A MOLECULAR DYNAMICS SIMULATION OF DROPLETS MERGING IN MIST FLOW OF FLOW BOILING IN MICROCHANNEL

摘要

The present paper is concerned with a molecular dynamics simulation of the behaviour of droplets merging in mist flow of flow boiling in microchannel. Two identical droplets were assigned in one simulation system and the process of their merging is investigated. The droplets are assumed to be composed of Lennards-Jones type molecules. Periodic boundary conditions are applied in three coordinate directions of a three-dimensional system, where there exist two liquid droplets and their vapour. The two droplets merge when they come within the prescribed small distance. The evolution of the merging process is simulated and presented.rnThe merging of two droplets apart from each other at different initial distances is tested and the possible larger (or critical) non-dimensional distance, in which droplet merging can occur, is discussed. The evolution of the merging process is simulated numerically by employing the molecular dynamics (MD) method. In the present modelling, the molecules near the boundary of one liquid droplet thermally fluctuate into the range of attraction of the other droplet, forming a bridge to connect the two droplets. A dumbbell shape is then formed and thereafter an elliptic merged droplet. Eventually a larger merged spherical droplet appears in the system and is in equilibrium with its vapour phase. More realistic simulation system will be established to further the present preliminary results for application in mist flow of flow boiling in microchannel.