[omid20110]

Hello everybody
May anyone read this:
https://bugs.openfoam.org/view.php?id=2773

And tell me what's wrong with my case as chris mentioned there?

[RobertHB]

Point 1: The site bugs.openfoam is supposed to be used for reporting bugs and not, as in your case, questions about having problems with setting up a case. (chris 2017-11-28 19:19)

Point 2: Your case is the problem, not the software. As such you wont get support there and no one overthere will bother with your case (chris 2017-11-29 13:36)

[wyldckat]

Greetings to all!

When in doubt about a bug and if you cannot hire commercial support, then you can always try asking here on the public forums.

As I've indicated on the bug report:

Therefore, in order to isolate the origin of the problem, a complete case that has the full cylinder is also needed for comparing the results and what is happening.

This would make it a lot easier to figure out where the problem is coming from, either from a problem with using an asymmetrical configuration or because of there could be a bug in OpenFOAM.

Now, even if the objective is to speed up the simulation, jumping directly into the final case configuration is just not a good idea. This is OpenFOAM (although the same can happen with any CFD tool), you should always take small steps when creating a case, specially if you are not yet familiar with what you're doing.


My first guess without looking at the case, is that the direction of the injection does not match the direction of the axis.


I've now taken a look at the case... @omid20110: What exactly were you expecting when using the following entry in "sprayCloudProperties.subModels.injectionModels.mo del1":

flowType        pressureDrivenVelocity;

And then forgetting to have any velocity or pressure difference in the "0" folder?

If I'm interpreting this correctly, it's as if you forgot to turn on the fan and expect it to work. No wonder people were upset with your bug report

Best regards,
Bruno

[omid20110]

Originally Posted by wyldckat

Greetings to all!

When in doubt about a bug and if you cannot hire commercial support, then you can always try asking here on the public forums.

As I've indicated on the bug report:

This would make it a lot easier to figure out where the problem is coming from, either from a problem with using an asymmetrical configuration or because of there could be a bug in OpenFOAM.

Now, even if the objective is to speed up the simulation, jumping directly into the final case configuration is just not a good idea. This is OpenFOAM (although the same can happen with any CFD tool), you should always take small steps when creating a case, specially if you are not yet familiar with what you're doing.


My first guess without looking at the case, is that the direction of the injection does not match the direction of the axis.


I've now taken a look at the case... @omid20110: What exactly were you expecting when using the following entry in "sprayCloudProperties.subModels.injectionModels.mo del1":

flowType        pressureDrivenVelocity;

And then forgetting to have any velocity or pressure difference in the "0" folder?

If I'm interpreting this correctly, it's as if you forgot to turn on the fan and expect it to work. No wonder people were upset with your bug report

Best regards,
Bruno

Hello dear Bruno,
Thanks for replying (although it's a little bit late )
First of all I should tell that I had run the case with a full cylinder and the problem was solved! Now I'm using a 30 degree vector of that cylinder (3D case) for my simulations and again the problem is solved and I'm sure that the problem is due to using a wedge case and boundary conditions!

Yes the flow type in the spray cloud properties is pressureDrivenVelocity and because of this I have specified a P_inj there!

Also about this problem...One of my friends had run the 2D(wedge) case with dieselFoam and didn't face this type of problem!

[wyldckat]

Quick answers:

Originally Posted by omid20110

First of all I should tell that I had run the case with a full cylinder and the problem was solved! Now I'm using a 30 degree vector of that cylinder (3D case) for my simulations and again the problem is solved and I'm sure that the problem is due to using a wedge case and boundary conditions!

I'm glad you've gotten the simulation to work with full and 30 degree cylinders! And you only changed the mesh and replace the wedge boundaries or did you need to change anything else?

Originally Posted by omid20110

Yes the flow type in the spray cloud properties is pressureDrivenVelocity and because of this I have specified a P_inj there!

That goes to show how little I know about this injection model

Originally Posted by omid20110

Also about this problem...One of my friends had run the 2D(wedge) case with dieselFoam and didn't face this type of problem!

With the same injector or a different injector? And did the case have an inlet and an outlet?

[omid20110]

Originally Posted by wyldckat

Quick answers:

I'm glad you've gotten the simulation to work with full and 30 degree cylinders! And you only changed the mesh and replace the wedge boundaries or did you need to change anything else?


That goes to show how little I know about this injection model


With the same injector or a different injector? And did the case have an inlet and an outlet?

In the 2D case I had created a wedge geometry (4 degrees) as described in OF user guide. Also I tried it with different mesh resolutions but it also didn't solve the problem.

Yes with the same injector. The case is a combustion chamber with an inlet and without any outlet. For more information you can check Sandia Spray H properties at this link:
http://www.ca.sandia.gov/ecn/cvdata/...h/frameset.php

I don't know what have been change in the sprayFoam compared to the dieselFoam that cause this type of problem in wedge 2d cases!