. History of spinal cord stereotaxy. (1996) J Neurosurg. 85(4): 725- 31. 11 11. Glass JD, Boulis NM, Johe K, Rutkove SB, Federici T...minimizing pressure on the abdomen and chest and consequent epidural venous bleeding (Figure 1). The frame also provides external immobilization of the... catheterized for fluid administration and any necessary drug delivery during surgery. Finally, the surgical field is prepped with alcohol and

Department of Clinical Investigation Annual Research Progress Report, Fiscal Year 1989

DTIC Science & Technology

1989-09-30

and DES. Patients with a history of deep vein thrombosis, cerebral embolus, stroke , congestive heart failure, or ischemic heart disease will not be...Adolescent Health Care 9(6): 498-500, 1988 Weir MR Intravascular Injuries from Intramuscular Penicillin. Clinical Pediatrics 27(2): 85-90, 1988 Weir...Military Medicine 154(9): 455-57, 1989 Piatt JH, Goodkin R Barbiturates in Severe Head Injury . J Neurosurgery 70(3): 501-02, 1989 * Piatt JH

Gain measurement of a CuBr laser by means of modified amplified spontaneous emission

NASA Astrophysics Data System (ADS)

Chan, W. C.; Liu, H. P.; Yen, S. H.; Chen, W. Y.; Lin, Y. H.; Chen, W. C.

1990-05-01

A modified amplified spontaneous emission technique has been introduced to measure the radial distributions of the gain and the saturation energy density of the output of a double-discharge pulsed CuBr laser. An asymmetric distribution of the gain was obtained. With the laser tube temperature at 420 °C, the peak value of the gain and the saturation energy density are 70 db/m and 85 μJ/cm3, respectively.

The Impact of Harmful Algal Blooms on USACE Operations

DTIC Science & Technology

2009-01-01

related poisoning in humans and livestock (Chorus and Bartram 1999) and is the dominant cyanobacteria in North America ( Carmichael 2005). It is important...penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1. REPORT DATE JAN 2009 2...hypertrophic freshwater reservoir. Hydrobiologia 559(1): 85-100. Britton, J. 2005. Telephone interview. September 30, 2005. Carmichael , W., ed. 2005. A world

Biomechanical Factors in Tibial Stress Fractures

DTIC Science & Technology

2004-08-01

these runners. A "stiff’ runner will spend less time in contact with the ground (Farley and Gonzalez, 1996 ) and will attenuate less shock between the...leg and the head (McMahon et al., 1987). This is in agreement with the findings of Farley and Gonzalez ( 1996 ) who suggested lower extremity stiffness...Crossley, K. ( 1996 ) Stress fractures: a review of 180 cases. Clin. J. Sport Med. 6, 85-89. Brudvig, T., Grudger, T. and Obermeyer, L. (1983) Stress

Toxicities of RDX or TNT Freshly Amended or Weathered-and-Aged in Five Natural Soils to the Collembolan Folsomia candida

DTIC Science & Technology

2013-05-01

Biodegradation of Nitroaromatic Compounds; Spain, J.C., Ed.; Plenum Press: New York , 1995; pp 69–85. Renoux, A.Y.; Sarrazin, M.; Hawari, J.; Sunahara...in Contaminated Soil. In Biodegradation of Nitroaromatic Compounds. Spain, J.C., Ed.; Plenum Press: New York , 1995; pp 1–18. Robidoux, P.Y...CANDIDA 1. INTRODUCTION Many sites associated with military operations that involve munition manufacturing, disposal , testing, and training

Environmental Support to Amphibious Craft, Patrol Boats, and Coastal Ships: An Annotated Bibliography

DTIC Science & Technology

2008-03-05

article describes the utility of the system to provide information on water level changes around Tampa Bay during Hurricane Andrew. Such a system could...sufficient observations. 85. Wyatt, Lucy R., Jim J. Green, Klaus-Werner Gurgel, Jose C. Nieto Borge, Konstanze Reichert, Katrin Hessner, Heinz Günther...through the ecosystems, and (5) patterns, frequencies and effects of disturbances such as hurricanes , landuse changes or forest harvesting. 99. Marine

Preclinical and Clinical Development of Low Dose Methamphetamine for the Treatment of Traumatic Brain Injury

DTIC Science & Technology

2014-04-01

methods of treating or reducing the occurrence of neuronal cell damage in a subject having a transient cerebral hypoxia and/or ischemic condition (e.g...2006. Signal trans- duction of MEK/ERK and PI3K/Akt activation by hypoxia /reoxygenation in renal epithelial cells . Eur. J. Cell Biol. 85, 1189e1199...cognitive impairment. The dentate gyrus region of the hippocampus contains a population of self-perpetuating neural stem cells . These cells

An analysis and implications of alternative methods of deriving the density (WPL) terms for eddy covariance flux measurements

Treesearch

W. J. Massman; J. -P. Tuovinen

2006-01-01

We explore some of the underlying assumptions used to derive the density or WPL terms (Webb et al. (1980) Quart J RoyMeteorol Soc 106:85-100) required for estimating the surface exchange fluxes by eddy covariance. As part of this effort we recast the origin of the density terms as an assumption regarding the density fluctuations rather than as a (dry air) flux...

Evaluation of Microcomputer-Based Operation and Maintenance Management Systems for Army Water/Wastewater Treatment Plant Operation.

DTIC Science & Technology

1986-07-01

COMPUTER-AIDED OPERATION MANAGEMENT SYSTEM ................. 29 Functions of an Off-Line Computer-Aided Operation Management System Applications of...System Comparisons 85 DISTRIBUTION 5V J. • 0. FIGURES Number Page 1 Hardware Components 21 2 Basic Functions of a Computer-Aided Operation Management System...Plant Visits 26 4 Computer-Aided Operation Management Systems Reviewed for Analysis of Basic Functions 29 5 Progress of Software System Installation and

Amplified Genes in Breast Cancer: Molecular Targets for Investigation and Therapy

DTIC Science & Technology

1999-09-01

checkpoints (Hartwell and Kastan, 1994). Mutations in genes involved in these transactions occur commonly during cancer progression and can greatly ele...induction of micronuclei as a measure of genotoxicity. A report of the U.S. Environmental Protection Agency Gene - Tox Program. Mutat . Res. 123:61-118...evidence for mutations at different loci in the HGPRT gene . J. Cell. Physiol. 85:307-320. 6 Capecchi, M.R., Hughes, S.H. and Wahl, G.M. (1975) Yeast

SEI Report on Graduate Software Engineering Education for 1991

DTIC Science & Technology

1991-04-01

12, 12 (Dec. 1979), 85-94. Andrews83 Andrews, Gregory R . and Schneider, Fred B. “Concepts and Notations for Concurrent Programming.” ACM Computing...Barringer87 Barringer , H. “Up and Down the Temporal Way.” Computer J. 30, 2 (Apr. 1987), 134-148. Bjørner78 The Vienna Development Method: The Meta-Language...Lecture Notes in Computer Science. Bruns86 Bruns, Glenn R . Technology Assessment: PAISLEY. Tech. Rep. MCC TR STP-296-86, MCC, Austin, Texas, Sept

Reliability of Multilayer Copper/Polyimide

DTIC Science & Technology

1993-11-01

LOIS H. WALSH R eliability R esearch E ng ineer -, . .....................-------- - - Reliability Physics Branch i-1’ , ý, Ay cci~i• es "AL f, , or Dist...average of 925 hours The chamber "as operated at 85 C󈨙 10 r h All the samples showed initial dielectric constant values consistent w%,ith previous...19. Matsumoto, 0., Katagiri, T., Thin Solid Films, 146, 283 (1987) 20. Malladi , D.P., J Membrane Sci., 19, 209 (1984) 21. Schubert, P.J., Nevin, J.H

Knowledge Acquisition for Expert Systems in Construction.

DTIC Science & Technology

1988-02-01

Trmble R J Aliwood A E Bryman C N Cooper -. Sixth interim report 4r " -Contract DAJA 45-85-C-0033 February 1988 i i 88 3 09 124 "I...Wheeler, has developed a experienced knowlae engineer Successful applications of expert sys- system for material selection of boier researching at...wanted to try engineer who may suddexiy become very also benefitted from application of artifi- the technology for some time, and his busy on a

Gasdynamic model of turbulent combustion in an explosion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuhl, A.L.; Ferguson, R.E.; Chien, K.Y.

1994-08-31

Proposed here is a gasdynamic model of turbulent combustion in explosions. It is used to investigate turbulent mixing aspects of afterburning found in TNT charges detonated in air. Evolution of the turbulent velocity field was calculated by a high-order Godunov solution of the gasdynamic equations. Adaptive Mesh Refinement (AMR) was used to follow convective-mixing processes on the computational grid. Combustion was then taken into account by a simplified sub-grid model, demonstrating that it was controlled by turbulent mixing. The rate of fuel consumption decayed inversely with time, and was shown to be insensitive to grid resolution.

The research on new type fast burning systems for biogas engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xia, L.; Zheng, B.; Chen, Z.

1996-12-31

In order to meet the demands of energy supply and environmental protection, the large and medium-sized biogas engineering are developed quickly. The biogas engines are also beginning to be developed in China. However, the problems of afterburning and short lifespan of spark ignited biogas engine have not been solved. According to the fast burning theory in gas engines, the authors developed four kinds of new combustion systems which could promote the fast burning of mixture gas and gained good effects. This paper discusses in detail the structural features and experimental results of one combustion system: the Fan shaped combustion chamber.

Correlation of Soot Formation in Turbojet Engines and in Laboratory Flames.

DTIC Science & Technology

1981-02-01

measured dependent variables were the flame radiation in the primary combustion zone and tile combus- tor liner temperature. Naegeli and Moses...Can-Type Turbine Combustion Systems," AFAPL- TR-79-2072, General Motors Corporation, April 1980. 9. Moses, C.A. and Naegeli , D.W., "Fuel Property...Effects on Combustor Perfor- mance," MED 114, Southwest Research Institute, March 1980. 10. Moses, C.A. and Naegeli , D.W., "Fuel Property Effects on

A verification of the gyrokinetic microstability codes GEM, GYRO, and GS2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bravenec, R. V.; Chen, Y.; Wan, W.

2013-10-15

A previous publication [R. V. Bravenec et al., Phys. Plasmas 18, 122505 (2011)] presented favorable comparisons of linear frequencies and nonlinear fluxes from the Eulerian gyrokinetic codes gyro[J. Candy and R. E. Waltz, J. Comput. Phys. 186, 545 (2003)] and gs2[W. Dorland et al., Phys. Rev. Lett. 85, 5579 (2000)]. The motivation was to verify the codes, i.e., demonstrate that they correctly solve the gyrokinetic-Maxwell equations. The premise was that it is highly unlikely for both codes to yield the same incorrect results. In this work, we add the Lagrangian particle-in-cell code gem[Y. Chen and S. Parker, J. Comput. Phys.more » 220, 839 (2007)] to the comparisons, not simply to add another code, but also to demonstrate that the codes' algorithms do not matter. We find good agreement of gem with gyro and gs2 for the plasma conditions considered earlier, thus establishing confidence that the codes are verified and that ongoing validation efforts for these plasma parameters are warranted.« less

Investigation of effect of propulsion system installation and operation on aerodynamics of an airbreathing hypersonic airplane at Mach 0.3 to 1.2

NASA Technical Reports Server (NTRS)

Cubbage, J. M.; Mercer, C. E.

1977-01-01

Results from an investigation of the effects of the operation of a combined turbojet/scramjet propulsion system on the longitudinal aerodynamic characteristics of a 1/60-scale hypersonic airbreathing launch vehicle configuration are presented. Decomposition products of hydrogen peroxide were used for simulation of the propulsion system exhaust.

14 CFR 61.58 - Pilot-in-command proficiency check: Operation of an aircraft that requires more than one pilot...

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Pilot-in-command proficiency check...-command proficiency check: Operation of an aircraft that requires more than one pilot flight crewmember or is turbojet-powered. (a) Except as otherwise provided in this section, to serve as pilot in command...

Preliminary Investigation of Several Root Designs for Cermet Turbine Blades in Turbojet Engine III : Curved-root Design

NASA Technical Reports Server (NTRS)

Pinkel, Benjamin; Deutsch, George C; Morgan, William C

1955-01-01

Stresses om tje root fastenings of turbine blades were appreciably reduced by redesign of the root. The redesign consisted in curving the root to approximately conform to the camber of the airfoil and elimination of the blade platform. Full-scale jet-engine tests at rated speed using cermet blades of the design confirmed the improvement.

Engineering Materials for Very High Temperatures: An ONRL Workshop

DTIC Science & Technology

1988-08-29

solving various pro- blems related to high temperature applications in which thermostructural ( turbojet and motor engines) or special (electromagnetic wave...the carbon (glassy carbon, polycrystalline gra- phite, pyrolytic carbon...) and mainly upon the temperature range of use. For the 1000-20000C...Bundesministerium fir Forschung und Technologie, Federal Ministry for Research and Technology), no doubt scared by the oil crisis and encouraged by the activity

Damping treatment for an aircraft hard-mounted antenna system in a vibroacoustic environment

NASA Astrophysics Data System (ADS)

Tate, Ralph E.; Rupert, Carl L.

1990-10-01

This paper discusses the design, analysis, and testing of 'add-on' damping treatments for the Band 6, 7, 8 radar antenna packages that are hard-mounted on the B-1B Aft Equipment Bay (AEB) where equipment failures are routinely occurring during take-off maneuvers at maximum throttle settings. This damage results from the intense vibroacoustical environment generated by the three-stage afterburning engines. Failure rates have been sufficiently high to warrant a 'quick fix' involving damping treatments that can be installed in a short time with minimal modification to the existing structure.

Experimental Investigation of Turbojet Thrust Augmentation Using an Ejector

DTIC Science & Technology

2007-03-01

mechanisms in which a particle can exchange energy. Thrust augmenting devices can be divided into two categories: ones that exchange net work or heat and...two categories from the energy equation discussion above. Thrust augmentation is achieved through turbulent entrainment where work and/or heat is...front sustained by compression waves from a trailing reaction zone. A deflagration wave is a subsonic flame front sustained by heat transfer

Studies on an aerial propellant transfer space plane (APTSP)

NASA Astrophysics Data System (ADS)

Jayan, N.; Biju Kumar, K. S.; Gupta, Anish Kumar; Kashyap, Akhilesh Kumar; Venkatraman, Kartik; Mathew, Joseph; Mukunda, H. S.

2004-04-01

This paper presents a study of a fully reusable earth-to-orbit launch vehicle concept with horizontal take-off and landing, employing a turbojet engine for low speed, and a rocket for high-speed acceleration and space operations. This concept uses existing technology to the maximum possible extent, thereby reducing development time, cost and effort. It uses the experience in aerial filling of military aircrafts for propellant filling at an altitude of 13 km at a flight speed of M=0.85. Aerial filling of propellant reduces the take-off weight significantly thereby minimizing the structural weight of the vehicle. The vehicle takes off horizontally and uses turbojet engines till the end of the propellant filling operation. The rocket engines provide thrust for the next phase till the injection of a satellite at LEO. A sensitivity analysis of the mission with respect to rocket engine specific impulse and overall vehicle structural factor is also presented in this paper. A conceptual design of space plane with a payload capability of 10 ton to LEO is carried out. The study shows that the realization of an aerial propellant transfer space plane is possible with limited development of new technology thus reducing the demands on the finances required for achieving the objectives.

Mathematical modeling and characteristic analysis for over-under turbine based combined cycle engine

NASA Astrophysics Data System (ADS)

Ma, Jingxue; Chang, Juntao; Ma, Jicheng; Bao, Wen; Yu, Daren

2018-07-01

The turbine based combined cycle engine has become the most promising hypersonic airbreathing propulsion system for its superiority of ground self-starting, wide flight envelop and reusability. The simulation model of the turbine based combined cycle engine plays an important role in the research of performance analysis and control system design. In this paper, a turbine based combined cycle engine mathematical model is built on the Simulink platform, including a dual-channel air intake system, a turbojet engine and a ramjet. It should be noted that the model of the air intake system is built based on computational fluid dynamics calculation, which provides valuable raw data for modeling of the turbine based combined cycle engine. The aerodynamic characteristics of turbine based combined cycle engine in turbojet mode, ramjet mode and mode transition process are studied by the mathematical model, and the influence of dominant variables on performance and safety of the turbine based combined cycle engine is analyzed. According to the stability requirement of thrust output and the safety in the working process of turbine based combined cycle engine, a control law is proposed that could guarantee the steady output of thrust by controlling the control variables of the turbine based combined cycle engine in the whole working process.

Idiotypic analysis of antibodies to hen egg-white lysozyme (HEL). II. Distribution and frequency of occurrence of idiotypes shared by A/J anti-HEL antibody.

PubMed Central

Semma, M; Sakato, N; Fujio, H; Amano, T

1981-01-01

Anti-HEL Ab from one A/J mouse (No. a-4),Ida-4(HEL), was s.c. inoculated into rabbits to induce anti-idiotypic (anti-Id) sera. After absorption with normal A/J Ig, two anti-Id serra (R101 and R102) were obtained. The interaction between 125I-Id(a-4)(HEL) and anti-Id sera was completely inhibited by unlabelled Ida-4(HEL), but not by non-specific Ig. The anti-Id sera were used to investigate the distribution of A/J (No. a-4) anti-HEL idiotypes in sera obtained from HEL-immunized animals. Idiotypes shared by Ida-4(HEL) were also detected in the sera of five examined mouse strains, but not in any of the examined rat, guinea-pig, goat, and sheep sear. Our experiments suggest the presence of inter- as well as intrastrain idiotype in mice. However, cross-reactivity appeared to be weak. When R101 and R102, respectively, were the anti-Id sera used, the frequency of occurrence of Ida-4(HEL) in stain A wa 1/106 and 1/53; in other mouse strains it was 1/277 and 1/85. PMID:7461724

Pollination efficiency of Apis mellifera Linnaeus, 1758 (Hymenoptera, Apidae) on the monoecious plants Jatropha mollissima (Pohl) Baill. and Jatropha mutabilis (Pohl) Baill. (Euphorbiaceae) in a semi-arid Caatinga area, northeastern Brazil.

PubMed

Neves, E L; Viana, B F

2011-02-01

Previous studies have shown the superior competitive ability of honeybees compared with native bees in the exploitation of floral resources and nesting sites besides their low efficiency in pollinating native plant species. However, there is little evidence of the effect of this invading species on autochthonous plant populations in natural environments. Thus experiments were performed to test the pollination efficiency of honeybees in two species of Jatropha (Euphorbiaceae), J. mollissima (Pohl) Baill. and J. mutabilis (Pohl) Baill., after a single flower visitation. Samplings were carried out between March and April 2006 in a hyperxerophilous shrub-arboreal Caatinga at Estação Biológica de Canudos, Bahia (9º 56´ 34" S, 38º 59´ 17" W), the property of Fundação Biodiversitas. Apis mellifera was efficient at pollinating J. mollissima (100%) and J. mutabilis (85%). This high efficiency may be explained by 1) the simple floral characteristics of both plant species, which facilitate access to the sexual organs of the plant; and 2) the body size of A. mellifera that fits the flower's dimensions.

Reduction of precursor decay anomaly in single crystal lithium fluoride

NASA Astrophysics Data System (ADS)

Sano, Yukio

2000-08-01

The purpose of this study is to reveal that the precursor decay anomaly in single crystal lithium fluoride is reduced by Sano's decay curve [Y. Sano, J. Appl. Phys. 85, 7616 (1999)], which is much smaller in slope than Asay's decay curve [J. R. Asay, G. R. Fowles, G. E. Duvall, M. H. Miles, and R. F. Tinder, J. Appl. Phys. 43, 2132 (1972)]. To this end, strain, particle, velocity, and stress in a precursor and near the leading edge of the follower changing with time along Sano's decay curve are first analyzed quantitatively. The analysis verified the existence of degenerate contraction waves I and II and a subrarefaction wave R', and the decay process [Y. Sano, J. Appl. Phys. 77, 3746 (1995)] caused in sequence by evolving followers C, I, II, R', Rb. Next, inequalities relating decay rates qualitatively to plastic strain rates at the leading edge of the follower, which are derived using the properties of the followers, are incorporated into the analysis. Calculation results showed that the plastic strain rates were reduced by low decay rates. This indicates that the precursor decay anomaly might be greatly reduced by Sano's decay curve.

Development of a turbojet engine gearbox test rig for prognostics and health management

NASA Astrophysics Data System (ADS)

Rezaei, Aida; Dadouche, Azzedine

2012-11-01

Aircraft engine gearboxes represent one of the many critical systems/elements that require special attention for longer and safer operation. Reactive maintenance strategies are unsuitable as they usually imply higher repair costs when compared to condition based maintenance. This paper discusses the main prognostics and health management (PHM) approaches, describes a newly designed gearbox experimental facility and analyses preliminary data for gear prognosis. The test rig is designed to provide full capabilities of performing controlled experiments suitable for developing a reliable diagnostic and prognostic system. The rig is based on the accessory gearbox of the GE J85 turbojet engine, which has been slightly modified and reconfigured to replicate real operating conditions such as speeds and loads. Defect to failure tests (DTFT) have been run to evaluate the performance of the rig as well as to assess prognostic metrics extracted from sensors installed on the gearbox casing (vibration and acoustic). The paper also details the main components of the rig and describes the various challenges encountered. Successful DTFT results were obtained during an idle engine performance test and prognostic metrics associated with the sensor suite were evaluated and discussed.

76 FR 45011 - Control of Air Pollution From Aircraft and Aircraft Engines; Proposed Emission Standards and Test...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-27

...This action proposes several new NOX emission standards, compliance flexibilities, and other regulatory requirements for aircraft turbofan or turbojet engines with rated thrusts greater than 26.7 kilonewtons (kN). We also are proposing certain other requirements for gas turbine engines that are subject to exhaust emission standards. First, we are proposing to clarify when the emission characteristics of a new turbofan or turbojet engine model have become different enough from its existing parent engine design that it must conform to the most current emission standards. Second, we are proposing a new reporting requirement for manufacturers of gas turbine engines that are subject to any exhaust emission standard to provide us with timely and consistent emission-related information. Third, and finally, we are proposing amendments to aircraft engine test and emissions measurement procedures. EPA actively participated in the United Nation's International Civil Aviation Organization (ICAO) proceedings in which most of these proposed requirements were first developed. These proposed regulatory requirements have largely been adopted or are actively under consideration by its member states. By adopting such similar standards, therefore, the United States will maintain consistency with these international efforts.

77 FR 36341 - Control of Air Pollution From Aircraft and Aircraft Engines; Emission Standards and Test Procedures

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-18

...EPA is adopting several new aircraft engine emission standards for oxides of nitrogen (NOX), compliance flexibilities, and other regulatory requirements for aircraft turbofan or turbojet engines with rated thrusts greater than 26.7 kilonewtons (kN). We also are adopting certain other requirements for gas turbine engines that are subject to exhaust emission standards as follows. First, we are clarifying when the emission characteristics of a new turbofan or turbojet engine model have become different enough from its existing parent engine design that it must conform to the most current emission standards. Second, we are establishing a new reporting requirement for manufacturers of gas turbine engines that are subject to any exhaust emission standard to provide us with timely and consistent emission- related information. Third, and finally, we are establishing amendments to aircraft engine test and emissions measurement procedures. EPA actively participated in the United Nations' International Civil Aviation Organization (ICAO) proceedings in which most of these requirements were first developed. These regulatory requirements have largely been adopted or are actively under consideration by its member states. By adopting such similar standards, therefore, the United States maintains consistency with these international efforts.

Internal flow characteristics of a multistage compressor with inlet pressure distortion. [J85-13 turbojet engine studies

NASA Technical Reports Server (NTRS)

Debogdan, C. E.; Moss, J. E., Jr.; Braithwaite, W. M.

1977-01-01

The measured distribution of compressor interstage pressures and temperatures resulting from a 180 deg inlet-total-pressure distortion for a J85-13 turbojet engine is reported. Extensive inner stage instrumentation combined with stepwise rotation of the inlet distortion gave data of high circumferential resolution. The steady-state pressures and temperatures along with the amplitude, extent, and location of the distorted areas are given. Data for 80, 90, and 100 percent of rotor design speed are compared with clean (undistorted) inlet flow conditions to show pressure and temperature behavior within the compressor. Both overall and stagewise compressor performances vary only slightly when clean and distorted inlet conditions are compared. Total and static pressure distortions increase in amplitude in the first few stages of the compressor and then attenuate fairly uniformly to zero at the discharge. Total-temperature distortion induced by the pressure distortion reached a maximum amplitude by the first two stages and decayed only a little through the rest of the compressor. Distortion amplitude tended to peak in line with the screen edges, and, except for total and static pressure in the tip zone, there was little swirl in the axial direction.

Entropy-Based Performance Analysis of Jet Engines; Methodology and Application to a Generic Single-Spool Turbojet

NASA Astrophysics Data System (ADS)

Abbas, Mohammad

Recently developed methodology that provides the direct assessment of traditional thrust-based performance of aerospace vehicles in terms of entropy generation (i.e., exergy destruction) is modified for stand-alone jet engines. This methodology is applied to a specific single-spool turbojet engine configuration. A generic compressor performance map along with modeled engine component performance characterizations are utilized in order to provide comprehensive traditional engine performance results (engine thrust, mass capture, and RPM), for on and off-design engine operation. Details of exergy losses in engine components, across the entire engine, and in the engine wake are provided and the engine performance losses associated with their losses are discussed. Results are provided across the engine operating envelope as defined by operational ranges of flight Mach number, altitude, and fuel throttle setting. The exergy destruction that occurs in the engine wake is shown to be dominant with respect to other losses, including all exergy losses that occur inside the engine. Specifically, the ratio of the exergy destruction rate in the wake to the exergy destruction rate inside the engine itself ranges from 1 to 2.5 across the operational envelope of the modeled engine.

Collateral Damage Probability Models

DTIC Science & Technology

1980-01-22

u 0 % CJ C-1 04J) * UU -j C) 04- co w~c r-=..A2 42 0 01 00 .1 L). < - zwI C)- V L L - I x C)4-~ 0 C) LA . C-, W LI.. C) C) C) C 0 C D ) C -4 G39VWVG...278 03 03 183 85 + 231 43 RCL 279 06 06 184 53 ( 232 05 05 280 53 ( 185 43 RCL 233 33 X2 281 53 ( * 168 Table B.2 Program Listing (Continued) 282

Final Environmental Assessment: Evaluation of J-85-5 Engine Test Burn

DTIC Science & Technology

2005-01-01

is highest in winter when birds migrate from the north. Most of the birds congregate during the winter at Reelfoot Lake and Dale Hollow Reservoir...Hydrological features include surface waters ( lakes , rivers, streams, and springs) and groundwater. Arnold AFB lies within the Duck River and the Elk...Smaller creeks R ow la nd C re ek Crumpton Creek Sinking Pond Woods Reservoir Normandy Lake Tims Ford Lake Retention Reservoir Duck River Figure 3-1 0

Component-Level Demonstration of a Microfabricated Atomic Frequency Reference

DTIC Science & Technology

2005-08-01

Kitching, L. A. Liew, and J. Moreland, "A microfabricated atomic clock," Applied Physics Letters, vol. 85, pp. 1460-1462, 2004. [4] R. Lutwak , P...Symposium on Frequency Standards and Metrology, P. Gill, Ed. St. Andrews, Scotland: World Scientific, 2001, pp. 155-166. [31] R. Lutwak , D. Emmons...Frequency and Time Forum. Tampa, FL, 2003, pp. 31-32. [71] R. Lutwak , D. Emmons, T. English, W. Riley, A. Duwel, M. Varghese, D. K. Serkland, and

Prime Contract Awards Alphabetically by Contractor, by State or Country, and Place, FY 85. Part 14 (Middletown Limousine Sus - North American Carbide Tooling).

DTIC Science & Technology

1985-01-01

Suite � .4 u ~~c s~~e IBo OFFICE SYP.40O 9 PROCUREMENT INSTRUMENT IDENTIFICATION NUMBER O(AN.’-i U0 j if aPPIicabJC) h,~ .. . (City State and ZIP...4 -4 4 4 A 9 o4 m1W "i 0 M () A W I0100 (n .n00 . . . . . . -.j 0 4 44 44 03 :O 󈧇 0-. (N UN001 WL 4 0 -44 4cm ito o-NN1100II0erP-s-40 -4 WC.1- 1󈧄...00 ( 0 I . ) ) 0-6(CO001 2Z00 000 00 c oG c ) 0 00 *00 Ga* c c 00000 to 0 so 0.aa.s4ha 90Omcc01caCO m((0 -101 - 009L - 009- 9 - LA- I 00 -0 00 444 00 44

Control Charts When the Observations Are Correlated.

DTIC Science & Technology

1987-05-01

l7 D-AiB6 388 CONTROL CHARTS WHEN THE OBSERVATIONS ARE CORRELATED(J) i/iPITTSBURGH UNIV PA CENTER FOR KULTIVARIATE ANALYSIS P R KRISHNAIAH ET AL MAY... Krishnaiah and B. Q. Miao F-49620-85-C-0008 S. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT. PROJECT. TASK AREA II WORK UNIT NUMBERS... Krishnaiah and B.Q. Miao Center for Multivariate Analysis University of Pittsburgh N DTIC E L 1Zk-, -I- OCT0 11987 Play 1987 Technical Report No. 87-09

Space WARC 1985 - Legal Issues and Implications.

DTIC Science & Technology

1984-01-01

public releoa.I |_Distribution Unlimited DISTRIBUTION STATEMENT ACCESSION FOR NTIS GRAM! DTIC TAB UNANNOUNCED E] JUSTIFICATION 3LC r DISTRIBUTIOND...EXHAUSTED. -7 77 7-7 77 .1- *~AD-A 150 972 "A INSTRUCTIONS____ 1.RGOVT AC(,.iN~.~j~ RECIPIENT’S CATALOG NUMBER * ~AFIT/CI/NR 85-9T IO EOT&PRO OEE r ...reere ide if neceeeesy anid identiy by bock numbas,) 20. ABSTRACT (Continue orn revere. sid. If nocep--ty end idetify by bla~ck r --mbsr) ATTACHED FORM

Upper-Thermospheric Observations and Neutral-Gas Dynamics at High Latitudes During Solar Maximum.

DTIC Science & Technology

1987-01-01

quickly, allowing the higher-latitude lines to spring back in towards the Earth ( Vallance -Jones, 1974). This also compresses and heats the plasma on high... Richards , and D. G. Torr. A new determination of the ultraviolet heating efficiency of the thermosphere. J. Geophys. Res., 85, 6819 - 6826, 1980b. Torr...M. R., D. G. Torr, and P. G. Richards . The solar ultraviolet heating efficiency of the midlatitude thermosphere. Geophys. Res. Lett., 7, 373 - 376

Ego Identity, Self Esteem and Substance Use During Adolescence.

DTIC Science & Technology

1985-08-24

RD-A173 665 EGO IDENTITY SELF ESTEEM AND SUBSTANCE USE DURING - /i ADOLESCENCE(U) ARIZONA UNIV TUCSON COLL OF MEDICINE R M JONES ET AL 24 AUG 85 UARZ...Security Classification) Ego Identity, Self Esteem and Substance Use during Adolescence. 12. PERSONAL AUTHOR(S) Jnnp5. Randall M-6 Hortmann- Rarhara R 13a...Adolescents. Drinking. Drug Use. 05 J 10 Self - Esteem . Smoking. Drug Abuse. Interpersonal Communi- 06 1 15 lratinn" Tnterprrnna1 Relatinn-hipn Sprnndarv

Design and Checkout of a High Speed Research Nozzle Evaluation Rig

NASA Technical Reports Server (NTRS)

Castner, Raymond S.; Wolter, John D.

1997-01-01

The High Flow Jet Exit Rig (HFJER) was designed to provide simulated mixed flow turbojet engine exhaust for one- seventh scale models of advanced High Speed Research test nozzles. The new rig was designed to be used at NASA Lewis Research Center in the Nozzle Acoustic Test Rig and the 8x6 Supersonic Wind Tunnel. Capabilities were also designed to collect nozzle thrust measurement, aerodynamic measurements, and acoustic measurements when installed at the Nozzle Acoustic Test Rig. Simulated engine exhaust can be supplied from a high pressure air source at 33 pounds of air per second at 530 degrees Rankine and nozzle pressure ratios of 4.0. In addition, a combustion unit was designed from a J-58 aircraft engine burner to provide 20 pounds of air per second at 2000 degrees Rankine, also at nozzle pressure ratios of 4.0. These airflow capacities were designed to test High Speed Research nozzles with exhaust areas from eighteen square inches to twenty-two square inches. Nozzle inlet flow measurement is available through pressure and temperature sensors installed in the rig. Research instrumentation on High Speed Research nozzles is available with a maximum of 200 individual pressure and 100 individual temperature measurements. Checkout testing was performed in May 1997 with a 22 square inch ASME long radius flow nozzle. Checkout test results will be summarized and compared to the stated design goals.

Heliobactor pylori Virulence Factors and Their Role in Pathogenesis

DTIC Science & Technology

2011-03-25

with duodenal ulceration in Belgium, South Africa , China, or North America. Clin Infect Dis 45:1204-6. 19. Argent, R. H., J. L. Hale, E. M. El-Omar...domestic dogs and cats, to farm animals (cattle and swine), to some non-human primates and humans (81, 85, 264, 330). H. pylori itself is a human and...duodenal ulcer-promoting gene (dupA) of Helicobacter pylori in patients with duodenal ulcer in North Indian population. Helicobacter 12:591-7. 18

Acoustooptic Processing of Two Dimensional Signals Using Temporal and Spatial Integration

DTIC Science & Technology

1989-05-12

AND SPATIAL INTEGRATION Demetri Psaltis, John Hong, Scott Hudson, Jeff Yu Fai Mok, Mark Neifeld, and Nabeel Riza, Dave Brady V 13U7101 4 NS7urtn-a...Jeff Yu Fai Mok, Mark Neifeld, and Nabeel Riza, Dave Brady DTIC Grant AFOSR-85-0332 ELECTE Submitted to: S J’ Dr. Lee Giles Air Force Office of...In addition we examine the capacity when the filter is binarized. Vector-matrix multipliers are fundamental components of many signal processing sys

Combinatorial Reliability and Repair

DTIC Science & Technology

1992-07-01

Press, Oxford, 1987. [2] G. Gordon and L. Traldi, Generalized activities and the Tutte polynomial, Discrete Math . 85 (1990), 167-176. [3] A. B. Huseby, A...Chromatic polynomials and network reliability, Discrete Math . 67 (1987), 57-79. [7] A. Satayanarayana and R. K. Wood, A linear-time algorithm for comput- ing...K-terminal reliability in series-parallel networks, SIAM J. Comput. 14 (1985), 818-832. [8] L. Traldi, Generalized activities and K-terminal reliability, Discrete Math . 96 (1991), 131-149. 4

Performance Investigations of a Large Centrifugal Compressor from an Experimental Turbojet Engine

NASA Technical Reports Server (NTRS)

Ginsburg, Ambrose; Creagh, John W. R.; Ritter, William K.

1948-01-01

An investigation was conducted on a large centrifugal compressor from an experimental turbojet engine to determine the performance of the compressor and to obtain fundamental information on the aerodynamic problems associated with large centrifugal-type compressors. The results of the research conducted on the compressor indicated that the compressor would not meet the desired engine-design air-flow requirements (78 lb/sec) because of an air-flow restriction in the vaned collector (diffuser). Revision of the vaned collector resulted in an increased air-flow capacity over the speed range and showed improved matching of the impeller and diffuser components. At maximum flow, the original compressor utilized approximately 90 percent of the available geometric throat area at the vaned-collector inlet and the revised compressor utilized approximately 94 percent, regardless of impeller speed. The ratio of the maximum weight flows of the revised and original compressors were less than the ratio of effective critical throat areas of the two compressors because of the large pressure losses in the impeller near the impeller inelt and the difference increased with an increase in impeller speed. In order to further increase the pressure ratio and maximum weight flow of the compressor, the impeller must be modified to eliminate the pressure losses therein.

Experimental Comparison of Speed : Fuel-flow and Speed-area Controls on a Turbojet Engine for Small Step Disturbances

NASA Technical Reports Server (NTRS)

Wenzel, L M; Hart, C E; Craig, R T

1957-01-01

Optimum proportional-plus-integral control settings for speed - fuel-flow control, determined by minimization of integral criteria, correlated well with analytically predicted optimum settings. Engine response data are given for a range of control settings around the optimum. An inherent nonlinearity in the speed-area loop necessitated the use of nonlinear controls. Response data for two such nonlinear control schemes are presented.

Wernher von Braun

NASA Image and Video Library

1968-10-01

Dr. von Braun inside the KC-135 in flight. The KC-135 provide NASA's Reduced-Gravity Program the unique weightlessness or zero-g environment of space flight for testing and training of human and hardware reactions. The recent version, KC-135A, is a specially modified turbojet transport which flies parabolic arcs to produce weightlessness periods of 20 to 25 seconds and its cargo bay test area is approximately 60 feet long, 10 feet wide, and 7 feet high.

Journal of Engineering Thermophysics (Selected Articles),

DTIC Science & Technology

1983-05-13

compressor, prediction of unsteady vibration , and prevention of unsteady vibration . This test was undergone on a turbojet engine. The paper stresses the...induce unsteady engine vibration . While studying the effect of inlet anomaly and variation of the first stage nozzle area of the turbine, the engine...constant revolution speed curve until unsteady vibration or stall appeared. In studying the influence of the starting sequence, starting was

J85 Rejuvenation Through Technology Insertion

DTIC Science & Technology

2000-10-01

and Sabre 75 business addition to military production, the J85 was jets . Number Model Produced Aircraft Type(s) Engine Type Thrust (lbs) J85-GE-4 740...REJUVENATION THROUGH TECHNOLOGY INSERTION T.A. Brisken, P.N. Howell, A.C. Ewing Military Engines Operation GE Aircraft Engines 1 Neumann Way Cincinnati...OH 45215, USA Summary thrust to weight ratio turbojet engines with potential application to early cruise missiles and drones. The history of the

Principles of Jet Engine Operation

DTIC Science & Technology

1978-05-01

and discharged from the rotor radially (perpendicular-to the axis .,f rotation). In-contrast, the axial flow compressor both admits and dis- charges... TurbofanS for most contemporary turbojet powered aircraft applications, the axial flow compressor is utilized. The remainder of the discussion will...usually installed on several radial arms which are evenly spaced around the compressor face. The spacing of the probes on the arms is such that they are