Thermal Analysis of Compressible Gaseous Nitrogen Flow of X-38 Pressure Control System for First Mission Phase

A SINDA/FLUINT model was developed for performing the thermal analysis of the compressible gaseous nitrogen (GN₂) flow of X-38 pressure control system (PCS). The purpose of this analysis is to predict the thermal performance of X-38 PCS for the first mission phase, and to ensure that the GN₂ pressure in tank stays above 1000 psi and the GN₂ temperature in tank stays above −65°F during a real mission phase. The model simulations of the X-38 PCS have been conducted with the flowrates of the first mission phase for different ambient and GN₂ temperatures with/without heating the GN₂ tank wall. The predicted results show that the GN₂ pressures and temperatures fulfill the requirements and limitations of the X-38 pressure control system without heating the GN₂ tank wall. The electrical heaters on the GN₂ tank exterior may be eliminated.