1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Pressure Wave from Rapid Balloon Expansion

  1. Aug 28, 2009 #1
    Hello physics forum,

    I'm interested in modeling the pressure wave created due to the rapid inflation of a balloon. Say I'm able to rapidly increase the temperature of the air in a balloon, faster than it can equilibrate its pressure with the outside air. It will expand to satisfy PV = T, and radiate a pressure wave. I'm interested in calculating the frequency power spectra of this pressure wave.

    What is the best way to solve for this? One way I can think of is to solve for the velocity of the balloon membrane as it expands, but I'm not sure how I would calculate the membrane velocity. I also thought that I might just be able to use the pressure wave Green's function, and integrate that over the volume of increased pressure.

    Please help! Thanks =)
     
  2. jcsd
  3. Aug 28, 2009 #2
    Upon further reflection, this bears resemblance to a shock wave. With this context in mind, is there some simple solution?

    I work primarily with optics, I feel like a fish out of water! References, anything would be much appreciated =)
     
  4. Aug 28, 2009 #3
    Read about Fermi's measurement of the Trinity Site blast in
    http://www.cfo.doe.gov/me70/manhattan/trinity.htm [Broken]
    "Probably the most mundane response of all was Fermi's: he had calculated ahead of time how far the blast wave might displace small pieces of paper released into it. About 40 seconds after the explosion, Fermi stood, sprinkled his pre-prepared slips of paper into the atomic wind, and estimated from their deflection that the test had released energy equivalent to 10,000 tons of TNT. "
    fermi was about 10,000 meters away.
     
    Last edited by a moderator: May 4, 2017
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook