# dimensional or dimensionless?

 Register Blogs Members List Search Today's Posts Mark Forums Read

 July 28, 2012, 17:29 dimensional or dimensionless? #1 Member   Amin Join Date: Mar 2012 Posts: 60 Rep Power: 12 Hi Foamers can some1 clear this for me plz: is OpenFoam a dimensional solver? or dimensionless solver like fluent?

 July 29, 2012, 09:45 #2 Senior Member   Nima Samkhaniani Join Date: Sep 2009 Location: Tehran, Iran Posts: 1,265 Blog Entries: 1 Rep Power: 23 fluent is dimensionless solver? however OpenFOAM, check dimensions, and its dimensional solver without doubt

 July 29, 2012, 14:47 #3 Member   Amin Join Date: Mar 2012 Posts: 60 Rep Power: 12 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

 July 29, 2012, 15:50 #4 Senior Member     A_R Join Date: Jun 2009 Posts: 122 Rep Power: 15 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 likes this.

 July 30, 2012, 08:37 #5 Member   Amin Join Date: Mar 2012 Posts: 60 Rep Power: 12 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?

July 30, 2012, 14:27
#6
Senior Member

A_R
Join Date: Jun 2009
Posts: 122
Rep Power: 15
Quote:
 Originally Posted by amin66 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.

 August 1, 2012, 09:20 #7 Member   Amin Join Date: Mar 2012 Posts: 60 Rep Power: 12 Thank you so much