how can we find volume fraction of fluid at atmospheric domain which coming out of the nozzle

Hey Jerin, would it be possible to add more details regarding the project? For example, the link, what exactly you are simulating, etc

Best regards,

Fillia

To begin with, the analysis here is incompressible, which means there is a single fluid(Water). The domain is filled with it, and there is no air inside. If you wish to have both fluids inside the domain, you should try a multiphase analysis instead: Multiphase Fluid Flow Analysis | Analysis Types | SimScale

If you want to calculate the volume that comes out, you just need to extract the average velocity of the outlet, and use the mass flow rate formula:

mass flow rate= rho * A * V

where *rho* is the density of the fluid, *A* is the surface area of the outlet, and *V* the average velocity of the face.

Best regards,

Fillia