热交换对喷气发动机过渡过程影响分析

ANALYSIS OF HEAT TRANSFER IMPACTING ON GAS TURBINE ENGINE TRANSIENTG

关键词:  涡轮喷气发动机  过渡流  加速性能  传热

Key words:  Turbojet engine  Transition flow  Acceleration performance  Heat transfer

摘要:

给出一种用于估算气流与零部件间热交换对过渡过程影响的方法。利用该方法计算了某双轴涡扇发动机在加速过程中各主要零部件与气流间的热交换随加速时间的变化，各部件热交换对推力响应的影响；计算和分析了该发动机在相同供油规律下“冷”和“热”两种加速过程，估算了典型部件换热面积和质量对加速性的影响。计算结果的分析表明：高温部件与气流的热交换对喷气发动机的过渡过程有不容忽视的影响；相同供油规律下由于热交换使“冷”和“热”加速过程的差异十分显著，“冷”加速过程允许采用补偿供油改善加速性；零部件换热面积和质量的估算精度对加速性有一定的影响，但不显著。

Abstract:

In order to simulate the engine real working processes during acceleration and deceleration,a model for estimating the heat transfer between gas and comPOnents is provided in this paper.By use of this model for simulating a two-spool mixed flow turbofan engine,some studies are carried out in this paper,which deal with:calculating the variety of heat transfer between gas and each comPOnent as accelerating time and the effects of heat transfer on thrust response;calculating and comparing two different accelerations named "cool" and "hot" of the engine under the same fuel schedule;estimating the effects of typical comPOnent watted area and metal mass on the Pefforrnance of acceleration.The results indicate that:(1) It can not be ignored that the heat transfer between gas and high temperature components influence on the transients of gas trubine engine;(2) Because of heat transfer the difference between "cool" and "hot" accelerations is significant,and fuel compensation is allowed to improve the Performance during the’cool" acceleration;(3) The estimation accuracy of the comas nent wetted area and mass has little influence on the performance of acceleration.