Field coordination analysis on flow past a circular cylinder at low Reynolds number

Many theory analyses, experiment researches and numerical simulations aimed at the flow and heat transfer properties of flow past a circular cylinder at all times. The flow patterns appeared absolutely different in various range of Reynolds numbers, although relatively simple boundary conditions. The phenomena were exceedingly complicated. The phenomena of disengagement and backwash could not emerge, at Reynold number less than 10 of flow past a circular cylinder. When the location of cylinder surface went further from the frontal stagnation point, the local Nusselt number became less, which is commonly thought as thickening of flow boundary layer. In this paper, the flow past a circular cylinder of Reynold number equating 4.0 has been calculated numerically in this paper. Based on field coordination principle, the all source items of local Nusselt number equation has been analyzed. The result reveals that the convection item contributes to the value of local Nusselt number mainly. The value of convection item is determined by its polar radial component mostly, and the polar radial component of convection item is determined by polar radial velocity component that fluid flowing toward the circular cylinder. Consequently, the value of local Nusselt number is determined mainly by the value of polar radial velocity component of fluid flowing toward the circular cylinder.