Resolving unexpected flow near distributed resistance regions in Simulation CFD

Nov 1, 2014


The resultant velocity field in some Autodesk® Simulation CFD simulations in which flow deflects off of or passes around a resistance material. Sometimes the result will start to trend towards divergence.


A new smoothing algorithm was introduced into CFdesign 2011 that improves velocity results near resistance materials. 

This algorithm assumes that the flow passes through the resistance, instead of deflecting off of it, and smooths the flow vectors using the upstream velocities. 

These upstream velocities provide the direction for the downstream nodes.  If the upstream nodes deflect the flow, then all downstream velocities will be deflected creating an odd looking vector field.

To resolve this issue set the following flag in the Flag Manager:

DRSmoothing -2

This disables the smoothing algorithm.




Simulation CFD