Hi, i am new to this dynamic mesh udf feature and i have a simple problem like i want to move a piston in a larged cylinder using a dynamci mesh feature.I am using FLUENT 6.2.16. when i compile it gives no error and successfully loaded.I have even tried to preview the mesh with a small time step but in vain.The dynamic mesh parameters i have used in my problem is that i used remeshing and smoothing algorithm. The dynamic zone i have used is that i defined the piston as rigid body and hooked my udf with this boundary. Can anyone help me in this matter. I will appreciate any help and associated examples with this features.

My code is like that:

#include "udf.h" #include "dynamesh_tools.h" DEFINE_CG_MOTION(piston, dt, vel, omega, time, dtime) { /* reset velocities */ NV_S (vel, =, 0.0); NV_S (omega, =, 0.0); if (!Data_Valid_P ()) return; vel[0]= 0.4 ; }

If you are using quadrilateral meshes then remeshing won't work. Instead you have to use layering. Further you can use smoothing instead of layering but smoothing has to be activated for a qaudrilateral mesh by the command-line statement

def/mod/dmc/smp/spr, Enter a yes to activate smoothing for quadrilateral cells.

Sincerely, Saad

well dear thanks for replying, further in addition to the last message, i am using the triangular mesh in the domain and near the object i use boundary layer and its only 2d problem.please help me in this matter and give me some samples of such kind of problem if you can. I am really thankful to u Mr. Saad bin Mansoor .

Hi

Check that the adjacent wall/axis is defined as 'deforming'.

in my case there is no axis, it is rigid body motion problem having linear velocity in x-direction.