Steady State Control Schedule Optimization for A Variable Cycle Engine

Abstract

Variable cycle engine (VCE) multi-variable steady state control schedule design and optimization is one of the key technologies of VCE development. The ‘Reverse Method’ is established for VCE steady state control schedule optimization. Based on the sensitivity matrix, this method substitutes the variable geometric parameters for state factors and components parameters in the VCE performance simulation model. The Isight optimization platform is employed to establish the model for VCE steady state control schedule design and the similarity law was introduced to describe the schedule. The subsonic cruise throttling control schedule optimization results show 8% and 16% decreasing in installed SFC in comparison with the fixed geometry double bypass and single bypass mode respectively. Also, the control schedule described in similarity parameters can improve VCE performance under other operating conditions, which indicates another advantage of the reverse method. It can be concluded that the reverse method is a practical way to design the optimal steady state control schedule for VCEs.