How can you submit CFX jobs to a PBS queue? |
<br>The basic idea for running any software under many of the batch queuing systems is quite similar. You have to submit a script to the batch system and there is header information in the... |
How can you submit CFX jobs to a SunGrid Engine (SGE) queue? |
<br>The basic idea for running any software under batch queuing systems is the same. You have to submit a script to the batch system and there is header information in the script that tells... |
Where can I find information on the User Swelling Standard Package? |
Please find attached the initial release of the User Swelling Standard Package. Included in the package are:<br>1. A Word document that describes the use of swelling in ANSYS including... |
Which version of Workbench will support Mechanical Desktop 2008 and Inventor 12? |
Workbench 11.0 SP1 will officially support Mechnical Desktop 2008. Since there are no code changes to make this happen, v11 release is just fine to run against them as well. We¿ve seen no... |
In CFX-Pre under Simulation Type for a transient simulation, how does changing the "Timestep Decrease Factor and "Timestep Increase Factor" work when adaptive timestepping is used and is based on the RMS or MAX Courant number? |
<br>The factors works as follows:<br><br>dt_new = dt_new_raw * factor + (1 - factor) * dt_old<br><br>If dt_new_raw > dt_old then the factor used is the... |
I created an FSI-acoustic model in Workbench. The switch to acoustic elements and application of relevant boundary conditions was accomplished with a command object. I opened the model in ANSYS from the Project tab in the workbench environment and solved it in the traditional ANSYS GUI. After the solution was complete, I went into the traditional ANSYS postprocessor to read in the sound pressure level (NMISC,4). I received a message saying the ETABLE data was unavailable. Why is the data not available and how can I work around this problem? |
Simulation writes an input file containing "OUTRES" command that instructs ANSYS to omit writing ETABLE data to the results file. If you add "OUTRES,ERASE" to your... |
When I set up my own RGP file, CFX uses the data from the saturation tables, even though the temperature and pressure for the model lie in the superheat region. |
<br>By default if no Thermodynamic State is set for a RGP material in CFX-Pre, the solver will treat the material as a liquid and always calculate the data from the saturation tables at the... |
Class 3 Error
SYMPTOM:
For conjugate heat transfer problems, it is possible to get incorrect temperatures, for example outside the expected bounds, when 1-1 domain interfaces are used. This can occur at fluid-solid interfaces when:
(1) there is a large conductivity ratio
(2) radiation is being modelled
(3) the flow is modelled as laminar,
and for solid-solid interfaces with large conductivity ratios.
PROBLEM:
There is a bug when using 1:1 domai |
WORKAROUND:<br>Use a GGI interface instead, except for some multiphase cases.<br><br>FIXED IN:<br>Release 12.0.
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I am trying to use the INISTATE command to write out a stress state, and then read in that stress state. When doing so, I get an error message, and ANSYS hangs... what am I doing wrong? |
Your input shows you are using the SOLID45 element type. The INISTATE command was developed only for use with the new element technology in ANSYS. The v11.0 documentation did not make reference... |
CFX Solver treats all variables used in a CEL expression as conservative variables. This includes integrated quantities as well. However in the output file, the solver itself reports mass and energy fluxes on the boundaries as hybrid quantities.
This can lead to a discrepancy between what is reported by the solver and what has been calculated in an expression.
Is there a way, one can force the solver to use hybrid variables in a CEL expression. |
This behavior of the solver to use conservative variables is hard coded. To make the solver use hybrid variables, use the below expert parameter:<br><br>old bcp aver = t
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How to model heat transfer in the solid matrix of a porous domain for both steady state and transient cases. |
There are two methods for handling this case in CFX. One uses an additional variable approach, the other uses a multiphase Eulerian-Eulerian approach.<br>The details are described in the... |
How do you calculate the unburnt char or carbon-in-ash from each burner in a CFX coal combustion calculation? |
<br>In CFX-Post:<br><br>1) Edit the "Res PT for HC Fuel" object, select Reduction Factor of 1, switch on "Filter" and select the start and end regions... |
I have a model under compression with large deflection. When I turn off stress-stiffening effects in PLANE42 elements by issuing "SSTIF,OFF", the solution converges. The solution does not converge with PLANE18X elements as they ignore the SSTIF command, regardless of element formulation used. Is it possible to modify the PLANE182 element to converge successfully in the same or in a similar pattern as PLANE42, all other things being equal? |
At 11.0SP1, "SSTIF,OFF,-1" will turn off stress stiffening effects in the 18X elements, even with "NLGEOM,ON". This will remain an undocumented feature. Users should be... |
When I insert a probe tool on a contact pair to extract the reactions, the "contact" (source) side reactions do not match the "target" side. Is this a bug? |
This is not a bug. Check for shared topology with other contact pairs and/or constrained surfaces. It is likely that either the target surface or contact (source) is sharing topology with another... |
Why is the temperature for my combustion simulation too low, ie: lower than the inlet gas temperature? This happens in CFX 10.0 and CFX 11.0, but does not happen when I run CFX 5.7.1! |
The reason for the observed temperature undershoots in CFX 10.0 and 11.0 is in the way the shared high resolution beta factor for energy and mass fractions is calculated:<br><br>1) The... |
I am trying to use a particle user routine to set the Multiphase Reaction Rate for a particle reaction in a Lagrangian particle tracking calculation in ANSYS CFX-Pre release 11.0. The solver documentation says that this is an allowable options and I see it listed in the RULES file. I am unable to select this option in CFX-Pre, however, and if I edit the CCL in the Command Editor I get an error message that says Particle User Routine is not an allowed option for Multiphase Reaction Rate.
How can I set this up and are there any example routines which show how to do this? |
<br><br>The Particle User Routine option for the choice of Multiphase Reaction Rate is disabled in the CFX-Pre GUI as it<br>is a beta CCL only feature for release... |
How do I model atmospheric flows? |
This is a complex subject. This Solution aims principally at microscale atmospherics, on timescales of minutes or hours and spatial scales of kilometres, although some of the concepts apply at... |
When running Distributed ANSYS on a Microsoft Compute Cluster and using more than 4 processors, the job runs extremely slowly. A job that took 1 minute locally took 20 minutes on the cluster using 7 processors. Why? |
If the Server has Windows 2003 Server SP1 and the Base installation of Compute Cluster Pack, the customer will run into this problem. The Microsoft Compute Cluster Machine (server) needs to have... |
A customer is considering installing MPI software on several machines.
The documentation states that MPICH is required for Windows 64-bit / Windows XP x64 systems.
The documentation also mentions MS-MPI for Windows 64-bit / Windows Server 2003 x64 and Windows Compute Cluster Server 2003.
Can either of these be used on Windows XP x64 machines? |
MPICH must be used on Windows XP x64.<br><br>MS-MPI is only used in a Microsoft Compute Cluster Server installation With Microsoft Compute Cluster Pack.
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I installed LINUX AMD 64 version of CFX-10.0 on Intel Xeon EM64T. When run in serial or parallel, there is an error:
"An error has occurred in cfx5solve:
The solver executable /ansys_inc/v100/CFX-10.0/bin/linux/solver-pvm.exe
could not be found, or is not readable. "
Why is CFX looking for the executable in bin/linux folder and not in the usual bin/linux-amd 64 folder? |
CFX-10.0 never had a version for a Xeon Chip. Xeon CPUs are not detected correctly by LINUX AMD 64 version of CFX-10.0.<br><br>Fixes:<br><br>1) Install CFX-11: A correct... |
How can I combine 2 separate TAS files into 1? |
In TAS, open one model. Then select File > Merge Model. Select the second TAS model. It will then give you the opportunity to enter a X, Y and/or Z offset. This offset is necessary to... |
Are there any Workbench Simulation examples showing how to resolve initial interference and load a hyperelastic material followed by geometry file creation from the deformed element shapes? |
Yes, please see the attached ANSYS Workbench Simulation 11.0 half-symmetry model of a rubber seal being held in place by two rigid bodies. The seal has significant initial interference. A rigid... |
When we report in the solution output that a "contact element xxxxxx has the highest chattering level "n", what does chatter level "n" mean? |
The number "n" is CNOS (= total number of contact status changes during this step) as documented in the elements manual for contac17x elements. The output message will be clarified... |
Is there a way to specify surface roughness while using the SST model? Is it possible to use scalable wall functions with these turbulence models? |
Wall roughness is a hidden beta feature for omega_based turbulence. To activate this, a manual CCL edit of the Fluid Models section and each wall boundary is required.<br><br>First,... |
Client workstation locks up when performing remote solve. Process is running on Server Manager PC. Can not exit WorkBench on client or download results from Server after run finishes. This used to work; what is the problem? |
It may be due to an OS Update or RSM corrupt file.<br><br>From log, RSM seems to be working fine.<br>Looks like COM events aren't working on the client if it locks... |