Discussion Forum

Hello,

I am attempting to simulate water, flowing out of a hole/slit, at the bottom of a tank (under the influence of gravity); entering into a domain (vertically downward), that contains air, and impinging on a curved surface. The idea is to simulate (in 2D) and obtain data on:

1. The distribution of water, as it flows along the surface, on two sides of the surface (for a 2D Simulation), for different initial points of impingement.

2. The (distribution of) stress produced, due to the impinging water, on the (different points of the) curved surface.

I have looked through a plethora of papers, as well as tutorials and none of them include, liquid/gas, flowing out, under gravity, into another domain, containing a different liquid/gas. I am assuming Laminar Flow and No Slip Boundary Condition, at the walls and the curved surface.

Here, as far as I know, I cannot define Inlet at the interface of the two domains. I have tried Multiphase (Phase Field), with no inlet and 1 outlet in the Air Domain (situated vertically downwards), but it did not converge. A Surface Plot of Fluid Velocity showed water, entering the Air Domain, but after a few more time steps, COMSOL threw a Did not converge error, thereby preventing the water from reaching the curved surface. I have tried making the hole into a nozzle (of sorts), with a smooth downward curve, but that did not change the outcome. Any help or hint is much appreciated.

Regards, JS

TL;DR: How do I simulate a hole, at the bottom of a (full) water tank?