I am looking at the effects of the collapse of a wave on a beach and effects on the beach as this wave flow rushes up and down the beach.

I am using the 2D Volume of Fluid simulation in fluent 6 and I have adapted a region in my mesh and patched it with water to represent the wave collapsing onto the beach, however when I run the simulation I have to use a very small time step in order for results to converge.

At present my time step is 5e-08 and after 7860 iteration the flow time is only 0.001366s seconds and it seems like it is taking an eternity to run and due to a lack of licences this is a major problem.

I was wondering if I have maybe made a mistake in setting up my simulation and I would be very grateful for any help given.

My mesh is a simple rectangular channel 0.55 meters by 6 meters. The mesh spacing is 0.005.

My solver settings are: 2d, segregrated, implicit, time - unsteady, velocity - absolute, 1st order, cell based, superficial.

Multiphase - Volume of fluid. 2 phases; air and water, water patch into region.

K-epsilion viscous model used. Momentum and Energy models not changed.

Operating conditions - Pressure located at top of mesh. Gravity is on on with X=0 m/s-2 and Y = -9.81 m/s-, specific gravity = 1.225.

Boundary conditions - all verticies are walls.

The turbulent velocity is 0 and in the solution control- Pressure discretization is standard and PISO is the Pressure-Velocity Coupling method.

Please reply to this post if you can help or email me at u11djs2@abdn.ac.uk to get in touch.

Yours sincerely
David