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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 901 records · Page 50
All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

The staging dynamics of a proposed space shuttle configuration

A mathematical model was developed to simulate the staging dynamics of a proposed space shuttle configuration. Included in the mathematical model is the kinematics and dynamics of the staging mechanism, thrust forces and thrust vector control, rigid-body dynamics, and structural dynamics of both the booster and orbiter stages of the configuration. The mathematical model was incorporated into a computer program so that the staging maneuver could be simulated. Results of the simulations are presented.

Hamilton, D. A.↗
NASA NTRS1973

Chemical nonequilibrium effects on the inviscid flow in the windward plane of symmetry of two simplified shuttle configurations

A theoretical study was made to delineate the effects of thermochemical nonequilibrium in the inviscid flow field of a representative space shuttle orbiter configuration. The study was based on experimental pressure data which was used as an input to a stream tube computer program. The pressure data from two configurations are tabulated. Calculations were restricted to the windward plane of symmetry and the calculations covered an altitude range from 200,000 to 250,000 feet at velocities of 16,000 to 24,000 feet per second respectively. Angles of attack of 20 and 40 degrees were included. The calculations show that the nonequilibrium effects are confined largely to the entropy layer expect at the highest altitude, where significant nonequilibrium effects are observed in the entire inviscid flow field.

Lordi, J. A.↗
NASA NTRS1973

Some effects of grooved runway configurations on aircraft tire braking traction under flooded runway conditions

An experimental investigation was conducted to study the effect of grooved runway configurations on aircraft tire braking traction on flooded runway surfaces. The investigation was performed, utilizing size 49 x 17, type VII, aircraft tires with an inflation pressure of 170 lb per square inch at ground speeds up to approximately 120 knots. The results of this investigation indicate that when the runway is flooded, grooved surfaces provide better braking traction than an ungrooved surface and, in general, the level of braking traction was found to improve as the tire bearing pressure was increased because of an increase in the groove area of either the surface or the tire tread. Rounding the groove edges tended to degrade the tire braking capability from that developed on the same groove configuration with sharp edges. Results also indicate that braking friction coefficients for the test tires and runway surfaces decreased as ground speed was increased because of the hydroplaning effects.

Byrdsong, T. A.↗
NASA NTRS1971

Heat transfer tests of the NASA-MSC space shuttle configuration at the Langley Research Center Mach 8 Variable Density Facility

The experimental investigations performed on the NASA-Manned Spacecraft Center Space Shuttle orbiter and booster configurations at a Mach 8 variable density facility are presented. The test program was a series of aerothermodynamic wind tunnel tests that were run over a range of angles of attack, yaw angles, and Reynolds numbers. Objectives of the test program were to obtain heat transfer data over the NASA-Manned Spacecraft Center Space Shuttle orbiter, booster, and launch configurations for a range of angles of attack from - 20 to + 30 deg, yaw angles of 0 and + or - 6 deg, and Reynolds numbers of 0.6, 2.0, and 3.7 x one million. The phase-change coating technique was used to obtain heat transfer data. Information received from these tests will be instrumental in performing thermal protection systems studies and vehicle aerodynamic design.

Connor, L. E.↗
NASA NTRS1973

Separation over a flat plate-wedge configuration at oceanic Reynolds numbers

An experimental study of flow over a two-dimensional flat plate-wedge configuration is presented. The investigation encompasses a range of Reynolds numbers characteristics of conditions encountered by deep submersible oceanic vehicles. Flow separation, similar to that found on high speed aircraft control surfaces, is reported and discussed in light of the laminar or transitional nature of the separated shear layer. As discovered in previous high Mach number studies of plate-wedge or ramp configurations, the dependency of the size of the separated region on free stream Reynolds number is reversed for laminar and transitional types of flow separation.

Campbell, D. R.↗
NASA NTRS1973

Tracking and data relay satellite system configuration and tradeoff study. Volume 1: Summary. Part 2: Final Report, 22 August 1972 - 1 April 1973

A Tracking and Data Relay Satellite System (TDRSS) concept for service of low, medium, and high data rate user spacecraft has been defined. During the study, four TDRS dual spin stabilized configurations (contractual requirement) were designed; two are compatible with Delta 2914, one with Atlas Centaur, and one with space shuttle launches. A summary of the study and the salient results are presented. The topics included are: (1) TDRSS operations, (2) telecommunications service performance, telecommunications service equipment, (3) TDRS configurations and their design characteristics, and (4) TDRS system reliability.

Source record↗
NASA NTRS1973

Tracking and Data Relay Satellite System configuration and tradeoff study. Volume 4: Space shuttle launched TDRSS. Part 2: Final Report, 22 August 1972 - 1 April 1973

Configuration data and design information for the space shuttle launched configuration is presented. The overall system definition, operations and control, and telecommunication service system including link budgets are discussed. A brief description of the user transceiver and ground station is presented. A final section includes a summary description of the TDR spacecraft and all the subsystems. The data presented are largely in tabular form.

Source record↗
NASA NTRS1973

An improved method for the aerodynamic analysis of wing-body-tail configurations in subsonic and supersonic flow. Part 1: Theory and application

A new method has been developed for calculating the pressure distribution and aerodynamic characteristics of wing-body-tail combinations in subsonic and supersonic potential flow. A computer program has been developed to perform the numerical calculations. The configuration surface is subdivided into a large number of panels, each of which contains an aerodynamic singularity distribution. A constant source distribution is used on the body panels, and a vortex distribution having a linear variation in the streamwise direction is used on the wing and tail panels. The normal components of velocity induced at specified control points by each singularity distribution are calculated and make up the coefficients of a system of linear equations relating the strengths of the singularities to the magnitude of the normal velocities. The singularity strengths which satisfy the boundary condition of tangential flow at the control points for a given Mach number and angle of attack are determined by solving this system of equations using an interactive procedure. Once the singularity strengths are known, the pressure coefficients are calculated, and the forces and moments acting on the configuration determined by numerical integration.

Woodward, F. A.↗
NASA NTRS1973

Some problems of the calculation of three-dimensional boundary layer flows on general configurations

An accurate solution of the three-dimensional boundary layer equations over general configurations such as those encountered in aircraft and space shuttle design requires a very efficient, fast, and accurate numerical method with suitable turbulence models for the Reynolds stresses. The efficiency, speed, and accuracy of a three-dimensional numerical method together with the turbulence models for the Reynolds stresses are examined. The numerical method is the implicit two-point finite difference approach (Box Method) developed by Keller and applied to the boundary layer equations by Keller and Cebeci. In addition, a study of some of the problems that may arise in the solution of these equations for three-dimensional boundary layer flows over general configurations.

Cebeci, T.↗
NASA NTRS1973

Laser Doppler velocimeter investigation of trailing vortices behind a semi-span swept wing in a landing configuration

Measured axial and tangential velocity profiles in the near wake vortices of a semi-span model of the Convair 990 wing in the NASA-Ames 7- by 10-foot wind tunnel are presented. A scanning laser Doppler velocimeter was used to obtain data at two different downstream stations (0.49 and 1.25 wing spans) at various angles of attack and configurations from wing alone to wing plus nacelles, anti-shock bodies, and flaps deflected 27 deg (landing configuration). It is shown that the velocity distributions within the wake are quite sensitive to span loading. Specifically, it is illustrated that an aircraft flying at given lift coefficient (C SUB L), can substantially reduce its trailing vortex upset potential by deploying its flaps and altering its flight attitude to maintain the same C SUB L. This might be taken into consideration along with performance and noise considerations in the selection of aircraft approach lift over drag.

Ciffone, D. L.↗
NASA NTRS1973

A study of an orbital radar mapping mission to Venus. Volume 2: Configuration comparisons and systems evaluation

Configuration comparisons and systems evaluation for the orbital radar mapping mission of the planet Venus are discussed. Designs are recommended which best satisfy the science objectives of the Venus radar mapping concept. Attention is given to the interaction and integration of those specific mission-systems recommendations with one another, and the final proposed designs are presented. The feasibility, cost, and scheduling of these configurations are evaluated against assumptions of reasonable state-of-the-art growth and space funding expectations.

Source record↗
NASA NTRS1973

Analytical study of takeoff and landing performance for a jet STOL transport configuration with full-span, externally blown, triple-slotted flaps

Takeoff and landing performance characteristics and field length requirements were determined analytically for a jet STOL transport configuration with full-span, externally blown, tripleslotted flaps. The configuration had a high wing, high T-tail, and four pod-mounted high-bypass-ratio turbofan engines located under and forward of the wing. One takeoff and three approach and landing flap settings were evaluated. The effects of wing loading, thrust-to-weight ratio, weight, ambient temperature, altitude on takeoff and landing field length requirements are discussed.

Washington, H. P.↗
NASA NTRS1973

Low-speed wind-tunnel investigation of the longitudinal characteristics of a large-scale variable wing-sweep fighter model in the high-lift configuration

The low-speed characteristics of a large-scale model of the U. S. Navy/Grumman F-14A aircraft were studied in tests conducted in the Ames Research Center 40- by 80-Foot Wind Tunnel. The primary purpose of the program was the determination of lift and stability levels and landing approach attitude of the aircraft in its high-lift configuration. Tests were conducted at wing angles of attack between minus 2 deg and 30 deg with zero yaw. Data were taken at Reynolds numbers ranging from 3.48 million to 9.64 million based on a wing mean aerodynamic chord of 7.36 ft. The model configuration was changed as required to show the effects of glove slat, wing slat leading-edge radius, cold flow ducting, flap deflection, direct lift control (spoilers), horizontal tail, speed brake, landing gear and missiles.

Eckert, W. T.↗
NASA NTRS1972

Electric dipole moment of diatomic molecules by configuration interaction. V - Two states of /2/Sigma/+/ symmetry in CN.

Previous accurate dipole moment calculation techniques are modified to be applicable to higher excited states of symmetry. The self-consistent fields and configuration interactions are calculated for the X(2)Sigma(+) and B(2)Sigma(+) states of CN. Spin hyperfine constants and spin density at the nucleus are considered in the context of one-electron operator properties. The values of the self-consistent field and configuration interaction for the spin density are compared with experimental values for several diatomic molecules.

Green, S.↗
NASA NTRS1973

A reliability and comparative analysis of two standby system configurations.

Equations are derived which enable one to calculate the system reliability for parallel or triple modular redundant systems with standby spares. Software error detection is introduced into the TMR/Spares system configuration in order to utilize fully all of the units. An indication of the sensitivity of the system reliability to an increase in the number of spares, partitioning, switching, variations in the powered and unpowered failures rates, and time is presented. A comparison of the parallel and the TMR/Spares system configurations, under similar conditions, is given.

Taylor, D. S.↗
NASA NTRS1973

Runway configuration improvement programming model.

The basic objectives of the study were to subject a set of runway configurations to cost analysis and to develop a dynamic programming model which would enable an airport to economically match the ground capacity to its air traffic demand. Quantitative differences in the capacity of runway configurations result from the various aircraft/aircraft and aircraft/air-system interactions. A problem formulation and solution procedure is presented which is intended to be a meaningful technique for the long-range planning of runway expansion programs.

Yu, J. C.↗
NASA NTRS1973

Effect of exhaust nozzle configuration on aerodynamic and acoustic performance of an externally blown flap system with a quiet 6:1 bypass ratio engine

A highly suppressed TF-34 engine was used to investigate engine and flap interaction noise associated with an externally blown flap STOL powered lift system. Noise, efficiency, and velocity decay characteristics of mixed and separate flow exhaust systems including convergent, co-annular, and lobed designs were determined with the engine operating alone. Noise data were then obtained for several of the exhaust configurations with the engine blowing a wing-flap segment. Noise for both the engine alone and the engine with blown flaps showed substantial differences for the various exhaust configurations tested. The differences in observed noise are related primarily to nozzle effective exhaust velocity, flap impingement velocity, and noise spectral shape.

Samanich, N. E.↗
NASA NTRS1973

Investigation of configuration effects on entry heating distributions at Mach no. equals 8.0 (OH41A)

The results are presented of aerodynamic heating investigations conducted on 0.006 scale models of three Rockwell International Space Shuttle Vehicles (SSV) orbiter configurations in the Mach 8 variable density tunnel. It was established that lower surface modifications to one of these configurations (Model SS-H-00326-4) would alleviate premature transition. Re-entry data were acquired on these models at angles of attack from 30 to 40 degrees for nominal Reynolds numbers per foot of 1.0, 3.0, 6.0 and 8.0 million utilizing the phase change paint technique. A total of 17 orbiter heating runs and 3 orbiter oil flow runs were completed.

Gorowitz, H.↗