Investigation of Bridging Method to Predict Rarefied Aerodynamics of Mars Entry Capsules.

Attempt has been made to analyze applicability of different bridging relations based on the Mars Pathfinder data. The difference of aerodynamics predicted by seventeen gas/surface interaction models is investigated. Free molecular limit Kn effect on aerodynamics is analyzed lastly. The results show that bridging relations, gas/surface interaction models and free molecular limit Kn number influence aerodynamics seriously. Present data predicted by erflog bridging relation shows a good agreement with computational data predicted by Direct Simulation Monte Carlo(DSMC) method than others. Sin-squared bridging relation is more efficient than erf-log one with some accuracy loss which can be avoided most by adjusting free molecular limit Kn number. Erf-log bridging relations is not sensitive to free molecular limit Kn number, but that Kn number value should be above 50 to keep the accuracy in free molecular regime. [ABSTRACT FROM AUTHOR]