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 kseon October 19, 2012 08:59

Marine turbine

Hi all

I am trying to do marine turbine simulation.
it should be placed 1 meter under the sea level, therefore the water pressure should be around 1 bar.
should i use operation condition to set 1 bar of water pressure or is there another way to set-up this condition?

 Jeremie84 October 19, 2012 15:46

Hi,

One option could be setting the operating pressure at 0, and the pressure outlet at the pressure corresponding to the depth of the turbine location (in your case, it is 1m, so you could set the pressure outlet at a little bit more than 1 bar).

Jeremie

 kseon October 22, 2012 10:39

so it is much better leave operation condition as dafault and change outlet gauge pressure as 101325 pascal, is that correct?
then how about the inlet gauge pressure?
do i need to change as well as 101325?

Kseon

 kseon October 22, 2012 11:10

Quote:
 Originally Posted by Jeremie84 (Post 387578) Hi, One option could be setting the operating pressure at 0, and the pressure outlet at the pressure corresponding to the depth of the turbine location (in your case, it is 1m, so you could set the pressure outlet at a little bit more than 1 bar). Jeremie
Hi Jeremie

so it is much better leave operation condition as dafault and change outlet gauge pressure as 101325 pascal, is that correct?
then how about the inlet gauge pressure?
do i need to change as well as 101325?

Kseon

 Jeremie84 October 22, 2012 11:32

Hello kseon,

"absolute pressure = operating pressure + gauge pressure"
The pressures you set for your pressure-inlet and pressure-outlet are "gauge pressure". So you have 2 options:
- you may set the operating pressure at 0. In that case, you will set your pressure-outlet at 101 325 Pa.
- or you may set the operating pressure at 101 325 Pa (default). Here, you will set your pressure-outlet at 0.

I guess you are simulating an incompressible flow. So, these 2 options will give identical results (operating pressure could be significant for low-Mach-number compressible flows).

For the inlet BC, I would suggest a velocity-inlet since you have an incompressible flow. But, pressure-inlet is good too. To determine the pressure-inlet, you have to deduce the pressure from the upstream flow velocity, using the Bernoulli's principle.

Regards,

Jeremie

 kseon October 26, 2012 07:38

Thanks Jeremie!!!!

it helped me a lot!!!! :)

regards

Kseon

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