Effect of atmosphere parameter oscillation at high altitude in the northern hemisphere for near space hypersonic flight aerothermodynamic prediction

Abstract

For real atmosphere parameter fluctuates from the standard atmosphere model according the time and geography with stochastic atmospheric wave, it is important to predict the deviation effect on the aerothermodynamics environment for gliding hypersonic vehicle. However, according to the experts at NASA Johnson Space Center, at present neither the standard atmosphere model or the reference atmospheric model is able to describe the complex real atmosphere accurately. Especially, above 70 km altitude, the atmosphere parameter varies complicatedly, and deviates from standard atmosphere model intensely. The measurement results of atmosphere parameter from SABER (Sounding of the Atmosphere using Broadband Emission Radiometry) on TIMED satellite, launched at 2001, are testified widely with data from other sources. In this paper, based on measurement results between 2002 and 2010 from SABER on TIMED satellite, the atmosphere parameter statistics characters for 85 km altitude in typical months (January, April, July and October) and typical northern latitudes (0°, 20°, 40°, 60°, 80°) are obtained. In every research case, over 5000 stochastic samples are produced, which are satisfied with Max-Min distributing or normal distributing for the atmosphere model. The heating transfer on stagnation for stochastic sample in the on-the-spot survey parameter has been also studied. Then the statistics characteristics of the heating transfer on stagnation can be obtained and compared with the results based on U.S.1976 standard atmosphere, which shows the atmosphere oscillation statistics effect. The effect for latitudes and seasons on aerothermodynamics prediction has been investigated. It is shown that fluctuation for the atmosphere parameter plays an important role on the aerothermodynamics environment in near space flight. In the high altitude zone, season factor has a notable effect on the heating distribution. However, close to the equator, season factor has a little effect. At the same reason, heating transfer in higher altitude zone is usually greater than that from the standard model; on the contrary, heating transfer in lower altitude zone is general lower than that from the standard model. In summer (July), the higher latitude zone locates, the higher heating distribution it gets. The maximum heating transfer appears in July on 80° latitude. In extreme case, the maximum stagnation heating exceeds the result from the standard atmosphere model about 40%. At the same altitude, the maximum heating transfer appears in April or July. In the future work, the affection about the difference between Northern and Southern Hemisphere, between ocean and land and atmosphere parameter relativity will be researched.