一种新型叉排直肋表面的流阻及换热性能研究

Research on Thermal and Hydraculic Performance of A New Air Dynamical Variable Cross-Section Rectangular Offset Strip Fin

本文研究了新型变截面叉排直肋结构的流阻与换热性能。采用数值模拟技术研究了变截面及另外两组对比组,并建立了雷诺数与努塞尔数、进出口压差、传热因子j和摩擦因子f之间的关系图。最终从数值模拟的结果可以计算出,在雷诺数为600时,变截面肋片的传热因子j比普通叉排直肋高约23.5%,比翼型叉排直肋也高出约14.4%;同时普通叉排直肋的摩擦因子f比变截面叉排直肋高约197.7%,翼型叉排直肋也比变截面叉排直肋高约31.2%。相对于普通叉排直肋肋片,翼型叉排直肋和变截面叉排直肋能在有效提高散热效率的情况下,大幅减小压降,并且变截面叉排直肋的换热性能比翼型叉排直肋更好,压降也更低。在航空飞机等需要高换热性能和低压降时,可以优先使用变截面叉排直肋。

To explore the flow resistance and heat transfer performance of the new variable cross-section rectangular offset strip fin structure. The new variable cross-section rectangular offset strip fin and two other comparison groups were studied by numerical simulation technology, and the relationship between Reynolds number and Nusselt number, inlet and outlet pressure difference, heat transfer factor j and friction factor f was established. The experimental results show that when the Reynolds number is 600, the heat transfer factor j of variable cross-section fins is about 23.5 % higher than that of ordinary rectangular offset strip fins, and about 14.4 % higher than that of airfoil rectangular offset strip fins. At the same time, the friction factor f of ordinary rectangular offset strip fins is about 197.7 % higher than that of variable cross-section fins, and the height of airfoil rectangular offset strip fins is about 31.2 % higher than that of variable cross-section fins. Compared with ordinary rectangular offset strip fins, airfoil rectangular offset strip fins and variable cross-section fins can greatly reduce the pressure drop while effectively improving the heat dissipation efficiency, and the heat exchange performance of variable cross-section fins is better than that of airfoil rectangular offset strip fins, and the pressure drop is also lower. When high heat transfer performance and low pressure drop are required, variable cross-section fins can be preferred.