What geometry import method would you recommend for reading data into BladeGen? |
<br>Using a Meanline file or RTZT (Radial, Tangential, Axial, Thickness) file is the native BladeGen format. The file format is documented in the online Help. A good alternative is the... |
Is it possible to scale a model in BladeGen 10.0 or do we need to do this in TurboGrid or CFX? |
<br>You can scale the geometry in Bladegen, using the 'Scale Mode' option under the Tools menu button. Also, it is recommended that you set the units under the Model->... |
How can I write out separate domains from TurbogGrid 10.0?
I created both meshes in Turbogrid 10.0 and when creating the meshes I selected the option to create OUTLET DOMAIN in the MESH DATA tab so the full mesh is created in the wireframe of the blades.
I am having a problem importing these meshes into the CFX 10 definition file. Can you please advise me on how to solve this problem? |
<br>When you export from TurboGrid 10.0, you have the option to write the mesh out as one assembly in one file, write out individual assemblies in one file or write out individual assemblies... |
Why do I see a difference in total pressure on either side of a frozen rotor domain interface in CFX 10.0?
I've been doing CFX calculations for an axial pump impeller with a diffuser, connected by frozen rotor domain interfaces. I got a well converged solution (rms-residuals < 10^-4). The results look good however when I calculate the massflow average of the total pressure (in stationary frame) at the frozen rotor domain interfaces, there is a significant difference in the calculated value for side 1 and side 2 of the interface. The difference is more than 3%; Int Imp Diff. The interfaces are coinciding and and there is a 100% overlap. What is the explanation for this difference? |
<br>There could be several reasons for the difference, with the most likely being the mesh on either side of the interface. You should check that on either side of the interface the meshes... |
Are there any guidelines for modelling tip clearances in turbomachinery applications using Turbogrid 10.0 and CFX 10.0?
I'm using Blademodeler, Turbogrid and CFX 10.0 for designing a liquid (water) pump (Q,H)=(120m3/h, 52m).
The impeller is open so the shroud is stationary and the gap between the blades and the shroud is 0.7 mm (b2 is approximately 16mm). I observe massive degradation of the efficiency when having this gap.
Naturally, according to physics, losses should be introduced with the open impeller and the gap; I just want to make sure that my simulation does not overestimate the loss. |
<br>There are some general guidelines with regard to modelling tip clearances in turbomachinery applications, but they equally apply to non-tip clearance models and other CFD applications.... |
Thin surface mesh does not come through from ICEM Hexa into CFX-Pre 10.0. |
Suggest that you try setting Internal Walls on appropriate surfaces in ICEM
|
How well can the CFX 10.0 cavitation model account for thermal suppresion as the fluid temperature increases? |
<br>It is true that the thermal effect in the cavitation modeling in CFX-10.0 are not taken into account. In CFX-11 the model does take into account the thermal and turbulence effect. It is... |
Q. Is it possible to restart from a .trn file (or turn a .trn file into a .bak file) as my last .bak file is a while ago?
A. I'm afraid you will have to start from the backup file as the trn files are only valid when referenced from a later res or bak file. |
Q. Is it possible to restart from a .trn file (or turn a .trn file into a .bak file) as my last .bak file is a while ago?<br><br>A. I'm afraid you will have to start from the... |
During the CFX 10.0 compressor simulation of one passage of an 8+8 splitter and diffuser, a periodic residual convergence is experienced. This is more evident approaching the stall margin. Is there an explanation for this? |
<br>This could be due to transient nature of the flow in certain locations that can be avoided by increasing the timestep to bypass the timescale of the transients. On approaching the stall... |
Why am I getting the error message below when I run the ADAMS
macro with BEAM188 in ANSYS 10.0?
*** ERROR ***
The number of modes expected (17) does not match the number found (15).
Most likely, the model has errors or there were more modes requested
than exist. Please review the prior modal solution for warnings. |
I ran your input and then listed the superelement that is created<br>by the macro, SELIST,subelem,3. I could see from the matrices<br>that there was no mass for the torsional dof... |
Can tabular arrays which are a function of x,y, or z be applied based on a local coordinate system? |
Yes. See the *DIM command: *DIM ,,, ,,, ,,, CSYSID
|
Is it possible to run a full harmonic analysis with a frequency dependent spring?
The user tried to run separate analysis for each frequency and change the stiffness
between every solution. The problem with this is that you get the results into different results file. |
It is a little non-standard, but the RMOD command can be used without<br>leaving solution to produce a frequency-dependent spring constant. In the<br>attached example the load is... |
Why doesn't this model imported to ANSYS with the Workbench ds.dat
file produce stress and strain. |
It will if you issue OUTRES,ALL,1 before issuing the solve command. The ds.dat file<br>contains an outres command based on the results that you had requested at the time<br>it was... |
Are single-frame restarts supported with 17x (contact) elements? |
Surprisingly, no, just multi-frame restarts. At 11.0 a warning will be issued that<br>results should be checked carefully if they are used in a single frame restart<br>(Ref: defect... |
What is the recommended procedure for solving multiple spectra with expansion
in a separate pass? |
The documented procedure utilizing multiple load steps for the mutliple spectra could<br>be used. When you do multiple load steps, the mode coefficients for each spectrum (load... |
Sometimes when using CFX 10.0 solver, the need arises to switch a quantity such as a boundary or source value on and off thoroughout the course of a run, or between a number of discrete values. A typical example is where the heat generation in a device has different values due to different modes of operation. Although this problem can be solved by carrying out a series of runs and manually changing the desired value at the start of each run, the process can be automated with some creative use of CFX Expression Language (CEL). |
<br><br>The CEL step function is very useful for this type of problem. Two examples are given below. For each example, a set of files is available for download. Both examples set the... |
I have installed BladeModeler 10 SP1, but the Blade Geometry icon is not visible on the Startpage of ANSYS Workbench. I can find and activate BladeEditor in the AddIns... menu, but it does not come up. Starting the DesignModeler returns the following error message:
WorkBench Initialisation Error!
Failed to load script file :
C:Program FilesAnsys IncCFXBladeModeler-10.0BladeEditorBMPagesscriptsbmMain.js
What is wrong? |
The service pack 1 has been installed without the original release beeing installed. Please install the original BaldeModeler-10.0 release BEFORE installing the service packs.
|
How can I add a table with acceleration data to post26 acceleration variable?
I need the absolute acceleration for an acceleration time-history transient run with
the base fixed. |
Attached is an example of how you could do this. The sample creates a table array<br>like your ACX with values every .005 seconds. It then creates a non-table array using... |
Can I use a tapered section to modal a coil spring? |
We require that the beam end stations lie on a line between the centroid<br>of the two sections defining the taper (Re: Section 16.3.4 of the Structural Analysis Guide.)<br>It does... |
How do you create a prestressed superelement? My run is aborting. |
You are trying to run a prestressed modal without having<br>generated the prestress information. There needs to be a static use pass<br>and expansion pass to create the... |
How do temperature dependent material property values input with the polynomial vary between the
input temps? Shouldn't they be based on the polynomial? |
No, the properties are evaluated at the temperatures specified with MPTEMP and straight-line<br>interpolation is used in between these values. As a result, the specification of more... |
How can I remove spectrum information from the database? I want to re-run the modal
analysis and the spectrum input is modifying the modal results. |
Issuing LSCLEAR,LSOPT should clear it out. If it doesn't, writing the model to an ASCII file<br>with CDWRITE and editting out the spectrum can be used.
|
Why don't SHELL181 mid-surface results reflect plastic stress-strain curve? Due to
transverse shear the mid-surface equivalent stress is higher than the top or bottom surface
and the value being reported is far beyond the yield stress. |
Development explained that SHELL181 treats the transverse shear linearly. Plasticity is not<br>considered. If transverse shear needs to be modeled with plasticity a 3d element is... |
What does message about an an array named _EPROP mean? |
This message has been seen in cases where users entered the contact<br>manager after partially creating contact manually. This can confuse the Contact<br>Manager. In the previous... |
Why is mass21 with rotated node giving wrong force under inertial load in ANSYS 10.0?
Are the MASS21 inertias not being correctly rotated? |
Development found that at 10.0 we are correctly rotating the mass21 inertias, but we are<br>incorrectly applying omega/domega in the rotated nodal coordinate system. This has... |