[shivasluzz]

I want to simulate 'the oil flow from jet entering inside a rotating drum with radial holes' (hollow cylinder, where one side is open to atmosphere and from that side oil is entering and leaving radially through the holes in drum due to the centrifugal force of rotation).

1. I modeled the flow volume. Do I need to define the flow volume with only one fulid (oil) and do I need to consider two fluids (oil and air).Here I dont bother about the air flow parameters and I am only interested in the oil flow. So do i need to consider single phase or multiphase? How the results are going to change for this problem, when we use single phase and multiphase mixture model?

2. Also When I started multiphase cfd, i got into a big confusion. Assume a normal analysis (single phase), where a narrow oil jet is entering a larger cylindrical domain. Since its not a multiphase analysis, the region outside the oil stream, will be filled with what? Is it like, the space other than fluid flow region in the domain is vaccum?

please help

Thanks