Numerical simulation of two droplets impacting on the wall continuously

Abstract

The application of spray system has been widely used in the industry. The impact of droplets between the wall impact has become one of the important studies of spray system. The investigation is to develop a numerical code for the simulation of two water droplets impinging continuously upon the wall. In the code, the structured single-block and staggered grid system are adopted for discretization of the space domain, while the finite volume method is applied to solve iteratively the governing equations of mass and momentum. The interconnection between the velocities and pressure is dealt by SIMPLER methods. In order to capture the boundary of the deformation of droplets, a level set function method is considered due to the advantage of handling the incorporation and breakup of the boundary easily. In the paper, the numerical verification of a water droplet impinged upon the wall are very accurate with the experimental values. Subsequently, a forward droplet with different Reynolds number of 100, 200, 400 and a backward droplet with the fixed Reynolds number of 200 vertically impact the wall continuously. According to the calculation results a forward droplet with smaller the Reynolds number shows the larger the maximum spread distance after merging. In impact process of different angles, the merged droplet moves along the wall, and produces also oscillates back and forth asymmetrically. As for the maximum horizontal spread distance of the merged droplet, the impact angle of 30 degrees is the smallest, and the impact angle of 60 degrees is the largest.