Verification of butterfly in indoor thermal environment simulation

indoor-temperature

#1

does any one tried to verify BF on indoor thermal environment simulation ?comparing the result with fluent or experimental result?


#2

Hi @WuXue,

Verifying BF against other results from fluent or experimental measurements is exactly the same with verifying OpenFOAM against fluent or experimental measurements. While there are not, yet at least, any such studies using BF there are numerous studies for OF and other software.

Kind regards,
Theodore.


#3

it’s such a surprise to receive your reply so quickly, thank you very much.
i got what you mean and searched studies about CFD simulation, i found that most cases used OF are outdoor wind environment, so is it appropriate and promising using BF to study indoor thermal environment?


#5

Well, of course OpenFOAM can be used or indoor thermal calculations, though it is advised to do some research and dig a little bit deeper into the theory of CFD. It depends on the detail, size and setup of your model, but indoor meshes can get quite large-ish and you need to make sure it is of good quality, which not only depends on cell size…
I used OF in my Master’s thesis a few years ago and compared several simulations to measurements from two different (2D-)testcases and depending on mesh quality and other factors like turbulence model, solver, physical properties like radiation etc. you can get good results compared to measurements (see attached plots of some simulation runs…)


Unfortunately, CFD (especially when using OF) is far from bein a one-click-method to obtain meaningful results…


#6

@AlbertPressler, is your thesis available online? We can learn a lot from your insight on setting up the default values for boundary conditions, etc.


#7

@mostapha sorry but it’s not available online and also it is written in German, so I guess ther won’t be many people here being able to enjoy it :wink: It basically only deals with trying to validate those two 2D-testcases in one part and with showing the OF-workflow using a (commercial) GUI in the other part.
But if I can be of any help, of course I’m happy to contribute if I can. I’ve been doing some more complex simulations since my thesis…


#8

hi @AlbertPressler

Thanks for sharing the results.

I’ve been using k-epsilon on a regular basis, for indoor heat transfers I’ve been trying to use k-OmegaSST in order to cope with near wall treatment, though I haven’t been able to set meaningful results for Omega. Could you recommend some litterature or papers or rule of thumb?

Cheers


#9

Well I have a ton of material lying on my drive regarding CFD and especially room air flows (many papers, guides etc.) I’ll see if I can curate some pieces. Additionally I could dump all that stuff in a Dropbox and share it if you are interested.


#10

dying to read all of it… to be totally honest.

big cheers


#11

Ok I’ve put together some papers and guides regarding indoor and outdoor CFD that I’ve found on my laptop. Probably haven’t read them all, but there’s some quite interesting stuff in there. Some material on turbulence models, validation, natural ventilation, thermal manikins, ventilation effectiveness etc.

check here:
https://drive.google.com/open?id=1r3nImlVOKHxVG67CfMBfSw3OAU1KA-j4

cheers


#12

Thanks @AlbertPressler!


#13

Thanks @AlbertPressler! We will bug you with some questions when we get back to do another round of development for Butterfly. I was hoping to do it before the London workshops but it’s not going to happen.


#14

Alright @mostapha, no problem! Good luck for the workshops!