Probabilistic transient thermal analysis of an atmospheric reentry vehicle structure

Thermal analysis plays an important role in the structural design of atmospheric reentry vehicles, which are subjected to severe aerodynamic heating. It is sometimes difficult to assess the design safety margin because of uncertainties in the predicted heat flux and the material properties used in the thermal analyses. However, probabilistic techniques allow the effects of uncertainties to be analyzed, and the present study demonstrates the probabilistic thermal analysis of the PARTT reentry vehicle using the Monte Carlo technique to investigate the probabilistic temperature responses. The temperature responses were found to depend significantly on time and location, and reliability was predicted at all locations. The peak temperature of the vehicle's main structure was found to be strongly correlated with heat shield temperature, and analysis of the contributions of random parameters showed that heat flux and heat shield emissivity significantly affect the peak temperature. These results indicate that the thermal design of the heat shield shell is very important for the whole structure. It is expected that such information will provide good insight for the design of a reentry vehicle's structure.