Swept Volume Theory

Discussion in 'Hydrodynamics and Aerodynamics' started by Sailor Al, Aug 2, 2022.

  1. Remmlinger
    Joined: Jan 2011
    Posts: 299
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    Location: Germany

    Remmlinger engineer

    In your bubble experiment you move the foil so slowly, that you get stokes flow (or creeping flow), where the inertia forces are negligible. This has nothing to do with the flow around a sail, where the Reynolds-number is higher by a factor of one million. You can see, that the rear stagnation point in your experiment is not on the trailing edge, but on the lee side of the foil. All similarity rules are violated in this experiment.
    gonzo likes this.

  2. Sailor Al
    Joined: Feb 2021
    Posts: 593
    Likes: 23, Points: 18
    Location: Sydney

    Sailor Al Senior Member

    I recorded the video in slo-mo on my phone.
    The foil was moving at ~1m/s over around .3 m giving an experimental Re of around 10^4.
    According to an unreliable source Stokes Flow occurs when upload_2023-1-18_9-26-29.png I think that means very much less than 1.
    Not a sail's Re I agree, but way out of range for Stokes Flow.

    Thanks for that. I can see that I need to provide a lot more information about the experiment.
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