含湿气流单缝冲击冷却数值模拟

对饱和湿空气夹带液滴的含湿气流单缝冲击冷却进行了数值模拟,比较研究了含湿气流中液滴相变换热/液滴载量比和单缝射流几何参数对强化换热效果的影响,研究发现:气流中液滴的加入对冷却效果的影响十分显著,热流密度为8 000 W/m2的条件下,空气中注入5％的液滴会比饱和湿空气对驻点区的冷却效果提高90％,当液滴载量比从1％提高到5％,冲击驻点区局部传热系数提高了32％；而合适的缝宽和冲击高度也是影响冷却效果的重要因素,在该条件下冲击高度与缝宽的比值为4.55时冲击冷却效果最佳.

Numerical simulation of mist/air cooling in a single slot jet impingement

Numerical simulation was carried out on the heat transfer characteristics in a mist/air impinging single slot jet. The effects of phase-changing heat transfer of the water droplets, the mist mass ratio in the air and the geometrical parameters of the slot jet were studied to reveal the enhancement of heat transfer. The simulated results show that adding liquid droplets in an air flow enhances the cooling effect drastically. 90% cooling enhancement at the stagnation point was achieved by injecting 5% of droplets with the heat flux of 8000W/m². When the mist/air mass ratio increases from 1% to 5%, the heat transfer enhancement of the stagnation region is 32%. Proper jet width and impinging height are important parameters for cooling effect. In this study, the best impinging cooling effect was achieved with the impinging height to jet width ratio of 4.55 .