1 Reply Latest reply on Nov 27, 2012 6:15 PM by Justin Strempke

    Non-Uniform Pressure issue with a Pressure Vessel

    Liam Griggs



      I have a "LPG Storage Tank" that is a cylinder with two hemispheres. The height is 2 metres, but the depth of the LPG is 1.8metres, above which is vapour.

      The assumed pressure of the vapour is 8bar, would this be a uniform pressure acting on the sections above of 8x10^5 Pa?


      My main issue is:

      The LPG has a density of 560kg/m^3 and is meant to be modelled using a non-uniform pressure load, up to the 1.8 metres point. Any help regarding how to model this would be very much appreciated. Do I set the Y value to gamma, rho*g (560*9.81)? And does the vapour pressure also apply being the + option with the rest except Y set to zero?

      This is what I have tried, as well as modelling the tank as alloy steel with set thickness and applying fixtures to supports at the bottom, but I get warning messages about displacements being too large... I can put some images up if required to make this more understandable if necessary.



        • Re: Non-Uniform Pressure issue with a Pressure Vessel
          Justin Strempke

          My suggestion is to create a split line where the top of the LPG would be, and a UCS at the center of that circle (+Y downward).  Then apply a uniform pressure to the inner top surface for the vapor, and use the non-uniform pressure with all coefficients set to 0 except Y, which would be gamma.  The only thing I'm not sure on is how to apply the exerted pressure of the vapor onto the lower surface.  I was thinking a split surface there too, just be sure to select both surfaces when doing the liquid pressure.