测量耙对小尺寸发动机性能影响的研究

采用燃气发生器法进行小尺寸涡喷/涡扇发动机性能评价时，测量耙对截面参数和喷管特性的准确获取存在影响，最终导致发动机标准净推力准确度降低。为了减小上述影响，降低标准净推力计算误差，讨论了测量耙对发动机共同工作的影响，分析了测量耙对发动机喷管性能的影响，并基于数值仿真研究带耙/无耙喷管特性、测量耙损失特性，结合测量耙后截面参数、带耙喷管特性，提出了降低测量耙影响的标准净推力修正方法。结果表明，当剔除其他因素修正时，仅采用本方法的带耙发动机推力与台架实测推力误差为4.75%,该方法为某小尺寸发动机飞行试验获取标准净推力计算提供技术支撑。

Research on the Effect of Measuring Rake on Performance of the Small-Size Engine

When using gas generator method to evaluate the quality of the small engine with turbojet or turbofan,the measuring rake has the great influence on the accurate acquisition of section parameters and nozzle characteristics,which eventually leads to the reduction of the accuracy of standard net thrust of the engine.In order to reduce the above effects and the calculation error of standard net thrust,the influence of the measuring rake on the joint work of the engine is discussed,the influence of the measuring rake on the performance of the engine nozzle is analyzed.Based on the numerical simulation,the characteristics of the nozzle with or without rake and the loss characteristics of the measuring rake are studied.Combined with the back section parameters of the measuring rake and the characteristics of the nozzle with rake,a standard net thrust correction method to reduce the influence of the measuring rake is proposed.The results show that when other factors are excluded,the error between the thrust of the engine with rake and the measured thrust on the bench is 4.75%.This method provides technical support for the calculation of standard net thrust obtained from a small-scale engine flight test.