A combined experimental and numerical study has been conducted in order to investigate the turbulent flow in a heated rotor-stator cavity of low gap ratio, subjected to a superposed centripetal flow. In the scope of this work, the fluid can be considered as incompressible, with the consequence that the heat transfer process is dissociated from the dynamical effects. The flowfield is characterized by two separated Ekman layers and a core region.
Detailed velocity measurements have been carried out. Reynolds stresses were examined in great detail using hot wire measurements, whereas temperature-velocity correlations were obtained using combined hot wire–cold wire measurements. The temperature distribution was specified on the stator and heat fluxes were measured with fluxmeters.
Numerical simulations of the above configuration have been carried out with the following turbulence models: a two equation k-1 model, an Explicit Algebraic Reynolds Stress Model (EARSM), and an anisotropic thermal extension of the k-1 ASM model. The agreement between experimental and numerical results is generally good for the nondimensional velocities, except in the Ekman layer region. A comparison of Reynolds Stresses is also provided. The heat flux on the stator appears to be underestimated, due to the poor prediction of the Ekman layer zone.
The numerical study reveals the critical importance of the inlet conditions, and in particular of the nondimensional tangential velocity on the flow inside the cavity. A comparison with experimental data also confirms that the anisotropy is of importance mainly in the Ekman layer region.