Heat transfer in a horizontal fluid layer heated from below upon rotation of one of the boundaries

The mixed convection in a horizontal fluid layer which is generated by uniform heating from below and by rotation of one of the boundaries of the layer was studied experimentally. The region occupied by the fluid is a cylinder of radius $320$ mm and height $45$ mm. Either the upper or the lower boundary together with the side wall rotates. For Rayleigh numbers $\mathrm{Ra}\simeq2\cdot10^7$, in a broad range of Reynolds numbers, based on experimental data we constructed mean-temperature profiles along the normal to the upper boundary and with a uniform step over the radius. In addition, we obtained data on the radial thermal stratification of the fluid, the integral flow through the fluid layer, and information on temperature fluctuations. The complicated character of the dependence of the heat transfer on the Reynolds number was shown. The obtained dependences of the heat transfer and temperature inhomogeneity on Reynolds numbers was explained qualitatively.