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How does air travel after leaving a nozzle?

  1. Nov 18, 2015 #1
    I am working on a project which involves air nozzles. I am interested in estimating the time it takes for air particles after they leave the nozzle to reach a particular distance away.
    I have the following information--- a converging nozzle, the speed with which it is coming out of the nozzle(I know when the air is choked it comes out at Mach number). I also believe that if the nozzle was blowing in vacuum, the air would continue travelling at Mach number. How would blowing out in "normal atmosphere" affect it? I just want a rough idea/guideline. Any help will be appreciated.
  2. jcsd
  3. Nov 18, 2015 #2


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    Why don't you take this as an opportunity to do some Mythbuster's style research with a rented high speed camera?
  4. Nov 19, 2015 #3


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    Just FYI, saying the air is moving "at Mach number" doesn't make sense. The Mach number is a dimensionless measure of velocity relative to the sound speed.

    I have a feeling that the situation is considerably more complicated than you seem to suspect. A jet such as this will tend to diverge after it leaves the nozzle as a function of its own properties and the surrounding pressure. It will also be subject to all manner of instabilities and very well may be turbulent, complicating matters.

    Your best bet is to start researching fluid jets.
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