Static heat spot on rotating drum
 

Hi everybody,

I am using ANSYS Fluent to simulate the rotation of a drum (made of titanium as external walls) and filled with water (so basically a rotating cilynder with a water volume inside and a titanium volume outside).

In order to make everything rotate, I set the frame motion in rotation (alwasy at 63 rad/s) in absolute reference, both for the solid and the water body settings. Then I also set the wall boundary condition of the fluid body with a rotational velocity of 63 rad/s on absolute reference.

I am now applying a heat spot both in solid and water volumes (it is a penetrating heat beam laser that pass through the solid walls and goes 3mm deep in the water). To simulate this I use 2 UDF define_source functions (one in solid volume and the other in water volume).

Velocity and pressure profiles seem correct from the result (so the drum is rotating). The beam spot on the solid wall seem to be indeed static while the wall rotates, creating then a heat wake, as seen in photo below.



But instead in the water volume, it seems that the heat spot and the water wall boundary are both static (so that the wall boundary is not rotating). But the velocity plot clearly show the correct rotational velocity gradient (max at the wall and decreasing towards the center).

I thought the problem could have been in the frame motion settings, but even changing them the result didn't change. Could be an interface problem (which I set as coupled)? I don't know.

Can someone please help me?



Thank you,



P

Rotation Setup
 

If both, the drum and the water inside, are supposed to be rotating, what is the objective behind applying a wall velocity. That is required only when the solid is not included in the simulation and the solid is supposedly stationary and not moving. You have solid included and it is in motion. So, you should not apply any rotation to the wall.