Thermal boundary effect on the heat transfer performance of a ribbed cooling channel with intersecting ribs

The current study focuses on the influence of thermal boundary conditions, especially for a ribbed cooling channel with two intersecting ribs. Numerical studies are carried out for the Reynolds number of 30 000 under two kinds of thermal boundary conditions, i.e., the constant wall temperature condition and the uniform heat flux condition. The local normalized Nusselt number distributions and area-averaged values are compared and further analyzed. The thermal boundary type and value both affect the heat transfer performance. The uniform heat flux condition always yields higher heat transfer than the constant wall temperature condition. A correlation for the wall-to-coolant temperature ratio is obtained and compared with previously published correlations.