Recent content by men5j2s

  1. men5j2s

    Estimate the temperature change due to vaporizing liquid

    Hi JBA, Thank you for the detailed response.. I'm hoping to model a 'steady state' scenario. I am assuming uniformity between the two orifices. I have calculated mass flow rate across the first orifice, but to do that I had P1, T1 and the viscosity of the liquid in chamber 1, I have no clue...
  2. men5j2s

    Estimate the temperature change due to vaporizing liquid

    Hi Russ... I am getting a bit overwhelmed by the theory in this field... I have a liquefied gas (high pressure - 6bar) Can is upside down (stem down), so gravity ensures that when I spray, I spray liquid. I am spraying into a second container with a volume a little larger than that of the...
  3. men5j2s

    Estimate the temperature change due to vaporizing liquid

    I'm releasing pressurized propellant into another chamber which is at atmospheric pressure, I want to estimate the temperature to which that chamber will drop to and the rate at which the liquid (collecting in the new chamber) will boil. The second chamber is open to atmosphere via a small...
  4. men5j2s

    Buoyancy - (helium in a sealed vessel)

    1.3 g/L * 0.0175 L (or 17.5ml) = 0.02275g (or 22.75mg) You are correct, I made an error in transposing (that's why we Verify :wink:), well spotted!
  5. men5j2s

    Buoyancy - (helium in a sealed vessel)

    Hi All, I'm trying to answer a question once and for all that has caused more debate than it ever should have (talking about an internal debate)... If I fill a sealed vessel (say an aluminium vessel with appox. 17.5ml of internal volume) with varying amounts of helium ( 1bar, 2bar, 3bar ...
  6. men5j2s

    Temperature of a compressed gas

    Yes, that's correct
  7. men5j2s

    Temperature of a compressed gas

    I'm not sure I'm with you here.. I calculated the number of moles by using 8.56m^3 (amount of helium in the cylinder, as per BOC) and 0.1785 g/l (as the density of helium). At STP I get 22.7 moles/L => 22.7*8.56 => 8560/22.7 = 377.1 moles in 8.56m^3 Also if i do Volume / density, then mass...
  8. men5j2s

    Can I calculate the flow rate of a compressed gas from pressure?

    I've decided to use a flow meter and pressure transducer, but this is going to be costly as I need 5 of each :(
  9. men5j2s

    Temperature of a compressed gas

    The cylinder is, but what I'm ultimately trying to do is use a supply cylinder to fill a smaller cylinder and I'm trying to get a feel for the temperature changes I can expect to see during this process.
  10. men5j2s

    Temperature of a compressed gas

    Quite possible that there's a mistake there... BOC stated 8.56m^3 as the volume (of He) at stp we have 1 mole in 22.7L 8560/22.7 = 377 moles. I used the physical height of the cylinder to estimate the volume, but looking at BOC website now, they give the "water capacity" of the cylinder as...
  11. men5j2s

    Temperature of a compressed gas

    I did PV/nR (296.08*112)/(377.1*0.082) What I would ideally like to do, is understand what's happening in the second vessel (the first one is just a pressurized helium cylinder acting as a reservoir), the second is going to be filled to around 8 bar, from empty. So if I can model the...
  12. men5j2s

    Temperature of a compressed gas

    How can I calculate the temperature changes of a pressurized gas as it is in a cylinder, then as it is when flowing into another vessel? my best guess was using the ideal gas law (with help from this forum), but I feel like I'm using it wrong. P = 300bar or 296.08 atm V = 112 L (is this...
  13. men5j2s

    Can I calculate the flow rate of a compressed gas from pressure?

    So I can obtain the pressure in the vessel that I'm filling at t=0 (1atm as its empty), then Pressure at t=1s, 2s, 3s...etc (likely to be in millisecs) and and use the mass in grams (derived from the mols of helium as given by the ideal gas law) to work out a mass flow rate in kg/s (m-dot)...
  14. men5j2s

    What is the Role of Physics in Bioengineering?

    Hi all, I'm new here and saying hello. I'm a PhD bioengineer working on mechanical devices, and have a sizable gap in my knowledge when it comes to physics. I'm hoping to learn a lot here J
  15. men5j2s

    Can I calculate the flow rate of a compressed gas from pressure?

    I am using a compressed gas tank to fill an otherwise empty container, The gas tank is around 50bar and the container will be filled to 6bar. If I am using a pressure transducer to determine when the container has been filled to 6bar, can I use the information I gain from it to derive the flow...
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