Equation for Rayleigh number in LH2Simulate.m

[SSavelyeva]

Dear researchers, thank you very much for publishing the simulation code!
I have a question conserning the formula for the Rayleigh number in LH2Simulate.m file (for example, in line 409):

Maybe I have missunderstood something, but could it be possible that in this equation the kinematic viscosity should be squared? I found the following equation for the Rayleigh number:

Please correct me if I am wrong.
Thank you very much in advance!

[db-code-rabbit]

Indeed 👍

[matrix7956]

Hello @db-code-rabbit and @SSavelyeva I need your help.
I am referring from "Boil-off losses along LH2 pathway ,G. Petitpas, May 2, 2018." from where I got the access to this code. After running the code my all results are getting matched except the heat transfer to liquid phase. I am attaching the literature as well as the compared results. Please can I get your inputs?

[https://drive.google.com/file/d/1p0zxnYC0EA0d2Dq9DoG9NP_nrhJ-gQ7-/view?usp=sharing] (THE LITRETAURE)
[[https://docs.google.com/presentation/d/1Rg2a5tc9flVrPUEXgWY4K59Mft_JdaiU/edit?usp=sharing&ouid=113248310358927375119&rtpof=true&sd=true] (THE COMPARISON )

Thanks for your time!

[db-code-rabbit]

Hello @db-code-rabbit and @SSavelyeva I need your help. I am referring from "Boil-off losses along LH2 pathway ,G. Petitpas, May 2, 2018." from where I got the access to this code. After running the code my all results are getting matched except the heat transfer to liquid phase. I am attaching the literature as well as the compared results. Please can I get your inputs?

[https://drive.google.com/file/d/1p0zxnYC0EA0d2Dq9DoG9NP_nrhJ-gQ7-/view?usp=sharing] (THE LITRETAURE) [[https://docs.google.com/presentation/d/1Rg2a5tc9flVrPUEXgWY4K59Mft_JdaiU/edit?usp=sharing&ouid=113248310358927375119&rtpof=true&sd=true] (THE COMPARISON )

Thanks for your time!

Hello @matrix7956. Regarding the heat transfer to the liquid phase. Start correcting the expression of the Rayleigh number in the code. there are some errors in the code as already noticed above. Take the time to look at the physics and correlations used by the author.

As you have already been advised, use this code as a basis (to improve or modify it) for your physical problem to study.

[matrix7956]

Hello @db-code-rabbit and @SSavelyeva I need your help. I am referring from "Boil-off losses along LH2 pathway ,G. Petitpas, May 2, 2018." from where I got the access to this code. After running the code my all results are getting matched except the heat transfer to liquid phase. I am attaching the literature as well as the compared results. Please can I get your inputs?
[https://drive.google.com/file/d/1p0zxnYC0EA0d2Dq9DoG9NP_nrhJ-gQ7-/view?usp=sharing] (THE LITRETAURE) [[https://docs.google.com/presentation/d/1Rg2a5tc9flVrPUEXgWY4K59Mft_JdaiU/edit?usp=sharing&ouid=113248310358927375119&rtpof=true&sd=true] (THE COMPARISON )
Thanks for your time!

Hello @matrix7956. Regarding the heat transfer to the liquid phase. Start correcting the expression of the Rayleigh number in the code. there are some errors in the code as already noticed above. Take the time to look at the physics and correlations used by the author.

As you have already been advised, use this code as a basis (to improve or modify it) for your physical problem to study.

Hello @db-code-rabbit
I did try correlating some formulas and still trying as I am beginner in MATLAB. I tried changing Rayleigh number and run the code but was not able to match the heat transfer to liquid phase result. I am matching the results because I want to validate the code with the provided results from literature(as I got the access from that ) and once validated I can modify it according to my physical problem.
It would be great help if you give me some inputs or help me in matching HT to liquid phase
Thankyou so much for your time @db-code-rabbit

[db-code-rabbit]

Hello @matrix7956, Have you fixed your heat transfer problem in the liquid phase at the trailer, found by comparing the results of the published code and the authors's paper.

First of all, Sorry for my reply time. So I have had time to look at the Code and as I previously said, there are some errors in the correlations used to calculate the heat transfer in the different tanks.

At least I think so! To be confirmed or denied by the authors of the published code.

But, by fixing these errors, I didn't get exactly the presented results in the paper of authors. We get the same trend of heat transfer in the liquid phase, but unfortunately, not the same magnitude values.

Below, the image results after modifications.
Ps : I obtained the same results like you by compiling the Code without modification

LiquidPhase.pdf
GasPhase.pdf

[db-code-rabbit]

Hello @db-code-rabbit and @SSavelyeva I need your help. I am referring from "Boil-off losses along LH2 pathway ,G. Petitpas, May 2, 2018." from where I got the access to this code. After running the code my all results are getting matched except the heat transfer to liquid phase. I am attaching the literature as well as the compared results. Please can I get your inputs?
[https://drive.google.com/file/d/1p0zxnYC0EA0d2Dq9DoG9NP_nrhJ-gQ7-/view?usp=sharing] (THE LITRETAURE) [[https://docs.google.com/presentation/d/1Rg2a5tc9flVrPUEXgWY4K59Mft_JdaiU/edit?usp=sharing&ouid=113248310358927375119&rtpof=true&sd=true] (THE COMPARISON )
Thanks for your time!

Hello @matrix7956. Regarding the heat transfer to the liquid phase. Start correcting the expression of the Rayleigh number in the code. there are some errors in the code as already noticed above. Take the time to look at the physics and correlations used by the author.
As you have already been advised, use this code as a basis (to improve or modify it) for your physical problem to study.

Hello @db-code-rabbit I did try correlating some formulas and still trying as I am beginner in MATLAB. I tried changing Rayleigh number and run the code but was not able to match the heat transfer to liquid phase result. I am matching the results because I want to validate the code with the provided results from literature(as I got the access from that ) and once validated I can modify it according to my physical problem. It would be great help if you give me some inputs or help me in matching HT to liquid phase Thankyou so much for your time @db-code-rabbit

Hello @matrix7956, Have you fixed your heat transfer problem in the liquid phase at the trailer, found by comparing the results of the published code and the authors's paper.

First of all, Sorry for my reply time. So I have had time to look at the Code and as I previously said, there are some errors in the correlations used to calculate the heat transfer in the different tanks.

At least I think so! To be confirmed or denied by the authors of the published code.

But, by fixing these errors, I didn't get exactly the presented results in the paper of authors. We get the same trend of heat transfer in the liquid phase, but unfortunately, not the same magnitude values.

Below, the image results after modifications.
Ps : I obtained the same results like you by compiling the Code without modification

LiquidPhase.pdf
GasPhase.pdf

[matrix7956]

Hello @db-code-rabbit and @SSavelyeva I need your help. I am referring from "Boil-off losses along LH2 pathway ,G. Petitpas, May 2, 2018." from where I got the access to this code. After running the code my all results are getting matched except the heat transfer to liquid phase. I am attaching the literature as well as the compared results. Please can I get your inputs?
[https://drive.google.com/file/d/1p0zxnYC0EA0d2Dq9DoG9NP_nrhJ-gQ7-/view?usp=sharing] (THE LITRETAURE) [[https://docs.google.com/presentation/d/1Rg2a5tc9flVrPUEXgWY4K59Mft_JdaiU/edit?usp=sharing&ouid=113248310358927375119&rtpof=true&sd=true] (THE COMPARISON )
Thanks for your time!

Hello @matrix7956. Regarding the heat transfer to the liquid phase. Start correcting the expression of the Rayleigh number in the code. there are some errors in the code as already noticed above. Take the time to look at the physics and correlations used by the author.
As you have already been advised, use this code as a basis (to improve or modify it) for your physical problem to study.

Hello @db-code-rabbit I did try correlating some formulas and still trying as I am beginner in MATLAB. I tried changing Rayleigh number and run the code but was not able to match the heat transfer to liquid phase result. I am matching the results because I want to validate the code with the provided results from literature(as I got the access from that ) and once validated I can modify it according to my physical problem. It would be great help if you give me some inputs or help me in matching HT to liquid phase Thankyou so much for your time @db-code-rabbit

Hello @matrix7956, Have you fixed your heat transfer problem in the liquid phase at the trailer, found by comparing the results of the published code and the authors's paper.

First of all, Sorry for my reply time. So I have had time to look at the Code and as I previously said, there are some errors in the correlations used to calculate the heat transfer in the different tanks.

At least I think so! To be confirmed or denied by the authors of the published code.

But, by fixing these errors, I didn't get exactly the presented results in the paper of authors. We get the same trend of heat transfer in the liquid phase, but unfortunately, not the same magnitude values.

Below, the image results after modifications. Ps : I obtained the same results like you by compiling the Code without modification

LiquidPhase.pdf GasPhase.pdf

Hello @db-code-rabbit
Thanks for replying. I tried many things but I was not able to match the tread line too. then I assumed REFPROP version plays major role(I feel this is the issue). because I am using REFPROP-7 and in the literature its REFPROP-9.1.
If you don't mind could you please tell what changes can I make or you could share the required edited code files to match the tread line I mean to get the results which you have got.
It would be a great help
Thankyou so much for investing your time.

[db-code-rabbit]

Hi @matrix7956,
Sorry for the delay. I will propose a new version of LH2Simulate.m with these minor modifications...

[matrix7956]

Hi @matrix7956, Sorry for the delay. I will propose a new version of LH2Simulate.m with these minor modifications...

Hello,
No issues Thankyou so much for replying and putting you time. or else you can share drive link.

[matrix7956]

@db-code-rabbit Hello
Could you share it, please?

[db-code-rabbit]

@matrix7956 Hello,
below is the link of the new release of the LH2TS Code. test it by following the instructions and tell me if it works correctly (numerically).
Release of LLNL-LH2Transfer

[matrix7956]

@db-code-rabbit Thankyou. means a lot .yes I will test it and get back.

[db-code-rabbit]

@matrix7956 Have you tested it , finally?

[matrix7956]

@matrix7956 Have you tested it , finally?

Hello @db-code-rabbit
yes i tested its working fine. Thankyou so much for helping me out. Currently i am working on my own problem statement i will let you know if any doubts.

[datum12345]

I, too, was unable to match the heat transfer in the vapor phase and the liquid phase using the old version of the code. Now, I will try the new version as suggested by @db-code-rabbit. I will update about the outcome. Thanks for sharing the code.

[datum12345]

@db-code-rabbit results of heat transfer in the vapor phase and the liquid phase are entirely different from the published paper with the new version of the code. Not matching well.

[datum12345]

On the Y-axis values are significantly large.