Very high value of p_rgh than theoretical value

Jung hoo · May 20, 2016, 05:26

hello, again me. I think that previous my question was too complicated and long. So here is summarized question!

As far as I know, p_rgh is (1/2)*rho*lUl^2. Is that right?

If so, the max value of p_rgh must be about 21125Pa at U(max) = 6.5m/s where rho is 1000kg/m^3.

But the mesured max value of p_rgh by paraview is about 300000Pa as below, and that is too high than theoretical value(about 21125Pa).

The number of mesuring points is three, and they are near the water surface(26m).

I'm wondering whether it is some kind of error or the theory for p_rgh that I know is wrong.

Additionally, the range of p_rgh is so weird measured at lower part of water surface as below.

Any idea can help me a lot!! Thanks!

Phicau · May 20, 2016, 05:42

Hi Lee Jung Hoo,

p_rgh is not dynamic pressure. Check my thesis (page 111):

http://www.tesisenred.net/bitstream/...pdf?sequence=1

Best,

Pablo

Jung hoo · May 24, 2016, 00:04

Oh!! Thank you for your help! But the link http://www.tesisenred.net/bitstream/...pdf?sequence=1 is not available now..

Can you post another way to approach that link?? Thank you so much!!!!

Phicau · May 24, 2016, 01:06

It is the middle of the night inSpain, the servers are probably under maintenance, try again later.

Jung hoo · May 24, 2016, 01:47

OK! I'll try it later. Thank you for your reply! ^_^

Jung hoo · May 25, 2016, 05:09

Hello Pablo, It's me again. I have read your paper that you recommended to me and now I can partially understand 'pseudo-dynamic pressure'.
I'm really appreciative of that!
Then.. could you please give me a way for measuring accurate values of p_rgh..?.
Does such utility exist? or Is that possible through paraview?
Thank you..!!

May 20, 2016, 05:26	Very high value of p_rgh than theoretical value	#1
Jung hoo Member Lee Jung Hoo Join Date: Dec 2015 Posts: 37 Rep Power: 10	hello, again me. I think that previous my question was too complicated and long. So here is summarized question! As far as I know, p_rgh is (1/2)rholUl^2. Is that right? If so, the max value of p_rgh must be about 21125Pa at U(max) = 6.5m/s where rho is 1000kg/m^3. But the mesured max value of p_rgh by paraview is about 300000Pa as below, and that is too high than theoretical value(about 21125Pa). The number of mesuring points is three, and they are near the water surface(26m). I'm wondering whether it is some kind of error or the theory for p_rgh that I know is wrong. Additionally, the range of p_rgh is so weird measured at lower part of water surface as below. Any idea can help me a lot!! Thanks!

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May 20, 2016, 05:42		#2
Phicau Senior Member Pablo Higuera Join Date: Jan 2011 Location: Auckland Posts: 627 Rep Power: 19	Hi Lee Jung Hoo, p_rgh is not dynamic pressure. Check my thesis (page 111): http://www.tesisenred.net/bitstream/...pdf?sequence=1 Best, Pablo

May 24, 2016, 00:04		#3
Jung hoo Member Lee Jung Hoo Join Date: Dec 2015 Posts: 37 Rep Power: 10	Oh!! Thank you for your help! But the link http://www.tesisenred.net/bitstream/...pdf?sequence=1 is not available now.. Can you post another way to approach that link?? Thank you so much!!!!

May 24, 2016, 01:06		#4
Phicau Senior Member Pablo Higuera Join Date: Jan 2011 Location: Auckland Posts: 627 Rep Power: 19	It is the middle of the night inSpain, the servers are probably under maintenance, try again later.

May 24, 2016, 01:47		#5
Jung hoo Member Lee Jung Hoo Join Date: Dec 2015 Posts: 37 Rep Power: 10	OK! I'll try it later. Thank you for your reply! ^_^

May 25, 2016, 05:09		#6
Jung hoo Member Lee Jung Hoo Join Date: Dec 2015 Posts: 37 Rep Power: 10	Hello Pablo, It's me again. I have read your paper that you recommended to me and now I can partially understand 'pseudo-dynamic pressure'. I'm really appreciative of that! Then.. could you please give me a way for measuring accurate values of p_rgh..?. Does such utility exist? or Is that possible through paraview? Thank you..!!