Performance analysis tool for turbine based combined cycle engine concept

This paper aims at developing a performance analysis tool to evaluate the performance and design constraints of a turbine based combined cycle engine concept with the tandem layout for a hypersonic cruise vehicle. To meet the conflict requirements in the long range from take-off to Mach 5, the combine cycle engine applies a variable cycle engine concept via the modulation of five variable geometries and fuel flow. This tool uses one-dimensional aerodynamic thermodynamic analysis techniques, considering the test proved components characteristics and the property of calorically perfect gas etc. The objects oriented software design method is adopted in the tool which can afford a platform suitable for parametric cycle analysis, performance cycle analysis and control law study of the turbofan mode, the ramjet mode and turbo/ram mode transition. Assisted by this tool, parametric cycle analysis of the turbofan mode and the ramjet mode was investigated. It shows recirculation margin is a key factor to be considered in the cycle parameters selection of the turbofan mode; high ramjet afterburner discharge temperature is favorable to the ramjet cycle performance.