Week 8- Moving zones approach in Fluent

1. What are the approaches by which you would model moving zones?

To model the moving zones, two options are available which are moving reference zone & moving mesh approach.

The Moving Reference Frame (MRF) approach is a steady-state method employed in industrial Computational Fluid Dynamics (CFD) to model problems with rotating parts. It is considered to be less computationally expensive and yet accurate enough for most industrial problems.

During the simulation phase, the MRF zone is rotated about the axis of the body and the body is kept stationary. In order to preserve the direction of Coriolis Forces on the body, the rotational velocity of the ball is reversed in the MRF zone.

2. Which approach would you use to model unsteady phenomena?

Moving Mesh Approach is used for Unsteady Phenomenon.

Used for Modelling Unsteady Phenomenon such as

• Vortex Induced Flows
• Interaction of Vortex with bodies

3. Simulate rotary motion for the geometry given

Rotational velocity has been inserted as 250 rpm with default rotational-axis origin & translational velocity.

For Pressure-velocity coupling

The flow courant number was chnaged from 200 to 10

The convergence criteria was increased for this case from 1e-03 to 1e-04.

Hybrid initialization has been used:

Results:

The velocity is lower in the inner frame, whereas as we move towards the outer frame, the velocity increases.