跨声速轴流涡轮特性预估方法

Characteristic prediction method of transonic axial flow turbine

[目的]在高亚声速和跨声速下,轴流涡轮静叶喉部出现跨声速气流,三维研究时间周期长且获取特性参数慢,为此,提出一套行之有效的涡轮特性预估方法体系。[方法]整合已有的损失模型及采用一维编程的方式预估涡轮特性,并通过三维数值模拟进行验证。[结果]研究结果显示,一维特性评估得到的级等熵滞止温比与三维的相对误差为11.53%,级滞止膨胀比的相对误差为11.77%,反动度的相对误差为14.23%。基于此,准确判断了静叶是否存在跨声速现象,且单级涡轮采用动叶出口温度的绝热指数所获得的特性预估较为准确。[结论]在误差允许范围内,可实现跨声速的涡轮特性快速预估,减少计算量。

[Objectives]Regarding transonic flow occurring at the throat of the stator blades of axial flow turbines at high subsonic and transonic speeds,it is will need a long period of time to have 3D reseach and to obtain the characteristic parameters.Therefore,an cost-effective approach for predicting turbine characteristic is required.[Methods]The existing loss models are integrated to predict turbine characteristics via one-dimensional programming and verify them via three-dimensional numerical simulation.[Results]The results show that the relative error of the isentropic stage-temperature ratio is 11.53%,that of the stage-expansion ratio is 11.77%and that of the reaction degree is 14.23%.Whether transonic phenomena occur at the static blade is judged accurately.The adiabatic index of the outlet temperature of the rotor blade is used to estimate the characteristics of the single-stage turbine accurately.[Conclusions]Within the range of acceptable error,this method allows the fast and accurate prediction of transonic turbine characteristics,thus reducing calculation time.