you will need to use an external simulation. External allows both internal and external flow conditions, but internal only allows internal flows.
You will set boundary conditions on the 2 solid surfaces such that the arrows point in the direction of flow and define either the velocity or mass flow rate, etc.
With an external simulation it will solve how those flows interact with the ambient out until the limits of your computational domain.
thank you for your answer.
I tried it before, but when I display the flow trajectories it will only show the ones of the external flow. Maybe one out of 500 lines comes out of the nozzle. Moreover, the traj. lines of the external flow do not seem to be influenced by the nozzle flow.
Could this be because the mesh isn't dense enough ?
have you tried making multiple trajectories to trace? one from each of the slots?
Or perhaps a better way would be to use 2 different fluids - use air as the default and the fluid from one slot, but use Nitrogen for the other. Because you are not doing a high-temperature study the difference between Nitrogen and Air will be insignificant but this will allow you to create a cut-plot to look at Mass Fraction of fluids. If you have a mix of gases near your object then you know that Flow 2 is not strong enough to prevent penetration by Flow 1.