A Coupled Heat Transfer Analysis with Effect of Thermal/Catalytic Cracking for a Regenerative Cooled Scramjet

摘要

A coupled heat transfer analysis including thermal/catalytic cracking of aviation kerosene at supercritical pressures was developed for a regenerative cooled scramjet. The internal flow of the scramjet, the coolant flow and the engine wall are calculated and coupled with the assumption of thermal equilibrium. Global models for thermal cracking and for catalytic cracking were introduced and implemented in the analysis. The heat transfer analysis was applied to study a regenerative cooling of a model scramjet with an inlet total temperature of 1600k, a mass flow rate of 1.74kg/s and an inlet Mach number of 5.0S. The results showed that thermal and catalytic cracking both supply extra heat sinks at a fuel temperature exceeding 750—800K due to endothermicity of reaction. An increase in the pressure loss of the coolant flow was observed for the cracking, which can be explained by the decomposition of the kerosene into small molecules. The present analysis including cracking effect is believed to provide more accurate results of regenerative cooling process for scramjet applications.