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October 18, 2009, 08:50 
Flow Past Cyilnder  Drag And Lift

#1 
Member
Primoz Ternik
Join Date: Apr 2009
Location: Maribor, Slovenia
Posts: 65
Rep Power: 8 
Hi all,
I know that there has been a lot of discussion on this subject, but I still miss the following for the flow (2D, laminar) past cylinder (circular, square):
Thanks in advance, Primoz. 

March 16, 2010, 13:49 

#2 
New Member
Evren
Join Date: Mar 2010
Posts: 20
Rep Power: 7 
Hi,
I don't know exactly but it should be the force calculated by using the pressure gradient. In this manner, it can be general if you don't consider viscoelastic forces. But some expert shall answer this question. I would like to ask some questions, why do you use simpleFoam? It's supposed to be for steadystate solver for incompressible turbulent Newtonian flows. Doesn't icoFoam work better for this case? Which reynolds number are you interested in and which geometry you're using. I am interested in your problem because I try to solve the same problem and I suggest to compare the results.??? Cheers, Evren 

March 18, 2010, 17:22 

#3  
Member
Primoz Ternik
Join Date: Apr 2009
Location: Maribor, Slovenia
Posts: 65
Rep Power: 8 
Quote:
thank you for your answers! Regarding the forces  in lift & drag calculation there are two components that contribute! One is due to the pressure (pressure lift and drag) and the other is due to the viscous forces (viscous drag and lift). Why I am using simpleFoam? I found it nice (gives good results) for laminar and steady flow of nonNewtonian fluids! Of course, you have to set the "RASmodel" to laminar (in RASProperties dictionary) and choose appropriate "transportModel" (i.e. nonNewtonian model) in transportProperties dictionary! Another option is to use "nonNewtonianIcoFoam" which is useful for numerical modeling of transient flow of nonNewtonian fluids... Regarding the "flow past cylinder case"  I am considering creeping and slowly moving flow conditions of nonNewtonian fluids! But, I am in a process of writing an article on this subject and therefore I rather do not post any results... I hope you understand. Of course, as soon as the paper is published (which sometimes takes quite some time) I can share it ("my personal copy") with you... Cheers, Primoz 

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