Assessment of Realizability Constraints in V2F Turbulence Models

Artikel i vetenskaplig tidskrift, 2004

The use of the realizability constraint in (v(2)) over bar -f turbulence models is assessed by computing a stator vane passage flow. In this flow the stagnation region is large and it is shown that the time scale bound suggested by [Int. J. Heat Fluid Flow 17 (1995) 89] is well suited to prevent unphysical growth of turbulence kinetic energy. However, this constraint causes numerical instabilities when used in the equation for the relaxation parameter, f. It is also shown that the standard use of the realizability constraint in the (v(2)) over bar -f model is inconsistent and some modifications are suggested. These changes of the 2 f model are examined and shown to have negligible effect on the overall performance of the (v(2)) over bar -f model. In this work two different versions of the (v(2)) over bar -f model are investigated and the results obtained are compared with experimental data. The model on a form similar to that originally suggested by Durbin (e.g. [AIAA J. 33 (1995) 659]) produced the overall best agreement with stator vane heat transfer data.