[monsoon]

Hi All,

I am running a simple case of incompressible fluid flowing through a cylindrical channel at Re= 100 (velocity = 0.07 m/s) with constant wall temperature. My flow should be fully developed at the end of the channel as per my calculations. Thus I should be expecting the maximum velocity at the exit to be twice the mean inlet velocity therefore making it 0.14 m/s.

My problem is that buoyantBoussinesqSimpleFoam gives me 0.12 m/s which is more than 10% error. I would not have expected such high error for such a simple case. Increasing the mesh density does not resolve the problem. My question is that is buoyantBoussinesqSimpleFoam the right solver for laminar cases or is there a better solver which handles this. I am also using zero gravity in my case. The mesh has been generated in Netgen as shown.
Any guidance would be appreciated.
Thanks
Aru

[duri]

Your results are not very off, there can't be problem with solver. Try using higher order accurate schemes you will get good match.

[monsoon]

Thanks Duri, You are right. changing to higher order scheme improve the results to 0.133 m/s which is just about 5 % error.

[norkistar]

Hi, Can you help to send me your case folder for my reference, I am currently doing similar project, I want to see how is the setting for 0, system and constant. Many thanks and best regards. norkistar@126.com