[Deng]

Hi, everyone

Firstly, I'd just like to say thank you for taking your time out to read my post, and also that I'm fairly new to this software but I'm very keen to get some experience under my belt.

I am modeling a wave by star-ccm+,but I have some questions.
The wave height is 0.15m and the period is 1.3s.
I run 100s and the wave modeled is very unsteady. The residuals are also big and unstedy.
I have attached the figure of the wave and residuals.

Anyone can help me and give me some suggestions?

Best regards,
Deng

[sky101001]

What's your courant number? It should be smaller than 0.5

[Deng]

Hi,

Thank you for your rely.

I do not use the courant number. I use the time step. I define the time step as 0.002s 0.003s 0.004s and 0.005s. However, the waves modeled are still unsteady and the residuals are some.

Do you model a wave by star-ccm+? Can you show me the waves you model? I hope it will not trouble you a lot.

Best reegardes,
Deng

[sky101001]

You can create a scalar scene to monitor the courant number of the free surface.
I think your time step is small enough. What's your mesh size?
Lowering the CFL_u and CFL_l of your VOF model might lessen the residuals. However the surface might be not so smooth.

[Deng]

Hi,

There are 100 meshes per one wavelength and 24 meshes per one waveheight. And the grid aspect ratio is 4.

I can send my case to you if you agree this ideal. And you can check the setups when you are convenient.

Thank you for your help.

Best regards,
Deng