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-   -   dimensional or dimensionless? (http://www.cfd-online.com/Forums/openfoam/105367-dimensional-dimensionless.html)

amin66 July 28, 2012 16:29

dimensional or dimensionless?
 
Hi Foamers

can some1 clear this for me plz:
is OpenFoam a dimensional solver? or dimensionless solver like fluent?

nimasam July 29, 2012 08:45

fluent is dimensionless solver?
however OpenFOAM, check dimensions, and its dimensional solver without doubt

amin66 July 29, 2012 13:47

Thanks Nima
i think i couldn't ask my question in a good way!

my means was that if in simulation we want the Re=(u*d)/nu=180 , Can we set velocity(u), diameter(d) or nu in arbitary values to obtain Re=180 ?

means: is simulation with u=180 m/s , d=1 m , nu=1 same with simulation with u=180*10^-6 , d=1 , nu=10^-6 ????

Regards

niaz July 29, 2012 14:50

mathematically, yes. but by the view of numerical method, it maybe has differences for numerical methods used.
but I checked it for a single cylinder as a test case, I have got the same answers.
U=100, nu=1,<==>U=1,nu=0.01
but there is difficulty in convergence of answer in first test case.

amin66 July 30, 2012 07:37

Thanks niaz, was useful

So, i can change the values of air and water's properties in interfoam to obtain the Reynolds and Froude number that i want. and the only difficulty is convergence?

niaz July 30, 2012 13:27

Quote:

Originally Posted by amin66 (Post 374335)
Thanks niaz, was useful

So, i can change the values of air and water's properties in interfoam to obtain the Reynolds and Froude number that i want. and the only difficulty is convergence?

yes, but be careful, to change all parameters correctly manner.

amin66 August 1, 2012 08:20

Thank you so much


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