【摘要】 液膜流动是喷雾冷却复杂热量传递过程的直接载体，因此，液膜动力学特性研究对理解喷雾冷却的传热机理至关重要。但由于雾化液滴与具有高湍流度薄液膜之间存在的强烈相互作用和扰动，研究者们对液膜在表面的演化过程知之甚少。本文研究了不同热流和压力下两相区HFE-7000在光滑表面液膜分布、流动速度和当量直径等特性。测量了不同工质在不同喷射压力下雾化液滴速度空间分布，并提出了经验预测关联式。测量了孤立液膜流动速度及其当量直径，同时求解了孤立液膜韦伯数分布及其平均值。最终，基于雾化液滴径向速度与孤立液膜速度的有机联系，结合表面温度梯度等条件，提出了孤立液膜平均速度和平均韦伯数的预测方法，相应的预测极限分别小于21.52%和24.3%.更多还原

【Abstract】 The liquid film is the direct carrier and thermal resistance of the complex heat transfer process in spray cooling, and thus it is important for understanding the heat transfer mechanism.However, the evolution of liquid films on the surface still remains unclear owing to the interactions and disturbances between the atomized droplets and the thin films with high turbulences. In this study, the liquid film dynamics of an HFE-7000 spray in a two-phase cooling regime on a smooth surface were quantitatively captured, including the film morphology, film velocity, and equivalent diameter under different inlet pressures, and the heat fluxes. The distributions of the atomized droplet velocities under different inlet pressures were measured and the related empirical correlation was proposed. Then, the velocities and the equivalent diameters of the isolated liquid film were measured, and the Weber numbers were obtained after that. Finally, based on the relationship between the atomized droplets and the liquid film, in combination with the thermal boundaries of the surface temperature gradient, a series of prediction methods for the surface-averaged velocity and the Weber number of the isolated films were proposed, via which the related predicting limitations were 21.52% and 24.3% respectively.更多还原