free falling of a wedge into water

ghoroobeaakhar · April 20, 2014, 12:40

I'm trying to model free falling of a wedge into water.

http://www.mediafire.com/watch/1d8k9...wr/CFXfull.mp4

the problem is that the velocity of wedge after impact doesn't reduce and it maintains its speed as you see.

thanks.

ghorrocks · April 21, 2014, 00:31

This could be real - if the wedge is heavy and you are looking at the first entry into the water it may be correct that the wedge has not slowed down much.

Or this could be due to simulation error or inaccuracy.

So before trying anything, are you sure what you are seeing is correct or not?

ghoroobeaakhar · April 21, 2014, 11:58

my results for velocity and acceleration of wedge
13 for velocity
14 for acceleration

ghoroobeaakhar · April 21, 2014, 12:04

but in fact something like the picture should happen.
(a sudden decreasing in speed)
thanks.

ghorrocks · April 22, 2014, 07:14

So it looks like your simulation is inaccurate. This is an FAQ: http://www.cfd-online.com/Wiki/Ansys..._inaccurate.3F

Manigandan.R · April 22, 2014, 07:30

Please increase the water height bit more may be it will help out to do the modelling , meshing & analysis once again. Or otherwise reduce the dropping velocity make it small. May be it will help you out.

ghoroobeaakhar · April 23, 2014, 13:28

ghorrocks and Manigandan.R
thanks.
I increased the water height and reduced the velocity and time steps.
I increased the number nodes and elements (meshing). it's running now and I hope it works.

April 20, 2014, 12:40	free falling of a wedge into water	#1
ghoroobeaakhar Member aliali Join Date: Apr 2014 Posts: 35 Rep Power: 12	I'm trying to model free falling of a wedge into water. http://www.mediafire.com/watch/1d8k9...wr/CFXfull.mp4 the problem is that the velocity of wedge after impact doesn't reduce and it maintains its speed as you see. thanks.

April 21, 2014, 00:31		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,871 Rep Power: 144	This could be real - if the wedge is heavy and you are looking at the first entry into the water it may be correct that the wedge has not slowed down much. Or this could be due to simulation error or inaccuracy. So before trying anything, are you sure what you are seeing is correct or not? ghoroobeaakhar likes this.

April 22, 2014, 07:14		#5
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,871 Rep Power: 144	So it looks like your simulation is inaccurate. This is an FAQ: http://www.cfd-online.com/Wiki/Ansys..._inaccurate.3F ghoroobeaakhar likes this.

April 22, 2014, 07:30		#6
Manigandan.R New Member Manigandan.R Join Date: Mar 2011 Posts: 10 Rep Power: 15	Please increase the water height bit more may be it will help out to do the modelling , meshing & analysis once again. Or otherwise reduce the dropping velocity make it small. May be it will help you out. ghoroobeaakhar likes this.

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April 23, 2014, 13:28		#7
ghoroobeaakhar Member aliali Join Date: Apr 2014 Posts: 35 Rep Power: 12	ghorrocks and Manigandan.R thanks. I increased the water height and reduced the velocity and time steps. I increased the number nodes and elements (meshing). it's running now and I hope it works.