Setting a pressure inlet

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Stéphane Blanchet

Setting a pressure inlet

Post by Stéphane Blanchet » Mon Apr 26, 2010 3:34 pm

Hi everybody,
 
I have some problems to set a pressure inlet for my simulation.

I started my simulation with a velocity inlet, but now, I am more interested about setting a pressure inlet instead. So I changed the usclim.f90 file, and now it seems Code_Saturne only takes into account
the velocity inlet I set for the first time.

Here is my code:

Code: Select all

 iphas=1 
 call getfbr('inlet', nlelt, lstelt) 
   
 do ilelt = 1, nlelt 
   ifac = lstelt(ilelt) 
   iel = ifabor(ifac) 
   
   itypfb(ifac,iphas) = ientre 
   icodcl(ifac,ipr(iphas))=1.d0 
   rcdocl(ifac,ipr(iphas),1)=380.d0 
   icodcl(ifac,iu(iphas)) = 3.d0 
   icodcl(ifac,iv(iphas)) = 3.d0 
   icodcl(ifac,iw(iphas)) = 3.d0 
 enddo 

I really don't know what I am doing wrong, so if you have any idea...
 
Best regards

Stéphane

Stéphane Blanchet

Re: Setting a pressure inlet

Post by Stéphane Blanchet » Wed Apr 28, 2010 3:32 pm

Hi,

I changed a little bit the code and copied the usclim.f90 file into the SRC folder (which was maybe a stupid omission from me) and now it works.
 
Thank you anyway.
 
Stéphane

Stéphane Blanchet

Re: Setting a pressure inlet

Post by Stéphane Blanchet » Fri Apr 30, 2010 7:05 pm

Hi again,
 
I have another question regarding the pressure inlet. I have seen that the total pressure is calculated as follow: Ptot = Pred + rho0*g*(z-z0) + P0, in my case I set g=0 and the reference value for total pressure (P0?) is 101325, and I need Pred=494. So in the code I use Ptot=494+101325=101819, and after the simulation, I get Pred=519. I'm guessing there is a problem with the reference value for the total pressure, but I don't know where.
 
Thanks in advance,
 
Stephane

Yvan Fournier

Re: Setting a pressure inlet

Post by Yvan Fournier » Sat May 01, 2010 12:02 am

Hello,

If you are using usini1.f90, make sure that p0 is set to 101325 Pascals and not just 101300. If you are using the GUI, also check the reference pressure. We have changed this very recently, but the reference pressure was often set at 101300 Pascals instead of 102325, and you have (Pred_expected - Pred_obtained) = (519-494) = 25, which might not be a coincidence.

Best regards,

  Yvan Fournier

Stéphane Blanchet

Re: Setting a pressure inlet

Post by Stéphane Blanchet » Mon May 03, 2010 10:54 am

Hello,

Thank you for your answer. I also guessed it was not a coincidence, and indeed p0 was set to 101300 Pa in usini.f90. Now it works just fine!

Best Regards,

Stéphane

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