[luciagalvez]

Hi, I am trying to make a wall move by using the named expression function in Fluent 2023 R1 and entering the boundary condition of that wall. Is there any way once initialized to be able to visualize the movement to see if it is really correct?

Because there are no errors and it does the run calculation but I don't know if the results it is giving me are correct because I don't know if the movement it is doing is really what I want.


Thanks in advance

[NickFL]

I am a little confused about what you mean by using Named Expressions for the wall movement. Is what you mean, your movement sinusoidal or something similar, and you are using a Named Selection to represent this? But you are still putting this in as a boundary condition, correct? Are you using the built-in Dynamic Mesh models in Fluent? If so, with layering or smoothing on the bottom there is a button where you can Preview the Mesh Motion. There are a couple of good videos on YouTube for setting up similar problems. Check this one out:https://www.youtube.com/watch?v=fbaV_knzzks


If you already simulated it, you should see the motion/deformation of your domain in the transient result files.

[luciagalvez]

Hi Nick, what I mean is that I use a sinusoidal expression in the moving wall option of the boundary condition of the wall I want to move (like in the image I include).

I tried the UDF files too with this file:

#include "udf.h"
#include "dynamesh_tools.h"

DEFINE_CG_MOTION(wave,dt,cg_vel,cg_omega,time,dtim e)
{
cg_vel[0]=0.0;
cg_vel[1]=(0.12e-6*(sin( 20*3.1415927* time)));
cg_vel[2]=0.0;

cg_omega[0]=0.0;
cg_omega[1]=0.0;
cg_omega[2]=0.0;
}

but when I trie to compile I obtain the following error: Warning: incorrect grid motion UDF wave::libudf1 on zone 4 (assuming no motion) and I tried to solved it but I can't get it.
I'm going to watch the video, thanks.