Discussion Groups
New Idea
7 Kudos

Could this flag be included in the interface rather than hidden as a flag?

 

It is already a huge time saver for anyone running transient analyses but not many users are aware of it.

 

It will only run the number of inner iterations required (based on a user prescribed percentage change between each inner iteration) rather than the same fixed that was set value for each time step.

 

 

 

4 Kudos
nhahn

Adjust stop iteration number during solving

Status: New Idea
by Valued Contributor nhahn on ‎07-03-2014 07:48 AM

I would like to be able to adjust the number of iterations during solving so I can cause the simulation to terminate earlier or later than originally intended, but not necessarily right now.

 

So if I originally asked it to run 1000 iterations, but based on how I see the solution evolving now I want it to stop at 500, I would like to be able to enter that during solving.

 

This could be useful during automatic mesh adapatation cycles where the convergence is happening sooner or later than expected.  I may want the current cycle to terminate soon so it can go to the next mesh level.

 

Alternatively if I underestimated the number of iterations then I would like to be able to extend the run time without starting and stopping the simulatin - this is especially important for large files/remote solves.

 

Being able to adjust other termination parameters while solving would also be useful (i.e. stop time in a transient, as opposed to iteration number; adjust the intelligent solution parameters to looser or tighter criteria; etc.)

 

 

1 Kudo

We have multitudes of 2D axisymmetric analyses that take about 2 minutes to run but the view factor calculations (radiation on) takes about 20 minutes. In other words it takes 10 times longer to calculate the view factors than it does to run the analysis. Many times we'll create several scenarios by cloning the previous scenario. We keep the geometry the same but we'll modify material like changing aluminum to stainless steel, or changing a thermal conductivity from 20 to 60. None of these changes should trigger a re-calculation of the view factors but it does. This is unnecessary and wastes a lot of time. Can this be changed? I don't know if it happens in 3D but it does happen in 2D.

 

Thanks, Dan

8 Kudos
pschneider

Combustion module

Status: New Idea
by pschneider on ‎05-09-2014 12:49 PM

Create a phase change combustion module to show proper heat release and flame impingements.  Having the ability to see post combustion chemical breakdown such as NOx or CO would be great but to be able to predict temperatures around combustion equipment is the primary desire.

7 Kudos

Improve the labeling for the advection schemes.  1-5 doesn't help, and every time I want to change it I have to go to the help file to remind me.  Put the name and/or a short list of what it's used for in the dialog box. 

 

Actually, to make it much more user-friendly make a wizard for different analysis types (internal compressible, pressure driven, AEC, natural convection, etc) that automatically pre-selects the right solution details per the help guidelines such as advection scheme, turbulence model, results outputs, etc.  This would be pretty cool now that I think about it. (Just let me skip the wizard if I want to.)

1 Kudo
ryan.arnaudin

Linux cluster support

Status: Comments Requested
by Employee on ‎07-24-2014 04:04 PM

I want to use a linux cluster to solve Simulation CFD analyses. 

 

If you vote on this one, please add a comment about the cluster you intend to use!

3 Kudos

Would be nice to get more response from the startup process in case of "forgotten" settings, e.g.:

  • for the use of gravity or compressed air you have to change to variable air
  • Inlet has no temperature defined
  • etc.

Thought of something similar like the interactive diagnosis in Creo Simulate.

13 Kudos

This option would be especially useful when you are running with ISC enabled or free surface to get a better idea of how long the solver has progressed.

 

There is a common mis-conception, especailly with free surface, that the time step is always 0.01 (if using guidelines), when it is really based on the free surface courant calculation.

1 Kudo
nhahn

Show values next to convergence plot

Status: New Idea
by Valued Contributor nhahn ‎07-03-2014 08:02 AM - edited ‎07-03-2014 08:04 AM

Give the option to show current iteration values on the convergence plot.  Perhaps by the legend as shown below.  Provide a checkbox to turn this on and off.

 

Edit: it would be even more useful if these values could also be in the same units as the main window (i.e. if I am showing PSI for pressure, show the convergence value in PSI, not the analysis units).

1 Kudo

Hi,

 

I have a conjugate heat transfer case that involves Motion.  I would like to track the temperature of the moving part.  But, monitoring point is stationary.  Once the moving part moves away from the monitoring point, then, the monitoring point reports temperature of something else (not the part of interest).  It will be nice to have monitoring point that "attach" to the moving part and report the temperature (or whatever interested) during run time.

 

Pei-Ying

1 Kudo

HI,

 

When I run conjugate heat transfer cases, quite often I need to see how average temperature of a solid part ramps up (or down) during run time.  Currently, the only way to achieve similar to this is using Monitoring Points.  However, the Monitoring Point gives temperature of a "point".  Although, I can create several Monitoring Points on the part, but, it will be a lot easier if Autodesk CFD can have this feature that display average temperature (or some other quantities) of a solid parts (or domain) during running the case.

 

Yes, it is possible to save several results during the run and compute the data needed based on the datasets saved.  But, this will not be possible if the model is very big and need fine resolution in data points.

 

Pei-Ying

8 Kudos
CJunxian

Mapping Velocity/Pressure results

Status: New Idea
by CJunxian on ‎07-30-2013 06:32 AM

Is there a way to map the velocity/pressure results from an outlet, and subsequently map the result to an inlet of some other components/systems?

 

An example of application would be: 

a centrifugal pump is simulate to obtain the simulated fluid's behaviour (velocity/pressure) at the outlet.

Next, the same results are mapped to the inlet of a rotating fluid tank that it is attached to. 

 

Of course, both the simulation can be done in one go, but if there are 2 or 3 different configurations for the fluid tank, but all are attached with the same pump design. It would save a lot of time by just applying the mapped results from the first simulation.

2 Kudos
dpounds9999

Heat Flux Profile Boundary Condition

Status: New Idea
by dpounds9999 on ‎04-01-2014 06:00 AM

It would be nice to have the ability to specify a spatially varying heat flux boundary condition, or in other words a heat flux profile or distribution.  This could be done by defining a function of heat flux as a function of position on a surface with appropriate limits.  As of right now, the only way to accomplish this is to break the surface into descrete surfaces and apply average heat fluxes to each region.  This can be especially painful when you have a steep slope in the distribution of heat flux vs. position function.

 

This would be useful for applications where the heat flux applied to a surface is non-uniform, such as concentrated solar power applications where you might have a hot spot in the center and a profile much like a gaussian distribution.

8 Kudos
OmkarJ

Exclusive licence for meshing and solving

Status: Under Review
by *Expert Elite* on ‎06-04-2013 01:40 AM

Hi

 

It is puzzling that while we are meshing, we have to give away a licence in solving, forcing us to stop the jobs running in the queue, just to be able to mesh. In most commercial CFD (or FEA) software packages that I know of, I see that meshing and solving are completely exclusive of each otherin a single licence.

 

Majority of time of every CFD engineer is occuppied in meshing at his workstation. At the same time, he can't finish his job unless these meshes are run, often in the remote cluster etc. Sorry if I sound rude, but is it me, or has Autodeksk really employed this unfair and unjust tactic to engage a solver licence in meshing, thereby indirectly forcing users to go for additional solver licences, so that they can continue both meshing and solving uninterrupted at the same time?

 

I know this may call for a major overhaul in code (or maybe not), but is it not reasonable to demand that  "meshing" and "solving" be treated exclusive of each other?

 

OJ

Status: Under Review
8 Kudos

Support fully developed flow for a mass flow rate boundary condition.

5 Kudos

Currently, the wall calculator outputs the pressure and shear drag as a sum. It would be beneficial for the user to be able to know how much the force is due to pressure and shear as well as the total sum.

2 Kudos

There needs to be some consideration taken to allow for reorganizing/regrouping analyses between different Design Studies.

 

I currently have a Design Study that has 4 analyses in it.  I coned one of the analyses and ran it.  When the results were complete, I tried to open it but the system crashed.  I was unable to ever get the results to load.  I could delete the folder with this analysis and get the Design Study to open, but then I didn't have my results.  Since it took quite a while to set up the analysis, I used the support file to run the analysis. I was then able to see the results in this new Design Study. 

 

So here's what I'm left with...  2 Design studies on the same project, all caused by your system not being able to see result your system generated.  Apparently at this point there is no way to move the analysis that worked and was viewable into the old Design study.  Thus, I cannot use any of the Summary features or any comparative analysis tools you provide and I have to manage 2 files instead of one.

 

As a side, there is also, no easy way to get my 15 cloud credits back when I'm not able to open the analysis files....

 

Tony

2 Kudos
hanfordke

Multiple solve computers

Status: New Idea
by hanfordke on ‎01-29-2014 10:22 AM

Can't managing multiple solves on different computers when there are enough solve licenses.

With one solve license & 2 users on different computers, the second user can't queue a solve on his computer when the first user has solve on his computer.  Remote solve using remote server would work but network security doesn't allow that for some installations.

8 Kudos

 

Some customers are facing the problem of license crashing due to network fluctuation.
Due to the license crashing they are losing the already completed iteration and have to start analysis again.
 
Added abilty where we can save all my completed iteration automatically without losing the data when the license is lost?  This it beyond the saved intervals options.  This would be the equivalent of click on the 'stop' button if the license was lost.

1 Kudo
huijin9055

Operative Temperature

Status: Under Review
by huijin9055 on ‎04-03-2014 09:30 AM

According to ASHRAE standard 55, human thermal comfort is defined by a range of operative temperatures, which is a combination of air temperature and mean radiant temperature. Only under certain circumstances, it is acceptable to assume operative temperature is equal to air temperature. For example, when there is no radiant heating or cooling systems. I notice Simulation CFD does not report operative temperature in the result, not sure if it is calculated in the solver. We're hoping that operative temperature will be available in a future release.

Status: Under Review
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