Application of a one-equation eddy-viscosity model to unsteady turbomachinery flow

Numerical Investigation of Wake Interaction in a Low Pressure Turbine

“…• realistic wake spreading rates, • numerical robustness and grid insensitivity, • moderate grid clustering requirements for the resolution of the laminar sublayer (y i' in the range of 2 to 3). The works of Spalart and Allmaras (1992), Birch (1993), Menter (1996), Shur et al (1996), Misters (1997) and the authors's (Eulitz et al, 1996c) demonstrate that a modern oneequation turbulence model can fulfill the above demands and, for shear flows, can produce results which are very competitive with those of many two-equation models. In the present case with wake boundary layer interaction, the model is somewhat applied beyond its range of recommended applications which is for use in airfoil and wing flow calculations.…”

“…In our case, however, it does affect the outer edge of a wake which migrates through several passages, and interacts with the outer part of the boundary layer. Therefore, the two-layer formulation proposed by the authors (Eulitz et al, 1996c) is used here for the treatment of the laminar sublayer. The convective term in (1) is discretized using second order accurate upwind differences instead of the usual first order accuracy so that with central differences for the diffusion term the model is integrated with second order accuracy.…”

“…The recent works of Spalart and Allmaras (1992), Birch (1993), Menter (1996), Shur et al (1996) and the authors' (Eulitz, 1996c) demonstrate that, for shear flows, a modem one-equation turbulence model can produce results which are very competitive with those of many two-equation models, but at much lower computational costs and with easier handling. Within the framework of RANS and a Boussinesq approach it is, therefore, assumed to be a good candidate.…”