|
|
My exit duct will be on the top of the wing, just aft of the maximum thickness. The airplane sits on the ground with approximately 9 degrees of nose up angle, so I wanted a design that make rain water/leaves/other debris run off the back rather than down into the duct.
I started by building up a form around the fiberglass wheel well that was even with the top skin, and then glassed it all around, leaving the top open. Then I made up some foam 'sticks', covered in packing tape, each about an inch wide. Both sides and the back are tapered. I lay on one at time, covering it with 2" tape. The next stick would lay on top of the excess tape from the previous. There are 6 sticks, each 9" wide and 1/2" high, for about 27"^2 of exit area. Each intake is a little more than 4"x6", for about 25"^2 intake area. Not the optimum ratio, but I expect to have excellent pressure recovery (full length K&W ducts), low losses (large, mostly straight, interim duct area), and a somewhat negative pressure on the exit area (due to the location on the airfoil). If I need more exit area, I have the option of opening the rear of the exit duct and fair it into the top skin without much effort. If I have too much cooling, I have the option of first removing the scoops from the intake, and then closing up one or more of the exit holes.
BuildingWheelWellDuct1.jpg
BuildingWheelWellDuct2.jpg
BuildingWheelWellDuct3.jpg
|
|