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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 235 records · Page 13
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NASA NTRSDate not supplied

It’s Hip To Be Square - Refurbishment of the NASA Langley National Transonic Facility Test Section Plenum Door

The “nearside” plenum door (NPD) at the 39-year-old NASA Langley Research Center (LARC) National Transonic Facility (NTF) has become increasingly recalcitrant during the opening /closing sequence. The NPD is the primary means of entry into the test section for personnel and for model installation. The sliding NPD hardware guide bearings have failed three (3) times within a one-year period and “quick fixes” were able to be made to guide rails, wheels and bearings to put the NPD back into operation. The NPD no longer can utilize a “quick fix” as the rolling hardware is at its limit for further modifications. This presentation will describe the NPD situation, the findings as to the cause of the periodic NPD failures, and the solution to remove, refurbish, and reinstall the NPD.

Test Facilities↗
NASA NTRS2013

Airborne Wind Profiling Algorithms for the Pulsed 2-Micron Coherent Doppler Lidar at NASA Langley Research Center

Two versions of airborne wind profiling algorithms for the pulsed 2-micron coherent Doppler lidar system at NASA Langley Research Center in Virginia are presented. Each algorithm utilizes different number of line-of-sight (LOS) lidar returns while compensating the adverse effects of different coordinate systems between the aircraft and the Earth. One of the two algorithms APOLO (Airborne Wind Profiling Algorithm for Doppler Wind Lidar) estimates wind products using two LOSs. The other algorithm utilizes five LOSs. The airborne lidar data were acquired during the NASA's Genesis and Rapid Intensification Processes (GRIP) campaign in 2010. The wind profile products from the two algorithms are compared with the dropsonde data to validate their results.

Beyon, Jeffrey Y.↗
NASA NTRS2005

Optically Based Flame Detection in the NASA Langley 8-ft High- Temperature Wind Tunnel

Two optically based flame-detection systems have been developed for use in NASA Langley's 8-Foot High-Temperature Tunnel (8-ft HTT). These systems are used to detect the presence and stability of the main-burner and pilot-level flames during facility operation. System design considerations will be discussed, and a detailed description of the system components and circuit diagrams will be provided in the Appendices of this report. A more detailed description of the manufacturing process used in the fabrication of the fiber-optic probes is covered in NASA TM-2001-211233.

Borg, Stephen E.↗
NASA NTRS1976

Mated aerodynamic characteristics investigation for the 0.04 scale model TE 1065 (Boeing 747-100) of the 747 CAM and the 0.0405 scale model (43-0) of the space shuttle orbiter in the NASA Langley V/STOL transition research wind tunnel (CA8), volume 1

Aerodynamic force data are presented in tables and graphs for the NASA Langley V/STOL Transition Research Wind Tunnel tests on a 0.04 scale model of the 747 with a 0.0405 scale Orbiter space shuttle. The investigation included the effects of flap setting, stabilizer angle, elevator angle, ground proximity, and Orbiter tailcone fairing. Data were obtained in the pitch plane only. The test was run at M = 0.15, with a dynamic pressure of 35 psf. Six static pressures were measured on each side of the 747 CAM nose to determine the effects of the Orbiter on the 747 airspeed and altitude indicators.

Source record↗
NASA NTRS1982

Production version of the extended NASA-Langley Vortex Lattice FORTRAN computer program. Volume 1: User's guide

The latest production version, MARK IV, of the NASA-Langley vortex lattice computer program is summarized. All viable subcritical aerodynamic features of previous versions were retained. This version extends the previously documented program capabilities to four planforms, 400 panels, and enables the user to obtain vortex-flow aerodynamics on cambered planforms, flowfield properties off the configuration in attached flow, and planform longitudinal load distributions.

Lamar, J. E.↗
NASA NTRS1982

Hypersonic airbreathing missile concepts under study at NASA Langley Research Center

The design and performance of several tactical and strategic hypersonic airbreathing missile concepts under study at the NASA Langley Research Center are discussed from an evolutionary perspective. A mid- and chin inlet missile design, constrained to the Navy's vertical box launcher, was investigated; a performance comparison is presented that is favorable to the mid-inlet approach. Parasol wing, confined flow field, and spatula-like cruise missile configurations were examined with strategic applications in mind. The preliminary results are encouraging with respect to aerodynamic and volumetric efficiency and choice of engine integration schemes.

Hunt, J. L.↗
NASA NTRS1993

Dynamic tests on the NASA Langley CSI evolutionary model

A modal analysis study, representing one of the anticipated 'Cooperative Spacecraft Structural Dynamics Experiments on the NASA Langley CSI Evolutionary Model', was carried out as a sub-task under the NASA/DLR collaboration in dynamics and control of large space systems. The CSI evolutionary testbed (CEM) is designed for the development of Controls-Structures Interaction (CSI) technology to improve space science platform pointing. For orbiting space structures like large flexible trusses, new identification challenges arise due to their specific dynamic characteristics (low frequencies and high modal density) on the one hand, and the limited possibilities of exciting such structures and measuring their responses on orbit on the other. The main objective was to investigate the modal identification potential of several different types of forcing functions that could possibly be realized with on-board excitation equipment using a minimum number of exciter locations as well as response locations. These locations were defined in an analytical test prediction process used to study the implications of measuring and analyzing the responses thus produced. It turned out that broadband excitation is needed for a general modal survey, but if only certain modes are of particular interest, combinations of exponentially decaying sine functions provide favorable excitation conditions as they allow to concentrate the available energy on the modes being of special interest. From a practical point-of-view structural nonlinearities as well as noisy measurements make the analysis more difficult, especially in the low frequency range and when the modes are closely spaced.

Troidl, H.↗
NASA NTRS1995

Recent developments and field tests of the NASA Langley Research Center airborne water vapor DIAL system

An airborne differential absorption lidar (DIAL) system has been developed at the NASA Langley Research Center for the remote measurement of water vapor (H2O) and aerosols in the lower troposphere. Significant modifications to the laser transmitters and other major subsystems have been implemented during the past two years to improve the system's performance and field reliability. The modified system is to be flight tested in late 1994, and the system performance characteristics and preliminary atmospheric H2O and aerosol data from these flights are discussed in this paper.

Higdon, Noah S.↗
NASA NTRS2000

Hyper-X Engine Testing in the NASA Langley 8-Foot High Temperature Tunnel

Airframe-integrated scramjet engine tests have 8 completed at Mach 7 in the NASA Langley 8-Foot High Temperature Tunnel under the Hyper-X program. These tests provided critical engine data as well as design and database verification for the Mach 7 flight tests of the Hyper-X research vehicle (X-43), which will provide the first-ever airframe- integrated scramjet flight data. The first model tested was the Hyper-X Engine Model (HXEM), and the second was the Hyper-X Flight Engine (HXFE). The HXEM, a partial-width, full-height engine that is mounted on an airframe structure to simulate the forebody features of the X-43, was tested to provide data linking flowpath development databases to the complete airframe-integrated three-dimensional flight configuration and to isolate effects of ground testing conditions and techniques. The HXFE, an exact geometric representation of the X-43 scramjet engine mounted on an airframe structure that duplicates the entire three-dimensional propulsion flowpath from the vehicle leading edge to the vehicle base, was tested to verify the complete design as it will be flight tested. This paper presents an overview of these two tests, their importance to the Hyper-X program, and the significance of their contribution to scramjet database development.

Huebner, Lawrence D.↗
NASA NTRS2000

Hyper-X Engine Testing in the NASA Langley 8-Foot High Temperature Tunnel

Airframe-integrated scramjet engine tests have been completed at Mach 7 in the NASA Langley 8-Foot High Temperature Tunnel under the Hyper-X program. These tests provided critical engine data as well as design and database verification for the Mach 7 flight tests of the Hyper-X research vehicle (X-43), which will provide the first-ever airframe-integrated scramjet flight data. The first model tested was the Hyper-X Engine Model (HXEM), and the second was the Hyper-X Flight Engine (HXFE). The HXEM, a partial-width, full-height engine that is mounted on an airframe structure to simulate the forebody features of the X-43, was tested to provide data linking flowpath development databases to the complete airframe-integrated three-dimensional flight configuration, and to isolate effects of ground testing conditions and techniques. The HXFE, an exact geometric representation of the X-43 scramjet engine mounted on an airframe structure that duplicates the entire three-dimensional propulsion flowpath from the vehicle leading edge to the vehicle base, was tested to verify the complete design as it will be flight tested. This paper presents an overview of these two tests, their importance to the Hyper-X program, and the significance of their contribution to scramjet database development.

Huebner, Lawrence D.↗
NASA NTRS2003

Survey of Primary Flow Measurement Parameters at the NASA Langley Transonic Dynamics Tunnel

An assessment of the methods and locations used to measure the primary flow conditions in the NASA Langley Transonic Dynamics Tunnel was conducted during calibration activities following the facility conversion from a Freon-12 heavy-gas test medium to R-134a. A survey of stagnation pressure, plenum static pressure, and stagnation temperature was undertaken at many pertinent locations in the settling chamber, plenum, and contraction section of the wind tunnel and these measurements were compared to those of the existing primary flow measurement systems. Local flow velocities were measured in the settling chamber using a pitot probe. Results illustrate that small discrepancies exist between measured primary tunnel flow conditions and the survey measurements. These discrepancies in tunnel stagnation pressure, plenum pressure, and stagnation temperature were found to be approximately +/- 1-3 psf and 2-3 degrees Fahrenheit. The propagation of known instrument errors in measured primary flow conditions and its impact on tunnel Mach number, dynamic pressure, flow velocity, and Reynolds number have been investigated analytically and shown to require careful attention when considering the uncertainty in measured test section conditions.

Piatak, David J.↗
NASA NTRS1997

Enhanced Capabilities of the NASA Langley Thermal Acoustic Fatigue Apparatus

This paper presents newly enhanced acoustic capabilities of the Thermal Acoustic Fatigue Apparatus at the NASA Langley Research Center. The facility is a progressive wave tube used for sonic fatigue testing of aerospace structures. Acoustic measurements for each of the six facility configurations are shown and comparisons with projected performance are made.

Rizzi, Stephen A.↗
NASA NTRS2005

NASA Langley Low Speed Aeroacoustic Wind Tunnel: Background Noise and Flow Survey Results Prior to FY05 Construction of Facilities Modifications

The NASA Langley Research Center Low Speed Aeroacoustic Wind Tunnel is a premier facility for model-scale testing of jet noise reduction concepts at realistic flow conditions. However, flow inside the open jet test section is less than optimum. A Construction of Facilities project, scheduled for FY 05, will replace the flow collector with a new design intended to reduce recirculation in the open jet test section. The reduction of recirculation will reduce background noise levels measured by a microphone array impinged by the recirculation flow and will improve flow characteristics in the open jet tunnel flow. In order to assess the degree to which this modification is successful, background noise levels and tunnel flow are documented, in order to establish a baseline, in this report.

Booth, Earl R., Jr.↗
NASA NTRS2014

Earth Radiation Budget Research at the NASA Langley Research Center

In the 1970s research studies concentrating on satellite measurements of Earth's radiation budget started at the NASA Langley Research Center. Since that beginning, considerable effort has been devoted to developing measurement techniques, data analysis methods, and time-space sampling strategies to meet the radiation budget science requirements for climate studies. Implementation and success of the Earth Radiation Budget Experiment (ERBE) and the Clouds and the Earth's Radiant Energy System (CERES) was due to the remarkable teamwork of many engineers, scientists, and data analysts. Data from ERBE have provided a new understanding of the effects of clouds, aerosols, and El Nino/La Nina oscillation on the Earth's radiation. CERES spacecraft instruments have extended the time coverage with high quality climate data records for over a decade. Using ERBE and CERES measurements these teams have created information about radiation at the top of the atmosphere, at the surface, and throughout the atmosphere for a better understanding of our climate. They have also generated surface radiation products for designers of solar power plants and buildings and numerous other applications

Smith, G. Louis↗
NASA NTRS2017

Computational Simulations of the NASA Langley HyMETS Arc-Jet Facility

The Hypersonic Materials Environmental Test System (HyMETS) arc-jet facility located at the NASA Langley Research Center in Hampton, Virginia, is primarily used for the research, development, and evaluation of high-temperature thermal protection systems for hypersonic vehicles and reentry systems. In order to improve testing capabilities and knowledge of the test article environment, an effort is underway to computationally simulate the flow-field using computational fluid dynamics (CFD). A detailed three-dimensional model of the arc-jet nozzle and free-jet portion of the flow-field has been developed and compared to calibration probe Pitot pressure and stagnation-point heat flux for three test conditions at low, medium, and high enthalpy. The CFD model takes into account uniform pressure and non-uniform enthalpy profiles at the nozzle inlet as well as catalytic recombination efficiency effects at the probe surface. Comparing the CFD results and test data indicates an effectively fully-catalytic copper surface on the heat flux probe of about 10% efficiency and a 2-3 kpa pressure drop from the arc heater bore, where the pressure is measured, to the plenum section, prior to the nozzle. With these assumptions, the CFD results are well within the uncertainty of the stagnation pressure and heat flux measurements. The conditions at the nozzle exit were also compared with radial and axial velocimetry. This simulation capability will be used to evaluate various three-dimensional models that are tested in the HyMETS facility. An end-to-end aerothermal and thermal simulation of HyMETS test articles will follow this work to provide a better understanding of the test environment, test results, and to aid in test planning. Additional flow-field diagnostic measurements will also be considered to improve the modeling capability.

Brune, A. J.↗
NASA NTRS1986

Pretest Report for the Full Span Propulsive Wing/Canard Model Test in the NASA Langley 4 x 7 Meter Low Speed Wind Tunnel Second Series Test

A full span propulsive wing/canard model is to be tested in the NASA Langley Research Center (LaRC) 4 x 7 meter low speed wind tunnel. These tests are a continuation of the tests conducted in Feb. 1984, NASA test No.290, and are being conducted under NASA Contract NAS1-17171. The purpose of these tests is to obtain extensive lateral-directional data with a revised fuselage concept. The wings, canards, and vertical tail of this second test series model are the same as tested in the previous test period. The fuselage and internal flow path have been modified to better reflect an external configuration suitable for a fighter airplane. Internal ducting and structure were changed as required to provide test efficiency and blowing control. The model fuselage tested during the 1984 tests was fabricated with flat sides to provide multiple wing and canard placement variations. The locations of the wing and canard are important variables in configuration development. With the establishment of the desired relative placement of the lifting surfaces, a typically shaped fuselage has been fabricated for these tests. This report provides the information necessary for the second series tests of the propulsive wing/canard model. The discussion in this report is limited to that affected by the model changes and to the second series test program. The pretest report information for test 290 which is valid for the second series test was published in Rockwell report NR 83H-79. This report is presented as Appendix 1 and the modified fuselage stress report is presented as Appendix 2 to this pretest report.

Stewart, V. R.↗
NASA NTRS2004

A Summary of DOD-Sponsored Research Performed at NASA Langley's Impact Dynamics Research Facility

The Impact Dynamics Research Facility (IDRF) is a 240-ft.-high gantry structure located at NASA Langley Research Center in Hampton, Virginia. The IDRF was originally built in the early 1960's for use as a Lunar Landing Research Facility. As such, the facility was configured to simulate the reduced gravitational environment of the Moon, allowing the Apollo astronauts to practice lunar landings under realistic conditions. In 1985, the IDRF was designated a National Historic Landmark based on its significant contributions to the Apollo Moon Landing Program. In the early 1970's the facility was converted into its current configuration as a full-scale crash test facility for light aircraft and rotorcraft. Since that time, the IDRF has been used to perform a wide variety of impact tests on full-scale aircraft, airframe components, and space vehicles in support of the General Aviation (GA) aircraft industry, the U.S. Department of Defense (DOD), the rotorcraft industry, and the NASA Space program. The objectives of this paper are twofold: to describe the IDRF facility and its unique capabilities for conducting structural impact testing, and to summarize the impact tests performed at the IDRF in support of the DOD. These tests cover a time period of roughly 2 1/2 decades, beginning in 1975 with the full-scale crash test of a CH-47 Chinook helicopter, and ending in 1999 with the external fuel system qualification test of a UH-60 Black Hawk helicopter. NASA officially closed the IDRF in September 2003; consequently, it is important to document the past contributions made in improved human survivability and impact tolerance through DOD-sponsored research performed at the IDRF.

Jackson, Karen E.↗