A numerical study of drop evaporation at high density ratios using Front-Tracking method.

Droplet evaporation is a typical multiphase flow with various applications in many natural phenomena and industrial processes. Different numerical methods have been used to simulate this type of flow. Front-Tracking is one of the common methods in the study and simulation of multiphase flows. The Front-Tracking method requires very fine resolution when dealing with high density ratios with phase change. As a result, Front-Tracking method has rarely been used for solving problems at high-density ratios. In this paper, by using a two-step algorithm for moving the front, the Front-Tracking method is modified for problems with high-density ratios. Also, the fluid around the droplet is considered as a gas mixture, and the generated vapor is considered as a different component from the primary gas that surrounds the droplet. The results of the two-step algorithm are compared with the existing algorithm, and the available analytical results for a static droplet. The evaporation of a falling droplet is also studied, and the results of the two-step algorithm and common algorithm are compared. The effect of droplet deformation on the evaporation process for a falling is investigated. The effect of vapor properties on evaporation rate is also studied. The two-step algorithm is used for different three-dimensional cases, and static droplet evaporation is simulated. Results are compared with existing analytical results. Next, a falling droplet is modeled and the results are compared with experimental data. The effect of density ratio on falling droplet evaporation is also investigated. Finally, two and three-dimensional results are presented and compared for a specified case. For some cases, the conservation of mass and the dependence of results to grid resolution are presented which indicates the accuracy of the numerical method. [ABSTRACT FROM AUTHOR]