Prediction and Analysis of Transitional Crossflows Using gamma - Re-theta t - CF+ Model

Abstract

In the present study, numerical assessment of the gamma - Re-theta t - CF+ transition model was carried out using a Reynolds-averaged Navier-Stokes (RANS) computational fluid dynamics (CFD) flow solver based on unstructured meshes. A three-dimensional bump-in-channel verification case was first tested in a fully turbulent manner to verify the implementation of the k - omega shear stress transport turbulence model, which was coupled with the laminar-turbulent transition model. In addition, to validate the gamma - Re-theta t - CF+ transition model, transition onset locations were compared with the experimental results for three angles-of-attack with a 6:1 prolate spheroid configuration. Then, the gamma - Re-theta t - CF+ transition model was utilized to predict the skin friction distributions, surface pressure distributions, and transition onset locations of the natural-laminar-flow version of the common research model (CRM-NLF). For this purpose, a grid-resolution study was carried out for a fixed angle-of-attack on coarse, medium, and fine meshes. The aerodynamic performance of the CRM-NFL was compared with the experimental for four angles of attack.