变外涵工况下风扇增压级双涵匹配机理

针对某型民机大涵道比风扇增压级，在不同外涵工况下开展数值计算，旨在研究风扇增压级双涵性能匹配规律和相应机理。通过分析计算结果，掌握了外涵工况对内涵特性的影响规律:当外涵工况从近堵点移向近喘点的过程中，内涵的流量、总压比、效率逐渐增大，且内涵稳定裕度呈持续增大的变化规律。同时也在获取内涵特性时，掌握了外涵气动性能的变化规律，在不同外涵工况下阐明了内涵逼喘过程中双涵气动性能的相互匹配机理取决于风扇的总压比?流量特性和内外涵流量再分配机制的共同作用。 

Twin-duct matching mechanism in fan booster under different bypass working conditions

Numerical research on a high?bypass?ratio fan booster of a civil?aircraft engine was conducted under different bypass working conditions，with the aim of understanding the twin?duct matching rule and corresponding matching mechanism.By analysis of the numerical results，it was understood that as the bypass working condition changed from the near choke point to the near surge point，the mass flow，pressure ratio and efficiency increased and the core surge margin first climbed up and then declined.In the process of acquiring core characteristics，the change law of bypass aerodynamic performance was mastered.Furthermore，during the forced surge process of the core，the twin?duct matching mechanism was subject to the combined actions of the fan characteristic of pressure ratio and mass flow and the redistribution of mass flow between the core and bypass.