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free falling of a wedge into water

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Old   April 20, 2014, 11:40
Default free falling of a wedge into water
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aliali
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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.
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Old   April 20, 2014, 23:31
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Glenn Horrocks
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ghorrocks is a jewel in the roughghorrocks is a jewel in the roughghorrocks is a jewel in the rough
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?
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Old   April 21, 2014, 10:58
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my results for velocity and acceleration of wedge
13 for velocity
14 for acceleration
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Old   April 21, 2014, 11:04
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but in fact something like the picture should happen.
(a sudden decreasing in speed)
thanks.
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Old   April 22, 2014, 06:14
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ghorrocks is a jewel in the roughghorrocks is a jewel in the roughghorrocks is a jewel in the rough
So it looks like your simulation is inaccurate. This is an FAQ: http://www.cfd-online.com/Wiki/Ansys..._inaccurate.3F
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Old   April 22, 2014, 06:30
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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.
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Old   April 23, 2014, 12:28
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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.
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