Performance evaluation of a novel re-cooled mixed-flow turbofan cycle for aviation power application

Abstract

A novel re-cooled mixed-flow turbofan cycle (RMTC) is proposed to meet the demand of high thrust-weight ratio for military aero-engine. Through adding a re-cooler during the compression process, the specific thrust can be improved by increasing the outer fan flow temperature and also the turbine cooling air consumption can be reduced by decreasing the inner fan flow temperature. This work conducts the modeling of ideal and actual RMTCs by using a verified original program. The effects of re-cooler location, heat transfer effectiveness, and bypass ratio on the specific thrust and fuel consumption rate are evaluated, and the RMTC performances in the entire flight envelope are discussed to estimate its applicable flight conditions. Based on the parametric analysis, locating the re-cooler after the compressor and increasing the heat transfer effectiveness are beneficial for the increase in specific thrust, while the effect of bypass ratio is related to the heat transfer capacity of re-cooler. The specific thrust improvement of RMTC is more significant at high flight Mach number, and hence, larger aircraft payload can be obtained with the same fuel mass. The assessment results show that the proposed RMTC system exhibits potential application for high-speed military aircraft.