On the motion of large-scale circulations in mixed convection

Abstract

We present investigations on the motion of the large-scale circulations (LSCs) in turbulent mixed convection in a cuboidal cavity. The experimental studies are performed by combined temperature and velocity measurements. Analysis of temperature measurements in previous studies revealed three different dynamical scenarios: stable LSCs, LSCs with spontaneous reversals as well as periodically oscillating temperature signals, which correspond to a continuous motion of the LSCs [8]. In the work presented here, we extend the temperature measurements by velocity measurements. These combined investigations help to answer open questions concerning the dynamics of the LSCs within the sample. In specific, we address the question which of the various dynamical processes observed in Rayleigh-Bénard convection in cylindrical samples, e.g. torsional oscillations or reversals of the LSC, [1] also occur in our cuboidal cavity in mixed convection.