Sensitivity Analysis of the Key Design Parameters of Turbomachinery in the Closed Helium Cycle System of Pre-cooling Air Turbo Rocket Engine

¹ School of Mechanical Engineering, Xi’an Jiaotong University, Xi’an 710049, China
² National Key Laboratory of Aerospace Liquid Propulsion, Xi’an 710100, China
³ Xi’an Aerospace Propulsion Institute, Xi’an 710100, China

Published online: 13 April 2026

Abstract

The Pre-cooling Air Turbo Rocket Engine (PATR) can meet the power demands of future aerospace vehicles across a wide range of speeds and altitudes. The closed helium cycle is the core of the thermal cycle of the PATR engine, and the design parameters of the turbomachinery determine the performance of the closed helium cycle. In this paper, a simulation model of the pre-cooling air turbo rocket engine was established based on the component method, and the effects of the design parameters of the helium compressor and turbine on the engine performance in the closed helium cycle were analyzed. The results show that increasing the efficiency of the helium turbine or reducing the pressure ratio leads to a linear increase in engine thrust; there exists an optimal design solution for the nonlinear relationship between helium turbine flow and engine thrust; increasing the efficiency of the helium compressor or reducing its flow leads to an approximate linear increase in engine thrust; and when the pressure ratio of the helium compressor increases, the engine thrust increases nonlinearly. The research results provide certain guidance for the design of closed helium cycle.