SYMPTOM:
When using a non-reflecting boundary condition, the solver crashes on the first iteration.
PROBLEM:
Release 10.0 SP1 introduced a bug in the CFX-Solver initializing the 'old nonreflecting pressure' (needed for the LODI equations) on the first timestep. |
WORKAROUND:<br>Running the CFX-Solver in double precision may help to resolve this problem.<br><br>Alternatively, do not install SP1 if you are using non-reflecting boundary... |
A calculation shows a large increase in residual values when restarting a CFX-5.7.1 oil combustion calculation in CFX-10. |
Due to a change in the naming of Lagrangian particle source terms in CFX-10, a restart from a CFX-5.7.1 results file, can show a large increase in residual values. A smoother restart can be... |
I have generated a velocity profile for my inlet boundary condition which uses a continuous fluid and at least one dispersed fluid. How can I apply my profile? |
In cases where a separate velocity field is specified for different fluids, clicking "Generate Values" on the profile boundary condition form does not automatically enter the... |
The solver reports an error "Insufficient Catalogue size" during my run, and terminates. |
This problem occurs rarely, and is the result of the solver's internal memory management system running out of space. You cannot change the Catalogue Size through the Graphical User... |
What is the difference between an 'ok' and an 'OK' under the linear solution section of an out file? |
<br><br>The three columns to the right of the residual diagnostics refer to the performance of the linear (inner) solvers. The first column is the average number of iterations the... |
When I start the CFX Launcher on Windows, it appears to be minimized, even when I click the task bar icon to display it. |
This problem can occasionally occur when the screen position (that the launcher logs) gets stored incorrectly. When this error occurs, the launcher window is usually set to appear above and to the... |
In DX (DesignXplorer), the user is unable to view graph labels or response chart labels. The labels are invisible unless you move the graph or pan the object in the zoom window.
When you do this, the labels flash on and off rapidly. When you stop the motion, the labels disappear completely. |
This is a problem with the double-buffering of the graphics card.<br><br>- Download and install the latest graphics driver from the card manufacturer's... |
After installing Ansys10 on a Sun Blade 1000 running Solaris 9, the GUI does not start. The message in the console indicates that the GUI is being activated, but nothing happens.
/INPUT FILE= /afs/cad.njit.edu/solaris/ansys_100/v100/ansys/apdl/start100.ans
LINE= 0
ACTIVATING THE GRAPHICAL USER INTERFACE (GUI). PLEASE WAIT...
What is causing the GUI to hang and not start? |
If system FONT is set to 3(Small) under Desktop Settings, then ANSYS 10.0 will not start.<br>This is a defect that will be fixed in the ANSYS 10.0 service pack.<br>The workaround is to... |
Q. With a porous region in CFX-10, is it enough to specify the Volume Porosity or do I have to specify a resistance as well?
A. Yes you do. If you only specify the volume porosity, then you only get a pressure drop in the region due to Bernoulli from the increase in velocity of the fluid through the porous region. The pressure would then recover when the fluid exist the porous region. You need to specify a resistance, through loss coefficients or quadratic/linear resistance conefficients, so that you get a pressure drop from forcing the fluid through the region. Deriving appropriate coefficients isnt easy, but there is a technical note on this: just look for "porous flow modelling in cfx10" in the knowledge base. |
Q. With a porous region in CFX-10, is it enough to specify the Volume Porosity or do I have to specify a resistance as well?<br><br>A. Yes you do. If you only specify the volume... |
Q. How can I import a mesh into CFX-Pre 10.0 from Nastran?
A. CFX-Pre should be able to read in a Nastran file directly, but occasionally you may get an error saying:
"Unable to import mesh: Invalid large field line"
This may be because you are unknowingly using an older and little-used 'wide line' version of the Nastran format. CFX-Pre will try to read this format, but it cannot be guaranteed. If you can, use a more recent version with the short lines.
A major consideration with mesh import is how to define the 2D regions so that they appear in CFX-Pre for use as boundary condition locations. Within the Nastran file, CFX-Pre reads the PLOAD4 (and to a lesser extent PLOAD and PLOAD2) fields and turns them into boundary locations. The answer is then to define some pressure loads on external surfaces of the mesh before export, separate load definitions for separate regions. |
Q. How can I import a mesh into CFX-Pre 10.0 from Nastran?<br><br>A. CFX-Pre should be able to read in a Nastran file directly, but occasionally you may get an error saying:<br> ... |
The bouncing block model from the ANSYS Dynamics Seminar aborts in ANSYS 10.0.
Is this a known problem? |
Yes. The old CONTAC48 elements are no longer supported. Updating the model to<br> use CONTA175 and TARGE169 elements instead works fine (see attached input... |
I get the following error message when I try to launch CFX 10.0 on Windows:
Aborting due to unexpected error:
socketError: RemoteEngineProtocol::engineCrash - Unexpected engine termination:
Aborting due to unexpected error: systemError: Directory::create - Directory::create: CreateDirectory C:/Documents and Settings/yang.PHYSICS/.cfx/CFX_TEMP_3332: The system cannot find the path specified.
Engine state was written to C:/Documents and Settings/yang/.cfx/10.0/cfxpre/dump.cst |
<br>1. From the Launcher window, select Show|Show All<br>This will create a long list of output. Near the top of the output you will see the path set for the variable... |
The CFX 10.0 solver has crashed leaving me with a backup file and a .mon file. How can I write the monitoring information into the back up file? |
Usually a full backupo file will alreday include the monitoring data. However insome situations, perhaps if the problem crashed due to lack of space, the backup file may not have the monitoring... |
Why is DPCG requiring many more iterations in ANSYS 9.0 than PCG? |
I see there are 222 constraint equations in the model. If any of those go across a CPU domain<br>boundary, then the behavior you are seeing could be related to a defect fixed in 10.0.
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Why isn't one of my point loads in Design Modeler being transferred
to Simulation? |
Point loads on multi-body parts are not supported in ANSYS 9.0 or 10.0.<br>Depending on which body it is placed on, it may or may not come across to Simulation.
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What are your recommendations for running a 4 million dof model with PPFA
on a machine with 8 Gb of RAM and 8 processors. Specifically,
1) How much memory is required?
2) Should we be using the AMG solver?
3) What workspace settings do you recommend?
4) When should we use the -f (no grow) command line option? |
Since each model is different, development recommendeds a trial and error approach<br>using a single load step static analysis. See how the analysis runs on 2 4 6 and 8 CPUS.<br>That... |
Why does the ANSYS 9.0 documentation say the active RSYS does not affect CYCPHASE results?
It does work as most people would want, so don't change how it works - just change the documentation.
Also, CYCPHASE,PUT does not work properly. The results are incorrect for an RSYS other than 0. |
The documentation has been corrected in ANSYS 10.0. Additional development has been done in<br>ANSYS 10.0 to make it unnecesary (and not permissible) to issue RSYS,SOLU after the... |
Can the MultiField solver handle rotated interface nodes? Forces from the magnetic solution
to the structural solution where rotated nodes exist on the boundary do not look correct. |
In ANSYS 9.0 when the nodes of the structural elements at an electrostatic-structural<br>interface are rotated, the electrostatic forces are applied incorrectly in<br>the rotated nodal... |
In what coordinate system are element stresses reported for SHELL elements? |
In Release 10.0, the coordinate system in which the stress results are reported is controlled by the RSYS command. By default the results are reported in the global Cartesian system (RSYS,0). If... |
Is it possible to calculate only the DOF solution? |
In Release 10.0, if you issue OUTRES,ALL,NONE followed by OUTRES,NSOL,LAST, ANSYS will suppress the element calculations. This procedure is unsupported and should be only used with caution, but... |
Is it possible to list the hoop stress for PIPE16 elements? |
In Release 10.0, it is possible to list the hoop stress for PIPE16 elements using an ETABLE. Below is a simple example that runs two load cases; one with an axial load and one with internal... |
Is it possible to turn off the edge outlines for Q-SLICE (/TYPE,,8) plot? |
In Release 10, the /GLINE,,-1 command will turn off the edges in a Q-SLICE... |
Is it possible to *GET the mass moment of inertia of a deformed model? |
In Release 10.0, interia relief can be used to compute the mass moment of inertia for a deformed model. *GET can them retrieve that... |
Is it possible to apply the load at the shear center of a BEAM188? |
In Release 10.0, it is possible to apply a load at the shear center of a BEAM188 element using the SECOFF,SHRC command. The calculated deflection of BEAM188 is greater if the load is applied at... |
In the ANSYS fatigue module, is it possible to specify S-N curves for different temperatures? |
In ANSYS Release 10.0, it is not possible adjust the S-N curve for temperature. The most common approaches taken by users are to manually pre-adjust one S-N curve using the highest temperature in... |