## Preprocessing

#### The size of the model changes greatly. Should it be divided into several parts for meshing?

• h395523899
Subscriber

My model will be used in fluent simulation. There are fluid channels and porous media in two parts. The structure mesh is firstly divided by icem and then converted into an unstructured mesh.

The overall model data: x length 20m, y width 10m, z thickness 5m.

There is a 5 mm thick sheet on the xy face of the model.

At the same time, a half-round body with a radius of 1.5 m is in the middle of the thin plate and is connected to the thin plate.

Both the plate and the hemisphere are fluid channels. The rest is porous media.

My thoughts and problems encountered: 1. Consider the thin plate and the hemisphere as a part, the porous medium is seen as a part, but it is found that the grid drawn by the thin plate and the hemisphere is of poor quality, and 2*2*2 has a negative existence. . 2. Think of the sheet as a partial mesh, see the hemisphere and the porous medium as a whole, and the mesh quality is OK. But I do not know if this has any effect on the simulation in fluent.

• raul.raghav
Subscriber

A 5mm thickness plate in a 5m z-direction domain length sounds like trouble to me. Can you explain what you're trying to model so that we can understand the whole setup?

And while meshing it in ICEM-CFD, you can create any number of blocks to get the desired grid (hexa). Eventually, you would have to include the specific blocks to the appropriate bodies (like porous or fluid).

• h395523899
Subscriber

A 5mm crack, a hemispherical cavity with a radius of 1.5m is a cavern, and the porous medium is a stratum.

First of all, thank you for your help.

1. I want to simulate the water level for the top of the oil to understand the remaining condition of the oil in the channel. The initial conditions in the model are all oil, water comes in from the entrance. This situation does not know whether to use Euler or vof.

2. I have drawn the model into three parts. The main part is a thin plate-shaped channel, and the second part is a semi-circular cavity communicating with the thin plate, which is located at the middle of one side of the thin plate. The third part is porous media, located on the semi-circular cavity side of the sheet. The boundary conditions I use are as follows: Euler's theorem, turbulent k-e equations, inlet velocity 2 m/s, free exit. The three parts are connected via interface.

3, I encountered the problem is: the same boundary conditions, I use the thin channel simulation, it can smoothly iterate. At the same time, I connected the thin-walled channel only to the porous media and it also smoothly passed through it. When I connect the sheet channel with the semi-circular cavity, or when the three parts are connected together, the iteration is always divergent.

• h395523899
Subscriber