[M.Sc_Student]

Hi dear friends
I'm doing a simulation of a flapping airfoil. I have a udf, and I have compiled it and I also created dynamic mesh zones related to motion, but I can not see the preview of motion by use of zone motion under the display tab. this is the udf:
______________________________________
#include "udf.h"
DEFINE_CG_MOTION(plunging_motion,dt,vel,omega,time ,dtime)
{
Thread *t;
face_t *f;
NV_S(vel,=,0.0);
NV_S(omega,=,0.0);
if(!Data_Valid_P())
return;
vel[1]=2.495*cos(6.2392*time);
}
_____________________________________
I have attached my airfoil and it's boundary to this thread.
I would really appreciate your help.
thanks

[svp]

I am not sure if display/zone motion is what you want to do to preview your mesh motion. Try Solve/Mesh Motion instead..

Let me know if it works.

[M.Sc_Student]

Dear svp
thanks for your advice, I done it, it was amazing, Do you have any idea how should I determine the dynamic mesh parameters to keep the resolution of the mesh? I mean for instance what should I enter for the maximum cell skewness in remeshing method or what should be the amount of spring constant factor in smoothing method?
thanks again

[svp]

The dynamic mesh parameters are dependent on what region of the model you are remeshing/layering etc. I think it is recommended to maintain the same order of magnitude as your original cell size for remeshing with regards to maximum and minimum height.. With regards to the skewness, you can choose 1.0 but if this is a region where most of the fluid mechanics of interest is then a value of 0.8-0.9 would be more appropriate in my opinion. This way you ensure you do not introduce numerical errors into the solution with skewed meshes..

I have not really used spring smoothing so far, so I cannot comment on that..