Dynamic Mesh for a Gear Pump
 

Hi all. My name is Alejandro Roger Ull. This spring I've been working on my final project for my aerospace engineering degree. I did a study on how to work with dynamic meshes in OpenFOAM, in particular for its application to a gear pump simulation. I want to share my work with you, so that anyone that may find it helpful can access to it.

Gear Pump Animation

The work consists on meshing the geometry with snappyHexMesh in parallel and extruding it with extrudeMesh to make it two-dimensional. Then a custom boundary condition for the movement of the mesh is created. Finally the simulation is run in parallel, by generating an initial mesh, moving it as much as possible, up to acceptable limits of deformation, and finally replacing it with a new mesh. Everything is completely automated.

You can download the document here. (2.63 MB) (CC BY-NC-SA 3.0)
Also, all the files I used can be downloaded here. (9.12 MB) (CC BY-NC-SA 3.0)

If you have any comments feel free to post them here.

Hi TRT,
You did a good job and thanks for sharing. I am about to do a moving mesh simulation in ANSYS Workbench and I am new to it. So i am trying to gather some info. The gear pump u described is similar to what i am looking at, even though the principles are a bit different. I wanted to know whether you did a similar mesh in ANSYS Meshing?

Thanks!
Jimmy

Nice job, thank you for sharing!

Hey Jimmy, unfortunately I do not have a clue about how to do this with ANSYS Workbench, so I can't help you. Thanks for your interest anyways.

Hi Jimmy, you may want to look at http://www.adina.com/newsgH107.shtml for a FSI gear pump analysis

So can ADINA simulate the inner flow of gear pump in 3D?

Gear Pump analysis
 

Hi shanxuewenjdx, Yes it can. The other examples on the webpage are 3D eg the flow meter. Exactly the same capabilities are used.

hello Alejandro
could yu please send me the complete pdf?
thanks.
force.of.love@gmail.com

There is a download button on my first post, and then another one on the dropbox webpage (top right).

I am very happy to see your share, cause I'm going to do an analysis just like that, but I'm in China, there are some reasons to block me from downloading those files by clicking the URL you give, would you please send me the PDF and case files in a zip?

My email: jianli.bjfu@163.com

Thank you!

hi,
can you send your results to me?
I need it immediately for my final project.
kind regards,
behnam Akhoondian
b.akhoondian@gmail.com

hi sparkbjfu,
did U finished your project? if U completed it,can you tell me how you changed the trt's geometry to your own geometry?
best regards,

Nice work!

Thank you for sharing!

Gear pump and moving mesh tutorial with custom BC
 

Excellent tutorial, you even go through the stumbling blocks in the process. Thank you very much for sharing

Hi Alejandro Roger Ull,

I was curious if the same problem can be solved using immersed boundary method in openFoam?

Thank you for sharing.

I know little about the immersed boundary method (I've only read about it because of your post), but, as far as I know, I don't think it will work. It seems to me that the immersed boundary method is useful when your boundary moves because of the flow, in response to fluid forces (correct me if I'm wrong). But in this case the movement of the gears is known.

Also, take into account that the movement involved in the gear pump is so extreme that probably re-meshing is always needed at some point. You can try to separate the zone with large movements from other steady zones and then stick them together, so that you only have to re-mesh a smaller volume, in order to use less computational power.

Thank you all for your interest in my work.

Alejandro

Hi,

I was curious because Ansys CFX uses the immersed boundary method to solve for flows around a lobe compressor which is basically same as a gear pump.

Anyway, that project is scrapped now since OpenFOAM doesn't support immersed boundary methods.

Hi TRT,

do you think that this will work for complex 3D simulations too? Its kind a hard work for such a job. I am interested in simulation of screw blower...


http://www.industriezeitschrift.de/g...er_element.jpg

Dropbox took the link for the PDF down due to a Dropbox vulnerability. You can find the PDF on the website of my University:

http://upcommons.upc.edu/pfc/bitstre...9/1/memory.pdf

May a moderator edit the first post to reflect this change? Thanks

Alejandro

Done!

Although if Dropbox has a vulnerability with PDF files... this is a bit annoying :(

Thanks a lot.

It was a privacy issue. If you clicked a link in a PDF (or other kind of shared file in Dropbox) the website linked could obtain the shared link and access the file.

More info: https://blog.dropbox.com/2014/05/web...-shared-links/

Taimoor
 

I wrote ./runAllMesh in the terminal window but it syas that the permission is denied. As I am new to OpenFOAM so need some help over here. ANybody available for helping me out?

Struggling with commands in the terminal window
 

Help required please!!! I changed the working directory in the terminal window to gearMain, and wrote chmod +x ./runAllMesh, but nothing happens. It simply goes to the next line. I was expecting it to take some time for mesh generation. Similarly, after performing the above command, I wrote chmod +x ./runAllMove and chmod +x ./runAllPimple but nothing happens. ANy ideas as to what is going on? Regards.

The chmod +x command only adds execution permissions to the files, so that you can now run them by typing:

./runAllMesh (for instance)

This is good reading about the Linux terminal:
http://www.howtogeek.com/140679/begi...inux-terminal/ (more links in the article)
http://lifehacker.com/5743814/become...ving-shortcuts

Keep in mind that I started using Linux 2 years before this project was started, it takes some time to get used to the terminal, but after you learn it, it is extremely useful.

Dear Alejandro, thanks a lot for your reply. I have started reading the the information provided on these links. By the time, I used chmod for permission, and then used ./runAllMesh but it gives a list of errors (please see the attachment). It seems that there is something related to the structure of the folders. Best Regards.

The "folder exists" warning is not a problem. But you need to do the chmod thing on every executable, it's because of this that you are getting the "permission denied" error.

But you really need more practice on your own if you are having trouble with this.

Dear Alejandro, If you see the snapshot that I attached in my previous post, I have indeed used chmod command before ./runAllMesh but it gave me errors mentioned. I have tried it a few more times now, also tried to get information online as to what is the problem, but still getting the same errors.

I'm in china too, and I need these files for my work to study this dynamicMesh, can you send it to me!
wwb@sjtu.edu.cn Thank you!

Thank you Alejandro for your generous contribution! Your work has helped me tremendously.

Miha

Hi Tobi,

Did you ever end up doing any simulations of a screw blower?
I would be interested to know what approach you ended up taking.

Thanks,
Pasi

Hi Alejandro.

Did you worked with internal walls? I'm trying to place baffles in a 2D axisymmetric clarifier using extrudeToRegionMesh, but it doesn't work. If I use extrudeMesh the internal walls disappear.

Thank you so much

[QUOTE=TRT;368540]Hi all. My name is Alejandro Roger Ull. This spring I've been working on my final project for my aerospace engineering degree. I did a study on how to work with dynamic meshes in OpenFOAM, in particular for its application to a gear pump simulation. I want to share my work with you, so that anyone that may find it helpful can access to it.

Gear Pump Animation

The work consists on meshing the geometry with snappyHexMesh in parallel and extruding it with extrudeMesh to make it two-dimensional. Then a custom boundary condition for the movement of the mesh is created. Finally the simulation is run in parallel, by generating an initial mesh, moving it as much as possible, up to acceptable limits of deformation, and finally replacing it with a new mesh. Everything is completely automated.

You can download the document here. (2.63 MB) (CC BY-NC-SA 3.0)
Also, all the files I used can be downloaded here. (9.12 MB) (CC BY-NC-SA 3.0)

Are the case files still available in 2021?! Stumbled on this fine work but now deleted from the dropbox link..

Hi James Willie,this is a meesage from 2021,could you please send TRT's gear pump files to me?Cause the dropbox he gave was out of date...I wonder if you downloaded it previously.:p:p:p

Do you mean the gear pump tutorial for OpenFoam? I can share it with you if you send me your email address.


Thanks!
James

Thank you so much James！My email is gwf-1000rd@outlook.com

I'm interested as well please! djasonmorg@yahoo.co.uk.

Thanks in advance

Hi can you send me the files please? carlosexequiel.a.s@gmail.com

Hi, can anyone just post the tutorial files here so that everyone can download?