Learning Forum

[tpatel04]

Hi everyone,

I am trying to simulate wavy condition using multiphase vof model. I have followed many tutorials but still have some issues with setup and i think with mesh as well. Geometry is quite simple, it contains only a rigid plate, which has been considered to float over the surafce. I knew that for rigid body I need a dynamic mesh 6dof and i have tried to apply it. Here I describe some of my boundary conditions.

Inlet: velocity inlet (avg flow vel = 0, Open channel wave bc) , wave checks passed for applied wave data

Outlet: Pressure outlet, open channel (Free surface is also considered as pressure outlet)

Cell zone: Fluid domain (Numerical beach is on, computed from inlet)

I will also provide dynamic mesh properties if someone can help me to sort this out.

Some questions :

Do I need a very fine mesh near Air-water Interface? And what aboout Interface between Solid plate and fluid?

What are some other parameterers that may cause errors, like floating point exception or Zone surface: cannot create surface from sliding interface.

Do anyone can suggest about 6DOF dynamic mesh properties. I am not good at simulation but willing to do so.

Any kind of help / suggestions would appreciated.

Thanks!

Regards,

tpatel04

[Rob]

You will want a finer mesh at the free surface to capture the position. Similarly if the floating plate is likely to have water over it and air under you'll need to resolve that (finer mesh).
The cannot create surface is a warning, and refers to the wall created by a nonconformal interface in Fluent.
Floating point exception is an error, and likely a result of the set up. There are a few tutorials & videos in the Help, click on "Help" in Fluent to navigate to them.

[tpatel04]

Thank You So Much Rob for your reply Yes, I am currently working on meshing at the free surface interface and refinement near the contact surface. Any other boundary conditions that should I keep in mind while developing this kind of simulation?
Also, I am using the latest student version of fluent, and I knew that I can apply 6dof properties without udf and I am trying to do so, would like to add something to that? I am also going through some videos and tutorials related to this.
Several times I had floating point exception error, what boundary setup cause this generally?
Thank you!

[Rob]

Floating Point tends to be a generic solver error. It's usually linked to dividing by zero type problems. Poor mesh can be a cause, but also badly defined model settings.
Re the free surface, have a look at adaption as you may find it's better to refine that way if the free surface is moving. The open channel boundaries are covered in the User's Guide and Theory Manuals.