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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 343 records · Page 19
All sourcesNASA NTRSDOE OSTI
NASA NTRS1981

Langley high-lift research on a high-aspect-ratio supercritical wing configuration

To determine the low speed performance characteristics of a representative high aspect ratio supercritical wing, two low speed jet transport models were fabricated. A 12-ft. span model was used for low Reynolds number tests in the Langley 4- by 7-Meter Tunnel and the second, a 7.5-ft. span model, was used for high Reynolds number tests in the Ames 12-foot Pressure Tunnel. A brief summary of the results of the tests of these two models is presented and comparisons are made between the data obtained on these two models and other similar models. Follow-on two and three dimensional research efforts related to the EET high-lift configurations are also presented and discussed.

Morgan, H. L., Jr.↗
NASA NTRS1984

Recent modifications and calibration of the Langley low-turbulence pressure tunnel

Modifications to the Langley Low-Turbulence Pressure Tunnel are presented and a calibration of the mean flow parameters in the test section is provided. Also included are the operational capability of the tunnel and typical test results for both single-element and multi-element airfoils. Modifications to the facility consisted of the following: replacement of the original cooling coils and antiturbulence screens and addition of a tunnel-shell heating system, a two dimensional model-support and force-balance system, a sidewall boundary layer control system, a remote-controlled survey apparatus, and a new data acquisition system. A calibration of the mean flow parameters in the test section was conducted over the complete operational range of the tunnel. The calibration included dynamic-pressure measurements, Mach number distributions, flow-angularity measurements, boundary-layer characteristics, and total-pressure profiles. In addition, test-section turbulence measurements made after the tunnel modifications have been included with these calibration data to show a comparison of existing turbulence levels with data obtained for the facility in 1941 with the original screen installation.

Mcghee, R. J.↗
NASA NTRS1982

High Reynolds number tests of a Boeing BAC I airfoil in the Langley 0.3-meter transonic cryogenic tunnel

A wind tunnel investigation of an advanced-technology airfoil was conducted in the Langley 0.3-Meter Transonic Cryogenic Tunnel (TCT). This investigation represents the first in a series of NASA/U.X. industry two dimensional airfoil studies to be completed in the Advanced Technology Airfoil Test program. Test temperature was varied from ambient to about 100 K at pressures ranging from about 1.2 to 6.0 atm. Mach number was varied from about 0.40 to 0.80. These variables provided a Reynolds number (based on airfoil chord) range from about .0000044 to .00005. This investigation was specifically designed to: (1) test a Boeing advanced airfoil from low to flight-equivalent Reynolds numbers; (2) provide the industry participant (Boeing) with experience in cryogenic wind-tunnel model design and testing techniques; and (3) demonstrate the suitability of the 0.3-m TCT as an airfoil test facility. All the objectives of the cooperative test were met. Data are included which demonstrate the effects of fixed transition, Mach number, and Reynolds number on the aerodynamic characteristics of the airfoil. Also included are remarks on the model design, the model structural integrity, and the overall test experience.

Johnson, W. G., Jr.↗
NASA NTRS1982

Pressure distribution data from tests of 2.29-meter (7.5-ft.) span EET high-lift research model in Langley 4- by 7-meter tunnel

A 2.29 m (7.5 ft.) span high-lift research model equipped with full-span leading-edge slat and part-span double-slotted trailing-edge flap was tested in the Langley 4- by 7-Meter Tunnel to determine the low speed performance characteristics of a representative high aspect ratio suprcritical wing. These tests were performed in support of the Energy Efficient Transport (EET) program which is one element of the Aircraft Energy Efficiency (ACEE) project. Static longitudinal forces and moments and chordwise pressure distributions at three spanwise stations were measured for cruise, climb, two take-off flap, and two landing flap wing configurations. The tabulated and plotted pressure distribution data is presented without analysis or discussion.

Morgan, H. L., Jr.↗
NASA NTRS1982

Production version of the extended NASA-Langley vortex lattice FORTRAN computer program. Volume 2: Source code

The source code for the latest production version, MARK IV, of the NASA-Langley Vortex Lattice Computer Program is presented. 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.

Herbert, H. E.↗
NASA NTRS1984

Langley experience with ADABAS/NATURAL

The use of the data base management system ADABAS and the companion software NATURAL and COM-PLETE at the Langley Research Center is evaluated. A brief overview of data base management system technology is provided as well as system upgrading, user requirements, and use of the system for administrative support.

Swanson, A.↗
NASA NTRS1984

High Reynolds number tests of the cast 10-2/DOA 2 airfoil in the Langley 0.3-meter transonic cryogenic tunnel, phase 2

Wind tunnel tests of an advanced technology airfoil, the CAST 10-2/DOA 2, were conducted in the Langley 0.3-Meter Transonic Cryogenic Tunnel (0.3-m TCT). This was the third of a series of tests conducted in a cooperative airfoil research program between the National Aeronautics and Space Administration and the Deutsche Forschungsund Versuchsanstalt fur Luft- und Raumfahrt e. V. For these tests, temperature was varied from 270 K to 110 K at pressures from 1.5 to 5.75 atmospheres. Mach number was varied from 0.60 to 0.80, and the Reynolds number (based on airfoil chord) was varied from 2 to 20 million. The aerodynamic data for the 7.62 cm chord airfoil model used in these tests is presented without analysis. Descriptions of the 0.3-m TCT, the airfoil model, the test instrumentation, and the testing procedures are included.

Dress, D. A.↗
NASA NTRS1984

Data from tests of a R4 airfoil in the Langley 0.3-meter transonic cryogenic tunnel

Aerodynamic data for the DFVLR R4 airfoil are presented in both graphic and tabular form. The R4 was tested in the Langley 0.3-Meter Transonic Cryogenic Tunnel (TCT) at Mach number from 0.60 to 0.78 at angles of attack from -2.0 to 8.0 degrees. The airfoil was tested at Reynolds numbers of 4, 6, 10, 15, 30, and 40 million based on the 152.32 mm chord.

Jenkins, R. V.↗
NASA NTRS1984

Cryogenic wind-tunnel model technology development activities at the NASA Langley Research Center

This paper summarizes the current cryogenic wind-tunnel model technology development activities at the NASA Langley Research Center. These research and development activities are being conducted in support of the design and fabrication of models for the new National Transonic Facility (NTF). The scope and current status of major research and development work is described and where available, data are presented from various investigations conducted to date. In addition, design and fabrication experience for existing developmental models to be tested in the NTF is discussed.

Young, C. P., Jr.↗
NASA NTRS1984

Investigation of sidewall boundary layer removal effects on two different chord airfoil models in the Langley 0.3-meter Transonic Cryogenic Tunnel

An investigation was carried out on two CAST 10-2 airfoil models with chords of 3 in. and 6 in. To evaluate the extent of sidewall influence on airfoil tests at transonic Mach numbers. The tests were conducted in the Langley 0.3-m Transonic Cryogenic Tunnel two-dimensional test section equipped with an upstream sidewall boundary layer removal system which reduces the boundary layer displacement thickness to about 1 percent of model halfspan from an initial 2 percent without boundary layer removal. Test results have shown the changes in the location of the shock on the upper surface of the airfoil to be about the same for both models with and without sidewall boundary layer removal. Even though large differences were noted in the high lift characteristics of the two models, the sidewall boundary layer removal had little effect on the differences. These tests also served to validate the boundary layer removal technique and the associated Mach number correction required with upstream boundary layer removal.

Murthy, A. V.↗
NASA NTRS1984

Modification of NASA Langley 8 Foot High Temperature Tunnel to provide a unique national research facility for hypersonic air-breathing propulsion systems

A planned modification of the NASA Langley 8-Foot High Temperature Tunnel to make it a unique national research facility for hypersonic air-breathing propulsion systems is described, and some of the ongoing supporting research for that modification is discussed. The modification involves: (1) the addition of an oxygen-enrichment system which will allow the methane-air combustion-heated test stream to simulate air for propulsion testing; and (2) supplemental nozzles to expand the test simulation capability from the current nominal Mach number to 7.0 include Mach numbers 3.0, 4.5, and 5.0. Detailed design of the modifications is currently underway and the modified facility is scheduled to be available for tests of large scale propulsion systems by mid 1988.

Kelly, H. N.↗
NASA NTRS1984

Dynamic flow quality measurements in the Langley Low Turbulence Pressure Tunnel

The results of tests to measure the disturbance levels across the cooler, screens, and nozzle in the test section of the rehabilitated Langley Research Center Low Turbulence Pressure Tunnel are reported and discussed. The velocity fluctuations measured upstream and downstream of the cooler were approximately equal and ranged from 5 to 15 percent. The attenuation of the measured velocity fluctuations across the screen agreed with predictions from Dryden's (1949) theory. Velocity fluctuations in the test section ranged from 0.025 percent at Mach 0.05 to 0.3 percent at Mach 0.2. Pressure fluctuations at the test section walls agreed with previous measurements made under a turbulent boundary. The autocorrelation functions indicated that there were large reductions in the integral scale of turbulence across the cooler and screens. The spectra measured upstream and downstream of the cooler were mostly broadband.

Stainback, P. C.↗
NASA NTRS1984

Validation of a wall-interference assessment/correction procedure for airfoil tests in the Langley 0.3-meter Transonic Cryogenic Tunnel

Validation of a wall-interference assessment/correction (WIAC) procedure for a given facility requires its application to several sets of test data. It is necessary therefore to create a somewhat automated method for processing data through the various steps in the procedure. An automated procedure is also welcomed by the test engineer or eventual user in order to reduce the required effort and opportunity for error. Such a procedure has been developed for the Langley 0.3-m Transonic Cryogenic Tunnel using the TWINTN4 WIAC code. This code provides a four-wall, 2-D, transonic correction; that is, it accounts for sidewall boundary-layer effects, as well as for top and bottom wall effects on the airfoil tests. The TWINTN4 code utilizes measured pressure data at the tunnel walls and on the airfoil model; thus, classical homogeneous-wall boundary conditions are not used in the correction procedure.

Gumbert, C. R.↗
NASA NTRS1984

Evaluation of the Langley 4- by 7-meter tunnel for propeller noise measurements

An experimental and theoretical evaluation of the Langley 4- by 7- Meter Tunnel was conducted to determine its suitability for obtaining propeller noise data. The tunnel circuit and open test section are described. An experimental evaluation is performed using microphones placed in and on the tunnel floor. The reflection characteristics and background noise are determined. The predicted source (propeller) near-field/far-field boundary is given using a first-principles method. The effect of the tunnel-floor boundry layer on the noise from the propeller is also predicted. A propeller test stand used for part of his evaluation is also described. The measured propeller performance characteristics are compared with those obtained at a larger scale, and the effect of the test-section configuration on the propeller performance is examined. Finally, propeller noise measurements were obtained on an eight-bladed SR-2 propeller operating at angles of attack -8 deg, 0 deg, and 4.6 deg to give an indication of attainable signal-to-noise ratios.

Block, P. J. W.↗
NASA NTRS1984

Sources, paths, and concepts for reduction of noise in the test section of the NASA Langley 4x7m wind tunnel

NASA is investigating the feasibility of modifying the 4x7m Wind Tunnel at the Langley Research Center to make it suitable for a variety of aeroacoustic testing applications, most notably model helicopter rotors. The amount of noise reduction required to meet NASA's goal for test section background noise was determined, the predominant sources and paths causing the background noise were quantified, and trade-off studies between schemes to reduce fan noise at the source and those to attenuate the sound generated in the circuit between the sources and the test section were carried out. An extensive data base is also presented on circuit sources and paths.

Hayden, R. E.↗
NASA NTRS1985

Description of the insulation system for the Langley 0.3-Meter Transonic Cryogenic Tunnel

The thermal insulation system of the Langley 0.3 Meter Transonic Cryogenic Tunnel is described. The insulation system is designed to operate from room temperature down to about 77.4 K, the temperature of liquid nitrogen at 1 atmosphere. A detailed description is given of the primary insulation sytem consists of glass fiber mats, a three part vapor barrier, and a dry positive pressure purge system. Also described are several secondary insulation systems required for the test section, actuators, and tunnel supports. An appendix briefly describes the original insulation system which is considered inferior to the one presently in place. The time required for opening and closing portions of the insulation system for modification or repair to the tunnel has been reduced, typically, from a few days for the original thermal insulating system to a few hours for the present system.

Lawing, P. L.↗
NASA NTRS1985

Langley Mach 4 scramjet test facility

An engine test facility was constructed at the NASA Langley Research Center in support of a supersonic combustion ramjet (scramjet) technology development program. Hydrogen combustion in air with oxygen replenishment provides simulated air at Mach 4 flight velocity, pressure, and true total temperature for an altitude range from 57,000 to 86,000 feet. A facility nozzle with a 13 in square exit produces a Mach 3.5 free jet flow for engine propulsion tests. The facility is described and calibration results are presented which demonstrate the suitability of the test flow for conducting scramjet engine research.

Earl H Andrews Jr.↗
NASA NTRS1985

Scientific and technical information output of the Langley Research Center for calendar year 1984

The scientific and technical information that the Langley Research Center produced during the calendar year 1984 is compiled. Approximately 1650 citations are included comprising formal reports, quick-release technical memorandums, contractor reports, journal articles and other publications, meeting presentations, technical talks, computer programs, tech briefs, and patents.

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