[Ahmed Elhanafi]

Hi All,

Id like to generate regular waves in Fluent. I successfully generated regular waves with laminar flow, but when tried to move to turbulent flow using either K-E or K_W and SST models, I got a problem with the results as you can see in the attachment.

Please, if you don’t mid helping me with this issue.

My Model Details are as follow:

Model details:
2-D model with 40m length 0.8m height and 0.5m water depth.
Free surface zone is 0.3m with 20 element/wave height and 100 element/wave length.
Mesh quality (Quad) 1.0.
I’m using open channel boundary conditions, Implicit solver.

Boundary conditions:

Left side: Inlet (open channel), Right side: no slip wall, bottom: no slip wall, top: outlet (open channel)

Solver settings:

Pressure-Velocity Coupling: PISO
Gradient: Least Squares Cell Based
Pressure: PRESTO! or Body Force Weighted
Momentum: Second order upwind
Volume Fraction: Compressive
For turbulence: Kinetic energy and dissipation: 1st and 2nd order upwind
Transient Formulation: Bounded 2nd order Implicit
Time step: 0.0025 sec.
No of Iterations: 20

[danielfc]

I am using a very similar setup, but my wave is a irregular sea state imposed by an udf. By performing a mesh density study, I chose a mesh just like yours.
The only difference I can see is the boundary conditions. Are you interested in the effects of shallow water? Which is the wave amplitude? Since I am simulating a deep water scenario, I always use free slip on the bottom and top regions, as long as they are far enough from the fs zone.