Swirl flow recirculation
 

Dear all,
I try to simulate a swirl flow using dieselFoam solver using swirl BC that I compiled in 1.6 version. I try to simulate spray in an open swirl-stabilized burner. So, my geometry could be as simple as a cylinder with spray and swirl flow coming from the inlet. To save computation time, I reduce the domain to a 36 degree sector with cyclic BC. However, I've problem in producing recirculation region and the rotational flow always ended up reaching the exit without producing clear recirculation region. Hereby attached part of the 0/U file:

swirl_inlet
{
type swirlFlowRateInletVelocity;
flowRate 0.021; // [kg/s]
rpm 2000;
value uniform (0 0 0);
}
other outlet BC's:
pressure is fixed
zeroGradient velocity
zeroGradient k and epsilon

inlet BC's:
swirl velocity (as attached above)
zeroGradient pressure
fixed value of k and epsilon

cylindrical surface:
symmetryPlane

Please advise....

Thanks,

Fairus
CFD Group,
Department of Engineering,
University of Cambridge
email: mfm38@cam.ac.uk

try to reduce the angle to less than 5 deg and use wedge BC.

Hi Hasan,

Thanks for the reply. The reason why I set the sector to be 36 deg angle is because the swirler has 10 vanes. Is there any way we can do it without changing the sector angle?

Fairus

Dear Fairus,

one of my colleges is working on swirling flow using simpleFoam and PisoFoam. He is facing a lot of troubles however he is using a 3d model. I think maybe the problem with the solvers. I don't really know what is going on? If you have any experience with swirling flow modeling in openfoam, it will be highly appreciated to share here.

Best Regards,
Hassan

Hi, friend, I would like to ask what the rpm and value exactly mean for swirled flow.