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-   -   Partitioning Error on HPC: ***Cannot bisect a graph with 0 vertices! (https://www.cfd-online.com/Forums/fluent/222541-partitioning-error-hpc-cannot-bisect-graph-0-vertices.html)

MJM November 28, 2019 05:21

Partitioning Error on HPC: ***Cannot bisect a graph with 0 vertices!
 
Good Day Everyone,

I am running a conjugate heat transfer analysis on an array of solar receivers on a HPC cluster and I seems to have some trouble with successfully partitioning my model.

I am using 9 nodes (128 GB RAM) with 24 cores/node on the HPC. So in total I am using 216 cores for running the simulation in parallel. I generated my case file with the correct settings using 5 cores on my local PC and uploaded it on HPC just to run the simulation. I used a coarse meshed (tetrahedral cells) model for the case file and my plan was to replace it with a finely meshed model (which I generated on my local PC) on HPC because my local PC does not have the required memory to successfully import the finely meshed model into Fluent. Hence, on HPC once the coarse meshed model is replaced with the finely meshed one, I later try and convert the tetrahedral cells it to polyhedral cells, but I come across the following error in the output file:

Setup conversion to polyhedra.
Creation of polyhedra mesh might take a long time.
Converting domain to polyhedra...
Creating polyhedra zones.
Processing face zones............................................. .................................................. ................................
Processing cell zones.........
Building polyhedra mesh................................
Optimizing polyhedra mesh......... Cannot bisect a graph with 0 vertices! *You are trying to partition a graph into too many parts!
Cannot bisect a graph with 0 vertices!
You are trying to partition a graph into too many parts!
Cannot bisect a graph with 0 vertices!
You are trying to partition a graph into too many parts!
Cannot bisect a graph with 0 vertices!
You are trying to partition a graph into too many parts!
Cannot bisect a graph with 0 vertices!
You are trying to partition a graph into too many parts!
Cannot bisect a graph with 0 vertices!
You are trying to partition a graph into too many parts!
Cannot bisect a graph with 0 vertices!
You are trying to partition a graph into too many parts!
Cannot bisect a graph with 0 vertices!
You are trying to partition a graph into too many parts!
..... Cannot bisect a graph with 0 vertices!
You are trying to partition a graph into too many parts!
Cannot bisect a graph with 0 vertices!
*You are trying to partition a graph into too many parts!

===============Message from the Cortex Process================================

Fatal error in one of the compute processes.

================================================== ============================

I have tried using different partitioning method (such as the Cartesian-x,y and z; Principle Axes, Principle Strip etc) other than the default Metis option but ended up with the same error each time. I am not sure what is causing the error and would appreciate if someone could advise me on a way of solving this problem.


Many thanks :)

Regards,
MJM


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