COMPARISON OF 2 3-DIMENSIONAL UNSTEADY NAVIER-STOKES CODES APPLIED TOA TURBINE STAGE FLOW-ANALYSIS

A comparison between two numerical flow solution methods, one based on structured grids and the other based on unstructured grids, is made b y using both methods to solve for steady and unsteady flowfields in tu rbomachinery blade rows. Numerical results from the two different meth ods are compared to each other as well as to available experimental da ta. Both methods solve the three-dimensional Reynolds-averaged Navier- Stokes equations using the finite volume technique, and can be run in steady-state or time-accurate unsteady modes. The structured solver us es a pressure-based method applied to hexahedral control volumes and a standard two-equation turbulence model, The unstructured solver uses a density-based method applied to tetrahedral control volumes and the one-equation Spalart-Allmaras turbulence objective of the comparison i s to assess the current capabilities of the unstructured flow soh er r elative to those of a well established structured flow solver, and to establish areas for further development to improve accuracy and econom y.