Is it possible to specify the mass fraction for multi-component particles from a user defined particle injection routine. |
It is not normally possible to set the particle component mass fraction from a particle injection routine, since this is not one of the variables available for use in the return variables list.... |
When setting up a table interpolation function or a user CEL function, an argument or return value must be dimensionless, but the form will not accept a blank entry for the units. How can an argument to an interpolation function be dimensionless? |
<br>Dimensionless arguments or return values can be specified with empty square brackets. e.g.<br><br>[]<br><br>If there is more than one argument to a function, a... |
When I modify the values of contour legend colors in Workbench Simulation, the contour colors get mixed up and do not look correct. This only seems to happen with Solution Combinations. Is this a bug? Is there a workaround? |
This is not a bug. If you go back to the original solution branches that are used to make up the solution combination and set those contour legends to be consistent with that of the solution... |
Do you have examples of self-inductance, mutual inductance, and force calculation of coils modeled with SOURC36 elements? |
Please see the attached quarter-symmetry model illustrating the procedure using SOURC36 and SOLID96. You may adjust the parameters of this input file and refine the mesh to obtain coil forces that... |
How do I solve a steady-state FSI case and then restart this as a transient case? |
<br>It is sometimes necessary to initialize a transient 2-way FSI case using a previous steady-state 2-way FSI solution. In general this is necessary when the initial (steady state) fluid... |
In the CFX documentation (version 11.0), under the section "ANSYS CFX Pre User Guide => Materials and Reactions => Materials => Material Details View: Pure Substance => Material Properties Tab => General Material => Equation of State - Value", it states that in order to express density as an expression which depends on temperature and/or pressure, enable the "Density Depends On" option. Where is this option located in the CFX GUI? |
<br><br>This is an error in the CFX documentation. That option was eliminated in the 11.0 release since the density dependency is automatically determined. The documentation has been... |
What equations are used to distinguish how DX parameters get rated?
*** (star mark 3)
** (star mark 2)
* (star mark 1)
x (X mark 1)
xx (X mark 2)
xxx (X mark 3) |
We basically divide each parameter range into 6 zones, or rating scales if you will. The location of design candidate value in the range is measured according to the rating scales. For example,... |
Why does Workbench Simulation not process the command /CONFIG,NRES,n? |
A few ANSYS commands, including /CONFIG, only work at the begin level. Command snippets inserted in Simulation that are noted to be issued prior to the first SOLVE command will be issued at the... |
Why is the total temperature equal to the critical temperature using the Redlich Kwong equation of state at conditions T>Tc and p>pc? |
<br>When running the the Redlich Kwong equation of state or a user supplied RGP file, the flow solver clips two dimensional property tables at the spinodal or saturation curves per... |
Trying to start ANSYS CFX-Pre or ANSYS CFX-Post on a Windows PC results in the following error:
========================
Fatal Error
The application has encountered an unexpected problem and will now terminate:
Aborting due to unexpected error:
comm::error: RemoteEngineProtocol::sendInternal - A fatal error has occurred
during communication with the engine
socketError: Socket::socketSend - send: connection reset
Please report this error, along with the circumstances in which it occurred
The following information may be useful to CFX Support:
Unexpected error: Aborting due to unexpected error:
comm::error: RemoteEngineProtocol::sendInternal - A fatal error has occurred
during communication with the engine
socketError: Socket::socketSend - send: connection reset
======================= |
<br>It is likely that this error is caused by a CFX Preferences file that is out of step with a recent system change - for example a change of user domain, change of temporary directory.... |
After running my analysis, I do some postprocessing in POST26. If I enter POST1 and issue the SET command, then go back to POST26, my time-history results change. What is going on? |
Please note that some values in the database may be overwritten by values in the results file. This is the documented behavior of the SET command:<br><br>"Values for applied... |
I am trying to setup damping in my FLUID29/FLUID30 elements, but I am seeing no effect. What am I doing wrong? |
We cannot simply use the structural damping multipliers to obtain damping in the acoustic fluid. You will likely need to define an absorbing boundary to see any phase shift. To do this, you will... |
My tests seem to show that "MP,DMPR" is not calculated correctly in CMS elements. There is no message in the output about an error. Is this a bug? |
No, MATRIX50 does not support MP,DMPR at this time. The documentation only makes reference to "MP,DAMP", not "MP,DMPR."<br><br>Because of this, there is no... |
I am getting an error in Simulation about low order pyramid element shapes that are not valid in the current analysis. Can I force a solution with low order pyramids? |
For the issue that you are having with the meshing in Simulation, you have probably asked the mesher explicitly to drop the midside nodes, and some hex-to-tet-transition pyramids were created in... |
I am attempting to perform a prestressed modal or harmonic analysis in ANSYS. The stresses from the static prestress do not seem to be included in the results for the prestressed harmonic/modal analysis. What am I doing wrong? |
The prestress from the static analysis has the effect of stiffening (or weakening, as the case may be) the structure only. The static stress is used to calculate an additional stiffening matrix,... |
I would like to apply an acceleration or a velocity constraint in a harmonic analysis. My attempts to use D,ACCX or D,VELX have not been successful. What am I doing wrong? |
The acceleration and velocity constraints (D,ACCX and D,VELX, respectively) are valid only for structural static and transient analyses (Basic Guide, Section 2.5). Remembering that a harmonic... |
*** Entered By: rlange @ 08/06/2008 05:29 PM ****
######## WORK NOTES COPIED FROM INCIDENT 788308 ########
Q. I have created a mesh in Simulation, and the resulting *.MSH file I have written from the "Write Fluent Input" in Simulation does not load. Fluent produces an error message similar to below:
Error: Build_Grid: grid error.
Clearing partially read grid.
Error:
FLUENT received fatal signal (ACCESS_VIOLATION)
Is the mesh corrupt? Is there a workaround? |
<br>The mesh itself is okay, but the *.MSH file is not correct.<br><br>One possible workaround is to open the case in Classic ANSYS and create a CDB file. Please follow-the... |
SYMPTOM:
When using the Automatic option for Timestep Initialisation in a transient compressible flow calculation, the convergence can be poor and in extreme cases can cause severe divergence and solver failure.
PROBLEM:
Automatic Timestep Initialisation is intended to give a better initial guess for the next timestep by extrapolating values from the previous timestep using local flow conditions. The decision to use extrapolation is based on the local flow-velocity Courant Number. However, in compressible flow cases a more appropriate quantity includes the local speed of sound. The exclusion of this quantity makes the decision to extrapolate more aggressive in these cases and can therefore lead to problems with convergence. |
WORKAROUND:<br>Use the Previous Timestep option for Timestep Initialisation.<br><br>FIXED IN:<br>ANSYS CFX Release 12.0.
|
Class 3 Error
SYMPTOM:
When viewing the results of a transient heat transfer calculation in CFX Post, the value of Heat Flux on boundaries sometimes does not reflect the true value at particular timesteps.
PROBLEM:
This is due to a bug in CFX Post. The updating of the variable Heat Flux is mistakenly skipped when the transient results file is not of the type Standard (Full). Files of type Selected Variable (Partial) will therefore show no update to th |
WORKAROUND:<br>Use Standard (Full) Transient Results files in your analysis, if possible.<br><br>FIXED IN:<br>ANSYS CFX Release 12.0.
|
Class 3 Error
SYMPTOM:
The wall scale equation is not solved each timestep in problems with transient rotor-stator (TRS) interfaces, leading to incorrect values for the wall scale near to non-overlap regions if they form or disappear during a simulation.
PROBLEM:
In most simulations, the wall scale is independent of time because it just depends on the mesh. This is not true for moving mesh simulations, where the software correctly recalculates the wall scale. This also needs to be done for TRS |
WORKAROUND:<br>No workaround is currently available.<br><br>FIXED IN:<br>ANSYS CFX Release 12.0.
|
Why are my results different depending on whether or not I run with multiple processors? |
While we may think that we are running multiple applications simultaneously on our computers, the operating system is actually switching between them so quickly that we cannot tell the difference... |
######## WORK NOTES COPIED FROM INCIDENT 769613 ########
SYMPTOM:
For the stator turbo report template and when the user updates a Blade loading Span chart at a given streamwise location, CFX-Post plots the chart with incorrect ranges.
PROBLEM:
This is due to a coding error. The normalization of the streamwise location for the blade loading chart is initialised when the report is fi |
WORKAROUND:<br>Set the axis range to be automatic and select the X-axis variable to be streamwise location.<br><br>FIXED IN:<br>ANSYS CFX Release 12.0.
|
Is it possible to create parameters in Workbench Simulation for things like material properties and loads, then pass the parameter values into Command Objects to use there? |
Yes, you can do this using the Parameter Manager utility in Simulation (note, this is not the DesignXplorer parameter manager). There is a sample model attached. In this example, define... |
Which is better - updating FKN (contact stiffness in the normal direction) each equilibrium iteration, each substep, or never updating FKN? |
The answer to the above should be evaluated by reviewing the amount of contact penetration--specifically, one should compare penetration values (in units of length) compared to the local and... |
When I try to install ANSYS software using the zip files downloaded from the Customer Portal I get the following message after double-clicking the file setup.exe contained in the zip file:
===================
Setup Needs the Next Disk
Please insert disk 1 that contains the file layout.bin
=================== |
<br>This error occurs if you try to install from the downloaded zip file without first extracting the contents. The zip files are created with WinZip; use WinZip to extract the contents to a... |