【摘要】 运用数学形态学提出了一种识别核态沸腾中高热流密度下汽化核心密度的算法.分析了在核态沸腾中,当气泡成长时,由于气泡底部的微液层蒸发,使气泡底部壁面处的温度低于其周围的温度,致使在反映加热壁面温度分布的红外图像中,灰度明显低于其周围像素灰度的像素组成的像素团,即对应于沸腾过程中的汽化核心的位置.该方法避免了气泡合并对汽化核心密度识别造成的困难,可以从红外图像中识别出这些像素团,其数量等于汽化核心的数量,对不同热流密度下的汽化核心密度进行了计算.更多还原

【Abstract】 A method based on mathematical morphology to identify the nucleation site density in high heat flux in nucleate boiling is presented.We analyzed that in nucleate boiling,due to the evaporation of the microlayer under the bubble,the temperature of the place under the bubble is lower than that of the ambient in heater surface,the spot composed of the pixels whose gray levels are lower than the gray levels of the background pixels in the infrared images reflecting the temperature distribution of the heater surface corresponds to nucleation site in the process of boiling.The method presented in this paper, avoiding the trouble caused by bubble coalescence on the identification of nucleation site density,can identify the numbers of the spots,which equal nucleation sites numbers,from the above infrared images.Nucleation site density equals the value of the nucleation site number divided by the actual capturing area an infrared image corresponds to.Different nucleation sites densities in different heat fluxes are calculated.更多还原