Prediction and Analysis of Transitional Crossflows Using $\gamma - {\text{Re}}_{\theta t} - {\text{CF}}^{ + }$ Model

Abstract

In the present study, numerical assessment of the $\gamma - {\text{Re}}_{\theta t} - {\text{CF}}^{ + }$ 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 $k - {\upomega }$ shear stress transport turbulence model, which was coupled with the laminar-turbulent transition model. In addition, to validate the $\gamma - {\text{Re}}_{\theta t} - {\text{CF}}^{ + }$ 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 $\gamma - {\text{Re}}_{\theta t} - {\text{CF}}^{ + }$ 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.