When we had my plane flipped over, C-Rod came over and remarked that I was probably getting a lot of drag from the underside of the wheel pant, and when you look at it, I'm sure he is right.
This was the only time I could do anything about it, so we I dug in. I figured I could make some kind of cover, but the trick would be holding it in place. I finally decided to put slot in the wheel pant to hold the aft end of the skirt, then I would use a single fastener for the front.
First, I make a crude template from stiff paper. Then I made up a couple of flay lay-ups using two layers of carbon fiber.
The slot was cut into the pant and I stuffed flox into it to stiffen it up. While the flox was still wet, I stuck in a piece of aluminum covered with clear tape (black arrow). That would form the slit in the slot.
I needed a way to stiffen the skirts, so I made some vertical stiffeners by laying up strips on the inside of the wheel pant. This would get me a general shape. The stiffeners were attached to the skirt, in situ, then finally the front attach point was added.
My thoughts are to use the skirts only while racing and to be able to remove them without having to jack up the plane. However, I will probably have to jack up the plane to insert them.
I hope this gains me a knot or two.
3 comments:
I agree you are probably getting a lot of drag there. I would have used something much "softer" (like pour in place foam covered by a single layer of glass). If you have a tire issue (like low pressure), your skirt would self destruct before it caused too much of a problem. If you only use the skirts while racing, you probably won't have a problem, but we both know you will be tempted to keep them on permanently!!
- Paul
Leave em on! Wonder how much speed you'll get. I may just try them also. Mike N3QP
Thanks to both you and Mike (N3QP)for generously sharing your "Q" knowledge...Out of curiousity, have you researched whether a set of Whitcomb (they'd look nice raked the same degree as the vertical stab) or Finchtip wing tips on the main wing would be of any performance advantage? Not sure the link to an EAA Sport Aviation article will work here but I will post it at the end. Also, "paul" has brought up an issue which I haven't yet seen an answer to..."What happens to the canard in the event of a flat tire? Also, somewhere in the data I've collected on the Q I saw someone else with the same type of fairing for the wheel well but there were no comments as to their improvements...I've tried to relocate it, no luck yet. An idea that had crossed my mind was a piece of "semi-hard" rubber custom contoured to the shape of the tire and wheel well, attached at the front of the well that would blow up tight against the tire in flight yet not give any drag when the wheels rotate on the ground.....this would also provide a sort of inflight brake that I've seen Mike use in flight videos....synergy, non? Don't know whether I'd learn more by seeing a windtunnel test of the Q200....or....adding $100 to the pot that you said someone put on your "head".....lol
Thanks again...and like Mike, I say "Leave thenm on".....:>)
Al
http://f1.grp.yahoofs.com/v1/EJjiR3MR8kY6ZWDGUhpGUU9Im03jtWIIDDUw3MItgqXiNPZ0mlUK4Cxfkdv-D_oDCrIVMOWVUyMhcKOfIe1WMYZBtikX/Oil%20Flow%20Patterns/Finchtip.doc
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