Enhancement of a correlation-based transition turbulence model for simulating crossflow instability

Abstract

In the present study, a laminar-turbulence transition model γ-Reθt-CF for threedimensional boundary layers including crossflow-induced transition has been developed by extending the existing γ-Reθttransition model. To predict the transition due to crossflow instability, C1-criterion by Arnal is locally evaluated using the Falkner-Skan-Cooke velocity profiles. In the present transition model, only local quantities are used for determining the onset of three-dimensional transition. As a result, the extended γ-Reθt-CF transition model is compatible with modern CFD codes, which work particularly based on unstructured meshes under massive parallel environment. This new transition model was implemented in a three-dimensional incompressible flow solver based on unstructured meshes. Validations of the new transition model were made for an infinite swept wing configuration and an inclined prolate spheroid. The results of the extended transition model were compared with those of the baseline model γ-Reθt-CF and experiment. It was found that the new transition model γ-Reθt-CF works well for capturing the crossflow-induced transition in three-dimensional boundary layers.