Nucleation and Critical Heat Flux in Spray Cooling

。[摘要]本提案涉及高热流密度应用的喷雾冷却。主要研究人员建议通过实验来确定强制对流、表面空腔的核沸腾和由撞击液滴捕获的空气/蒸汽核引起的二次核沸腾的相对重要性。高速摄像机将与半透明的合成金刚石薄膜结合使用，以可视化煮沸过程。为了计算喷雾冷却中核沸腾的贡献，需要确定气泡密度、生长速率等相关参数。通过与浸没射流进行的二次成核特性的比较，可以确定二次成核沸腾的贡献。

. 9616344 Chow, Louis C. ABSTRACT This proposal deals with spray cooling for high heat flux applications. The principal investigators propose to experimentally determine the relative importance of forced convection, nucleate boiling from surface cavities, and secondary nucleate boiling due to air/vapor nuclei entrapped by the impinging droplets. A high-speed camera will be used in conjunction with a semi-transparent synthetic-diamond film to visualize the boiling process. Relevant parameters such as the bubble density, growth rate, etc. will be determined for calculating the contribution of nucleate boiling in spray cooling. The contribution of secondary nucleate boiling will be established by comparing the nucleation characteristics with that conducted with a submerged jet where secondary nucleation is absent.