Multiphase flow is a transient analysis. Transient simulations are time-dependant. Which means, timestep will significantly effect the computational time and cost. Therefore, try to keep the smallest element size as big as possible in multiphase simulations. Check our Knowledge base article for more information regarding transient analysis.
To control smallest cell size,
- Avoid generating “boundary layers“
- Keep the mesh simple as possible, which means try not to use additional refinements.
- Limit your smallest cell size
You can use our Hex-dominant parametric mesher as follows:
- Select Hex-dominant parametric mesher:
- Check the coordinates of your bounding box:
- Assign the relevant resolution values to keep the cells “cubic”. Resolution in X, Y and Z directions will divide the domain with the number defined:
To conclude, Check that the following are applied:
- Have a uniformed mesh
- Make sure each region has enough elements
- Ensure mesh quality is acceptable
How the mesh should look:
The photo below shows an example of a bad mesh: