离散缝气膜加热效率及换热系数的测量和数值模拟

Measurement on Calorific Efficiency and Heat Transfer Coefficient of Film for Discrete Slots and Numerical Simulation

本文采用液晶瞬态测试技术对带离散缝平板的气膜加热效率及换热系数进行了测量,并把测量结果与数值模拟结果进行了对比。实验结果显示:主流速度较高时,吹风比大,平均效率也高。在主流速度较低时,这种情况并不明显。不同吹风比下反应出来的平均换热系数的差别在靠近缝口的区域较明显,沿下游方向这种差别逐渐减少。同一吹风比下,主流速度较高的,平均效率及平均换热系数也较高。在垂直于流动方向,缝中心线附近区域的效率较高,两缝之间区域较低;而换热系数则是相邻两个缝之间的区域较高,缝中心区域较低。这与数值模拟结果是一致的。

The liquid crystal has been used to measure the calorific efficiency and heat transfer coefficient of the film for the discrete slots. When the mainstream velocity is higher, the higher the blow ratio is, the higher the average efficiency is. And the average heat transfer coefficient near the slots is different between different blow ratios, while far away from the slots, the difference diminish. Under the constant blow ratio, the higher the mainstream velocity is, the higher the average effectiveness and average heat transfer coefficient are. In the vertical direction of the flow, the higher effectiveness appear near the centerline of the discrete slots, but the higher heat transfer coefficient appear between two discrete slots. These agreed with the result of numerical simulation.