2 Replies Latest reply on Jan 15, 2015 3:08 PM by Jared Conway

    fluid flow and high acceleration

    Siew Goh
    Siew Goh Jan 13, 2015 11:01 AM

      Hello, I am new to the flow simulation. I would like to simulate the flow in a cavity when the whole system is moving in high acceleration (127.53 m2/s). There is an inlet and outlet flow (please refer to attached file). The general setting are as follow:

       

      General Setting:

      Analysis: Internal , exclude cavities without flow condition

      Gravity: Y component (-127.5 m/s^2)

      Flow: Water

      Inlet volume flow- 25 litre/min , uniform, absolute

      Environment pressure outlet

       

      I checked the result with the setting- gravity: Y component (-9.81 m/s^2) and I found that there is no difference with the result with the setting of gravity (-127.5m/s^2). I think my setting is no correct in this case. I would like to know how I can make the whole system accelerate?

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        • Re: fluid flow and high acceleration
          Amit Katz
          Amit Katz Jan 13, 2015 2:11 PM (in response to Siew Goh)

          The gravity component manifests itself mostly in potential energy changes as your flow goes through large elevation changes. Additionally the potential energy factor is usually only significant in flows with low dynamic pressure changes (such as low Reynolds number flows.) Is that the case here? You mention your flow rate is 25 L/min but without any sense of scale of this object it's hard to say what your flow velocities are.

          I notice that your inlet and outlet are at the same elevation relative to the gravitational potential, and your internal flow cavity looks rather flat, so I don't expect gravity to play a huge role here.

          • Re: fluid flow and high acceleration
            Jared Conway
            Jared Conway Jan 15, 2015 3:08 PM (in response to Siew Goh)

            what is the effect of the acceleration on the fluid?

             

            like amit said, the gravity just changes the pressure essentially based on rho g h

             

            an interesting question though, i think you're expecting to have a the acceleration be applied to the flow "molecules" as well?