Turbulent jet dispersion

[shardiali]

Hi all,

I have a fluid dynamics question. I have a turbulent jet (water) coming into still ambient (also water) and I am looking for a solution to disperse the turbulent jet as short and quickly as possible. I have the freedom to change the outlet design. However, the pressure drop has to be more and less in the same order. I already tried blunt body concept and the CFD result showed that the mixing happens within the jet itself and not between the jet and the ambient. I appreciate your valuable input. Thanks.

Alireza,

 

[btrueblood]

A baffle plate, or series of same, with some distribution of holes of various diameters is one of the most effective devices.

 

[MikeHalloran]

See "Lee Visco Jet".


Mike Halloran
Pembroke Pines, FL, USA

 

[bimr]

As btrueblood posted, some type of distribution header with outlets is normally used. See the link:

http://www.tvrl.lth.se/fileadmin/tvrl/files/vvr176/lecture7.pdf

 

[MikeHalloran]

CFD will say that a jet of liquid entering a half-universe of still liquid will disperse slowly.

Practice will say that a jet entering a container of finite size will induce a toroidal flow within that container, and the induced flow will cause mixing. If the container is small relative to the jet, and has one exit in addition to the one entrance, and is followed by a number of similar chambers, complete mixing will take place within a relatively small gross volume, and the fluid will lose some energy.

That's sort of how a Visco-Jet works, though the VJ also accelerates and decelerates the fluid in a series of cyclones and anti-cyclones.




Mike Halloran
Pembroke Pines, FL, USA

 

[shardiali]

Hi all,

Thanks very much for the replies.

@btrueblood: Thanks for the reply. I will perform a CFD to check for the effect of baffled plates. Nice one.

@MikeHalloran: I will investigate the Lee product more in details. Thanks for the nice suggestions. Regarding your second note, I have to say that the jet is supposed to bbe dispersed in the sea where you have practically no effect of jet on the flow field in the container (infinite size).

More suggestion are appreciated.

Regards,
Alireza,