Parallel speedup appears sometimes to be quite poor when the mesh is mixed hex-tet (hex dominant or hexa core). All the partitions seemed to have similar numbers of nodes, which is the target of the MeTiS kway algorithm, but some partitions ended up with predominantly tets whereas the others are predominantly hex. Hence there are lots more elements in some partitions compared to others. This means some partitions have a lot more work involved in the solver assembly than others, and so the efficientcy of speedup is poor. |
We have an expert parameter 'part cvs weighting' which, if set to true, weights each vertex within partitioning by the number of control volume sectors it touches. It has helped... |
SYMPTOM:
When running some parallel jobs on large cases, the jobs may hang with no warning or error message. Often one or more solver processes become inactive, and the Solver Manager may become unresponsive.
PROBLEM:
This is due to an over-estimation of space needed for the Memory Management System (MMS) by the solver. |
WORKAROUND:<br>Scale down the allocated space for the MMS by adding the following command to the CCL:<br><br>...<br> SOLVER CONTROL:<br> Catalogue Size... |
When running a laminar multicomponent chemistry problem using high resolution differencing for energy mass fractions the temperature field shows very large spatial oscillations with a range which is very unphysical. |
<br><br> By default the energy gradient is not used in computing beta for the energy mcf group of equations. This can cause the standard second order oscillatory behaviour for... |
Do you have the files for the 'Acoustics and Fluid Structure Interaction, Rev 5.0 Tutorial'? |
See attached zip file.
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Is there a way to display density in mg/m^3 in CFX-Post? |
Yes.<br> - Go to 'Edit/Options/Units' in the CFX-Post menu<br> - Switch the unitsystem from SI to Custom<br> - Click on 'More... |
How can I verify that I filled my multimaterial Euler mesh correctly? (Verify proper mass/volume was filled) |
There are a couple of ways to accomplish this:<br><br>1) The Euler cells can be partially filled. Hence, to review this, one can plot a contour of material fraction.<br>If... |
I would like to know what my initial pressure field is. How do I plot this? |
Pressure is evaluated based on the material EOS. The initial pressure is calculated by the material EOS from material initial conditions. The initial conditions include initial material density... |
When starting ProEngineer , the following message dialog is displayed:
! Message : Startup of application "WB100PluginPro2001" failed. |
This error occurs because the Workbench Part Manager did not register successfully upon installation, but the ProE plugin did however register successfully.<br><br> Manually... |
SYMPTOM:
When running parallel jobs on Windows using the PVM communications method, the performance can be poor, especially when it comes to writing files such as trn and res files. This poor performance also occurs in distributed parallel runs between Windows and unix/linux machines.
PROBLEM:
This is just due to PVM not being very efficient on Windows. |
WORKAROUND:<br>Use MPICH.<br><br>FIXED IN:<br>Not fixed yet.
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Customer has Workbench 10.0 Vista and is trying to read a Workbench 10.0 SP2 dsdb file. He receives the following error:
This file was saved with a future version of the product and cannot be opened.
Should they be able to read 10.0 SP2 dsdb files in Workbecnh 10.0 Vista? |
No.<br><br>Vista will only read in Workbench 10.0 dsdb files.<br>If the user wants to review 10.0 SP1 or 10.0 SP2 files,<br>the only workaround is to install the full... |
How can you visualize the position of a surface level in CFX Post 10.0 for a free surface flow? |
The fluid level is not a variable. One needs to use other available variable to detect the position of the free surface.<br>A good indicator is a gradient of density or volume fraction. This... |
SYMPTOM:
When using grid adaption, it is possible to get error messages similar to the following:
Assertion failed: success && noOfSides == 4, file j:CFX-5.7-buildsrcrefinersrc.ElementsTriColumn.ixx, line 669
OR
refiner.exe: /home2/cfx5test/CFX-11.0-build/src/refiner/src/./Elements/Triangle.ixx:279:
virtual void Triangle::getFaceEdges(int, int&, Edge**) const: Assertion `face > -1 && face < noOfFaces' failed.
OR
Assertion failed: 0, file /devel2/cfx5test/cfx/src/5.6/refiner/src/./Elements/TriColumn.cxx, line 374
PROBLEM:
The grid refiner code was written for a typical mesh, with or without inflation, from CFX-Mesh or for meshes with single element types, and other grid types, perhaps with
many element types, are not supported by the refiner. |
WORKAROUND:<br>A potential workaround, which works in most cases, is to set the Environment Variable CFX5_REFINER_NO_TRICOLUMNS to a value of 1.<br><br>FIXED IN:<br>ANSYS CFX Release... |
SYMPTOM:
Having built a User Fortran library in CFX 11.0 using the Compaq Visual Fortran compiler on Windows, the solver fails with an error similar to the following:
"Error opening d:supportproject1winntcfx11UserRoutines.dll: The specified module could not be found."
PROBLEM:
The CFX 11.0 installation does not include the CVF runtime libraries DFORMD.DLL and DFORRT.DLL, which are required for User Fortran routines to work. This is because the supported compiler has changed to Intel Fortran 9.0. |
WORKAROUND:<br>On machines that have CVF already installed, no changes should be necessary as the libraries are provided with the Fortran installation. However, for machines where there is... |
Both ANSYS and FLEXlm installations lock up, specifically during configuration according to the status window.
No error, just a message that it's configuring the system to install ANSYS and/or FLEXlm during the installation process.
What causes this? |
In this case, a program called Retrospect was running. After shutting this down, the installation continued successfully.
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How can I access in CFX 10.0 the volume fraction of an Algebraic Slip Model (ASM) species, e.g. for the calculation of drag force in User Fortran? |
<br>The limitation on volume fraction is caused by settings in the VARIABLES file. You can find this in the etc subdirectory of your installation directory. By default, volume fraction is... |
How can I make sure that transient results are written at specified times during a restarted run? In the initial run it is OK to specify a TIME INTERVAL. If this run is stopped on an intermediate time step, how do I control the writing of these files from a restarted run? If frequent saving of transient results is needed, then it is difficult to write a TIME LIST. |
<br>The easiest way to do this would be to restart the run from the last full transient file but that would mean repeating some time steps. An alternative would be to include a Perl script... |
When I use a CEL expression in CFX 10.0 that is a function of the system variable "r" it does not behave as I would expect. For example, I want to define the Velocity Theta Component of a swirling flow on an inlets as r*omega. |
<br>The system variable "r" is defined in terms of x and y in the reference co-ordinate frame (see Table 1 in ANSYS CFX, Release 10.0: Reference Guide | CFX Expression Language... |
I want to run the CFX 10.0 solver on a Linux machine, starting the run from Windows with an rsh command. How can I specify the working directory when I do this? |
<br>This is something you can set interactively from the Define Run menu of the CFX-Solver Manager but there isn't a command line argument to do this.<br><br>Instead you... |
When I use the Monte Carlo radiation model and then plot temperature against distance, the profile is very bumpy. Should I increase the number of histories to obtain a smoother curve? |
<br>Profiles of this type can be caused by the statistical variation inherent in the Monte Carlo model. Rather than increasing the computational requirements by increasing the number of... |
I get the following error message 'invalid vertex number found ...'. What's the problem? |
The .par file wasn't updated after changing boundary condition physics. Please re-run the partitioner and start the solver with the new .par... |
How can you use the Mixture Model in CFX 10.0 to simulate a system with phase inversion, such as bubbles in liquid in the bottom of the domain and droplets in gas in the top? |
Please see the attached doc for model details and how to set up in CFX 10.0.
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I have mixed Tetra/Prism and Hexa meshes in one domain. Now the partitions are unbalanced. Is that because of the hybrid character of the mesh? |
Yes, this behaviour is normal for the default setting with hybrid meshes. This is because the partition weighting is vertex based and different element types have different control... |
I often have problems running 2 CFX 10 solvers in parallel and I think it may be related to the acfx_anymodule key. I have the following keys in my license file:
1 acfx_solver
1 acfx_nolimit
1 acfx_parallel
4 acfx_par_proc
2 acfx_anymodule
4 acfx_par_proc
Consider 2 scenarios:
1) I start a CFX parallel solver running and while this is running I start a second parallel solver running. Both parallels ran fine.
2) I start a CFX serial solver running and while this is running I start a second CFX solver running, this time in parallel. I then stop the serial run and start a second parallel run while the first parallel run is still going. The second parallel run fails. So in this scenario I can only run one parallel solver whereas in scenario 1) I could run two.
Can you explain what is happening in the second scenario? |
In theory, to run the solver in parallel you need EITHER an acfx_solver key and an acfx_parallel key OR 2 acfx_anymodule keys. However in your scenario 2) you appear to have highlighted an error... |
Can not see Advanced CFD Icon in Workbench 10.0 on Linux 64 bit machine. Why not? |
One will not see the Advanced CFD Icon until the following command is run:<br>/ansys_inc/CFX-10.0/bin/cfxwbinst<br>Example:If Workbench is installed under:... |
I am getting the following solver error message from CFX 10.0:
+--------------------------------------------------------------------+
| ERROR #001100279 has occurred in subroutine ErrAction. |
| Message: |
| Stopped in routine SRF_ORT |
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+--------------------------------------------------------------------+ |
<br>Here are some suggestions.<br><br>1) If R=0 at the interface. In this case set the parameter "Transformation Type = None" for this interface in... |