基于燃气发生器法的小型中涵道比发动机性能计算分析

Calculation and Analysis of Small Medium Bypass Ratio Engine Performance Based on Gas Generator Method

关键词:  涡扇发动机  燃气发生器法  涵道比  发动机性能  飞行试验

Key words:  Turbofan engines  Gas generator method  Bypass ratio  Engine performance  Flight test

摘要:

为了研究小型中涵道比分排涡扇发动机装机性能，建立了基于燃气发生器法的性能计算模型。由CFD数值模拟计算喷管特性，由发动机地面台架试验及针对小型中涵道比的特点发展的修正方法获取内外涵喷管进口总压和总温的修正系数曲线，经高空模拟台试验验证，发动机最大状态下的推力计算误差≤0.5%。再基于飞行试验测试数据，计算得到发动机在装机条件下的空气流量与飞行推力，与发动机设计厂家的模型计算结果相比，发动机各状态下推力最大误差≤1.3%，流量最大误差≤2.5%。结果表明：发展的性能模型修正方法适用于小型中等涵道比涡扇发动机的装机性能确定；同时修正中等涵道比分排发动机的内外涵喷管进口压力可提高模型推力计算精度；同时修正小流量分排发动机内外涵喷管进口温度可提高流量计算精度。

Abstract:

In order to study the installed performance of small turbofan engine with middle bypass ratio， a performance calculation model based on gas generator method was established. The nozzle characteristics are calculated by CFD numerical simulation， and the correction coefficient curves of total pressure and total temperature at the inlet of the internal and external nozzles are obtained by engine ground bed test and the correction method developed according to the characteristics of small-sized middle bypass ratio. It is verified by altitude test that the calculation error of thrust at the maximum state of the engine is not more than 0.5%. Then， based on the flight test data， the air flow and flight thrust of the engine under the installed condition are calculated. Compared with the model calculation results of the engine designer， the maximum thrust error and the maximum flow error of the engine in each state are not more than 1.3% and 2.5%， respectively. The results show that the developed performance model correction method is suitable for determining the installed performance of small turbofan engines with medium bypass ratio. Both correcting the inlet pressure of the inner and outer nozzles of the engine with medium bypass ratio can improve the thrust calculation accuracy of the model. The accuracy of flow calculation can be improved by both correcting the inlet temperature of internal and external nozzles of a small separated flow engine.