Laminar forced convection heat transfer around two rotating side-by-side circular cylinder

The present study numerically investigates two-dimensional laminar force convection heat transfer past two rotating circular cylinders in a side-by-side arrangement at a various range of absolute rotational speeds (|α| ⩽ 2) for four different gap spacings (g∗) of 3, 1.5, 0.7 and 0.2 at Reynolds number of 100, and a fixed Prandtl numbers of 0.7 (air). As |α| increases, the thermal field became stabilized and eventually steady beyond the critical rotational speed depending on the gap spacing. In general, as |α| increases, because the vertical motion of flow in the region of gap is strongly inhibited, the inner isotherms are early merged and shorter than the outer isotherms in the free-stream sides elongating further downstream. As |α| increases, because the rotating fluid near the cylinders surrounded much space where the steady conduction mode is predominant to the heat transfer, the behavior of the time- and surface-averaged Nusselt number has the decaying pattern with increasing |α| for all gap spacings considered in this study.