HEAT TRANSFER PREDICTION FROM LARGE EDDY SIMULATION OF A ROTATING CAVITY WITH RADIAL INFLOW

The paper describes a Large Eddy Simulation (LES) conducted for a non adiabatic rotating cavity with a radial inflow introduced from the shroud. The dimensionless mass flow rate of the radial inflow is C-w = 3500 and the rotational Reynolds number, based on the cavity outer radius, is equal to Re-theta = 1.2 x 10(6). The time averaged local Nusselt number on the heated wall is compared with the experimental data available from the literature, and with those derived from the solution of two Unsteady Reynolds Averaged Navier-Stokes (URANS) eddy viscosity models, namely the Spalart-Allmaras and the k - omega SST model. It is shown that the Nusselt number is under-predicted in the lower part of the disc and over-predicted in the outer region by both URANS models, whereas the LES provides a much better agreement with the measurements. The behaviour results primarily from a different flow structure in the source region, which, in the LES, is found to be considerably more extended and show localized buoyancy phenomena that the URANS models investigated do not capture.