COMPUTATION OF UNSTEADY VISCOUS-FLOW USING A PRESSURE-BASED ALGORITHM

The objective of this research is the development of an efficient and accurate numerical analysis for the prediction of unsteady turbulent flows using a Navier-Stokes solver. The technique developed is to be used for incompressible now and is an extension of the pressure-based method. The finite volume approach and a nonstagger grid formulation are used. A predictor-corrector type algorithm is applied to the governing equations to ensure time accuracy. The convergence is improved using a multigrid scheme. A low Reynolds number form two-equation turbulence model is used to simulate the turbulent flow. The code is first calibrated against existing analytical solutions for an oscillating flat plate. To test the two-equation model, a steady-state flow calculation is made and compared with the available experimental data for a turbine stator. Good agreement is obtained between the prediction and the experimental results. The prediction of unsteady viscous flow through a flat plate cascade subjected to a transverse gust is presented. Finally, unsteady flow through a compressor cascade subjected to a gust is predicted and compared with the experimental data. The unsteady blade pressure distribution and the time-dependent wakes are well-captured.