0 Replies Latest reply on Jun 18, 2010 7:04 PM by Christian Bauer

    Problem with compressible liquid

    Christian Bauer

      Recently I tried to create a custom compressible liquid with the following parameters:

       

      Density Type: Power Law

      Reference Pressure: 40 bar

      Reference Density: 59.27 kg/m³

      B: 274473 Pa

      n: 0.908810518

       

      To test these values a simple pipe was used as model, where the fluid is injected at 270 K / 5 m/s and a counter pressure of 60 bar. This produced the required fluid properties quite well for this temperature.

       

      To make the fluid applicable to a greater temperature range the B, n, and Rho_0 values were specified at various temperatures. The result was, that density and the other properties still matched quite well, however, the fluid temperature would oscillate greatly. Depending on the exact values of the parameters, temperature would be anywhere from 0K to 5000 K, which obviously makes no sense.

      The same problem occurs, if even only one parameter is specified as temperature dependant - even if that single parameter specifies only one data point, with the value used earlier.

       

      Does anyone have experience with creating custom compressible liquids? Could this be a bug? Or am I overlooking something important? Any hint on how to solve this problem would be greatly appreciated!