Performance Analysis of Liquid Air Turborocket

Abstract

The performance of a kerosene and liquid oxygen based ATR (Aero turbo-rocket) was analyzed and simulated in this paper. A thermodynamic model for the ATR was formulated and programmed in C to perform the quasi one dimensional thermodynamic cycle analysis and to calculate the operating conditions in each component along the flow path. The numerical Newton-Raphson iterative approach was employed for the off-design analysis using scaling law of the known component performance maps. The characteristics of ATR were explored firstly using “rubber engine” cycle analysis. It was found that the specific impulse increased with the gas generator temperature and the turbine pressure ratio but decreased with the compressor pressure ratio, whereas the specific thrust showed just the opposite trend of variation when the compressor pressure ratio greater than 2. The results also showed that the component design parameters such as compressor pressure ratio, turbine pressure ratio and flame temperature of gas generator should be matched in order that the temperature in the flow system does not exceed the limits. The off-design performance was studied on assumed ATR cycles. The specific impulse was shown increased but the thrust decreased with flight altitudes.