A Correlation-Based Transition Model Using Local Variables: Part II — Test Cases and Industrial Applications

Abstract

A new correlation-based transition model has been developed, which is built strictly on local variables. As a result, the transition model is compatible with modern CFD methods using unstructured grids and massive parallel execution. The model is based on two transport equations, one for the intermittency and one for the transition onset criteria in terms of momentum thickness Reynolds number. The proposed transport equations do not attempt to model the physics of the transition process (unlike e.g. turbulence models), but form a framework for the implementation of correlation-based models into general-purpose CFD methods. Part I of this paper gives a detailed description of the mathematical formulation of the model and some of the basic test cases used for model validation. Part II (this part) of the paper details a significant number of test cases that have been used to validate the transition model for turbomachinery and aerodynamic applications, including the drag crisis of a cylinder, separation induced transition on a circular leading edge and natural transition on a wind turbine airfoil. Turbomachinery test cases include a highly loaded compressor cascade, a low-pressure turbine blade, a transonic turbine guide vane, a 3-D annular compressor cascade and unsteady transition due to wake impingement. In addition, predictions are shown for an actual industrial application, namely a GE Low-Pressure turbine vane. In all cases good agreement with the experiments could be achieved and the authors believe that the current model is a significant step forward in engineering transition modeling.