Experimental and computational analysis of Shuttle Orbiter hypersonic trim anomaly
| Autor: | John W. Paulson, JL James Weilmuenster, Gregory J. Brauckmann |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
Physics
Hypersonic speed business.industry Aerospace Engineering Reynolds number Mechanics law.invention Physics::Fluid Dynamics symbols.namesake Orbiter Mach number Space and Planetary Science law Compressibility symbols Hypersonic wind tunnel Heat capacity ratio Pitching moment Aerospace engineering business |
| Zdroj: | Journal of Spacecraft and Rockets. 32:758-764 |
| ISSN: | 1533-6794 0022-4650 |
| DOI: | 10.2514/3.26680 |
| Popis: | During the high-Mach-number, high-altitude portion of the first entry of the Shuttle Orbiter, the vehicle exhibited a nose-up pitching moment relative to preflight prediction of approximately Delta Cm = 0.03. This trim anomaly has been postulated to be due to compressibility, viscous, and/or real-gas (lowered specific heat ratio gamma) effects on basic body pitching moment, body-flap effectiveness, or both. In order to assess the relative contribution of each of these effects, an experimental study was undertaken to examine the effects of Mach number, Reynolds number, and ratio of specific heats. Complementary computational solutions were obtained for wind-tunnel and flight conditions. The primary cause of the anomaly was determined to be lower pressures on the aft windward surface of the Orbiter than deduced from hypersonic wind-tunnel tests with ideal- or near-ideal-gas test flow. The lower pressure levels are a result of the lowering of the flowfield gamma due to high-temperature effects. This phenomenon was accurately simulated in a hypersonic wind tunnel using a heavy gas, which provided a lower, gamma, and was correctly predicted by Navier-Stokes computations using nonequilibrium chemistry. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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