Wings

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Ciro Pabón
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Joined: 11 May 2005, 00:31

Wings

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Are they in the same aerodynamic regime? Or, can a humble roach be a source of inspiration? :)
Ciro

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joseff
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Joined: 24 Sep 2002, 11:53

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Of course not. An insect is so small air feels very thick, almost like a liquid. They 'swim' in air when they fly.

dcdabest
dcdabest
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Joined: 12 May 2005, 09:41
Location: Dunedin, New Zealand

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joseff wrote:Of course not. An insect is so small air feels very thick, almost like a liquid. They 'swim' in air when they fly.
Even so, wouldn't the concepts relating to movement through air also apply to liquids?
Im thinking of all the li'l starving Africans...

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joseff
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Joined: 24 Sep 2002, 11:53

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Yea fluid dynamics but it's like saying an aircraft propeller and a marine propeller are the same.

It's time to let our aero people take over, I'm in way over my head here.

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Ciro Pabón
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Joined: 11 May 2005, 00:31

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joseff, you're right, the reynolds number is smaller. I thought that the superhigh frequencies of insects with asinchronous muscles (1.000 hertzs) could provide a super-high speed, but it barely reaches 70 kph.

(if, for example, the stroke is 1 cm, each movement would move the wings 2 cm, and at 1000 vibrations per second, this means 20 meters per second, wich is roughly 70 kph).

So, the Reynolds number barely reaches 10000 for big insects.

Anyway, here there are two more examples, the first of a venation (the veins on the wing) that has millions of years of evolution behind (for "structural fans" here, it's a beauty, I think: try to do this with carbon fiber!), and the second is a "hairy" wing that I don't know if could be used on some surface by a crazy aerodynamicist:

Structure of a dragonfly wing. Notice how the size of the "cells" vary, probably according to the wing load at each particular position.
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Intriguing insect hairy wing (for the Ferrari 2020? ;)).
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Finally, heavily edited quotes from Wikipedia's "Insect flight", that I find very intriguing. Either I'm crazier than what I suppose (a good possibility) or these animals seem to thrive in the vortexes caused by the previous wing stroke, unlike modern F1 cars, that have troubles with the wake caused by the preceding car:

"Identification of major forces is critical to understanding insect flight. The first attempts to understand flapping wings assumed a quasi-steady state... The calculated lift was too small by a factor of three, so researchers realized that must be unsteady phenomena providing aerodynamic forces. ... Through computational fluid dynamics, some researchers argue that there is no rotational effect. They claim that the high forces are caused by an interaction with the wake shed by the previous stroke.
...
One of the most important phenomena that occurs during insect flight is leading edge suction... At high angles of attack, the flow separates over the leading edge but reattaches before reaching the trailing edge. Within this bubble of separated flow is a vortex. Because the angle of attack is so high, there is a lot of momentum transferred downward into the flow. These two features create a large amount of lift force as well as some additional drag. The important feature, however, is the lift. Because the flow has separated, yet it still provides large amounts of lift, this phenomenon is called “delayed stall.” This effect was observed in flapping insect flight, and it was proven to be capable of providing enough lift to account for the deficiency in the quasi-steady state models.

All of the effects on a flapping wing can be reduced to three major sources of aerodynamic phenomena: the leading edge vortex, the steady-state aerodynamic forces on the wing, and the wing’s contact with its wake from previous strokes."


I only hope Newey reads this... :lol: Anyway, I plan to follow with some structures for birds that I find have some promise... I suppose somebody must have tried to take a look before. Do you have any links for bionics and F1?
Ciro

Carlos
Carlos
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Joined: 02 Sep 2006, 19:43
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Ahhh - Yes - Ciro : This is a subject, close to my heart, a source of inpiration and admiration - organic models as creative well spring for real life engineering and design. Perhaps I am a romantic bemused.

An insect's wing, a birds wing - frozen in time - resembles an airfoil, or should I say an airfoil is a low quality adaptation of nature's craft? - a very primitive echo. A bird or insect's wing is a mobile surface of rippling adaptation to a wonderous variety of aero events. Advanced fighter plane research is stretching to embrace flexible wings without conventional control surfaces - inspired, by nature's example. Many technologies are inspired by natural selection. But - the FIA has dealt with this flexible wing problem already - as it did offer a real world advantage in F1. Ahhh- that is proof of my opinion. :wink:

I am surely mistaken - but wasn't the Fibanachi sequence derived from the entrancing curl - of a single strand - of a woman's hair? :wink:

As a further extension of a related subject - nature producing the artifical - spend a few minutes watching one of the videos at http://www.valsartdiary.com also on Youtube. Very endearing - Non? :wink:

miqi23
miqi23
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Joined: 11 Feb 2006, 02:31
Location: United Kingdom

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True, real life scenarios can form a source of inspiration. The Wright brothers being the biggest examples. However, the picture posted by Ciro can be considered as a source of inspiration as well but not a direct relation. Obviously the reynolds number would be different and it changes every thing.

Most importantly, those cover things like Aerodynamics of flapping wings and lot of research is being done on such topics where as the Renault front wing isnt flapping!

My guesses are that it is always an interaction issue between different components and trust me its surprising when you see large gains being made by slightly changing surface shapes etc. Optimisation that is!

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Ciro Pabón
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Joined: 11 May 2005, 00:31

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The Fibonacci sequence from a curl of hair? Well, I don't know, it may be. What I've heard is that Fibonacci deduced it from the breeding of rabbits. But I don't believe in what I see with my own eyes, much less in what I hear.
miqi23 wrote:... the Renault front wing isnt flapping!
You've got me totally wrong, miqi: I was thinking about the McLaren wing... (go, Alonso!) :)

Anyway, Reynold number and all, can't the delayed stall used as a source of downforce?

Here you have some more food for thought: "What they found is that insects use three distinct but interacting techniques to gain lift... Interestingly, the flexibility of the wing seems unimportant" (this proves to me that they are smarter than some of last year's aerodynamicists!).

About the delayed stall, I find: "Under some conditions, however, a structure called a "leading edge vortex" can form and sit on the top surface of the wing to create lift. The Concorde supersonic airplane takes advantage of this vortex during takeoff, as explained by Charles Ellington at Cambridge University."

And also: "Insects can get lift from the wake even after the wing stops."

How do they do it? And why McLaren (or Renault) can't? I know some can conclude they are not at the intellectual height of roaches, but... they're probably Ferrari fans. :lol:
Ciro

Apex
Apex
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Joined: 08 Jul 2005, 00:54

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Ok, here's one for you Ciro:

If you had the wing loading for the dragon fly, with all loads (inertia, aerodynamic etc...) It would be possible to model the wing with FEM, similar to a truss structure for instance (but with the membrane connected along the entire length of the beam).
With each vein as an individual structural member and each membrane's properties (such as shear resistance) would you get a near even stress distribution?

I think nature would have optimised the wing to such an extent that the stress distribution would be close to even as possible. Similar to an optimisation done by FEM methods.
Dont dream it, do it.

miqi23
miqi23
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Joined: 11 Feb 2006, 02:31
Location: United Kingdom

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Some literature on insects!

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Ciro, you might find this link interesting.

http://www.tecplot.com/showcase/contour ... icle01.htm

Thanks.

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joseff
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syguy
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Joined: 22 Feb 2007, 04:06
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Aviation has often looked to birds and more recently bugs for inspiration. Maybe F1 should cut out the middle man (aviation) and go directly to the source: birds and bugs :)
Symscape, Computer-Aided Engineering for all