ASSESSMENT OF THE SSG PRESSURE-STRAIN MODEL IN 2-DIMENSIONAL TURBULENT SEPARATED FLOWS

Data from a number of benchmark two-dimensional turbulent separated ho ws are used to assess the performance of the Speziale, Sarkar and Gats ki model [28] for the fluctuating pressure-strain correlations and, in particular, to determine whether the model can reproduce the effects of rigid boundaries without recourse to ad-hoc corrections. Comparativ e predictions are also obtained with a standard Reynolds-stress closur e in which such correlations are necessary and these serve to distingu ish the models' true performance from spurious computational artifacts . The models were implemented in a finite-volume method which solves t he Navier-Stokes equations on non-orthogonal grids with colocated stor age arrangement. Details of the numerical treatments adopted to obtain stable and fast-converging solutions are described and the outcome of rigorous grid-independence checks are reported for each test case. It is found that both models yield essentially similar results for the m ean flow and turbulence fields. The implications of this result to the choice of Reynolds-stress closure for complex engineering simulations are discussed.