Marangoni流动对液滴撞击过热液池影响的数值模拟  

Numerical simulation of Marangoni flow on droplet impingement on a superheated pool

作　　者：赵烁 张杰[2] 倪明玖 ZHAO Shuo;ZHANG Jie;NI Mingjiu(School of Engineering Science,University of Chinese Academy of Sciences,Beijing 100049,China;State Key Laboratory for Strength and Vibration of Mechanical Structures,School of Aerospace,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]中国科学院大学工程科学学院,北京100049 [2]西安交通大学航天学院机械结构强度与振动国家重点实验室,西安710049

出　　处：《中国科学院大学学报（中英文）》2024年第3期289-297,共9页Journal of University of Chinese Academy of Sciences

基　　金：国家自然科学基金(51636009,11872296,U1732276)资助。

摘　　要：对液滴撞击过热液池的动态过程进行数值模拟,着重关注由液池表面不均匀温度引起的马兰戈尼效应(Marangoni effect)对液池内的流场和温度场演化过程的影响。当乙醇液滴落入过热油池后,液池表面温度随着液滴的靠近而迅速下降,从而在径向上产生很大的温度梯度。由此引发的沿径向向内的Marangoni力会与沿径向向外的蒸汽剪切应力相抗衡,进而在蒸汽层最薄的位置形成一个“热射流”结构。随着时间的推进,占据主导地位的Marangoni力逐渐将“热射流”向内推动,直至在液滴下方形成下沉羽流。此外,随着液池黏度的增加,液池内由表面蒸汽应力引起的流动将被抑制,进而导致界面附近的换热效率大幅下降。We numerically investigate the dynamic behaviors of a droplet impacting onto the non-volatile superheated liquid pool,and focuse on the influence of the Marangoni effect resulted from the inhomogeneous temperature distribution at the surface of liquid pool.Particularly,the time evolution of the flow field and the temperature field inside the pool during and after the impacting are studied.We find that the pool surface,made of oil,is cooled quickly as the ethanol droplet approaches,and a large temperature gradient is produced along the radial direction.Correspondingly,the Marangoni force directs radially inwards to resist the radial outward vapor stress,and a“jet”like structure is formed at the position where the vapor layer becomes thinnest.As the time advances,the Marangoni force becomes dominant and the“jet”is pushed radially inwards until the rear of the droplet and form the downward plume flow.In addition,as the viscosity of the liquid pool increases,the flow induced by the vapor stress is suppressed which further reduce the heat exchange efficiency near the interface.

关 键 词：莱顿弗罗斯特 马兰戈尼效应 液滴撞击液池 气-液相变 

分 类 号：O359.1[理学—流体力学]