某型混合排气涡扇发动机喷管特性计算方法研究

Study on Nozzle Characteristics Computation Method of a Mixed Exhaust Turbofan Engine

针对某型混合排气涡扇发动机,建立了其喷管特性的数值计算模型,并利用地面台架试验数据对该模型的可靠性进行了验证,流量系数与推力系数数值计算结果与台架试验结果最大偏差分别为0.97%和0.54%。提出了假想面积系数法,将混排发动机喷管进行了转化,建立了混排喷管理想推力与理想流量的可行性计算方法。在此计算方法基础上,通过数值计算得到了该型混排发动机喷管的流量系数与推力系数,并研究了其基本规律,比较了其与分排发动机喷管特性计算的不同,为该型发动机后续型号试飞中飞行推力的确定提供了技术基础。

A numerical simulation method was set up on a mixed exhaust turbofan engine in this paper, and the reliability was verified with the data of the ground bench test. The largest errors between the numerical results and the experimental resuhs for discharge coefficient and thrust eoeffieient are 0.97% and 0.54% separately. The hypothetic area coefficient method was then put forward. Then the mixed exhaust turbofan engine was transfolaned and the feasible computation method of theoretical thrust and mass flow was established. On the basis of this method, numerical simulation of thrust coefficient and mass flow coefficient was conducted. After that, the rule of the coefficient variation and the difference of that from the separate exhaust turbofan engine were studied. The technological base for the in-flight thrust measurement of the follow-up flight tests was thus provided.