CFD Online Discussion Forums

CFD Online Discussion Forums (
-   Fluent UDF and Scheme Programming (
-   -   Deforming zone using DEFINE_GEOM (

raghu mohan December 23, 2011 22:54

Deforming zone using DEFINE_GEOM
I am using this UDF to get deformation in a wall(line):

#include "udf.h"
#include "stdio.h"

position[1] = position[0]*position[0];

Basically I am trying to understand how the function DEFINE_GEOM works.

I used this UDF with dynamic mesh Smoothing method and specified DEFORMING (Geometry Definiton - UDF, Meshing Options - both smoothing & Remeshing) to create dynamic zone. Then I checked the deformation in that zone(wall) using DEFINE - Zone Motion by giving Time Step and No.of Steps but there was no deformation (Is this the way to check the deformation?).

Can you please help me to get(check) the deformation in the wall.

If you have any example related to deformation of Domain please send me to

skyblue_mech March 25, 2013 19:26

I am stuck with a similar problem where I have to model a moving boundary with time. I am using Define_Geom to define it. Did you find any help or tutorial?


vasava March 26, 2013 03:22

I think that you must have something else in your UDF that describes the motion/position of other faces/boundaries in your domain. While you have moving/dynamic face/boundary the motion of mesh attached to this face affects the meshes attached to other faces/boundaries.

I suggest you have a close look at the tutorial titled 'Using a UDF to Control the Dynamic Mesh of a Flexible Oscillating Membrane'.

All times are GMT -4. The time now is 13:31.