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At least 613 records · Page 34
All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

Effect of configuration modifications on the low-subsonic aerodynamic characteristics of a space shuttle orbiter concept with a blended delta wing-body

An investigation of several configuration modifications to improve the subsonic stability and performance of a blended delta wing-body space shuttle-orbiter concept has been conducted in the Langley low-turbulence pressure tunnel. These modifications included variations in vertical-tail location and orientation, wing planform shape, and afterbody shape. The model was tested at a Reynolds number, based on body length, of 17 x one million, at a Mack number of 0.25, and at angles of attack from about -4 deg to 22 deg.

Freeman, D. C., Jr.↗
NASA NTRS1972

Space shuttle: High angle of attack transition and low angle of attack launch phase aerodynamic stability and control of GD/C B-18E-2, B-18E-3 delta wing booster, and launch configuration of MSC-040A orbiter and twin pressure fed boosters

The test was a conventional stability and control test except for two aspects. One was the very high angles of attack at which the delta wing configurations were tested (up to 60 degrees) at Mach numbers of 3 and 4.96. The other was the installation of the orbiter and twin boosters in a manner that caused the support system to induce normal forces and side forces on the aft portion of the boosters at all Mach numbers; i.e., the support and the booster bodies were close together, side by side.

Debevoise, J. M.↗
NASA NTRS1972

Lee-side flow phenomena on space shuttle configurations at hypersonic speeds. Part 1: Flow separation and flow field viscous phenomena of a delta-wing shuttle orbiter configuration

Results of a pitot pressure investigation of the flow field on the lee side of a delta wing shuttle orbiter are presented. The results delineate the extent of the lee side separated flow and give a tentative cross sectional definition to the shock wave structure for angles of attack of 15 deg and 30 deg. It is shown that while, in general, the effects of Reynolds number on the flow field are not large, detailed effects are observed that may have significant bearing on the heating estimate. Two examples are cited for an angle of attack of 15 deg; these are: (1) The scope of the vertical tail exposed to the unseparated flow increases with increasing Reynolds number and (2) the depth of the separated flow adjacent ot where the bow wave crosses the wing appears to decrease with increasing Reynolds number. In addition, it is shown that at a spanwise station outboard of the wing-fuselage juncture, increasing Reynolds number decreased the pitot pressure in the unseparated flow. This defect of pitot pressure appears associated with the flow over the wing-fillet-fuselage juncture.

Cleary, J. W.↗
NASA NTRS1972

Aerodynamic studies of delta-wing shuttle orbiters. Part 1: Low speed

Numerous wind tunnel tests conducted on the evolving delta-wing orbiters have generated a fairly large aerodynamic data base over the entire entry operation range of these vehicles. A limited assessment is made of some of the aerodynamics of the current HO type orbiters, and several specific problem areas selected from the broad data base are discussed. These include, from a subsonic viewpoint, discussions of trim drag effect; effects of the installation of main rocket engine nozzles, OMS and RCS packages, Reynolds number effects, lateral-directional stability characteristics, and landing characteristics.

Freeman, D. C., Jr.↗
NASA NTRS1972

Review of delta wing space shuttle vehicle dynamics

The unsteady aerodynamics of the delta planform, high cross range, shuttle orbiter were investigated. It has been found that these vehicles are subject to five unsteady flow phenomena that could compromise the flight dynamics. They are: (1) leeside shock induced separation, (2) sudden leading edge stall, (3) vortex burst, (4) bow shock-flap shock interaction, (5) forebody vorticity. Trajectory shaping is seen as the most powerful means of avoiding the detrimental effects of the stall phenomena. However, stall must be fixed or controlled when traversing the stall region. The other phenomena may be controlled by carefully programmed control deflections and some configuration modification. Ways to alter the occurrence of the various flow conditions are explored.

Reding, J. P.↗
NASA NTRS1972

Heat transfer investigation of two Langley Research Center delta wing configurations at a Mach number of 10.5, volume 1

Heat transfer tests for two delta wing configurations were conducted in the hypervelocity wind tunnel. The 24-inch long models were tested at a Mach number of approximately 10.5 and at angles of attack of 20, 40, and 60 degrees over a length Reynolds number range from 5 million to 23 million on 4 May to 4 June 1971. Heat transfer results were obtained from model surface heat gage measurements and thermographic phosphor paint.

Eaves, R. H.↗
NASA NTRS1972

Experimental surface flow patterns and flow-field phenomena of a delta-wing space-shuttle orbiter

Composite photographs of the surface flow and shadowgraphs of the shock wave pattern are presented that depict the hypersonic flow field of a typical delta wing space shuttle orbiter. Results from a wind tunnel test in air are given in side, oblique, and projected plan views for angles of attack from 0 to 60 deg. The tests were conducted at a Mach number of 7.4 and for Reynolds numbers based on body length of 6,000,000 and 9,000,000. The interrelationship is shown for the intersecting bow and wing leading edge waves with the surface flow for angles of attack for which: (1) the leading edge wave is attached, and (2) the leading edge wave is detached.

Cleary, J. W.↗
NASA NTRS1972

Space shuttle: Heat transfer investigation of the McDonnell-Douglas delta wing orbiter at a nominal Mach number of 10.5

Heat transfer tests for the delta wing orbiter were conducted in a hypervelocity wind tunnel. A 1.1 percent scale model was tested at a Mach number of approximately 10.5 over an angle of attack range from 10 to 60 degrees over a length Reynolds number range from 5 times 10 to the 6th power to 24 times 10 to the 6th power. Heat transfer results were obtained from model surface heat gage measurements and thermographic phosphor paint. Limited pressure measurements were obtained.

Eaves, R. H.↗
NASA NTRS1972

Effects of Leading-Edge Camber on Low-Speed Characteristics of Slender Delta Wings: Techniques and Tabulated Data

Special tests to determine the importance of transition fixing and Reynolds number variation on forces produced by thin delta wings are discussed. Transition fixing was achieved by applying cement to models and sprinkling grit on wet adhesive. Strips were applied along lines emanating from the apex located along sixty-five percent semi-span rays. Tests were made with grit on both surfaces, upper surface only, lower surface only, and on clean surfaces. Reynolds number varied by testing at three dynamic pressures. Correspondence between dynamic pressure and Reynolds number based on the mean aerodynamic chord are shown. No significant changes are noted due to either Reynolds number variation or transition fixing, within the range of Reynolds numbers used for the test.

Wentz, W. H., Jr.↗
NASA NTRS1972

Pitot-pressure distributions of the flow field of a delta-wing orbiter

Pitot pressure distributions of the flow field of a 0.0075-scale model of a typical delta wing shuttle orbiter are presented. Results are given for the windward and leeward sides on centerline in the angle-of-attack plane from wind tunnel tests conducted in air. Distributions are shown for three axial stations X/L = .35, .60, and .98 and for angles of attack from 0 to 60 deg. The tests were made at a Mach number of 7.4 and for Reynolds numbers based on body length from 1,500,000 to 9,000,000. The windward distributions at the two survey stations forward of the body boat tail demonstrate the compressive aspects of the flow from the shock wave to the body. Conversely, the distributions at the aft station display an expansion of the flow that is attributed to body boat tail. On the lee side, results are given at low angles of attack that illustrate the complicating aspects of the canopy on the flow field, while results are given to show the effects of flow separation at high angles of attack.

Cleary, J. W.↗
NASA NTRS1972

Space shuttle: Aerodynamic characteristics of a double delta wing space shuttle orbiter (M equals 0.6 - 5.0)

This test program was the first wind tunnel investigation of a double delta wing space shuttle orbiter. The 0.004 scale model used for this test was the first model constructed of this configuration and as such lacked certain refinements incorporated in later models, the principal differences being that the wing is located 0.1 inches model scale further forward than later models and that the nose contours are slightly different.

Ellis, R. R.↗
NASA NTRS1972

Effect of configuration modification on the hypersonic aerodynamic characteristics of a blended delta wing-body entry vehicle

The longitudinal, lateral, and directional aerodynamic characteristics of a delta-wing configuration were obtained experimentally at Mach 20 in helium with Reynolds numbers, based on model length, of 1.5 million and 2.9 million and at a Mach number of 6 in air with a Reynolds number, based on model length, of 4.8 million. The angles of attack varied from 0 deg to 55 deg for two sideslip angles. The effects of the addition of dorsal fins, the removal of wing tip fins, an increase in elevon span, and changes in elevon hinge-line sweep angle are discussed. The unmodified vehicle had a maximum lift-drag ratio of 2.1 at Mach 19 and of 2.4 at Mach 6 with about the same lateral and directional stability level at both Mach numbers. As the Mach number increased from 6 to 20, the longitudinal center of pressure moved forward and more positive elevon deflection was therefore required to maintain a given trim angle. The removal of wing tip fins increased the maximum lift-drag ratio and had a negligible effect on longitudinal stability, but caused directional instability that was not corrected by the dorsal fins examined. The shape of the wing and elevon hinge-line sweep had a large influence on the induced yawing moment due to roll control.

Arrington, J. P.↗
NASA NTRS1972

Supersonic aerodynamic characteristics of a lifting-body orbiter model with a blunted delta planform at Mach 2.30 to 4.60

An investigation has been made in the Langley Unitary Plan wind tunnel to determine the aerodynamic characteristics of a lifting-body orbiter model with a blunted delta planform. The model was tested at Mach numbers from 2.30 to 4.60, at nominal angles of attack from -4 deg to 60 deg and angles of sideslip from -4 deg to 10 deg, and at a Reynolds number of 2.5 million per foot.

Blair, A. B., Jr.↗
NASA NTRS1972

Delta launch vehicle isogrid structure NASTRAN analysis

Structural analysis applications of NASTRAN to the isogrid structure of the Delta launch vehicle are discussed. Isogrid is a method employed to stiffen the booster cylindrical shell surface by integrally machining ribs and skin from one piece of metal. The ribs are arranged in a repetitive equilateral triangular pattern; this results in a structural surface whose stiffness is orthogonally isotopic. For that structure, both static and general instability buckling analyses are described and the theoretical results are compared to test data. One of the parameters included in the analysis is the effect of pressure loadings on the buckling allowable load. In addition, a description of a supplementary computer program is presented.

Knighton, D. J.↗
NASA NTRS1971

The Delta and Thor/Agena launch vehicles for scientific and applications satellites.

Description of the Delta Model 904 and the Thor/Agena Model 9A4 scientific and applications satellite launch vehicles, with projections of future growth and launch costs. These launch vehicles are shown to offer scientific and applications satellite mission planners a broad spectrum in performance capabilities together with unprecedented mission flexibility. Depending on the mission, these two medium class launch vehicles can be configured on the new universal boattail (UBT) Thor booster in either two or three stages with thrust augmentation of the UBT ranging from three to nine strap-on solid propellant motors. Both vehicles incorporate strapdown inertial guidance systems that allow flexible mission programming by computer so ftware changes rather than by adjustments.

Gunn, C. R.↗