Announcement

Collapse
No announcement yet.

Using the Boundary Layer to Gain Effective Wing & Propeller Blade Area.

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Using the Boundary Layer to Gain Effective Wing & Propeller Blade Area.

    During WW I Ludwig Prandtl identified the boundary layer and discovered that wires and struts produce much more drag than would be expected from their small frontal areas, making a strong case for wireless monoplanes (however, with modern materials and wingtip tanks, cantilever biplanes or triplanes without wires or struts can be made very aerodynamic). A small wire produces more drag than expected, because some air adheres to it, increasing the effective diameter (boundary layer), around which the air has to flow. Accordinly, the Fokker D.VII eliminated the wire stays between the wings with welded steel tubing N struts.

    Because most current private plane wings are large, the boundary layer has a negligible effect on wing area. However, if a higher wing loading & multiple, narrow, tandem wings are used instead of a single large wing, the greater effect of the boundary layer will result in a larger effective wing area than the actual wing area. Moreover, since in laminar flow the boundary layer is thicker at low speed & sea level than at high speed & 11,000 ft, the plane has a very slightly larger effective wing area during TO than at cruising speed.

    By extension, since a propeller blade is just a rotating wing, a prop with 4 fold the number of blades (each blade 1/4 as wide as in the original prop) will have the same total area but a higher effective area, owing to the greater effect of the boundary layer.

  • #2
    So, who cares? Take your theories to Cessna and Beech. I'm sure that they will be as entertained as we are by your military scenarios.

    Comment


    • #3
      If You don't care bugger off. I wasted time repeating that the plane was pressurized after You claimed to have been waiting for months for the answer. I don't waste time telling people how uninteresting their threads are & suggest You do the same.

      BTW the companies You mention are much more concerned about coping with frivolous law suits than about coping with the laws of physics (innovation). Strangely, they did invest an enormous amount developing an expensive & completely impractical Rutan design, which didn't sell.
      Last edited by Dracoco; 26 Dec 15, 19:05.

      Comment


      • #4
        What is your flawed point?

        Comment


        • #5
          Originally posted by Tyramon View Post
          What is your flawed point?
          Drano doesn't have points. He just spews written diarrhea.

          Comment


          • #6
            No need for such hostility. But I do agree; what is your point?
            Wisdom is personal

            Comment


            • #7
              Originally posted by Karri View Post
              No need for such hostility. But I do agree; what is your point?
              You're obviously not aware of Draco/Dracoco's history...

              Comment

              Latest Topics

              Collapse

              Working...
              X