振动对液滴撞击壁面铺展特性的影响  

Effects of vibration on spreading characteristics of droplet impacting on surface

作　　者：朱劭恺 胡定华[1] 李强[1] ZHU Shaokai;HU Dinghua;LI Qiang(MIIT Key Laboratory of Thermal Control of Electronic Equipment,Nanjing University of Science and Technology,Nanjing 210094,China)

机构地区：[1]南京理工大学电子设备热控制工信部重点实验室,南京210094

出　　处：《航空学报》2023年第16期53-64,共12页Acta Aeronautica et Astronautica Sinica

基　　金：国家自然科学基金(52276070)。

摘　　要：在航空航天领域的喷雾冷却过程中,被冷却器件时常处于振动状态,因此确定振动对喷雾冷却液滴撞击壁面动态行为的影响有重要意义。基于VOF方法和动网格模型建立了液滴撞击垂直简谐振动壁面的数值模型,研究了壁面振幅、频率和初始相位角对铺展特性的影响。结果表明,相同撞击条件下,壁面振动不仅影响着最大铺展因子和铺展时间的大小,还会使液膜发生断裂抑制和飞溅行为;初始相位角为0°时,铺展时间随振幅和频率的增加而减小;最大铺展因子随振幅的增加一直增加,振幅较小时,最大铺展因子随频率的增加先增加后减小,在共振频率处取得最大值且减小程度随振幅的增大逐渐降低,振幅较大时,最大铺展因子随频率的增加变为一直增加;铺展时间和最大铺展因子随初始相位角的变化趋势主要与频率有关,频率较小时,初始相位角对铺展时间和最大铺展因子无明显影响,随着频率的增加,铺展时间先后在180°和90°相位最大,最大铺展因子先后在0°和180°相位最大。During the spray cooling in aerospace field,the devices need to be cooled are in a constant state of vibra⁃tion.It is significant to study the effects of vibration on droplet impacting behaviors of spray cooling.Based on the Vol⁃ume of Fluid(VOF)method and the dynamic mesh model,the numerical model of droplet impacting on vertical simple harmonic vibrating solid surface was established,and the effects of vibration amplitude,frequency and initial phase angle on the spreading characteristics were analyzed.The results showed that,under the same impact condition,the surface vibration not only affects the maximum spreading factor and the spreading time,but also causes the fracture suppression and splashing behaviors of film.When the initial phase angle is 0°,the spreading time decreases with the increase of amplitude and frequency,and the maximum spreading factor increases with the increase of amplitude.When the amplitude is small,the maximum spreading factor increases first and then decreases with the increase of frequency,the maximum value is obtained at the resonant frequency and the degree of decrease gradually decreases with the increase of amplitude.When the amplitude is large,the maximum spreading factor becomes increasing with the increase of frequency.The trend of the spreading time and the maximum spreading factor with the initial phase angle is mainly related to the frequency.When the frequency is small,the initial phase angle has no significant influ⁃ence on the spreading time and the maximum spreading factor.With the increase of frequency,the phase of spread⁃ing time is maximum at 180°and 90°successively,and the phase of maximum spreading factor is maximum at 0°and 180°successively.

关 键 词：液滴撞击 壁面振动 铺展特性 动态行为 铺展因子 

分 类 号：V245.3[航空宇航科学与技术—飞行器设计]