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Qualitative advice on two phase flow problem.

  1. Oct 14, 2013 #1
    Hi guys I have a rather qualitative question. let's imagine a tank with two openings. pressure is measured at one opening (A) to be at a constant 33 bar at time t=0s. the other opening(B) is at atmospheric pressure.
    Inside the tank we have a two phase flow half is N2 gas and the other half is H2O2(hydrogen peroxide in liquid form) the tank itself is made out of aluminium for weight saving purposes and it's not very big about the size of a paintball tank.
    The question here is if we closed opening A with a valve (solenoid) so that pressure at A becomes 0, how fast would the pressure decrease. I know this is not an easy question because it is time dependent. I had to try and simulate this on solidworks but two-phase flow is not available. So before trying it with Comsol I would like to know maybe from someone's experience if it will be fast pressure drop(<5sec) or a slow one(>10sec)
  2. jcsd
  3. Oct 14, 2013 #2


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    Gold Member

    Fast I think.

    With a pressure drop as big as that, the flow velocity would be sonic (i.e. choked flow) I assume?

    Your description sounds less tank and more a nozzle or a pipe.
  4. Oct 14, 2013 #3
    the B opening leads to a nozzle indeed. Thanks for your insight
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