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Results for “AERODYNAMIC CHARACTERISTICS”

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 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
NASA NTRS1979

Aerodynamic characteristics of wheelchairs

The overall aerodynamic drag characteristics of a conventional wheelchair were defined and the individual drag contributions of its components were determined. The results show that a fiftieth percentile man sitting in the complete wheelchair would experience an aerodynamic drag coefficient on the order of 1.4.

Coe, P. L., Jr.↗
NASA NTRS1989

Wind-tunnel investigation of aerodynamic characteristics and wing pressure distributions of an airplane with variable-sweep wings modified for laminar flow

A wind tunnel test was conducted to evaluate the aerodynamic characteristics and wing pressure distributions of a variable wing sweep aircraft having wing panels that are modified to promote laminar flow. The modified wing section shapes were incorporated over most of the exposed outer wing panel span and were obtained by extending the leading edge and adding thickness to the existing wing upper surface forward of 60 percent chord. Two different wing configurations, one each for Mach numbers 0.7 and 0.8, were tested on the model simultaneously, with one wing configuration on the left side and the other on the right. The tests were conducted at Mach numbers 0.20 to 0.90 for wing sweep angles of 20, 25, 30, and 35 degrees. Longitudinal, lateral and directional aerodynamic characteristics of the modified and baseline configurations, and selected pressure distributions for the modified configurations, are presented in graphical form without analysis. A tabulation of the pressure data for the modified configuration is available as microfiche.

Hallissy, James B.↗
NASA NTRS2011

Error Estimate of the Ares I Vehicle Longitudinal Aerodynamic Characteristics Based on Turbulent Navier-Stokes Analysis

Numerical predictions of the longitudinal aerodynamic characteristics for the Ares I class of vehicles, along with the associated error estimate derived from an iterative convergence grid refinement, are presented. Computational results are based on the unstructured grid, Reynolds-averaged Navier-Stokes flow solver USM3D, with an assumption that the flow is fully turbulent over the entire vehicle. This effort was designed to complement the prior computational activities conducted over the past five years in support of the Ares I Project with the emphasis on the vehicle s last design cycle designated as the A106 configuration. Due to a lack of flight data for this particular design s outer mold line, the initial vehicle s aerodynamic predictions and the associated error estimates were first assessed and validated against the available experimental data at representative wind tunnel flow conditions pertinent to the ascent phase of the trajectory without including any propulsion effects. Subsequently, the established procedures were then applied to obtain the longitudinal aerodynamic predictions at the selected flight flow conditions. Sample computed results and the correlations with the experimental measurements are presented. In addition, the present analysis includes the relevant data to highlight the balance between the prediction accuracy against the grid size and, thus, the corresponding computer resource requirements for the computations at both wind tunnel and flight flow conditions. NOTE: Some details have been removed from selected plots and figures in compliance with the sensitive but unclassified (SBU) restrictions. However, the content still conveys the merits of the technical approach and the relevant results.

Aerodynamic characteristics↗
NASA NTRS1985

Experimental and theoretical study of the longitudinal aerodynamic characteristics of delta and double-delta wings at Mach numbers of 1.60, 1.90, and 2.16

An experimental and theoretical study was conducted to investigate the supersonic aerodynamic characteristics of delta and double-delta wings. Testing was conducted in the Langley Unitary Plan Wind Tunnel at Mach numbers of 1.60, 1.90, and 2.16. The double-delta wings exhibited lower zero-lift drag values than the delta wings having the same aspect ratio, whereas delta wings provided the lower drag due to lift. Deflections of the trailing-edge flaps for pitch control revealed that the induced aerodynamic forces were only a function of the flap planform and were independent of wing planform. The supporting theoretical analysis showed that the supersonic design and analysis system (SDAS) did not consistently predict all the longitudinal aerodynamic characteristics of the low-sweep, low-fineness-ratio wing-body configurations under investigation.

Wood, R. M.↗
NASA NTRS1961

Investigation of the Aerodynamic Characteristics of Two Preliminary Designs of Scout Research Vehicle at Mach Numbers from 1.77 to 4.65

A wind-tunnel investigation has been conducted to determine the aerodynamic characteristics of two preliminary designs of the Scout research vehicle. The first model was tested at Mach numbers from 1.77 to 2.87 at Reynolds numbers of 3.7 x 10(exp 6) to 4.0 x 10(exp 6) per foot. A variable angle-of-attack range of -2 degrees to 14 degrees was used in determining the effect of nose shape, size of interstage flare base diameter, size of trapezoidal first-stage fins, and fin tip-control deflection on the aerodynamic characteristics of the model.

Keynton, Robert J.↗
NASA NTRS1961

Aerodynamic Characteristics in Pitch and Sideslip of a 1/15-Scale Model of the Scout Vehicle at a Mach Number of 2.01

An investigation has been made t o determine the aerodynamic characteristics in pitch and sideslip of a 1/15-scale model of the Scout vehicle at a Mach number of 2.01. The effects of two sets of cruciform fins, of inline and indexed fin arrangements, a flare , and accessories such as antennas, launch fittings, and control tunnels were measured for combined angles of attack and sideslip to about 8deg. The tests were made in the Langley 4- by 4-foot supersonic pressure tunnel at a Reynolds number of 4 x 10(exp 6) per foot. The Addition of the rear fins or the flare increased the longitudinal and directional stability, whereas the front fins, either indexed or inline, had a destabilizing effect. All configurations became directionally unstable with increasing angle of attack. The accessories had only a small effect on the aerodynamic characteristics other than an increase in axial force.

Robinson, Ross B.↗
NASA NTRS1990

Experimental and predicted aerodynamic characteristics of a proposed Assured Crew Return Vehicle (ACRV) lifting-body configuration at Mach 6 and 10

The effects of Mach number, Reynolds number, and ratio of specific heats on the aerodynamic characteristics of a proposed Assured Crew Return Vehicle (ACRV) lifting-body configuration were examined for a range of angles of attack from -5 deg to 50 deg. Predictions made with a Langley-developed, three-dimensional Navier Stokes solver known as LAURA, which was exercised as an Euler solver for the present study, are compared with the experimental results. Unlike the Shuttle Orbiter, which experienced a significant nose-up increment in pitching moment with decreasing specific heat ratio (i.e., real gas effects), the aerodynamic characteristics of this lifting-body configuration are insensitive to changes in specific heat ratio. The maximum trimmed lift-to-drag ratio achieved was about 1.5. Predicted inviscid values of aerodynamic coefficients were generally in good agreement with measurement.

Micol, John R.↗
NASA NTRS1975

Calculation of static longitudinal aerodynamic characteristics of STOL aircraft with upper surface blown flaps

An existing prediction method developed for EBF aircraft configurations was applied to USB configurations to determine its potential utility in predicting USB aerodynamic characteristics. An existing wing-flap vortex-lattice computer program was modified to handle multiple spanwise flap segments at different flap angles. A potential flow turbofan wake model developed for circular cross-section jets was used to model a rectangular cross-section jet wake by placing a number of circular jets side by side. The calculation procedure was evaluated by comparison of measured and predicted aerodynamic characteristics on a variety of USB configurations. The method is limited to the case where the flow and geometry of the configuration are symmetric about a vertical plane containing the wing root chord. Comparison of predicted and measured lift and pitching moment coefficients were made on swept wings with one and two engines per wing panel, various flap deflection angles, and a range of thrust coefficients. The results indicate satisfactory prediction of lift for flap deflections up to 55 and thrust coefficients less than 2. The applicability of the prediction procedure to USB configurations is evaluated, and specific recommendations for improvements are discussed.

Mendenhall, M. R.↗
NASA NTRS1977

Longitudinal aerodynamic characteristics of a low-wing lift-fan transport including hover characteristics in and out of ground effect

The longitudinal aerodynamic characteristics of a six-fan, tip-driven (remote) lift-fan VTOL transport through transition were determined by an investigation conducted in the Langley V/STOL tunnel. Tests were also made with the large midspan lift-fan pods and lift-cruise fans removed to determine their their influence on the stability and control of the configuration. Data were obtained for a range of model height above ground.

Hoad, D. R.↗