Experimental and Numerical Investigation of the Turbulent Flow in a Smooth Lid-Driven Cavity

Experiments were carried out to study the flow behavior in a smooth lid-driven cavity with small inlet and outlet gaps. It was found that a thin shear layer close to the moving wall occurred whereas the larger part of the flow domain was characterized by large fluctuating eddies. The recirculation flow started with a regular vortex. Later this vortex became unstable due to a Kelvin-Helmholtz-like instability. In the steady-state, the transition from a laminar boundary layer flow at the inlet to a turbulent flow close to the outlet followed the classical route for a flat plate. Whereas the primary disturbance modes had large wave lengths, smaller Taylor-Goertler-like vortices were observed in case of developed flow. Based on an analytical treatment of the resulting steady-state flow structure in the smooth cavity, a logarithmic velocity profile was obtained. Detail measurements by means of Laser-Doppler-Anemometry (LDA) agreed well with this prediction. Turbulence quantities and secondary flow phenomena were measured and visualized for a large portion of the cavity. Extensive Large-Eddy-Simulation (LES) calculations were conducted, and a reasonable agreement between the experimental data and the LES results were found. Finally, the potential of RANS methods were assessed, too. The results indicated that particular the Detached-Eddy-Simulation (DES) approach offers a high potential whereas RANS methods are systematically unable to cover the recirculation phenomena adequately.