Numerical study on flow and heat transfer performance of square channels with high blocking ratio and perforated ribs

In this study, numerical simulations were conducted to understand the flow and heat transfer behaviour of square channels with high blocking ratio and perforated ribs (referred to as SCPR). The flow and heat transfer characteristics of SCPR were analyzed in detail and compared with the square channel with solid ribs. The influences of hole diameter, hole number and hole spacing on the flow and heat transfer of SCPR were discussed in depth. The findings show that when hole diameter is 5 mm, the heat transfer performance and overall performance of the SCPR exhibits a higher value compared to that of the square channel with solid ribs. When hole diameter is 10 mm and 15 mm, the heat transfer performance and overall performance of the SCPR are lower than those of the square channel with solid ribs. As the hole diameter increases, the wall mean Nusselt number, friction factor, and overall performance factor of the SCPR gradually decrease. The increase in the number of holes has little effect on the heat transfer performance of the SCPR, but it improves the flow performance of the SCPR to a certain extent. Overall, when the number of holes is 3, the overall performance of the SCPR is better. The increase in hole spacing can slightly improve the heat transfer, flow, and overall performance of the SCPR. In summary, this study systematically investigates the effects of hole diameter, number, and spacing on the flow and heat transfer performance of a square channel with a high-blockage-ratio (50%) and perforated ribs, providing new insights into performance trade-offs and optimal design under such extreme blockage conditions.