[mailoan2306]

Hi, everyone!

I am a new member of this forums.
I am doing a project relative to GMO in flow 3D and I am studying flow 3D software several weeks ago.
My target is cylinder rolling in water with sand, rock, or mud in bottom based on current speed
My question is what are the kinds of physical I have to use? and How can I set up for boundary conditions to obtain the target?
I hope to receive your advice.
Thank you in advance.

[thunde47]

The main model here will be the GMO model. You can either just do one-way coupling where the cylinder affects the fluid or a two-way coupling where both fluid and cylinder affect each other.

The boundary conditions will depend on the type of water body your cylinder is in. If its a pool of water, with nothing moving in and out, then symmetry or wall BC will work.

[mailoan2306]

Thank you for your reply.

The cylinder is located in the water tank and it stationary in the position in calm water.
However, my simulation is cylinder rolling due to flow speed, so how can I setup characteristic of GMO? is it need translational velocity in space system and angular velocity in body system or I just input velocity at Specified velocity in boundary condition?
Please help me with this problem.
Thank you so much.

[thunde47]

If you activate the two-way coupling in GMO model, then water will just roll the cylinder along.

Now, in order to assign velocity to the fluid, you can provide velocity at the boundary condition.

[mailoan2306]

I am so sorry, please describe in the more detail about the motion of the cylinder. Where can I active the 2-way coupling motion? and In moving object properties, how can I define constraints (How can I set up the motion? type of moving object is prescribed motion or coupled motion, should I using 6DOF or fixed any axis and initial/prescribed velocity in space system and body system?