Numerical simulation of droplets collision with account of surface tension at axisymmetric statement

Abstract

To model and develop rocket, gas turbine and diesel, engines, as well as other devices operating on liquid fuel (for example, boilers and furnaces), the mechanism of interaction of individual droplets, which is a fundamental aspect for understanding processes occurring in heterogeneous systems, should be studied. In addition, the interaction of droplets plays an important role in modeling engines, the work of which is based on detonation combustion of fuel, since the presence of individual droplets in the stream is one of the key factors affecting the spread and formation of a sustainable detonation wave.

The paper presents the model for simulation multimaterial compressible flows with surface tension. Numerical method of sharp interface type is supplemented with surface tension model in terms of continuum surface stress model. Each integration step is divided into stages, pure hydrodynamic stage and surface tension stage. Smoothing procedure for volume fractions is additionally introduced to evaluate surface tension stress tensor. Suggested method is verified by problems with analytical solutions: static droplet, oscillating droplet and Rayleigh–Taylor instability development. Using the verified numerical method, the problem of ethanol droplet collision with different velocities was simulated. The numerical method described in this paper was verified by comparison with analytical solutions and validated on the basis of experimental data.