Prediction of Separation-Induced Transition on High Lift Low Pressure Turbine Blade

Abstract

This paper deals with the development and validation of the Menter and Langtry correlation-based transition model in the RANS code elsA. Two types of experimental linear cascades of low pressure turbine (LPT) airfoils having different loading distributions have been considered for the validation: the T106C and T108 blades. Experimental data have been provided by the Von Karman Institute in the framework of the European program TATMo. Different Reynolds numbers varying from 80 000 to 250 000 and different freestream turbulence intensities have been investigated. The results obtained for the T106C blade are in good agreement with the experimental data: the bubble size and the kinetic energy losses are well predicted. Sensitivity to freestream turbulence is also well demonstrated for the considered Reynolds numbers. However the results for the T108 blade show the limitations of the current version. These limitations are explained and discussed in this paper. The second part of this paper deals with the numerical and physical aspects of periodical unsteady inlet conditions which are introduced in order to take into account the incoming wakes. The original Menter and Langtry transition model has required a modification for performing correct unsteady computations of wake induced transition which is discussed in this paper. The unsteady results obtained with elsA are in quite good agreement with the experimental data.