Mansoor Saatloo, Mahtab
In this thesis, a flow solver based on the cell-centered scheme was constructed to solve complex flow problems, including turbulent flows around the helicopter ro- tors. The SU2 platform, which is a leading open source flow solver especially for the external flows, was considered as the baseline of this work. The implemented cell-centered scheme could support any mesh types, including Cartesian grids. To improve the unsteady simulation of hovering rotors, Hybrid RANS-LES technology or Detached Eddy Simulation (DES) was adapted to the cell-centered flow solver. In addition to the available DES by the Spalart-Allmaras in the SU2, DES by the Stan- dard Shear Stress Transport (SST) model was added to newly developed cell-centered solver. A new formulation based on the Vortex Tilting Measurement was employed in the Improved Delayed Detached Eddy Simulation (IDDES) to achieve more accurate prediction of detached boundary layers and also vortex structures. We could compute the exact length of re-attachment region for the incompressible flow over the Back- ward Facing Step by the Vortex-Tilting Adjustment. The improvement in accuracy of the new technique over the SST-IDDES was shown for the viscous flows over airfoils at high angle of attacks. Finally, the Vortex Tilting Adjustment assessment on the rotating frames was conducted by the application of hovering Caradonna-Tung test case. The investigation revealed that the strength of the captured vortex by the new approach is superior to the standard SST-IDDES, and the results of aerodynamic features match accurately with the experimental data.
Citation Formats
M. Mansoor Saatloo, “THE DEVELOPMENT OF TURBULENCE MODELING FOR HOVERING ROTORS BY CELL-CENTERED SCHEME,” Ph.D. - Doctoral Program, Middle East Technical University, 2023.