FLUENT: How to manually partition the grid such that each fluid zone is defined as a separate partition
A FLUENT grid may have a number of fluid zones and it is desired to partition the grid in such a way that each fluid zone is defined as a separate partition. How can this be done?
It is possible to define partitions such that each contains a single fluid zone. The approach is to mark every fluid region as an adaption register and then make sure that:
a) all cells in adaption register 0 (first fluid zone) belong to partition 0
b) all cells in adaption register 1 (second fluid zone) belong to partition 1
c) all cells in adaption register 2 (third fluid zone) belong to partition 2
- To mark a fluid region as an adaption register, create registers based on iso-value of cell-info/Cell Zone Index.
- To set the partition id for marked cells in a register, use the following text interface (TUI) command:
(set-partition-in-marked-region 2x y)
where x is the register id and y is the partition-id.
(set-partition-in-marked-region 0 0)
(set-partition-in-marked-region 2 1)
(set-partition-in-marked-region 4 2)
(set-partition-in-marked-region 6 3)
This will work only in the serial version of FLUENT. After partitioning, the case file can be read into the parallel version.
For a structured mesh where each fluid zone has nearly the same number of elements, this approach will result in a very balanced number of cells in each partition. The interface between the zones may also have the minimum interfacial area, which is also a desired characteristic.