Comments - 601XL wing fairings - Zenith Aircraft Builders and Flyers2024-03-29T04:57:47Zhttps://zenith.aero/profiles/comment/feed?attachedTo=2606393%3ABlogPost%3A77146&xn_auth=noHi All,
Thanks for the compli…tag:zenith.aero,2010-10-21:2606393:Comment:772762010-10-21T18:14:27.595ZLouis W. Otthttps://zenith.aero/profile/LouisWOtt
Hi All,<br />
Thanks for the compliments. Jake, your finished fairings look great. I knew I needed perfect molds to accomplish what I wanted, but hurryupitis got in the way. Oh well, lessons learned I guess. I ripped one of the upper tendons in my right bicep and that put me out of commission for airplane work for about 6 weeks. Then, hurry up to finish before winter came. I did find a tool I wish I had during sanding the concave shape. It's a bowl sander. It has a 1/4" spindle to fit in any drill…
Hi All,<br />
Thanks for the compliments. Jake, your finished fairings look great. I knew I needed perfect molds to accomplish what I wanted, but hurryupitis got in the way. Oh well, lessons learned I guess. I ripped one of the upper tendons in my right bicep and that put me out of commission for airplane work for about 6 weeks. Then, hurry up to finish before winter came. I did find a tool I wish I had during sanding the concave shape. It's a bowl sander. It has a 1/4" spindle to fit in any drill and has a convex flexible backing disk. The disks have scalloped edges to prevent digging in and leaving gouges.<br />
<br />
Juan - Yes, using the more dense blue or pink foam would have been a better choice and no doubt given a better result. The reason for the fairings and their shape stems from information from several sources gleaned over a number of years. Examples are Hoerner's book on drag reduction, Kent Paser's book "Speed with Economy", and various magazine and web based sources such as <a href="http://www.utdallas.edu/~klaus/Airplane/wing_root_fairing.html" target="_blank">http://www.utdallas.edu/~klaus/Airplane/wing_root_fairing.html</a>, <a href="http://myaviationtutor.com/aerodynamics-of-flight/aviation-parasite-drag/" target="_blank">http://myaviationtutor.com/aerodynamics-of-flight/aviation-parasite-drag/</a>. I felt the advantage for the 601XL would be found in lower stall and landing speed, higher rate of climb, and equal cruise speed at lower power. The 601XL/650 fuselage width changes along the wing root chord being narrow at the leading edge, widest about 2/3rd back and sharply narrowing again at the trailing edge. This change in fuselage width causes air to flow span wise as it transits from front to back. This causes loss of lift, turbulence, and drag. Ideally, the fuselage width would be constant width from leading edge to trailing edge. Van's RV designs attempt to keep the fuselage width constant at the wing junction and don't need such fairings. I extended the fairings behind the training edge to help contain the higher pressure air under the fuselage and keep it from curling upward at the trailing edge of the wing root. The TD landing gear is mounted so it is under the fuselage bottom with about 5/8" space between the top of the gear and bottom of the fuselage. This is a very high drag source. That coupled with the high drag method of attaching the gear had to be fixed. That's why I brought the fairing forward and wrapped it under to enclose the gear attach hardware. I think that will help smooth the air as it goes over the inboard leading edge. The tri-gear arrangement is much better in the wing root leading edge junction with the fuselage.<br />
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Gary - Thanks for the gear fairing information. I do plan to fair in the rear of the gear legs too. I figured an aluminum sheet, or CF, fairing should help drag reduction as well as give a channel to place the brake line. I have wheel fairings but I felt they were needed to keep rocks from throwing back and denting the flaps and stabilizer leading edge as much as drag reduction. Louie, you did a great job! U…tag:zenith.aero,2010-10-21:2606393:Comment:772712010-10-21T13:51:38.298ZJake Reynahttps://zenith.aero/profile/JakeReyna
Louie, you did a great job! Unfortunately, you are also a critic. That being said, you're much better at composites.<br />
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Since I wasn't looking for the "cool factor" of carbon, I was able to sand down my wing root fairings to remove the high spots, in some places paper thin. I filled low spots with an epoxy glass bubble mixture, cured, sanded and then added one layer of 9 ounce cloth. There is still work to be done, but they were good enough to mount and start test flying. I managed to keep the…
Louie, you did a great job! Unfortunately, you are also a critic. That being said, you're much better at composites.<br />
<br />
Since I wasn't looking for the "cool factor" of carbon, I was able to sand down my wing root fairings to remove the high spots, in some places paper thin. I filled low spots with an epoxy glass bubble mixture, cured, sanded and then added one layer of 9 ounce cloth. There is still work to be done, but they were good enough to mount and start test flying. I managed to keep the weight to 2.75 pounds each and expect a completed weight of 3 pounds each. The rubber seal weighs 1.5 pounds. A 4.5 pound weight gain, but a big reduction in drag under the wing. Thought I had better pictures, here are a couple. The first is the rough fairing.<br />
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<p style="text-align: left;"><img width="721" src="http://storage.ning.com/topology/rest/1.0/file/get/2170976481?profile=RESIZE_1024x1024" alt=""/></p>
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<p style="text-align: left;"><img width="721" src="http://storage.ning.com/topology/rest/1.0/file/get/2170964097?profile=RESIZE_1024x1024" alt=""/></p> that looks fantastic!! Few qu…tag:zenith.aero,2010-10-21:2606393:Comment:772642010-10-21T13:40:37.712ZJuan Vegahttps://zenith.aero/profile/JuanVega
that looks fantastic!! Few questions. Would you suggest using blue foam? it looks to sand better. also while I was looking at it, I rememner reading that the airfoil lift is calculated all the way to the wing root. Even though the 601 has tons of extra lift with its voluminous wing, I would how we can calculate the lift lost due to wing faring changing the lift. would it effect the plane number in a stall turn? I doubt it but curious.<br />
we probably eed to turn to some of our engineering guys on…
that looks fantastic!! Few questions. Would you suggest using blue foam? it looks to sand better. also while I was looking at it, I rememner reading that the airfoil lift is calculated all the way to the wing root. Even though the 601 has tons of extra lift with its voluminous wing, I would how we can calculate the lift lost due to wing faring changing the lift. would it effect the plane number in a stall turn? I doubt it but curious.<br />
we probably eed to turn to some of our engineering guys on here, cause I know enough to be very dangerous. I plan on copying your design!<br />
Juan Thanks for sharing your exper…tag:zenith.aero,2010-10-21:2606393:Comment:772372010-10-21T11:56:13.086ZGary Rayhttps://zenith.aero/profile/GaryRay
Thanks for sharing your experience:<br />
This helps since I want to do the same.<br />
I have made simple gear leg fairings to test for increase speed and find that there is at least 6 mph or approximately 100 f/min better climb by tapering the straight section of the gear legs plus wheel pants. I measured the biggest increase with the leg fairings and not so much with just the wheel pants. The bolts and brackets that hold the gear on are also out there in the wind and could use streamlining. I think…
Thanks for sharing your experience:<br />
This helps since I want to do the same.<br />
I have made simple gear leg fairings to test for increase speed and find that there is at least 6 mph or approximately 100 f/min better climb by tapering the straight section of the gear legs plus wheel pants. I measured the biggest increase with the leg fairings and not so much with just the wheel pants. The bolts and brackets that hold the gear on are also out there in the wind and could use streamlining. I think there is a lot of improved performance to be found in these mods with very little additional weight and expense. Now, that is a good tip. It w…tag:zenith.aero,2010-10-20:2606393:Comment:771642010-10-20T23:55:45.719ZLouis W. Otthttps://zenith.aero/profile/LouisWOtt
Now, that is a good tip. It would have saved me a lot of trouble.
Now, that is a good tip. It would have saved me a lot of trouble. Hi Louis
Looks like you got a…tag:zenith.aero,2010-10-20:2606393:Comment:771522010-10-20T22:24:36.439ZPhill Barneshttps://zenith.aero/profile/PhillBarnes
Hi Louis<br />
Looks like you got a good result in the end. One little trick I will let you in on from building model aircraft with foam core wings for 20 years, is when you want to glue polystyrene foam together and sand it without seeing a hard join line, use 3M 77 spray adhesive. It is latex based so it does not dry hard but sticks better than s**t to an army blanket.<br />
<br />
Well done<br />
Phill
Hi Louis<br />
Looks like you got a good result in the end. One little trick I will let you in on from building model aircraft with foam core wings for 20 years, is when you want to glue polystyrene foam together and sand it without seeing a hard join line, use 3M 77 spray adhesive. It is latex based so it does not dry hard but sticks better than s**t to an army blanket.<br />
<br />
Well done<br />
Phill