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-   -   UDF for Hydrogen Storage in Porous Media (http://www.cfd-online.com/Forums/fluent-udf/106969-udf-hydrogen-storage-porous-media.html)

er.mkumar September 13, 2012 12:07

UDF for Hydrogen Storage in Porous Media
 
Dear All,

I have been working on this problem for 2 months now. Having gone through many posts on this forum has definitely increased my understanding but yet I have not been able to solve my problem.

Kindly help !
------------------------------------------------------------------------
My problem : A unsteady state model

1) An annular cylinder filled with porous media (por = 0.5) which shall store Hydrogen as Metal Hydride.
2) Hydrogen enters through inner mantle area @ fixed pressure of 10 Bar say (how do one fix this inlet condition).
3) There is heat generation term which is dependent upon rate of reaction (dx/dt where 'x' is concentration at adjacent 'time-step'; I'm using [ C_UDSI(c,t,0) - C_UDSI_M1(c,t,o) ] to find out 'dx' part).
4) Outer surface has Convective boundary condition to dissipate heat generated.

Help:
1) How to fix inlet pressure criteria fixed @ say 10 Bar
2) How to be sure that there is no major pressure drop in the model. (I tried various models: pressure inlet, velocity, mass flow rate; But none showed my actual pressure at inlet while post-processing.
3) Post processing : How to track temp, pressure & rate of advancement (I'm using 'mass weighted avg' type for tracking these changes usinging surface monitors by selecting 'default interior' )

--------------------------------------------------------------------------
Seeking desperate help !

With Warm regards,
Mukesh

karl fisher October 13, 2012 07:39

hi, contact me by SKYPE : Charles Fishmann or by email : k.lahmer77@gmail.com
Because i have lot of documents for you

Regards

mdarzy January 2, 2013 15:56

Metal Hydride simulation
 
Dear Mkumar,
have you simulated the absorption process in metal hydride tank with Fluent code?
I am working on it, I am going to simulate the tank with novel heat exchanger for cooling. I wrote a udf for mass and heat source but I could not validate my result with others which are published in journals. if you have simulated and validated any case, Please inform me. I can send my UDF to you.
Best,
Mojtaba

mdarzy January 2, 2013 16:04

Metal Hydride simulation
 
Dear Mkumar,
have you simulated the absorption process in metal hydride tank with Fluent code?
I am working on it, I am going to simulate the tank with novel heat exchanger for cooling. I wrote a udf for mass and heat sources but I could not validate my result with others which are published in journals. if you have simulated and validated any case, Please inform me. I can send my UDF to you.
Best,
Mojtaba

er.mkumar January 3, 2013 01:45

Mr. Darzi,

Yes I did managed to simulate the H2 storage using fluent with the help of UDF. But My results were not exactly in sync with results of published journal i.e. the maximum temperature observed with my simulation were less than those published although my UDF did gave similar pattern. Uptill now I am yet to figure out what's missing as I believe I am moving correctly. let's see how it pans out. keep trying.

I would be happy to bring correction to your UDF if at all I may.

Regards,
Mukesh

mdarzy January 3, 2013 07:03

Mh run
 
Dear MKumar,
the temperature in my result reaches to maximum temperature which has given in other works (Jemni or Arvind phate). my problem is related to reaction rate that cause to absorb the hydrogen in shorter time and susequently the temperature fall down in eralier time (after 600s) while it should decrease after (3000s). I think we can work together. what do you think?
could you give me your email address? OR
My email address is m.darzy@gmail.com. could you send an email to this address, please?
I can send my udf and case and data to you. or you send to me your udf......
Best,

jehadyam January 30, 2013 01:28

I need to start my grad project in same area of Hydrogen metal hydride.
 
My project is concerned with using 3 different materials and comoare their relative performance.
Is there anyone who can help.
I have little time and have just started the ANSYS learning yesterday!!!
Best regards to all. and Thanks in advance.

er.mkumar January 31, 2013 03:08

Jehad,
From what you have mentioned it's not clear what you intend to do.
All I can say is yes if you try sincerely you can work and get the results.
Have patience.

Best of Luck!

Mukesh

jehadyam January 31, 2013 12:12

Thank you Eng Mukesh.
My project is only related to testing the storage capacity of three different materials under varying inlet pressures and cooling temperatures.
With 2 months in hand and just starting to learn ANSYS, i think i only need a start.
All the materials in the net and tutorials depend on loading ready
made mesh geometries, rather than telling how they were made.
If there is any FORTRAN, MATLAB or any code i will be grateful.
Thanks for your kind reply.

er.mkumar January 31, 2013 17:10

Dear Jehad,

Yes you can carry out the comparision of storage capacity of different materials provided you have got the necessary proprties of the material.

You have to write UDF for the source terms.
You can refer to one of the UDF codes I have posted on the forum.
Please search....hydrogen storage

Regards,
Mukesh

er.mkumar January 31, 2013 17:21

You can refer to Cornell University tutorials on Fluent analysis:
That's a very good site to get a good understanding on mesh generation and solution in FLUENT.

https://confluence.cornell.edu/displ...arning+Modules

Please have patience to go through all the tutorials and be assured you will feel confident to work on fluent within a weeks time. One tutorial a day is sufficient.

Sorry I haven't worked on MATLAB or FORTRAN with this problem.
Best of Luck

Regards,
Mukesh


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