|July 29, 2015, 17:52||
water inject tube, huge different results by icoFoam and Fluent
Join Date: Jul 2015
Posts: 2Rep Power: 0
Hi all, I am a beginner to use openfoam. A simple case: water injection into 2D tube, x*y=2*0.4. But the velocity distribution is huge different when use openFOAM and Fluent. Why?
The icoFoam and Fluent were both used to simulate the steady-state process. The BCs are:
left: fixed velocity 0.05 m/s, zeroGrident for p
right: zeroGrident for U, fixed 0 for p
upDown: fixed (0,0,0) for U, zeroGrident for p
left: velocity-inlet 0.05 m/s, zeroGrident for p
right: pressure-outlet, fixed for pressure
upDown: wall, no-slip
Attached is the comparisons of the openFOAM and Fluent results. Thanks!
Last edited by cchuran; July 29, 2015 at 21:19.
|July 31, 2015, 06:27||
kinematic viscosity of 0.01
Join Date: Mar 2009
Posts: 210Rep Power: 10
Have a look into the transportProperties inside constant folder.
The kinematic viscosity of 0.01 is ten thousand times larger than the one of water 1.004e-6. This gives you a perfect parabolic profile even withing this large diameter tube.
|July 31, 2015, 08:30||
Join Date: Jan 2014
Posts: 105Rep Power: 4
It looks like that you are simulating different Reynoldsnumbers and in assumption that you set the velocity (0,05 m/s) and the viscosity (water=1.04e-06) for both Fluent and OF, there is one left, the scaling of your geometry!
Please, verify that your case in fluent AND in OpenFOAM is set up in meters.
If you want to simulate laminar pipe flow, the critical Reynoldsnumber should be
your OF simulation looks for laminar pipe flow right, cause the peak velocity of the parabolic profile should be around 2*u_in = 2*0,05=0,1m/s
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