[Techies]

Hey all,
I'm just trying to get into CFD using ICEM
I have a problem about my O-grid
Now when trying to make a O-grid, i don't understand what is Around Block(s) and how to use it. I saw that everyone usually use Offset 0.5 or 1 for Around Block(s).
I have 2 question about it:
1. What is Offset ? Is it a quantity same millimeter or meter....?
2. When do we use Absolute or not ?

[aero_head]

1. Offset specifies the height of the O-grid layer and behaves like a relative distance: A value of 1 places the O-grid at a location where the resulting blocks will be distorted the least. Increasing the value makes the inner blocks of the O-grid smaller, with the surrounding blocks larger, and vice versa for decreasing the value.

2. Enabling Absolute would allow you to specify the actual length of the radial edge of the O-grid i.e. assigning a Offset of 5 would make all the radial edges of the O-grid 5 units (same as your geometry units) in length.

[Techies]

Originally Posted by aero_head

1. Offset specifies the height of the O-grid layer and behaves like a relative distance: A value of 1 places the O-grid at a location where the resulting blocks will be distorted the least. Increasing the value makes the inner blocks of the O-grid smaller, with the surrounding blocks larger, and vice versa for decreasing the value.

2. Enabling Absolute would allow you to specify the actual length of the radial edge of the O-grid i.e. assigning a Offset of 5 would make all the radial edges of the O-grid 5 units (same as your geometry units) in length.

Thanks for helping :P

[Techies]

Hello, i overcame the problem about Around block but the new issue comes when i try moving into the Fluent. The system said i have non-positive volume. I actually dont know what is negative volume, how it affect and how to detect it in ICEM and fix pls. Can u help me? Thanks

[aero_head]

Originally Posted by Techies

Hello, i overcame the problem about Around block but the new issue comes when i try moving into the Fluent. The system said i have non-positive volume. I actually dont know what is negative volume, how it affect and how to detect it in ICEM and fix pls. Can u help me? Thanks

Hello,

Run a mesh check in ICEM and show me a photo of the output along with the mesh. It will show you the locations of the negative volume elements. Highlight these elements then we can discuss how to fix it.