液滴碰撞倾斜热壁面数值模拟研究

摘要

为了研究液滴碰撞复杂热壁面过程中液滴的铺展特性和传热特性,文中基于FTM(Front-Tracking Method)方法对液滴碰撞倾斜固体热壁面过程进行了模拟研究,通过改变壁面倾斜角度、表面张力系数σ,从压力场、流场、惯性力、表面张力等角度对换热现象进行分析和研究.结果表明:液滴撞击倾斜壁面时,在液滴下滑方向一侧三相点处热流密度取得最大值;壁面倾斜角度越大,液滴铺展程度越低,传热减弱;σ影响液滴中后期的铺展特性,σ越大液滴最大铺展系数越小,且回缩越迅速;由于传热大部分发生在液滴碰撞壁面初期铺展阶段,所以σ对液滴与壁面间传热特性影响较小.%In order to study the spread characteristics and heat transfer characteristics of the droplet impacting on the complex hot wall,the droplet impacting on the inclined hot-wall was simulated,based on the FTM (FrontTracking Method).By changing the angle of the wall and the surface tension coefficient σ,the heat transfer phenomenon was analyzed and studied from pressure field,flow field,inertial force and surface tension.The results show that the maximum value of the heat flux at the three-phase point is on the side of the droplet descending when the droplet strikes the inclined wall.When the angle of the wall inclining is larger,the degree of droplet spreading is reduced and the heat transfer is weakened.σ affects the spreading characteristics of the droplet at medium and late.When it is larger,the droplet spreading is lower and retraction is faster.While σ has little effect on heat transfer characteristics between droplets and wall because most of the heat transfer occurs in the initial spreading stage of the droplet when impacting on the wall.