How to simulate a water turbine?

macRC · February 10, 2015, 09:53

Hi,

I´m thinking about CFD-simulating a Kaplan turbine in OpenFOAM 2.3.0 in the frame of my master thesis (I`m studying Energie technology and Energy business). Maybe you can helb me with my decision. In my institute, we already have got a CAD model, which I can use for the geometry. (stl, snappyhex). For simulating I can probably use a 16 CPU Intel Xoen.

So my first question is, is it possible at all? Is it the worth effort?

If yes, which solver can you recommend? I´ve read about the pimpleDyMFoam, but is this the only one?

Which tutorial would you suggest?

How to handle the problem with cavitation? Or would you suggest a one phase case?

Maybe you even can gibe me some literatur? So far I´ve just found something about a Pelton turbine.
Thanks for your held in advance.

Best regards, Dominik

Blanco · February 11, 2015, 07:29

Hi macRC,

I'm not an expert in water turbine sim. but I think you will find useful the "Full OpenFOAM validation test cases" section at the following link

HTML Code:

https://openfoamwiki.net/index.php/Sig_Turbomachinery_/_Validation_test_cases

You can find some OF literature also at this link

HTML Code:

https://openfoamwiki.net/index.php/Sig_Turbomachinery_/_Publications

but unfortunetely many links are broken, you have to ask google to find them.

Hope this could help you to start your work.

Regards

macRC · February 17, 2015, 17:33

Hi Blanco,

thanks a lot for your very helpful response. There are some really interesting links!

Here is another link, which really helps me a lot!!

http://de.slideshare.net/fumiyanozak...using-openfoam

Thus, I decided to write my thesis about water turbine CFD-Simulation. I´m looking forward to.

macRC · March 12, 2015, 07:46

cheers,

oh yes, there is a lot to do

I decided to apply the frozen rotor methode (simplefoam + fvsolutions) due to a limited CPU power of course.

at the moment my two mayor problems are the following:

- How to determine and implement the MRFZone (rotor) and its patches? AMI, GGI, cellZone, which dicts (blockmesh, mapFields, TopoSet...) and so on. Which dicts do I have to apply? There are so many things to observe and at the moment I don´t have got an idea

- Can I take into account the gravitation in simplefoam? I think at first I have to change the solver, am I right?

Thanks in advance for your answers.
Best regards, Dominik

macRC · April 13, 2015, 08:42

Hi Foamers,

here is my first result.

Approch:
- Frozen Rotor
- Full Whell
- Single Mesh Region
- single Phase (water)

Methodology:
- Creating stl-Files via GMsh
- blockmesh
- snappyhexmesh (importing stl-Files)
- Creating MRF Zone via toposetDict
- Solver: Simplefoam (+ fvoptions)

Checkmesh:
1.7 Mio cells, Mesh ok (expected some Screwness, but doesn´t matter)

Residuals:
Unfortunately I still don´t have got the plot, but after 1000 iterations less than 10e-5.

My next challenges are:
- Improving mesh
- How to define MRF Zone optimally?
- How to change/ optimize the inlet area?
- How to compute the Rotor torque?

I would be happy, if somebody can help me.

Best regards and have a nice day.
Dominik

aminem · April 13, 2015, 10:18

Hi,

For mesh you can use cfMesh. I find him better than snappyHexMesh.

You can generate MRF zones by using setSet and setsToZones

Thanks

macRC · April 13, 2015, 11:59

Hi aminem,

thanks for your reply.
I already generated the MRF Zone with toposet (toposet is the "new" setset).
My question is basically, where to set the borders of the frozen rotor zone, how large should it be respectively.

br

aminem · April 14, 2015, 11:06

There are no general rule. You can use an MRF area with a diameter of 6.5 cm if your turbine is a diameter of 6 cm. The variation of the diameter of the MRF area doesn't change results (test performed for speeds below 200 rpm)

morteza 1374 · April 4, 2016, 03:24

hi
I am the student of fluid mechanics and now I am studying on fluid project. The subject of my project is about blade turbine that Oil radially impacts to the turbine blades by a nozzle, causing the turbine to spin. I have a problem in modeling of turbine that I don’t know how to obtain moment of inertia of blade and fluid and how to relate this challenge to the Cg motion until I can model this turbine in fluent software. Please help me
Thank for your attention

February 10, 2015, 09:53	How to simulate a water turbine?	#1
macRC New Member Domi Join Date: Feb 2015 Posts: 26 Rep Power: 11	Hi, I´m thinking about CFD-simulating a Kaplan turbine in OpenFOAM 2.3.0 in the frame of my master thesis (I`m studying Energie technology and Energy business). Maybe you can helb me with my decision. In my institute, we already have got a CAD model, which I can use for the geometry. (stl, snappyhex). For simulating I can probably use a 16 CPU Intel Xoen. So my first question is, is it possible at all? Is it the worth effort? If yes, which solver can you recommend? I´ve read about the pimpleDyMFoam, but is this the only one? Which tutorial would you suggest? How to handle the problem with cavitation? Or would you suggest a one phase case? Maybe you even can gibe me some literatur? So far I´ve just found something about a Pelton turbine. Thanks for your held in advance. Best regards, Dominik

February 11, 2015, 07:29		#2
Blanco Senior Member Blanco Join Date: Mar 2009 Location: Torino, Italy Posts: 193 Rep Power: 17	Hi macRC, I'm not an expert in water turbine sim. but I think you will find useful the "Full OpenFOAM validation test cases" section at the following link HTML Code: https://openfoamwiki.net/index.php/Sig_Turbomachinery_/_Validation_test_cases You can find some OF literature also at this link HTML Code: https://openfoamwiki.net/index.php/Sig_Turbomachinery_/_Publications but unfortunetely many links are broken, you have to ask google to find them. Hope this could help you to start your work. Regards

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February 17, 2015, 17:33		#3
macRC New Member Domi Join Date: Feb 2015 Posts: 26 Rep Power: 11	Hi Blanco, thanks a lot for your very helpful response. There are some really interesting links! Here is another link, which really helps me a lot!! http://de.slideshare.net/fumiyanozak...using-openfoam Thus, I decided to write my thesis about water turbine CFD-Simulation. I´m looking forward to.

March 12, 2015, 07:46		#4
macRC New Member Domi Join Date: Feb 2015 Posts: 26 Rep Power: 11	cheers, oh yes, there is a lot to do I decided to apply the frozen rotor methode (simplefoam + fvsolutions) due to a limited CPU power of course. at the moment my two mayor problems are the following: - How to determine and implement the MRFZone (rotor) and its patches? AMI, GGI, cellZone, which dicts (blockmesh, mapFields, TopoSet...) and so on. Which dicts do I have to apply? There are so many things to observe and at the moment I don´t have got an idea - Can I take into account the gravitation in simplefoam? I think at first I have to change the solver, am I right? Thanks in advance for your answers. Best regards, Dominik

April 13, 2015, 10:18		#6
aminem Member amine Join Date: Jan 2014 Location: FRANCE Posts: 84 Rep Power: 12	Hi, For mesh you can use cfMesh. I find him better than snappyHexMesh. You can generate MRF zones by using setSet and setsToZones Thanks

April 13, 2015, 11:59		#7
macRC New Member Domi Join Date: Feb 2015 Posts: 26 Rep Power: 11	Hi aminem, thanks for your reply. I already generated the MRF Zone with toposet (toposet is the "new" setset). My question is basically, where to set the borders of the frozen rotor zone, how large should it be respectively. br

April 14, 2015, 11:06		#8
aminem Member amine Join Date: Jan 2014 Location: FRANCE Posts: 84 Rep Power: 12	There are no general rule. You can use an MRF area with a diameter of 6.5 cm if your turbine is a diameter of 6 cm. The variation of the diameter of the MRF area doesn't change results (test performed for speeds below 200 rpm)

April 4, 2016, 03:24		#9
morteza 1374 New Member mortezasekaloo Join Date: Apr 2016 Posts: 4 Rep Power: 10	hi I am the student of fluid mechanics and now I am studying on fluid project. The subject of my project is about blade turbine that Oil radially impacts to the turbine blades by a nozzle, causing the turbine to spin. I have a problem in modeling of turbine that I don’t know how to obtain moment of inertia of blade and fluid and how to relate this challenge to the Cg motion until I can model this turbine in fluent software. Please help me Thank for your attention