暖机对涡扇发动机加速过程中压气机叶尖间隙影响分析

Effects of Heating of Turbine on Turbofan Engine Compressor Tip Clearance During Acceleration Process

关键词:  暖机  冷推  热—固耦合  加速过程  压气机  叶尖间隙

Key words:  Heating of turbine  Cold push  Thermal-solid coupling  Acceleration process  Compressor  Tip clearance

摘要:

为了研究涡扇发动机暖机程序是否合理，分析了暖机与不暖机对发动机加速过程中压气机叶尖间隙变化造成的影响，并进行了两种情况下变化规律的对比分析。建立了转子模型，在综合考虑转子离心载荷与温度载荷基础上，运用该发动机暖机与不暖机情况下台架测试数据绘制载荷谱，并基于Workbench平台采用热—固耦合分析方法对加速过程中发动机转子径向位移进行仿真计算。根据转子径向间隙计算模型，利用仿真结果计算获得暖机与不暖机情况下的叶尖间隙。结果表明，充分暖机后的压气机叶尖间隙值明显小于不暖机情况下的间隙值，相对原始装配间隙，两者在慢车状态时相差19.86%，在最大加力状态相差8.04%，且加速过程中叶尖间隙变化规律均为随时间增加而不断减小，在慢车至中间状态过程中迅速减小，在加力过程中缓慢减小。

Abstract:

In order to study whether the heating program of a turbofan engine is reasonable, the effects of heating and unheating on compressor tip clearance change of the engine during acceleration are analyzed and the change rules under this two conditions are compared. The rotor model was established. On the basis of considering centrifugal and temperature load of the rotor, the load spectrum was drawn by using engine bench test data under heating and unheating conditions. The radial displacement of the engine rotor during acceleration was simulated by using thermal-solid coupling analysis method based on Workbench. According to the calculation model of the rotor radial clearance, the tip clearances under heating and unheating conditions were calculated by the simulation results. The results show that the tip clearance of compressor after fully heated is significantly smaller than that without heating. Compared with the original assembly clearance, the difference between two tip clearances is 19.86% in idle state and 8.04% in maximum afterburning state. During the acceleration process, the tip clearance decreases rapidly from the idle to the intermediate state and slowly during the afterburning process.