VOF: Capillary Effects
This tutorial demonstrates how to set up a capillary effects problem in Simcenter STAR-CCM+. It simulates two-dimensional forced flow of liquid glycerine through a nozzle and into an air-filled chamber at atmospheric pressure.
The mesh that is used (shown below) is the same as in VOF: Gravity-Driven Flow except that, in this instance, the physical dimensions of the problem are scaled down by a factor of 1,000. Therefore, the nozzle width is about 1 mm. The boundary on the left of the problem geometry is an inlet with fluid velocity of 1 mm/s and the boundary on the right is at atmospheric pressure. The boundary at the bottom is a symmetry plane and all other boundaries are solid walls.
Initially, the left chamber is filled with liquid and the remainder of the solution domain is filled with air. For the given geometry and inlet velocity, the flow can be assumed to be laminar. Gravity acts in the positive x-direction and so helps to drive the flow through the nozzle. The shape of the free-surface that develops in the chamber downstream of the nozzle depends on the contact angle between liquid and wall. This contact angle is specified as 45o.
The Interface Momentum Dissipation phase interaction model is included in the simulation. This model stabilizes the solution significantly by reducing irregular velocities near the liquid-gas interface.
