about dynamic mesh macro
 

Hi I'm a user of Fluent.There're three questions while running Fluent. I would be so glad if i could get some advises from you.

Q1 I would like to simulate one flow field of moving boundary , so the tool of dynamics mesh is needed. There're three kinds of MACROs about dynamics mesh in Fluent, including define_cg_motion,define_geom,and define_grid_motion. In my recent work,the function of "define_geom(name,d,dt,position)" is used. But I'm not sure about the exact meanings of the forth argument(position) of this function. By the way, the type of "position" is REAL, and i feel confused by the example in the manual. --->position[1]=-position[0]*position[0]+position[0]+1

Q2 The way of boundary moving is a fuction of time. But how to add the argument of "time step size" into the function of "define_geom"? for example , y=x*2*time.

Q3 Could you make an example of using "define_geom" for me? I really appreciate the answer from you.

thank you very much

Re: about dynamic mesh macro
 

I've been working a lot with fluent's dynamic mesh UDF's and I'd like to compare notes. Send me an email about what your problem is.

I have done a few different projects and I have tried all 3 of the dynamic mesh UDF's. The most powerful UDF is define_grid_motion, it requires a little more programming, but everything can be done using that UDF. I have been unable to get define_geom to work, and the example you mention in the Fluent guide is worthless.

-Pat