Wings?

[olboatman]

Scribed.....Great history guys!!!!! Gary

[shadowcat]

where's T2x these days -this is the perfect thread for him to comment on?

[RogerH]

Ted, I'm pretty sure that RIch & Doreen are getting ready or actually doing their move to Granite Quarry, NC. the week.

[shadowcat]

todays vintage events have straightaways to short I believe for the wing to fly- however I can tell you in no uncertain terms - the design does definitely work-my wing sits on a pontoon boat trailer and on my way home from clayton last year I followed right behind my son who was towing the switzer wing and I noticed to my amazement at one point when he was driving over 70 (which I don't recommend) that the whole front of the boat raised up off the trailer and was in the air-needless to say I now tie down the front of the boat to the frame also instead of just the winch- she loves the air

[GENE LANHAM]

however I can tell you in no uncertain terms - the design does definitely work-----she loves the air

Hi Ted---the 'Lift Formula' is a very simple formula----with some very complicated numbers.

Every one that goes fast in a car, airplane or boat should be familiar with it---

[2us70]

Does this formula take into consideration ground effect? I thought ground effect kicks in at about 1/2 wingspan altitude. For a Switzer wing wingspan is easy to measure for a tunnel not so easy.

[GENE LANHAM]

Does this formula take into consideration ground effect? I thought ground effect kicks in at about 1/2 wingspan altitude. For a Switzer wing wingspan is easy to measure for a tunnel not so easy.

Ground effect changes C/L (coefficient of lift) by a numerical factor---(also the Center of lift)---that is where the numbers get complicated---

[Jimboat]

Great thread guys! It's wonderful to hear the background and 'hands-on' history of such legendary hull designs! Thank you!

Does this formula take into consideration ground effect? I thought ground effect kicks in at about 1/2 wingspan altitude. For a Switzer wing wingspan is easy to measure for a tunnel not so easy.

Ground effect changes C/L (coefficient of lift) by a numerical factor---(also the Center of lift)---that is where the numbers get complicated---

Lift and drag of a tunnel hull wing are highly influenced by:
a) height above water surface (h/C), C = effective wing chordlength leading edge to trailing edge
b) aspect ratio of deck/tunnel region (b/C), b = effective wing span
c) deck/surface thickness ratio (t/C), t = thickness upper surface (deck) to lower surface (tunnel roof)
d) aerofoil (deck/tunnel) shape*
e) angle of attack (α)
f) other factors

The sponson sides of tunnel hulls also act as 'end-plates' to the aerodynamic 'wing' section, which is shown to further enhance Lift/Drag performance.

Dynamic Stability changes dramatically with each of the influencing factors too! Gene is right, it's a tricky analysis, but sure is fun!

Typical Ground effect (alone) is shown to be effective at h/C = 1.0, so even higher tunnel heights have aerodynamic impact. The 'wing designs' are fantastic, trend-breaking examples of true aero engineering in performance boat design.

Love this stuff! Thanks for all your great discussion and history, guys!

http://www.aeromarineresearch.com/research.html

http://www.aeromarineresearch.com/wi...l_testing.html

[shadowcat]

wow- Gene and Jimboat- totally impressed!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[lilabner]

And when Dave Switzer came up with the idea, he went to a local airport, got a piece of wing I think off a Piper of some type, mounted it away from a wall, sent Bob to get a roll of butcher paper, taped it on the wall, shined a light on the wing section so a shadow would project on the butcher paper, and drew the shape for the very famous and beautiful Switzer Wing. Now all you Einsteins and Von Braun's get a hold of yourselves and tell us where all the math got into this design..He never even had plans!!

[Mark75H]

And when Dave Switzer came up with the idea, he went to a local airport, got a piece of wing I think off a Piper of some type, mounted it away from a wall, sent Bob to get a roll of butcher paper, taped it on the wall, shined a light on the wing section so a shadow would project on the butcher paper, and drew the shape for the very famous and beautiful Switzer Wing. Now all you Einsteins and Von Braun's get a hold of yourselves and tell us where all the math got into this design..He never even had plans!!

Correct, the whole thing was a very lucky educated guess based on what their father knew about flying, or maybe more correctly - taking off and landing.

[BarryStrawn]

And when Dave Switzer came up with the idea, he went to a local airport, got a piece of wing I think off a Piper of some type, mounted it away from a wall, sent Bob to get a roll of butcher paper, taped it on the wall, shined a light on the wing section so a shadow would project on the butcher paper, and drew the shape for the very famous and beautiful Switzer Wing. Now all you Einsteins and Von Braun's get a hold of yourselves and tell us where all the math got into this design..He never even had plans!!

Plenty of math went into the US Army or NACA airfoil they copied. And I expect a lot of cut and try to get the rest working.

[Jimboat]

And when Dave Switzer came up with the idea, he went to a local airport, got a piece of wing I think off a Piper of some type, mounted it away from a wall, sent Bob to get a roll of butcher paper, taped it on the wall, shined a light on the wing section so a shadow would project on the butcher paper, and drew the shape for the very famous and beautiful Switzer Wing. Now all you Einsteins and Von Braun's get a hold of yourselves and tell us where all the math got into this design..He never even had plans!!

Bob & Dave's legend is a great one. While there may not have been detailed lift calculations at the time, it is clear that the Switzer brothers were the first to recognize and capitalize on the benefits of aerodynamics in performance boat design. The shape may have been somewhat arbitrary, but the Switzers knew that planform, thickness and height all affected aerodynamic overall lift. The brothers Switzer were the first designers to realize that significant aerodynamic lift in a hull design would reduce hydrodynamic drag significantly - and they proved it on their first hull! Incredibly, their first boat had no method controlling angle of attack (no power trim), so driving was a delicate balance to prevent 'over-flying' the hull.

[2us70]

The 2 versions of fiberglass wings were all the same but I was of the impression all of the wood boats were different.

[GENE LANHAM]

Great thread guys! It's wonderful to hear the background and 'hands-on' history of such legendary hull designs! Thank you!

Love this stuff! Thanks for all your great discussion and history, guys!

Thanks for joining our little group, Jim--and for contributing your knowledge to these discussions!!

I have always been fascinated with 'aerodynamics'---and have been flying (airplanes) for nearly 45 years. Your writings (boats) and Peter Garrison's (planes) are the best----