[o.b.m]

Hello everyone,
Actually I am doing my Bachelor’s theses and I have to model a water bell (kind of water fountain) using FLUENT 14.5 (please see diag1: 1/8 of a waterbell in a air box). For this simulation I am using the VOF model in order to model the bell geometry in the air and their interaction, also the κ-ε Turbulence model since the flow inside the pipe is turbulent. As an inlet I used a water velocity inlet with magnitude of 1.04m/s and a pressure of 7.5bar=750000PA. As primary Phase is the Water and as secondary phase is the air. Initially all the domain is felled by air. The gravity is also used und the specified operating density.
The problem is, that after 2300 iteration with 0,001s as time step the water (simulation time t= 2,3s) the water start to reach the top of the pipe with a length l=145mm (which normally needs 0,14sec) (please see the diag2).
Another problem is, that after the water reach the top of the pipe, the water stop there even at simulation time t = 10s. I tried every think I changed the mesh and its size, I have done a 3d and 2d simulation, I changed even the simulation parameter but the problem is the same even with other inlet velocity.
Please if anyone is familiar with the VOF code or/and this kind simulation, please help me. I am really stuck here since 1 month and I didn’t figure out the solution.
Thank you in advance

[devesh.baghel]

Hi,

1. Apart from velocity inlet, any other BC and where are you applying ? magnitude ?
2. Plot the volume fraction only in "two color" mode i.e. use only two color bandwidth, inst of 20, so that clarity will be more on volume fraction plot of water and air.