Comparison Analysis between Expander Cycle and Recooling Cycle for a Scramjet

Abstract

An expander cycle is one potential fuel feeding cycle for a scramjet, which has been successfully applied in the liquid rocket. However, very little literature exists about the fuel feeding cycle for a scramjet. A recooling cycle has been newly proposed for a scramjet to reduce the fuel flow for cooling, the secondary function of which acts as the fuel feeding cycle. To illustrate the difference between the expander cycle and the recooling cycle, the model of the components, the pump, the turbine, and the cooling-channel are proposed in terms of hydrodynamic, thermal, power balance, and Machnumber constraints. The applicability of expander cycle as the fuel feeding cycle for a scramjet is investigated, and then the differences in working principle, functions, components, performance, and so on between the expander cycle and the recooling cycle are discussed. Furthermore, the new limitations introduced by the recooling cycle are also analyzed.