[Aidan100]

Hey just a simple question I hope,

I have 2 wings...an outer wing with en enclosed inner wing.
I have defined the motion using a profile.c file and am trying to simulate two morphing strategies to analyse the dynamics within the TRANSIENT solver.

1) Telescopic extension and retraction of inner smaller wing
2) Rotation of 2a. outer wing only, 2b both wings simultaneously
* See attached jpeg of geometry

However I am having difficulties with Dynamic meshing and receiving the usual error of negative cell volume, which I'd imagine is quite typical for first time DM rookies like me! I've successfully achieved a small number of timestep motions though no matter what combination of remeshing/smoothing/changing parameters and settings eventually after about 10% of the motion (1) or (2) I get the neg cell V error. Warning: negative cell volume detected! Error: Update dynamic mesh failed!
I also receive warnings like cell-skewness being > 0.95 etc, which I think leads to the Neg C V.



-> Suggestions for how to overcome this? How to set up DMesh properly?

Thanks in advance, thesis due in just over a month! Oh boy..

[Aidan100]

I've got it! Just had to use Diffusion Parameter of 1-1.5 instead of spring based smoothing, and also remeshing Cell Zones for the interior section.

NOW my next problem, who can tell me the best way to not permit airflow from entering the internal section of the hollow wing? I'm trying to make a surface to close the gap, specifying the interior air as solid so airflow doesn't come in etc, but it's hard to get it loaded into setup.

Thanks in Advance!

[cinclus]

Hello,

I remember a 2D simulation of a pressure valve where the user applied a porous region between the valve and the wall. I guess you'll be able to find it somewhere here

[Aidan100]

Originally Posted by cinclus

Hello,

I remember a 2D simulation of a pressure valve where the user applied a porous region between the valve and the wall. I guess you'll be able to find it somewhere here

Would you know exactly where I could find this cinclus? I've tried searching but did not find what you were referring to. Thanks for the reply.