ATR Performance Improvement Based on Optimization Technique on Components Matching

Abstract

In this paper the ATR (Air turbo-rocket) performance improvement technique was studied based on the integration of an ATR thermodynamic model and an optimization solver. It is concluded from previous researches that the components of ATR should be matched in the engine preliminary design in order to meet the performances and safe operation requirements in the whole flight envelop, with engine dimension and weight limitations. Mathematically, this is an optimization problem under multiple constrains and can be solved by matching the thermodynamic cycle parameters of ATR. The thermodynamic model for a liquid propellant ATR was formulated and programmed in C to calculate the engine performance and the operating conditions in each component along the flow path. The specific heat variation was considered in the model and the numerical Newton- Raphson iterative approach was employed for the off-design analysis using scaling laws to component performance maps. The thermodynamic model was integrated into the solving algorithm of the commercial solver ISIGHT9.0 for the optimization characteristics with multiple variables and multiple constrains. An optimization result is demonstrated for a sample engine under constrains on variables at design point, on operating conditions and on performances. The results showed that the component design parameters such as compressor pressure ratio, turbine pressure ratio, and flame temperature of gas generator have been matched such that the goal of specific impulse was balanced on the basis of the temperature and pressure limits along the flow path.