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Small supersonic diffuser design

  1. Sep 27, 2005 #1
    I want to design a very small supersonic diffuser to be used in a pneumatic valve. Can anyone provide some help?

  2. jcsd
  3. Sep 27, 2005 #2
    and you posted the same topic twice... why? there was nothing wrong with your last post if you thought there was some kind of problem. just give it a day and you'll get some good posts

    sorry dude this is not my field so i cant help you design anything. i say ignore detail until later and just stop and consider every possibility
    Last edited: Sep 27, 2005
  4. Sep 28, 2005 #3


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    What exactly are you wanting help with? Can you define the basic design parameters you require? What is the end application?
  5. Oct 17, 2005 #4
    well fred,
    i want to design a diffuser with inlet dia of about 4 to 5 mm and incoming air pressure of about 100 bar. The purpose is to lower the pressure of the vent port in a pneumatic valve. I want to know how to design the interior surface of the diffuser.
  6. Oct 17, 2005 #5


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    There are a couple of things that are confusing me about your last statement. I'm probably just misunderstanding what you are trying to achieve.

    Are you wanting to vent to sub-atmospheric pressures? What is your vent currently venting to?

    The purpose of a diffuser is to increase pressure by trading off velocity pressure for static presssure. What is your expected configuration in the valve to have the diffuser do what you stated it is needed for? Are you thinking along the lines of an ejector perhaps?
  7. Nov 1, 2005 #6
    what are you asking for the area the material I really dont understand
  8. Nov 4, 2005 #7


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    Most design concepts start with defining the existing condition vs the desired condition. Numbers are very helpful in this regard.
  9. Nov 7, 2005 #8
    Last edited by a moderator: Apr 21, 2017
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