Numerical simulation of droplet ejection based on VOF method

摘要

Taking ejection process of the ink droplets from ink-jet nozzle as the prototype, a similar numerical model of droplet ejection was established. The VOF method was applied to track the interface of droplet ejection process and it is shown that the numerical results simulated by the VOF method were accurate and reliable. Six kinds of liquid with different physical properties were chosen as the research object. The numerical results were analyzed and compared. Finally, the effect of the surface tension, viscosity and density on the droplet ejection process was discussed. Droplet injection technology is developed in recent years. A new technology of rapid prototyping, in ink-jet printing, biological medicine, microelectronics, function gradient material preparation, and other fields is widely used [1-3]. Especially for inkjet printing, droplet spray is the most important and basic problem. How to make the droplets with smaller steady jet volume and jet droplets uniformity, are all important factors affecting the quality of ink-jet imaging, so analysis of droplet spray process and the research has very important practical significance. The track of sport is the key to the simulated droplet spray process, the most widely used on the surface of the sport tracking technology has a Level Set method [4] and VOF method, the Level Set method is relatively less amount of calculation, also relatively easy to implement, but its calculation accuracy improvement. VOF method is based on the flow of the tracking method, advantages are obvious: application simple, small, high precision, tracking memory interface is sharp, so by comparison VOF interface tracking method is more suitable for the droplet spray process. The paper with ink droplets from inkjet printer nozzle jet process as the prototype, a similar droplet spray numerical calculation model is established, the VOF method is used to interface tracking of droplet spray process, and to study the surface tension, viscosity, density effects on droplet spray process.