dynamic mesh udf

hillat · February 12, 2014, 09:18

hello I am trying to bulid a dynamic mesh in which the wall is moving like:

0.01sin(12x-20time)

when I am running the case it's written to me

Update dynamic mesh failed. negative cell volume detected

I chose smoothing method for the wall and User defined

what the problem can be?

vasava · February 21, 2014, 04:47

Can you post pictures of your case? Also are there other walls in contact wit the wall in motion?

hillat · February 22, 2014, 02:40

to here

https://drive.google.com/file/d/0B2-...it?usp=sharing

hillat4 is what i am trying to put as dynamicmesh on wall 5

pumpkin · March 1, 2014, 17:53

I have done some simulations with moving walls. One very important thing to avoid negative cell volumes is that you make sure that every time step the wall (and the mesh associated with it) does not move a distance bigger than a single cell.

Try setting a time step small enough and you won't have negative cell volumes.

February 12, 2014, 09:18	dynamic mesh udf	#1
hillat New Member hilla tor Join Date: Nov 2012 Posts: 22 Rep Power: 14	hello I am trying to bulid a dynamic mesh in which the wall is moving like: 0.01sin(12x-20time) when I am running the case it's written to me Update dynamic mesh failed. negative cell volume detected I chose smoothing method for the wall and User defined what the problem can be?

February 22, 2014, 02:40	i uplode the case file	#3
hillat New Member hilla tor Join Date: Nov 2012 Posts: 22 Rep Power: 14	to here https://drive.google.com/file/d/0B2-...it?usp=sharing hillat4 is what i am trying to put as dynamicmesh on wall 5

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Dynamic mesh udf for oscillating wall	QBeast	Fluent UDF and Scheme Programming	3	December 17, 2020 03:03
Moving mesh	Niklas Wikstrom (Wikstrom)	OpenFOAM Running, Solving & CFD	122	June 15, 2014 07:20
Dynamic mesh UDF problem	Peter	FLUENT	2	November 12, 2007 03:10
writing a dynamic mesh udf	ALPER ALBAYRAQ	FLUENT	0	October 24, 2005 09:41
Problem related with UDF for dynamic mesh	Ryan	FLUENT	6	April 29, 2004 10:29

February 21, 2014, 04:47		#2
vasava Senior Member Paritosh Vasava Join Date: Oct 2012 Location: Lappeenranta, Finland Posts: 732 Rep Power: 23	Can you post pictures of your case? Also are there other walls in contact wit the wall in motion?

March 1, 2014, 17:53		#4
pumpkin New Member Marc Pelegri Join Date: Mar 2014 Posts: 5 Rep Power: 12	I have done some simulations with moving walls. One very important thing to avoid negative cell volumes is that you make sure that every time step the wall (and the mesh associated with it) does not move a distance bigger than a single cell. Try setting a time step small enough and you won't have negative cell volumes.