How do I get the current iteration number as a variable into a junction box routine, which is called after each coefficient loop? |
<br>You can get this information from the MMS data structures.<br>The iteration number is stored in the data area '/FLOW/SOLUTION/AITERN'.<br>The time step number... |
When Post-porcesseing large simulations win CFX-Post 10.0, what sort of memory requirements will I need? |
For CFX-Post, there are two main memory issues: Loading the problem is the first memory hit, but then the requirement also increases depending on how many variables you plot and whether you use... |
I want to model porous baffles within a moving domain. Are there any issues with setting this up? |
There is nothing stopping you using porous domains with moving meshes, but there are some issues with the resistance/loss models in CFX-10. The main problem is that the standard loss models use... |
According to PLCAMP documentation for the new ANSYS 10.0 command PLCAMP, a comparison between complex
mode shapes is used to track the modes versus the rpm excitation axis. Could you provide further information what
is done here for my advanced dynamics seminar? Is it a sort of MAC (modal assurance criterion)? |
You are right. We are using the modal assurance criterion to compare the complex mode shapes at 2 different load steps.<br>If the result if less than 0.7, we issue a warning to let the user... |
Why are load case combinations in POST1 so slow? |
On large models, load case combination cannot be done in memory and<br>generate IO to file.page. Some ways to reduce this are the following:<br>1. After solution, return to ANSYS... |
Why do my Simulation frequency response results change when I change the
frequency range? |
The range determines which modes are used in the harmonic. With the narrower<br>range you specified, the first natural frequency wasn't used, changing the result. ... |
Why do my Single Parameter Sensitivities in DesignXplorer vary so much with the value of the parameter?
My response surfaces are linear, so according to generic definition of the sensitivity, the sensitivities should
be the tangent of the surface which is (almost) constant. But the sensitivities shown in "Single Parameter Sensitivies"
were not the tangents and varied a lot as I changed the value of a parameter. And these sensitivities are very different
from the sensitivities under the six-sigma analysis. |
First of all, Single Parameter Sensitivity (SPS) is different from correlation-based sensitivities, e.g., Pearson Linear (PLS)<br>or Spearman Rank (SRS) Sensitivity used in ANSYS PDS and DX... |
How can I use a user-specified contour range for von-mises stress while animating it? |
The animation is produced by the ANCNTR command, a macro in the APDL directory.<br>In the macro you will find the line below. If you comment out this line the animation will<br>use... |
Why do my ANSYS10.0 PSD post26 results become wrong when I use 120 modes?
They are correct when only 10 modes are used. |
This is defect 43658, fixed in 11.0. Closely-spaced modes are not being handled<br>correctly. A workaround is to use NPTS<6 on the POST26 STORE command (default is 5.)
|
I have been using an "Environment" command snippet with a /sys command
in it, which suspends solution and allows me to issue commands from
the system prompt. When I close the system window, solution execution
resumes. Why doesn't this work anymore at 10.0? |
This behaviour was turned off intentionally to prevent many windows from<br>popping up, which was annoying to most people. The change was made to ANSYS<br>batch behavior and is not a... |
Why am I getting wrong answers with PCG solver and solid95, keyo(1)=1? |
This is due to the MSAVE command being ON for the PCG solver case. MSAVE,ON is the default for certain cases when using the PCG solver.<br>When non-isotropic material properties are used... |
Does CFX have Real Gas Property tables for steam? |
<br>Yes. These are in the materials-extra subdirectory, within the etc directory of the CFX-10 installation. There are several different files, and to find out what each one means,... |
CFX-Pre and CFX-Post viewer stay white for meshes with more than 300k nodes. |
This was observed as a conflict with the firewall Agnitum Outpost (http://www.agnitum.com/). Check if the issue remains after deactiviating or updating the firewall. In this case only a change to... |
When meshing with ICEM CFD , I get a mesh with a hole in it, why? |
<br>One reason is due to missing surfaces within the geometry. There are ways in which you can repair the mesh, but if you have a whole surface or surfaces missing then often it is more... |
When creating a surface in ICEM it creates a strange looking surface which does not follow the external curves. |
<br>This is due to the surface being quite complex. Two approaches might resolve this, firstly you can section your complicated surface into smaller more simple surfaces which can get be... |
I am trying to plot pressure along a predefined path. I set up a polyline using a data.txt file with the point locations. I then create a graph specifying the polyline as the location. It graphs pressure at each of the points in the data.txt file but does not interpolate between and pick up the data along the polyline. Is there a way to do this? |
<br>Unfortunately there isn't, you either need more data points in your txt file, or perhaps view the data in another package like Excel.
|
I have a run where at the start there is a wall between two independent meshes, and during the run it is removed. |
<br>If the two meshes are non conformal, you will need to have a GGI connection between the two meshes.<br>First run the solver with the wall there, then stop the... |
How much RAM do I need to run my CFX 10.0 solver problem? |
<br>A conservative guideline to use for the 'RAM to cells' ratio is 1 Mbyte should solve 2000 tetrahedral cells (around 400 nodes). So 1 Gbyte of RAM should solve around... |
When running a mesh deformation case in CFX-10, the following warning appears:
+--------------------------------------------------------------------+
| ****** Notice ****** |
| |
| The Second Order Backward Euler transient scheme is not supported |
| for the continuity equation in domains with mesh deformation. |
| This simulation will continue using a First Order scheme for the |
| continuity equation in the domain: |
| exhaust |
+--------------------------------------------------------------------+
Can continuity be forced to high Res? |
The reason for reverting to first order is that the mass inside a closed system is not being conserved when running second order. It is recommended that you use first order as you will conserve... |
What is the maximum number when creating density boxes in ICEM CFD Tetra 10.0? |
<br>The maximum number is 8.
|
;
How can I show two units for a variable in CFX-Post 10.0? |
<br>This is strictly not possible automatically within CFX-Post. However there is a workaround to achieve this, as described below.<br><br>For example, to show temperature in... |
How can I control the rate of mesh size away from the surface in ICEm CFD Tetra 10.0?
I have a surface with mesh size 2 and a volume mesh size of 16 say. Is there any way of controlling the rate that the tetra size increases from 2 through to 16 away from the surface? I know I could use density boxes with sizes 2, 4 & 8 but with a complex surface shape its not really an ideal option. |
<br>There is no direct way to get a nice smooth transition from your small cells to the larger background one. However, there are parameters which are available:<br><br>1) ... |
When trying to create a solid in DesignModeler, I get the following error:
"Error: Self intersecting or invalid profiles
"Context: Extrude Feature Extrude1" |
This is a limitation with DesignModeler which has been reported to the developers. The workaround here is to set the model up using mm, use the same dimension values as that of meters. You can... |
What's the best way in TurboGrid 10.0 to duplicate or create multiple blade rows for a full 360 degree wheel? |
<br>Suggest you try using CFX-Pre to transform and duplicate the initial grid.
|
The Solver crahes with no helpful error, but does give the following warning on the iteration before failure:
+--------------------------------------------------------------------+
| ****** Notice ****** |
| Newtons method failed to converge in 100 iterations. This |
| occurred while computing the following variable: |
| |
| Variable Name : Total Temperature |
| Location Name : sparks |
| Mesh location : VERTICES |
| Mesh entity : |
| Last 3 Changes : 1.26616E+03 1.26326E+03 1.26767E+03 |
| Tolerance : 1.0000E-02 |
| |
| The Newton iteration was diverging. The solver will continue |
| with the variable field as it was on the final iteration. If |
| this situation continues you might try decreasing the Netwon |
| iteration under relaxation factor. This can be changed by |
| setting one of the following parameters: |
| |
| Temperature : "Constitutive Relation Under Relaxation" |
| Pressure : "Newton Pressure Under Relaxation" |
| |
| for your mixture using the definition file editor. |
+--------------------------------------------------------------------+ |
<br><br>Check the CCL for your combustion calculation. For each domain, the combustion model section might read as follows:<br><br>In dom1:<br><br> FLUID... |