2 Replies Latest reply on Jul 12, 2017 2:07 PM by Gian Flavio Violi

    Flow Simulation Boundary Condition

    Ramalingam Parthiban

      Hi every one,

      I am havinng a small query regarding SolidWorks Flow Simulation Boundary condition. Can anyone explain when to use Static pressure condition and when to use Environmental Pressure Boundary condition? if possible kindly help to explain using simple case studies. Thanks for the help.

        • Re: Flow Simulation Boundary Condition
          Siavash Khajehhasani

          Here is your answer:

          "The only difference between static pressure and environmental pressure depends if there is vortex

          flow near the opening. If there is no vortex flow then there should be no difference.

          If there is a vortex near the opening, the flow that is coming back through the opening is calculated

          using static pressure if a static pressure boundary condition is applied at the opening. If

          environmental pressure is used as the boundary condition then the flow is calculated assuming total

          pressure. Environmental pressure is more accurate if there is vortex flow near the opening. If there

          is no vortex flow near the opening then the results should be the same no matter if you use static

          pressure or environmental pressure."

          Reference: S-060892

          • Re: Flow Simulation Boundary Condition
            Gian Flavio Violi

            Hello Ramalingam,


            Static pressure refers to the component of pressure without kinetic energy involvement.


            Enviromental Pressure refers to:

            • Total pressure (static + dynamic pressure) if the boundary condition is an inlet (e.g.: fluid entering the computational domain). Total pressure = static pressure + 1/2*density*velocity^2.
            • Static pressure if the boundary condition is an outlet (e.g.: fluid leaving the computational domain).

            Source: SolidWorks Flow Simulation Help


            When to use which? Depends on the variables of your problem, if you are going to meassure static pressure or total pressure. If you are ever going to validate this results with experiments, then just see which kind of barometer you've got, if it accounts for the dynamic component or not. Then you'll know your answer.


            One quick tip: if you are using Enviroment pressure as an outlet condition, better use static pressure at the inlet to calculate the pressure drop. Makes no sense to calculate static vs total pressure drop.