|Institution:||University of Toledo|
|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.