5 Replies Latest reply on Aug 11, 2014 12:07 AM by Jared Conway

Difference between pressures in real test and flow simulation test

Oshri Nitzan Aug 7, 2014 1:21 AM

Hi,

I have a long pipe with 2 pressure gauge in it, static pressure gauge/

When I measured pressure in real (examination test in my laboratory) I got pressure of 1.46 bar and 1.27 bar

When I tried to simulated that in flow simulation my input boundary condition was of 1.46 bar static pressure as inlet pressure but as you can see in the
picture the pressure in the other gauge is 1.41 bar not 1.27 bar as in real test i did

What could be the problem?

Thanks,

Oshri

Re: Difference between pressures in real test and flow simulation test

Mark Keown Aug 7, 2014 1:56 AM (in response to Oshri Nitzan)

Possibly you need to add surface roughness to the pipe and this would reduce the pressure.
Check to see that your gages are calibrated. Look at both your test setup and the simulation setup for refinement. Cheers, Mark
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- Re: Difference between pressures in real test and flow simulation test
  
  Oshri Nitzan Aug 7, 2014 2:01 AM (in response to Mark Keown)
  
  Thanks mark
  Is there a option to add roughness only on the pipe part? and how?
  
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  - Re: Difference between pressures in real test and flow simulation test
    
    Mark Keown Aug 7, 2014 2:40 PM (in response to Oshri Nitzan)
    
    Oshri,
    
    Insert / Boundary Condition / Pick the surface / Type = Wall / Rz = roughness in micro meters.
    Use Flow Sim Help to look up 'Boundary Condition' Cheers, Mark
    
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    - Re: Difference between pressures in real test and flow simulation test
      
      Oshri Nitzan Aug 7, 2014 6:30 AM (in response to Mark Keown)
      
      Thanks mark
      asking again
      is it possible to insert the roughness only for the pipe (part) not for all the assmbley?
      
      oshri
      
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      - Re: Difference between pressures in real test and flow simulation test
        
        Jared Conway Aug 11, 2014 12:07 AM (in response to Oshri Nitzan)
        
        the method that mark describes is face by face
        if you want to apply to all, the easiest is to set the default in the study options
        
        regarding your initial problem, you'll have to describe your problem a bit more. you said you have a pressure inlet, what is your other boundary condition?
        what is the goal of your analysis?
        
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