Development and Application of a Local Correlation-Based Transition Model in an Unstructured Grid CFD Solver

by Jingyu Wang

Institution: University of Toledo
Department: Mechanical Engineering
Degree: PhD
Year: 2015
Keywords: Mechanical Engineering
Record ID: 2060200
Full text PDF: http://rave.ohiolink.edu/etdc/view?acc_num=toledo1408444919


Computational Fluid Dynamics (CFD) has been widely used in scientific research and engineering designs of aerospace vehicles. However, most Reynolds-averaged Navier-Stokes CFD applications today still assume fully turbulent flows, and so are unable to capture the boundary layer transition phenomenon. In the present study, the Local Correlation-based Transition Model (LCTM) was investigated and implemented in an unstructured CFD solver - U2NCLE, which is coupled with both one-equation Spalart-Allmaras (S-A) and two-equations Shear Stress Transport (SST) turbulence models. An innovative method was developed to evaluate the local free stream turbulence intensity for the transition model coupled with the S-A turbulence model. The current transition model was systematically validated on several benchmark cases including a flat plate with and without pressure gradients, two-dimensional airfoils, and realistic three-dimensional helicopter rotors. Both the S-A and SST based transition models were also used to predict the aerodynamic interactions in a lift fan configuration, to further explore the unsteady aerodynamic phenomena for internal viscous flows.