Enhancement of a Correlation-Based Transition Turbulence Model for Simulating Crossflow Instability

Abstract

A new laminar-turbulence transition model gamma-(Re) over tilde (theta t)-CF for capturing three-dimensional boundary layers involving crossflow-induced transition has been developed by extending the existing gamma-(Re) over tilde (theta t) transition model. In the present transition model, to resolve transition due to crossflow instability, the C1-criterion was evaluated locally using the Falkner-Skan-Cooke velocity profiles. Thus, only local flow quantities are used in determining the onset of three-dimensional transition. As a result, the extended gamma-(Re) over tilde (theta t)-CF transition model is compatible and works well with modern computational fluid dyanmics flow solvers, particularly for those based on unstructured meshes, under massive parallel environment. The new transition model was implemented in a three-dimensional incompressible unstructured mesh flow solver. Validations of the new transition model were made for an infinite swept-wing configuration and an inclined prolate spheroid by comparing the results with those of the baseline gamma-(Re) over tilde (theta t) model and experiment. It was found that the new transition gamma-(Re) over tilde (theta t)-CF model works well by capturing the crossflow-induced transition inside three-dimensional boundary layers more accurately than the baseline gamma-(Re) over tilde (theta t) model.