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本文以沸腾固气液界面为研究对象,建立了包括孔穴活化、液膜蒸发、气泡生长与脱离、壁面热传导等子过程的耦合模型,以探究固气液界面传热对高热流密度沸腾过程的影响.为了能够分辨微米量级的孔穴,模型中10 mm×10 mm的沸腾表面被划分为诸多子区域,每一个子区域中孔穴大小和数量随机分布,当子区域的过热度大于孔穴活化的临界过热度时,一部分孔穴活化生成气泡.进一步结合大液膜蒸发模型获得沸腾传热热流密度,并将其作为边界条件分析加热器热传导特性,从而通过对不同过程的多尺度耦合模拟不同表面粗糙度条件下高热流密度区的核态沸腾曲线,并进一步分析了孔穴数量及分布对加热壁面温度的影响.结果表明:预测所得沸腾曲线与实验结果基本相符,加热表面孔穴数量的增加使沸腾曲线左移,同时,孔穴数目的增多还会使活化点密度对壁面温度波动更为敏感,从而产生交替出现的长短周期.“,”A multi-scale model is proposed to investigate the effect of the characteristics of boiling surface on high heat flux pool boiling,where the processes of the activation of the conical cavities,the evaporation of macrolayer,the growth and detachment of a coalesced bubble as well as the heat transfer in the copper heater were considered.In order to identify the active nucleate sites with only a few microns in diameter,the 10 mm×l0 mm boiling surface is divided into several subdomains,where a few cavities are scattered randomly.When the wall superheat is higher than the critical value,a part of potential nucleates become active and subsequently form vapor stems.The heat flux of nucleate boiling can thus be obtained by using the model of macrolayer evaporation.Furthermore,the heat flux is given as the boundary condition of the transient heat conduction of the heater.The coupling process becomes a steady state when the corresponded superheat with the input heat flux is founded.The boiling curves were obtained with different heater surface roughness,and the effect of surface roughness on the heater temperature and wall dry pattern were evaluated.A good agreement for the simulated boiling curves with available experiment data is gained.Results show that higher roughness value decrease the wall superheat,hence the boiling curve moves to the left.Meanwhile,nucleation site density is more sensitive to the wall superheat for the surface with higher roughness,resulting in the appearance of two successive bubble departure cycles different periods.