Learning Forum

[bxddstl]

Professor, ,I am a novice.I have a simulation, a simulation of the coupling of the transient structure and the fluent. There are four bodies, valve, water, Pipe, and rod (the name is pull). I want to pull the rod in the transient structure, and rod will drive valve up or down.Then the volume of water will increase or decrease, and the material of Rod is relatively soft, so Rod will swing around in the water (which affects the grid of the interface between inside face of water and the Rod), so I would like to ask how to set the dynamic mesh of water?

https://youtu.be/yhN6bnnJKoU My simulation

  I want to solve two problems: 

   1. The lower surface of water will rise or fall, but the distance of rise or fall is uncertain (this is determined by the transient structure), so the dynamic grid of the lower surface of water needs to be set. How to set the dynamic grid?

   2. Inside the cylindrical water, there is an empty area occupied by rod. The surface of this area may change, but the change is random, depending on the move of the flexible rod.So how to set the water surface that contact with rod?

     

   I have asked questions about dynamic mesh on the net, and most of the answer will give me about dynamic ,mesh usage of the video, but most of the video is about the dynamic mesh in fluent software, not about fsi dynamic mesh, so I want to ask how fsi dynamic mesh set (the movement of the mesh is not from the definition of udf,It depends on the transient structure.)

   So can you help me solve the two problems?

   Thank you?

[Karthik Remella]

Hello,
You will most likely need to use layering (if your mesh is structured) or remeshing (if it is an unstructured hex). I would prefer using an unstructured mesh since you are talking about an FSI simulation.
For all practical purposes, the dynamic meshing component, whether you are working on FSI or non-FSI, is pretty much the same (with some very minor differences). But since you bring this up, you could have a look at some of the tutorials outlined on Ansys Help under System Coupling. Here is the link.
System Coupling Tutorials (ansys.com)
You should be able to find the corresponding files as well here.
I hope this helps.
Karthik

[bxddstl]

So you mean i do not need to use udf,i just need to define remeshing dynamic mesh settings as the same as what if i use udf to define the motion of mesh,right?
And i want to ask if six DOF is necessary in coupling system to define the motion of fluid?
Can you help me?
thank you

[Rob]

Do the tutorials and watch the help videos, they'll cover most of your questions and explain what's going on.