Investigation Of Contact Characteristics And Heat Transfer Performance After Droplet Impact Onto Wall And Liquid Film

The phenomenon of droplet impacting can be seen widely in the industrial and agricultural production process as well as daily life, and different contact characteristics could affect the dynamic evolution and heat exchange, so investigation of this phenomenon could provide theoretical basis for industrial application. The experimental method which using a high speed camera for observing and record combined with simulation method to investigate the dynamic characteristics and heat exchange effect after droplet impacting respectively onto isothermal wall, heated wall and film which is tiled on the wall. The main work as follows:(1)The high speed camera is used to investigate the process of droplet impacting onto stainless wall, spreadding factor, dimensionless height and dynamic contact angle on on the impact of different characteristics over time are obtained. And then analyse the impact of velocity, droplet diameter and concentration on the dynamic characteristics after droplet impacting onto wall.(2) CLSVOF method is used to simulate the process of droplet impacting onto stainless wall, the experiment is used to verify the correction of the simulation model, the result shows the consistency. The spreading factor, heat flux of wall over time and heat flux distribution along radical direction on the wall are obtained, and then investigate impact of different velocity, wall temperature and concentration on the dynamic characteristics and heat transfer after droplet impacting onto wall.(3) CLSVOF method is used to simulate the process of droplet impacting onto heated film, the jet height, wall heat flux over time and heat flux distribution along radical direction on the wall are gained, and then analyse impact of differernt liquid film thickness, wall temperature and velocity on the dynamic characteristics and heat transfer after droplet impacting onto film.