[tricha122]

Hi,

I have an incompressible flow pipe with a pressure inlet, and 2 outlets. One outlet is ambient, and the other is an imposed outlet mass flow rate (it points radially like a jet).

I am using a UDF to ramp up the outlet flow rate gradually in parallel with ramping up the rotational velocity of the whole domain.

When i solve this with frame rotation, my UDF is like "ignored" and the mass flow at the outlet doesnt match the UDF, and is much larger.

When i solve this without frame rotation, my UDF is respected and the mass flow at the outlet is as expected.

Could this be related to the tangential velocity generated as a result of rotation? How might i achieve my goal of a fixed mass flow rate normal to the boundary?

Any help would be greatly appreciated

Thanks,

Tyler