Research On Loss Prediction Method Of Aero Turbine

The internal flow of turbine, especially of the cooling turbine, is very complex, the theoreticalcalculation method about the flow loss is not yet mature, and the CFD method has disadvantage oflong cycle and heavy workload, so through the use of accurate turbine experience loss models caneffectively improve the efficiency of the turbine cascade design and modeling of the blade. Based onintegrating a variety of loss models used to calculate the non-cooled turbine and cooling turbine bythe foreign scholars in the past six decades, this paper fully expounded their calculation principle, thebasic assumptions and calculation steps, and to compare and discuss them. At the same time develop aset of loss calculation software by C++to verify the accuracy of the model.In terms of non-cooling, to put the second level of self-designed two-stage turbine as a researchobject, we carry out a comparative study on the calculation of11turbo-loss models and computationalfluid dynamics (CFD). By the use of software to calculate both the turbine losses of stator and rotor atdesign point in three sections on the blade hub, mid and tip and the efficiency of the turbine stage, bythe same time, we also predicted the losses under different attack angle and blade pitch. Comparisonshows that: The efficiency calculation results by Traupel model, Zehner model, Soderberg model,AMDC model, Kacher model and Moustapha model are good, which differ from0.1%to0.7%compared with the CFD. Among them, Zehner model and the Kacher model can accurately predict thesize of the losses under different attack angle at the off-design point.In terms of cooling, the calculations of the film cooling select independent design turbine whichuse source term point technology to simulate the film hole in the stator, and the calculations of trailingedge jet cooling select the published plane cascade with trailing edge split seam. Several coolingmodel calculation results for the additional losses show that: In the film cooling, Velocity Coefficientmodel and base Shapiro model can basically reflect the relationship between additional losses andmass flow, with a difference of14.9%and19.1%in the relative flow rate of0.05, compared to theCFD results. In the trailing edge jet cooling, the results of Velocity Coefficient model and Schobeirimodel agree well with the experimental results, wherein the scope of application of VelocityCoefficient model is that the relative cool air flow rate does not exceed0.05, while the scope ofapplication of Schobeiri model is relatively large, can reflect the variation of the loss in the large flow.