Dear all,

So I've modelled the geometry of the jet nozzle, now I'd like to know how can I model the jet flow in a current properly.

To be specific, what are the B.C. I should use at (i) upstream of the jet ? (ii) exit of the jet nozzle ? (iii) downstream of the jet ?

I also want to know what's the usual practice in meshing such case, just let Gambit do the job?

Adrian

1- Is it a convergent nozzle or a convergent divergent Nozzle

2- What is the diameter of What you call "exit of the jet nozzle"

3- You need a C or O type mesh to study the interaction between the jet and its surrounding

4- Explain you problem properly

Dear Ahmed,

1. say convergent nozzle 2. order of 1 cm 3. would you mind explaining what is C/O type of mesh? (sorry I'm new to CFD) 4. say, certain tracer is discharging to an uniform current in the form of a jet (free jet, without boundary effect), I want to obtain the pressure field and the velocity field induced by this jet (interaction between the ambient and the jet).

Adrian

Hi Adrain, Its look almost related to my thesis work let me share with u some aspects 1)Say u r jet is issuing fluid from North to south that is vertical Impinging Jet 2)U need not bother about C/O type mesh u just take it as plane rectangular Cartesian grid (2-D). 3)U consider Jet pipe little extended to inside of u r solution domain and Define Ambient coniton conditon next to jet pipe throughout North side of the domain.(Called Entrainment Boundary conditon). 4)for east u put Outflow condition, soutn as Wall(coldflow) or Isothermal if its includes Thermal problem, West u can consider Symmetry (Slip conditon). Note:U try to simulate Symmetry of the flow model dont take full model that is why i told consider symm Boundary conition on west.

The real Physiscs flow had Entrain towards the domain from north and it should not give out of the flow (i.e not blowing out it has to suck towrds the Strong Stagnation region of the jet)

If u need furthur deatils mail me I will xplain and provide me wat exactly u need with a sketch

all the best

Alex