10/23/2014

Introduction to CFX -Moving Zones

Domain Motion
Rotating Fluid Domains
Single Frame of Reference
Multiple Frames of Reference
Frame Change Models
Pitch Change

Mesh Defomation
Appendix
Moving Solid Domains
Translation

Rotation
Many engineering problems involve flows through domains which contain moving components

Rotational motion:
Flow though propellers, axial turbine blades, radial pump impellers, etc.

Translational motion:
Train moving in a tunnel, longitudinal sloshing of fluid in a tank, etc.
General rigid-body motion
Boat hulls, etc.

Boundary deformations
Flap valves, flexible pipes, blood vessels, etc.
There are several modeling approaches for moving domains:
For rotational motion the equations of fluid flow can be solved in a rotating reference frame
Additional acceleration terms are added to the momentum equations
Solutions become steady with respect to the rotating reference frame
Can couple with stationary domains through interfaces
Some limitations apply, as discussed below
Translational motion can be solved by moving the mesh as a whole
Interfaces can be used to allow domains to slide past each other

More general rigid-body motion can be solved using a 6-DOF solver combined with mesh motion, or the immersed solid approach

If the domain boundaries deform, we can solve the equations using mesh motion techniques
Domain position and shape are functions of time
Mesh deformed using smoothing, dynamic mesh loading or remeshing
Get free full Tutorial!
Please send me email:
cadxneter@hotmail.com

No comments: