hai friends i would like to find out the centre line velocity decay of the jet of water issuing from the circular orifice, discharging into the quiscent atmospheric air.

how to simulate the above problem? the computational domain is 2d axi-symmetric.

hai friends i would like to find out the centre line velocity decay of the jet of water issuing from the circular orifice, discharging into the quiscent atmospheric air.

how to simulate the above problem? the computational domain is 2d axi-symmetric.

You'll probably want to use the VOF model. This model requires good nodal reolution of the interface. If your jet is more like a spray then this might be difficult. Also, transient works best and the NITA solver works good for speeding up time steps. Hopefully, that gets you started.

thanks for your reply

I have used vof model. but there is no option to define (zone) water as "inletboundary" condition. fluent offers jones to faces and volumes but not for edges.

i want to define "one edge" (inlet velocity) as water and remaining domain as air.

plz give me your valuble suggestions.

thank you

It should be available as long as you define the edge that you want as the inlet to be a separate zone when you mesh in Gambit. You will set it either as a mass flow inlet boundary or a velocity boundary--you will then specify the mass flow (or velocity) of each phase (water and air) on the boundary (set flow of air = 0 if that is the case).