Experimental study and numerical simulation of microchannel heat exchanger structure optimization based on heat transfer and flow

Microchannel heat exchangers are widely used in fields such as chemical engineering, microelectronics, and energy engineering due to their efficient heat transfer capabilities. But with the continuous improvement of thermal management requirements in these fields, exploring a more efficient microchannel heat exchanger has become a research focus. This study proposes a leaf vein biomimetic microchannel heat exchanger based on airfoil microchannel. The effects of Reynolds number (Re) and primary and secondary leaf vein structures on thermal and hydraulic performance were experimentally studied. CFD simulation was used to optimize the microchannel structure. The addition of both primary and secondary venous ribs has a positive impact on heat transfer performance within the range of Re 1700~2800, but the primary venous rib has a greater effect on increasing flow resistance than on flow heat transfer, while the secondary vein ribs have a greater effect on enhancing heat transfer than on flow resistance. The f of the optimized microchannel is 0.0431, the Nu is 65.27, the average heat transfer strengthening coefficient is 1.85, and the comprehensive performance index PEC is 1.26, which is 26% higher and 85% higher than that of the airfoil channel.