LAUSR

An unsteady flow is generated over a hot plate using a rotating cylinder in the proximity of the plate, and its effect on the heat transfer rate is investigated numerically in this study. The rotating cylinder is embedded over a plate at five different non-dimensional gap spaces such as $$G/D=0.1$$G/D=0.1, 0.5, 1.0, 1.5, and 2.0 from the plate under laminar condition. In addition, several non-dimensional rotating speeds (RS) in the range of $$0\le \hbox {RS}\le 4$$0≤RS≤4 are considered in order to show the effects of the cylinder rotation on the unsteady flow development over the hot plate. Computations are carried out at the Reynolds number of 200 based on the free-stream velocity and cylinder diameter. The obtained results revealed that at a small gap space of $$G/D=0.1$$G/D=0.1, development of the local jetlike flow between the plate and cylinder enhances the rate of heat transfer between the hot plate and fluid flow as a function of the RS. On the other hand, by increasing the gap space, the effect of jetlike flow attenuates, and in this case, vortex shedding mechanism plays a significant role in the heat rejection from the hot plate. It was also obtained that by increasing the RS, vortex shedding process eliminates, gradually.