离心力场下细微封闭通道内R12的热驱动换热研究

本文以试验的方法,研究了一种利用彻体力场下封闭通道内流体的热驱动循环流动来强化换热的新型冷却技术。主要讨论了封闭循环通道宽度d为1mm,氟利昂R12为工质的热驱动流动和换热特性,重点分析了随转速(即离心加速度)的变化,R12的热驱动流动和换热变化规律,以及热端壁面的温度分布及变化规律。研究结果表明:离心力场下流体热驱动流动和换热特点同重力场下基本相似;随着转速的提高,R12的热驱动强度不断增加,热端壁面温度逐步下降,同时热端壁面的温度梯度也逐渐降低;在转速为1140r/min时,总平均传热系数达到了1550W/m2·K。 

Experimental Investigation of Flow and Heat Transfer About the Thermal Driving of R12 in Rotating Small-Size Circular Enclosures

With the development of the aero engine,the temperature before turbine is increasing greatly and it becomes more and more important to study new cooling technology and equipment.Experiments have been carried out to investigate a new cooling technology which used the thermal driving of fluid in small size circular enclosure to enhance the heat transfer rate.In this paper,the characteristics of flow and heat transfer of the thermal driving of R12 varying with the rotating speed were investigated.All the results show that the characteristics are similar with those in gravity;and the average temperature,the gradients of temperature of the heated wall decrease when the rotating speed increases;and at the same time,the average heat transfer rate is enhanced greatly.When the rotating speed reaches 1140 r/min,the rate will go to 1550 W/m2·K.