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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 127 records · Page 7

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NASA NTRS1975

Noise reduction studies of several aircraft to reduce their aural detection distances

A study was conducted to assess the extent to which practicable reductions of the external noise level of various aircraft could be achieved by different methods. The aircraft included in the study are the O-1, O-2, U-10, OV-1, and A-6. The noise signatures obtained from field measurements and the estimated aural detection distance of aircraft operating in low speed cruising flight are presented. The characteristics of each aircraft and the modifications made to reduce the aerodynamic noise are explained. Tables of data are included to show the effectiveness of the noise reduction modifications for each aircraft.

Dingeldein, R. C.↗

NASA NTRS1976

AP-8 trapped proton environment for solar maximum and solar minimum

Data sets from Ov-3 and Azur indicate a need for improvement in models of the stably trapped proton flux with energies between 0.1 and 400 MeV. Two computer accessible models are described: AP8MAX and AP8MIN. The models are presented in the form of nomographs, B-L plots, R-lambda plots, and equatorial radial profiles. Nomographs of the orbit-integrated fluxes are also discussed. The models are compared with each other, with the data, and with previous AP models. Requirements for future improvements include more complete data coverage and periodic comparisons with new data sets as they become available. The machine-sensible format in which the models are available are described.

Sawyer, D. M.↗

NASA NTRS1977

Program Documentation for Elapsed Time to Oxygen and Hydrogen Caution and Warning System for Captive/active 1 and 3 Flights

High pressure gas storage simulation runs were made to compute the elapsed time from T-O disconnect (transfer to onboard reactant) to the caution and warning pressures for the primary oxygen (O2) and hydrogen (H2) systems of Orbiter Vehicle (OV) 101. The simulation runs were made for approach and landing test flights Captive/Active 1 and Captive/Active 3.

Hurst, J. E.↗

NASA NTRS1979

Summary of the Orbiter mechanical systems

Major mechanical systems of the Orbiter space vehicle are summarized with respect to general design details, manner of operation, expected performance, and, where applicable, unique features. A synopsis of data obtained during the five atmospheric flight tests of spacecraft OV-101 and status of the systems for the first orbital spacecraft STS-1 are presented.

Kiker, J.↗

NASA NTRS1981

Program of Research in Laminar Flow Control in the JIAFS at NASA Langley Research Center

At high Reynolds numbers, the performance of a low drag suction LFC airplane is essentially controlled by the induced drag and the turbulent friction drag of the nonlaminarized area. The question then arises as to how the airplane cruise lift to drag ratio (L/D) sub cruise) cruise increases with increasing extent of laminar flow 0 sub lam./0 sub total (0 = airplane wetted area). In particular, the question arises as to the airplane performance in the optimum case with all laminar flow over the airplane wetted area. Design approaches of all laminar flow LFC airplanes which optimize the airplane range . R = eta sub ov times (L/D) times H times lambda n(W sub 0/W sub E) are considered.

Pfenninger, W.↗

NASA NTRS1981

Measurement of systematic outflow from the solar transition region underlying a coronal hole

This letter presents measurements of small Doppler shifts in the line center position of 629A OV obtained with a new high-resolution EUV spectrometer flown aboard a sounding rocket. A major result is the detection of an apparent systematic outflow (relative to the quiet sun) of approximately 3 km/s average and 5 km/s maximum in the solar transition region underlying a well-defined low-latitude coronal hole. This is reminiscent of a similar apparent outflow observed by Cushman and Rense in the coronal line 303A Si XI. The hypothesis that this is evidence for acceleration of the high speed solar wind deep in the transition region and inner corona is explored briefly.

Rottman, G. J.↗

NASA NTRS1983

Pressure distributions obtained on a 0.04-scale and 0.02-scale model of the Space Shuttle Orbiter's forward fuselage in the Langley continuous flow hypersonic tunnel

Results from pressure distribution tests on 0.04-scale and 0.02-scale models of the forward fuselage of the Space Shuttle Orbiter are presented without analysis. The tests wre completed in the Langley Continuous Flow Hypersonic Tunnel (CFHT). The 0.04-scale model was tested at angles of attack from -5 deg to 45 deg and angles of sideslip from -3 deg to 3 deg. The 0.02-scale model was tested at angles of attack from -10 deg to 45 deg and angles of sideslip from -5 deg to 5 deg. The tests were conducted in support of the development of the Shuttle Entry Air Data System (SEADS). In addition to modeling the 20 SEADS pressure orifices, the wind-tunnel models were also instrumented with orifices to match Development Flight Instrumentation (DFI) port locations currently existing on the Space Shuttle Orbiter Columbia (OV-102). This DFI simulation has provided a means for comparisons between reentry flight pressure data and wind-tunnel data.

Bradley, P. F.↗

NASA NTRS1983

Pressure distributions on a 0.04-scale model of the Space Shuttle Orbiter's forward fuselage in the Langley unitary plan wind tunnel

Pressure distribution tests on a 0.04-scale model of the forward fuselage of the Space Shuttle Orbiter are presented without analysis. The tests were completed in the Langley Unitary Plan Wind Tunnel (UPWT). The UPWT has two different test sections operating in the continuous mode. Each test section has its own Mach number range. The model was tested at angles of attack from -2.5 deg to 30 deg and angles of sideslip from -5 deg to 5 deg in both test sections. The test Reynolds number was 6.6 x 10 to the 6th power per meter. The tests were conducted in support of the development of the Shuttle Entry Air Data System (SEADS). In addition to modeling the 20 SEADS pressure orifices, the wind-tunnel model was also instrumented with orifices to match Development Flight Instrumentation (DFI) port locations currently existing on the Space Shuttle Orbiter Columbia (OV-102). This DFI simulation has provided a means for comparisons between reentry flight pressure data and wind-tunnel data.

Bradley, P. F.↗

NASA NTRS1983

Pressure distributions obtained on a 0.04-scale and 0.02-scale model of the Space Shuttle Orbiter's forward fuselage in the Langley 20-inch Mach 6 air tunnel

Results from pressure distribution tests on 0.04-scale and 0.02-scale models of the forward fuselage of the Space Shuttle Orbier are presented without analysis. The tests were completed in the Langley 20-Inch Mach 6 Tunnel. The 0.04-scale model was tested at angles of attack from 0 to 35 and angles of sideslip from 0 to -4. The 0.02-scale model was tested at angles of attack from -10 to 45 and angles of sideslip from 0 to -4. The tests were conducted in support of the development of the Shuttle Entry Air Data System (SEADS). In addition to modeling the 20 SEADS pressure orifices, the wind-tunnel to models were also instrumented with orifices to match Development Flight Instrumentation (DFI) port locations currently existing on the Space Shuttle Orbiter Columbia (OV-102). This DFI simulation had provided a means for comparisons between reentry flight pressure data and wind-tunnel data.

Bradley, P. F.↗

NASA NTRS1983

Energetic electrons as an energy transport mechanism in solar flares

A review is conducted of the observations and theory relating to the role of energetic electrons in the solar flare, with particular emphasis on discriminating between 'thermal' and 'nonthermal' origins of these electrons. Diagnostics in hard X-rays, especially those relating to the recent observations of the SMM and Hinotori satellites are discussed. Attention is briefly given to the response of the atmosphere to energy input in the form of high energy electrons, in particular through the diagnostics of both the Fe K-alpha feature and optically thin transition region lines such as OV. Finally, the relative roles of electron and proton heating in gamma-ray flare events are discussed.

Emslie, A. G.↗

NASA NTRS1983

Space shuttle orbiter reusable surface insulation flight results

The first five flights of the orbiter Columbia provided the initial data required to certify the operational performance of the reusable surface insulation (RSI) thermal protection system (TPS). The flight performance characteristics of the RIS TPS are discussed. The discussion is based primarily on postflight inspections and postflight interpretation of the flight instrumentation. TPS modifications of the future orbiters (OV-099, 103, and subs) are also discussed.

Dotts, R. L.↗

NASA NTRS1983

Observational evidence for solar wind acceleration at the base of coronal holes

An EUV spectrometer with a microchannel plate detector was developed to measure Doppler shifts of coronal and transition region lines. The results of three sounding rocket fights of this instrument indicate that EUV resonance emission lines are systematically shifted toward shorter wavelength within coronal holes. This "blue-shift" signature, first identified within compact low latitude holes, was also observed in a well developed polar coronal hole. The maximum measured shift within these coronal holes corresponds to a velocity relative to the remaining solar disc of 12 km/s in lambda 625 Mg X T to the approximately 10 to the 6.15 K power and 7 km /s/ in lambda 629 OV (T to the approximately 10 to the 5.4 K power). The existing data indicate that these blue-shifts are a common (and possibly universal) signature of coronal holes. These data provide important information on the acceleration of coronal plasma in open magnetic field regions, although the interpretation of observed Doppler shifts to derive a systematic mass flux is to some extent model dependent. A straightforward hypothesis is that the blueshift signature is a direct manifestation of the high speed solar wind deep within the transition region and inner corona.

Rottman, G. J.↗

NASA NTRS1984

The Development of an Airborne Instrumentation Computer System for Flight Test

Instrumentation interfacing frequently requires the linking of intelligent systems together, as well as requiring the link itself to be intelligent. The airborne instrumentation computer system (AICS) was developed to address this requirement. Its small size, approximately 254 by 133 by 140 mm (10 by 51/4 by 51/2 in), standard bus, and modular board configuration give it the ability to solve instrumentation interfacing and computation problems without forcing a redesign of the entire unit. This system has been used on the F-15 aircraft digital electronic engine control (DEEC) and its follow on engine model derivative (EMD) project and in an OV-1C Mohawk aircraft stall speed warning system. The AICS is presently undergoing configuration for use on an F-104 pace aircraft and on the advanced fighter technology integration (AFTI) F-111 aircraft.

Voice synthesizer↗

NASA NTRS1984

Test-engine and inlet performance of an aircraft used for investigating flight effects on fan noise

As part of the NASA Flight Effects on Fan Noise Program, a Grumman OV-1B Mohawk aircraft was modified to carry a modified and instrumented Pratt & Whitney JT15D-1 turbofan engine. Onboard flight data, together with simultaneously measured farfield acoustic data, comprise a flight data base to which JT15D-1 static and wind-tunnel data are compared. The overall objective is to improve the ability to use ground-based facilities for the prediction of flight inlet radiated noise. This report describes the hardware and presents performance results for the research engine.

Golub, R. A.↗

NASA NTRS1984

Shuttle flight data analysis

As the STS moves into routine operations, the direction of the work is shifting to an in-depth assessment of performance and its impact on the design and development of a future generation of vehicles. Particular emphasis is placed on providing an accurate physical explanation of anomalies, assessing the quality of simulation provided by the ground test facilities utilized, understanding the ground to flight extrapolation procedures, and the limitations of theoretical prediction techniques. The results are expected to provide direction and focus for future research and technology programs to enable substantial technological improvements in the next generation vehicles. The recent approval of the Orbital Experiments (OEX) Program's Shuttle Infrared Leeside Temperature Sensing (SILTS), Shuttle Entry Air Data System (SEADS), and Shuttle Upper Atmospheric Mass Spectrometer (SUMS) experiments to be integrated for flight on OV-102 in late 1985 is a firm indication of a strong commitment to a continuing and vigorous program in shuttle flight data analysis.

Walberg, G. D.↗

NASA NTRS1984

The Development of an Airborne Instrumentation Computer System for Flight Test

Glenn A Bever↗

NASA NTRS1984

National Space Transportation Systems Program mission report

The 515-41B National Space Transportation Systems Program Mission Report contains a summary of the major activities and accomplishments of the sixth operational Shuttle flight and fourth flight of the OV-099 vehicle, Challenger. Since this flight was the first to land at Kennedy Space Center, the vehicle was towed directly to the OPF (Orbiter Processing Facility) where preparations for flight STS-41C, scheduled for early April 1984, began immediately. The significant problems that occurred during STS-41B are summarized and a problem tracking list that is a complete list of all problems that occurred during the flight is given. None of the problems will affect the STS 41C flight. The major objectives of flight STS-41B were to successfully deploy the Westar satellite and the Indonesian Communications Satellite-B2 (PALAPA-B2); to evaluate the MMU (Manned Maneuvering Unit) support for EVA (Extravehicular Activities); to exercise the MFR (Manipulator Foot Restraint); to demonstrate a closed loop rendezvous; and to operate the M.R (Monodisperse Latex Reactor), the ACES (Acoustic Containerless Experiment System) and the IEF (Isoelectric Focusing) in cabin experiments; and to obtain photographs with the Cinema 360 Cameras.

Collins, M. A., Jr.↗

NASA NTRS1984

National Space Transportation Systems Program mission report

The STS 41-C National Space Transportation Systems Program Mission Report contains a summary of the major activities and accomplishments of the eleventh Shuttle flight and fifth flight of the OV-099 vehicle, Challenger. Also summarized are the significant problems that occurred during STS 41-C, and a problem tracking list that is a complete list of all problems that occurred during the flight. The major objectives of flight STS 41-C were to successfully deploy the LDEF (long duration exposure facility) and retrieve, repair and redeploy the SMM (Solar Maximum Mission) spacecraft, and perform functions of IMAX and Cinema 360 cameras.

Collins, M. A., Jr.↗