CFD Online Discussion Forums - Increasing Inlet Flow Velocity Over Time

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Increasing Inlet Flow Velocity Over Time

Hello all, I have what should be a relatively simple question. I am simulating the flow over three cylinders to observe the vortex shedding. I am currently using a constant inlet velocity, but I would now like to increase the inlet velocity over time.

In 0/U, I currently have the code:

Code:

inlet

    {

        type            uniformFixedValue;

        uniformValue    constant (1 0 0);

    }



outlet 

    {

        type            pressureInletOutletVelocity;

        inletValue      uniform (1 0 0);

        value           uniform (1 0 0); 

    }

In order to increase the inlet velocity over time, I believe I will modify "inlet" as e.g.

Code:

inlet

    {

        type            uniformFixedValue;

        uniformValue    table

        (

            (0    (1 0 0))

            (5    (2 0 0))

            (10    (3 0 0))

        );

    }

My question is this – do I need to make a similar modification to outlet? It would just be this simple?

Code:

outlet 

    {

        type            pressureInletOutletVelocity;

        inletValue      table

        (

            (0    (1 0 0))

            (5    (2 0 0))

            (10    (3 0 0))

        );

    }

Thank you in advance for any comments or insights!

Simulation Running

I have got the simulation running by modifying outlet as such:

Code:

    outlet 

    {

        type            pressureInletOutletVelocity;

        inletValue      table

        (

            (0    (1 0 0))

            (15    (2 0 0))

            (30    (3 0 0))

        );

        value           uniform (1 0 0); 

    }

This feels naive to me, so we'll see what the simulation looks like once it finishes.