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91
Fluent / Re: 999999 (..\..\src\mpsystem.c@1210): mpt_read: failed: errno = 10054
« Last post by william on July 11, 2012, 06:28:50 PM »
When reading in a large mesh or case file on 2 or more computers this error may appear:

999999 (..\..\src\mpsystem.c@1210): mpt_read: failed: errno = 10054

999999: mpt_read: error: read failed trying to read 4 bytes: No such file or directory

The problem is usually because you ran out of memory.

By default, the partitioner in FLUENT is "principal axis" which uses up a lot of memory. You can set a different partitioning method before reading the mesh or case file. If you are using MPICH as the communicator we recommend using the Metis partitioner.

Start FLUENT in network parallel with 4 or more processors and plenty of memory.

1.In FLUENT select the "Parallel" menu
2.Choose "Auto Partition"
3.Unselect "Case File"
4.Select "Metis" as the partition method
5.Choose OK
You should now be able to load the mesh or case file without memory problems.
92
Fluent / 999999 (..\..\src\mpsystem.c@1210): mpt_read: failed: errno = 10054
« Last post by infocfd on July 11, 2012, 06:26:35 PM »
I get the following when I load the case and data file:

999999 (..\src\mpsystem.c@1149): mpt_read: failed: errno = 10054

999999: mpt_read: error: read failed trying to read 4 bytes: No such file or directory
MPI Application rank 0 exited before MPI_Finalize() with status -1073741819
 The Parallel FLUENT process could not be started.


Can any one give suggestion?

Thanks.
93
Fluent / DPM Injections
« Last post by lakhi on July 11, 2012, 05:38:19 PM »
Using DPM, if I want to inject, say, 2000 particles from inlet and simulate to get the results, what I have to do in FLUENT 14?
How to keep track of the particle positions?
There is an option in FLUENT "Injection-Type: group", where the variables, namely: x-,y-, and z-positions are required for first point and last point. What are these first point and last points.
For surface type injection, we have, start time and stop time. I guess there are injection time (discrete phase injected for 5 sec) in the continuum phase. If this is true, how does FLUENT inject discrete phase? I mean if I choose "start time = 0" and "stop time = 5 sec", how will FLUENT react to these time variables. I think it won't inject desirable number of particles.
I'm not very familiar with DPM, so please explain me in details.
94
I think the built-in option in Fluent  "Custom Field Function" can solve the problem. After defining the desired parameters, use "data sampling" to average-out those parameters.
95
Fluent / Standard Collision Macro
« Last post by sfotovati on July 11, 2012, 12:02:29 AM »
Hi all,

I am writing a UDF for particles collision. At some point and under some certain situations, I need to call the standard Particle Collision macro that Fluent uses by default.

Does anyone know how should I do that?

thanks.

Sean
96
Fluent / UDF for heat convection coefficient with fixed surface temperature
« Last post by boo85 on July 10, 2012, 01:34:00 PM »
Hello everyone.

I am basically doing a simulation for air flow in a room.

What i would like to know if it would it be possible to specify a fixed heat transfer coefficient for the heat transfer into the fluid domain and a fixed surface temperature for a surface as boundary conditions?

Would it be possible with a UDF? I was looking through the UDF manual and saw that Define_Profile allow for the specification of a heat transfer coefficient, however i think its for an external flow outside the domain. Am i right?

CFX has this feature that allows for the specification of heat transfer coefficients via CCL by replacing the turbulent wall function.

Therefore how would it be possible to create a UDF to allow the input of both Heat transfer coefficient and fixed surface temperature into the fluid domain. If so can anyone direct me to a right direction.

Thanks alot!
97
Fluent / non newtonian viscosity problem
« Last post by moloy_kb on June 27, 2012, 11:23:50 AM »
Dear all,
I am simulating the problem of blood flow through an artery in 2D considering laminar flow. For this I am using the Walburn and Scneck model to define the blood viscosity using the equation:
mu_lam=K*(strain)^(n-1), where K=14.67*10^(-3) and n=0.7755. In order to define the viscosity I am using the following UDF:
#include "udf.h"
DEFINE_PROPERTY(cell_viscosity_power_law,c,t)
{
double mu_lam;
double strain;
double muinf = 14.67e-3;
double n = .7755;
strain = pow(C_DUDX(c, t),2)+ pow(C_DVDY(c, t),2)+
2*pow(C_DUDY(c, t)+ C_DVDX(c, t),2)+
2*pow(C_DUDZ(c, t),2)+
2*pow(C_DVDZ(c, t),2);
strain = pow(strain, 0.5);
strain =fabs(strain);
mu_lam=muinf*pow(strain,n-1);
return mu_lam;
}
But, once I try to solve it the solver gives the error: Divergence detected in the AMG solver.
Please help me...
98
Fluent / Re: Body Force UDF problem
« Last post by sfotovati on June 26, 2012, 12:48:31 AM »
Thanks,

But apparently, if you want to combine the above with define_dpm_body_force, it cannot be done. All you mentioned is correct if one does not aim to combine it with macros which consider tracked particles in sequential order.

Thank you anyway,
99
Fluent / Re: How to mark two different region in complex geometry
« Last post by lucaaa on June 21, 2012, 06:04:01 PM »
There is solid phase
100
Fluent / Re: How to mark two different region in complex geometry
« Last post by william on June 21, 2012, 05:57:02 PM »
What is in the black region?
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