3 Replies Latest reply on Sep 29, 2011 11:00 AM by Jerry Steiger

    Sketch aerofoil

    Roisin McConnell

      Hey guys,

      Not sure if this is the right group to place this question, but can't quite hurt. I am drawing the belly fairing on an aircraft, it is the joint between the wing and the cabin for those who do not know what I mean.

      I need to draw the aerofoil shape to where the fairing meets the wing, I can easily draw the aerofoil, clearly as I done it for the wing, but I need the aerofoil to correctly match which becomes quite tricky if the wing is twisted/swept.

      Any ideas of how I find the exact match, especially if the wing geometry changes but the fairing stays the same!?! I don't really want any intersection points....

       

      BellyFairing.jpg

       

      BellyFairing2.jpg

       

      You can see the interference between the surfaces already, plus the gap between the wing and aerofoil cut on the fairing.

       

      Roisin

        • Re: Sketch aerofoil
          Charles Culp

          Create a boundary surface. Only use direction 1. Select the edge of the existing fairing where it ends, touching the cabin. That will be one contour. Then select the edge of the wing where you want it to end. This will be the second contour. Set both end conditions to "curvature continuous". You may have to press the button with two arrows to switch the direction on the first curve. You want it to match the existing surface. This should create a nice smooth transition from one to the other.

          • Re: Sketch aerofoil
            Mauricio Martinez-Saez

            The old time method at BOEING Eng. Dep.  (not a joke... this is really how wing aerofoils where traced)

             

            boeing-spline.jpg

            • Re: Sketch aerofoil
              Jerry Steiger

              Roisin,

               

              If you can live with the intersection between wing and fairing lying in a plane, then you can put a plane at the intersection and then use Intersection Curves to define the edges. If you can't live with a planar intersection, then you could build a surface more or less perpendicular to the wing that gives you the intersection that you want and use that surface to trim the wing. Thinking about it, even if you want a planar intersection, you will probably want to trim the wing so that you can use tangent to surface conditions, as Charles suggested. If the wing actually passes through the fuselage, you may need to use offset surfaces and trim them.

               

              Jerry Steiger