非等温粗糙表面液滴撞击特性试验与仿真研究  

Experimental and Simulated Investigation on the Droplet Impact Characteristics on Non-Isothermal Rough Surfaces

作　　者：岳出琛 戴庆文[1] 陈磊[1] 黄巍[1] 王晓雷[1] YUE Chuchen;DAI Qingwen;CHEN Lei;HUANG Wei;WANG Xiaolei(National Key Laboratory of Science and Technology on Helicopter Transmission,Nanjing University of Aeronautics and Astronautics,Jiangsu Nanjing 210016,China)

机构地区：[1]南京航空航天大学直升机传动技术重点实验室,江苏南京210016

出　　处：《摩擦学学报》2023年第6期692-705,共14页Tribology

基　　金：国家自然科学基金(51805252);清华大学摩擦学国家重点实验室开放基金(SKLTKF21B02)资助。

摘　　要：非等温固体表面液滴碰撞现象广泛存在于航空航天领域机械零部件中,液滴碰撞动力学行为的研究对提升机械零部件传热换热以及润滑性能具有重要意义.为获得液滴在非等温粗糙表面的撞击特性,研究了硅油在金属表面撞击、铺展和回缩的动力学行为,并着重分析了硅油黏度、撞击速度、油滴初始直径、金属表面粗糙度及温度对硅油撞击特性的影响.结果表明,在等温表面,液滴最大铺展直径与撞击速度、基体表面温度及液滴初始直径正相关,与基体表面粗糙度、硅油黏度负相关;当表面粗糙度介于6.3~25μm时,其对液滴最大铺展直径影响较小;在非等温表面,液滴回缩过程中少量液体残留并形成尾迹,且残留尾迹随基体温度升高而愈发明显;随后数值模拟了硅油在非等温粗糙表面的碰撞过程,并揭示了基体温度和表面粗糙度的影响机制.本文中研究成果为理解非等温粗糙金属表面液滴的撞击行为提供了丰富的理论和试验依据.The phenomenon of droplet impact on non-isothermal solid surfaces widely exists in mechanical parts in the field of aerospace,and the study of droplet impact dynamic behavior is of great significance to improve the heat transfer and lubrication performance of mechanical components.For the sake of obtaining the impact characteristics of droplets on the non-isothermal rough surfaces,silicone oil and non-isothermal rough surface that similar to the surface of the inner cavity of engine were selected to carry out solid-liquid collision research.An experimental platform for droplet impact investigation was built and the dynamic behaviors of impacting,spreading,and retracting of silicone oil droplets on metal surfaces with different characteristics were observed via high-speed camera.The impact dynamic was interpreted by dimensionless numbers including Reynolds number(Re),Weber number(We)and Ohnesorge number(Oh),the effects of silicone oil viscosity,impact velocity,initial diameter of oil droplets,metal surface roughness and temperature on the impact characteristics were highlighted.The results showed that on the isothermal surface,the maximum spreading diameter of droplets was positively correlated with impact velocity,temperature of substrate surface and initial diameter of droplets,and negatively correlated with the roughness of substrate surface and the viscosity of silicone oil;the maximum spreading diameter was less affected by Weber number,and there was no direct correlation between Ohnesorge number and the maximum spreading diameter.In particular,compared with that before increasing the initial diameter,the relative deformation of oil droplets did not increase significantly,because the kinetic energy increment could not significantly offset the negative impactof viscous dissipation,and the change of morphology was still limited.After changing the surface roughness of the substrate(6.3~25μm),the spreading diameter and temperature at the forward end of each time node were similar.On the non-isothermal surface,wh

关 键 词：液滴撞击 非等温表面 表面粗糙度 数值仿真 浸润铺展 

分 类 号：TH117.1[机械工程—机械设计及理论]