regarding dynamics mesh?

suki

HI,

I would try to simulate a simple problem before a complecated situation. I saw UDF manual provided by FLUENT.INC., but couldn't understand. My simple situation is that upper wall(rigid body) is moving up and down with a sinusoidal function in a parallel plate. Inlet velocity is given uniformly. No-slip condition is given in lower wall. I found out that there are three types of dynamic mesh define macros,ie DEFINE_CG_MOTION, DEFINE_GEOM, and DEFINE_GRID_MOTION.

What type of macros shoud I use for solving the problem?

The upper wall is moving as follows: r=r_mean + r_amp*sin(omega*time) r_mean = mean position r_amp= amplitude of postion omega=angula velocity(=1)

If you can knw how to set up udf, could you please write it here for me? Your help would be greatly appreciated.

Thanks again