[zkzkzk010537]

Dear all,

I have recently written a UDF for a transient problem - inlet pressure, this pressure varies depends on the time steps, say

P=1 when time step = 1-50
P=2 when time step = 51-100

In order to do this, i have used F_UDMI(f,t,0)=b; in my udf to memorize the time step.

However, as introduced n fluent manual, to use F_UDMI(f,t,0);, we need define memory first, but there are two memory locations to be defined in fluent version 14.5.

The number of user-defined memory locations and number of user-defined node memory locations.

May i ask what value should i give for each one? I have tried to give 1 for each locations but i met the error after interpretation and select udf in the setting of boundary condition.

The error occurs only when i run fluent in parallel:
(UDF works well when i use fluent in serial)
999999 (..\src\mpsystem.c@1172): mpt_read: failed: errno = 10054

999999: mpt_read: error: read failed trying to read 4 bytes: Invalid argument
MPI Application rank 0 exited before MPI_Finalize() with status -1073741819
The fl process could not be started.

Message from Cortex process==> Connection with host is broken. It may have crashed.

I tried 4 computers, and 3 of them give error in parallel condition and the other computer works well in both parallel and serial. Can anyone help?

Thanks,
Kai.

[`e`]

The mesh node user-defined memory (UDM) locations are different to the cell centred and face UDM. You only need to enable the latter for your simulations. What is the UDF you are using? Have a read of the parallelisation section in the UDF manual.

[zkzkzk010537]

Thanks, i will read the parallel section first, it seems there is an answer for it.

Kai.