竖直矩形微槽内的特殊干涸与换热行为

利用宽视场体视显微镜、高速摄影仪以及CCD摄像系统对纯蒸发和沸腾换热情形下竖直矩形毛细微槽内液体的特殊干涸行为进行了观察,对液体沿微槽槽道方向的润湿高度进行了观察测量,并对液体沿微槽槽道方向的相变换热特性进行了实验研究.实验结果表明:竖直矩形毛细微槽群是一种高性能的相变换热强化表面,微槽中液体的蒸发与沸腾对干涸点高度的变化有着复杂的影响,热流密度和相变换热系数沿槽道方向的分布不均匀.

SPECIAL BEHAVIORS OF DRYOUT AND HEAT TRANSFER IN VERTICAL RECTANGULAR MICROGROOVES

Using a wide field stereo-microscope,a high-speed camera and a CCD video camera,liquid dryout behaviors and axial wetting height in vertical rectangular capillary microgrooves were observed and measured under the conditions of pure evaporation and boiling heat transfer.An experimental study of axial phase-change heat transfer characteristics in the microgrooves was conducted.The results show that the surface with vertical rectangular capillary microgrooves has a high performance of phase-change heat transfer.Evaporation and boiling heat transfer have complicated effects on wetting height.There exist nonuniform distributions of heat flux and phase-change heat transfer coefficient along the axial direction of the microgrooves.