3 Replies Latest reply on Sep 12, 2006 11:55 AM by

    CW > Liquid > density ????

      Hi John, the 1 & the 0.029 values (in addition to the y location on the surfaxce in this case) multiply to produce the actual pressure that gets applied. The factor 0.029 is based on the specific gravity of the fluid applied. The pressure factor for water at room temperature is about 0.036 psi/inch of depth. Water has a density of 1000 kg/m^3 so I would expect you can multiply 0.036 psi/in times 3.6 for your value. (Pardon the mixed units but I think in IPS)

      Vince
        • CW > Liquid > density ????
          Hi John, I can see why you might find the "1 psi" confusing your first time thru. Essentially, there are 2 factors that combine to define the pressure on your surface in a non-uniform distribution: The "pressure" value, P; geometric function, f(y) (in this case.) The function in this case contains the correct multipler for Y in terms of pressure/depth. It doesn't have to though. Therefore, the 1 in the pressure field essentially tells COSMOS that the factors in the function don't need to be scaled any further since 1*f(y) = f(y). I'm not sure I know any other way to explain it.

          As far as your scale factor, if your fluid has the same viscosity as water, then you should be able to use 3.6*0.036psi/in = 0.13 psi/in. I'm going to add a disclaimer here that you are still responsible for checking references to confirm this for your industry. It seems straightforward but years of consulting taught me not to take anything for granted. Machinery's Handbook discusses this as should any reference on fluids and PV design.

          Good luck!

          -- Vince
          • CW > Liquid > density ????
            I am sorry.
            1. Could you explain to me where is value "1 psi" in CW tutorial come from ?
            I am still confuse about 1 psi.

            2. If I have liquid with density 3600 kg/m^3 = 0.1300583 pound /in^3, Could you help me to fill parameter in CW, SEE MY IMAGE PLEASE !!!

            Thank you Vince.........
            • CW > Liquid > density ????
              Dear All.....

              I want to analize a container.
              The container will fill with a liquid. Density of the liquid is 3600 kg/m^3.
              How to input the density value to my model as non uniform pressure ?

              I look at the COSMOS online tutorial and read nonuniform study.
              But I am still confuse about some input value. See attached image for detail, please.

              Please, give me suggestion.
              This is urgent case.

              Thank you.