Lift onset, planing, and lift coefficient

Discussion in 'Hydrodynamics and Aerodynamics' started by sandhammaren05, Aug 13, 2018.

  1. DCockey
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    DCockey Senior Member

    Are you assuming that anyone with criticisms of your theory does not "understand the paper"?
     
  2. Ad Hoc
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    Ad Hoc Naval Architect

    That seems to be the crux of it...
     
  3. sandhammaren05
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    sandhammaren05 Senior Member

    I haven't read any real criticism of my paper.
     
  4. sandhammaren05
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    sandhammaren05 Senior Member

    I'm waiting for your report of how that design performs as planing hull with an outboard. Try it and let me know the results.
     
  5. DCockey
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    DCockey Senior Member

  6. DCockey
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    DCockey Senior Member

  7. sandhammaren05
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    sandhammaren05 Senior Member

  8. sandhammaren05
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    sandhammaren05 Senior Member

    Plowing. Not planing. Pushing the bow through the water an an angle.
     
  9. DCockey
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    DCockey Senior Member

    Interesting definition of criticism. And based on my reading several fundamental "errors" have been identified.
     
  10. DCockey
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    DCockey Senior Member

    In this video for example Lee Baxter’s Awesome 26′ BARTENDER Storm Crow | Bartender Boats https://bartenderboats.com/lee-baxters-awesome-26-bartender-storm-crow/ the Bartender is traveling at a speed considerably higher than "hull speed" with the boat significantly higher relative to the water surface than the static trim height. That satisfies common definitions of planning, though perhaps not that of the original poster who appears to have his own, unique definition of planing.
     
  11. sandhammaren05
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    sandhammaren05 Senior Member


    For me 'hull speed' is the speed of the hull. I'm not into naval architecture misconceptions based on a paramemter like U/L that's useless for planing hulls.
    The bar boat's not planing, it's plowing. There's an inadequate transom in front of the motor, and they've added side-planars to try to get the stern to ride a bit higher. hy on earth would anyone want such a DUMB design-?! Why not just cut a big hole in my Glastron and stick a possum down there to paddle its legs and push the boat.
     

    Attached Files:

  12. DCockey
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    DCockey Senior Member

    How do you define "plowing"? It is clear in the video that the CG of the boat is above it's static height and the boat is being supported primarily by hydrodynamic pressure on on the bottom which is a common definition of planing.
     
  13. sandhammaren05
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    sandhammaren05 Senior Member

    It's plowing: its dragging the bow through the water trying without success while to ride up the bow wave. It never climbs up onto the bow wave. There is therefore no evidence in the photo for your claim that lift carries weight compared with buoyancy. What's the depth of boat in the water compared with the static depth? Moreover, where's the picture of the entire boat bottom? Unless you see the bottom (need the boat upside down for that) then you don't know what you're talking about. It's necessary to see a boat bottom in order to form any opinion at all.
     
  14. sandhammaren05
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    sandhammaren05 Senior Member

    Added comment. Run the film in slow speed (1/4 speed) and stop it from time to time. As he accelerates the boat tries to ride up the bow wave but the trim angle never changes after that. The bow is higher and the stern is deeper in the water. I see a break like a spray rail along the bow, otherwise the water from the plowing of the bow would run up the sides and onto the front deck. This is plowing.
     

  15. CT249
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    CT249 Senior Member

    In what way is the motive power relevant? Your paper makes sweeping claims that are not limited to outboard powered craft.

    Fact- those craft have no transom and yet they plane.
     
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