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sam May 25, 2005 05:27

Cannot preview the dynamic mesh
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 ; }

Saad bin Mansoor May 25, 2005 07:52

Re: Cannot preview the dynamic mesh
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

sam May 25, 2005 12:54

Re: Cannot preview the dynamic mesh
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 .

antun May 26, 2005 05:12

Re: Cannot preview the dynamic mesh

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

sam May 26, 2005 06:58

Re: Cannot preview the dynamic mesh
in my case there is no axis, it is rigid body motion problem having linear velocity in x-direction.

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