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A fundamental principle of aeronautical engineering has been overturned

wired.com

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Re: A fundamental principle of aeronautical engineering has been overturned

#11

Post by 6stringmerc »

I wrote about this ages ago, in that shark skin is an evolutionary adaptation worth study because water is thicker than air, but when air compounds, blah blah blah. Basically think of making a composite mold with directional tiny tiny dorsal fin looking surface. If you rub your hand on it the wrong way it cuts you open. Could even be scaled for large cargo ship hulls.

Next up: my personal wing invention which uses leading edges modeled on humpback whale fins, because the use case / stall profile is better.

Sigh, I’m going to have a great time in Heaven chatting with Leonardo da Vinci…

Re: A fundamental principle of aeronautical engineering has been overturned

#12

Post by r3trohack3r »

6stringmerc wrote: post #11

I wrote about this ages ago, in that shark skin is an evolutionary adaptation worth study because water is thicker than air, but when air compounds, blah blah blah. Basically think of making a composite mold with directional tiny tiny dorsal fin looking surface. If you rub your hand on it the wrong way it cuts you open. Could even be scaled for large cargo ship hulls. Next up: my personal wing invention which uses le…

From the featured article:

> This technology is fundamentally different from the “rivulet (shark skin) process,” which is known as a typical aerodynamic drag reduction technology. The rivulet process mimics the fine longitudinal grooves in shark skin, and by carving grooves approximately 0.1 mm wide along the direction of airflow, it aligns the vortices that occur near the wall surface of turbulent airflow areas. DMR, on the other hand, delays the switch from laminar to turbulent flow by means of random and minute irregularities. The flow zones it affects and the mechanisms it employs are based on completely different concepts.

Re: A fundamental principle of aeronautical engineering has been overturned

#15

Post by beering »

mlmonkey wrote: post #9

> It's long been accepted that the smoother the surface, the lower the aerodynamic drag. That turns out not always to be the case. Huh... I'd always heard that a golf ball's dimples help reduce drag?

TFA makes it clear that this is a very different phenomenon than golf ball dimples, and even goes as far as to say they are opposing.

Re: A fundamental principle of aeronautical engineering has been overturned

#16

Post by Swizec »

mlmonkey wrote: post #9

> It's long been accepted that the smoother the surface, the lower the aerodynamic drag. That turns out not always to be the case. Huh... I'd always heard that a golf ball's dimples help reduce drag?

> Huh... I'd always heard that a golf ball's dimples help reduce drag?

Yep also vortex generators in cars have become common. So common that they've filtered down to after market parts you can put on a honda civic

Vortexes break up large air pockets and reduce drag.

Re: A fundamental principle of aeronautical engineering has been overturned

#18

Post by imoverclocked »

sgc wrote: post #8

If the application method is as rudimentary as sandblasting, it sounds rather simple to retrofit to existing aircraft. If it works as they state it does, it's a virtually free same-day fuel efficiency boost. However, I did not see what the actual net improvement was. When they talk percentages, they are talking only about "in the transition zone". They say the coefficient improves throughout, but in theory, it could…

… theoretically meets reality pretty quick in aviation. You’ll likely find a lot of red tape to modifying any particular aircraft until it has been tested or certified. Well, for certified aircraft anyway. Even in the experimental world you might find some (excuse the pun) resistance to sand blasting someone’s wing.

Re: A fundamental principle of aeronautical engineering has been overturned

#19

Post by zonkerdonker »

sgc wrote: post #8

If the application method is as rudimentary as sandblasting, it sounds rather simple to retrofit to existing aircraft. If it works as they state it does, it's a virtually free same-day fuel efficiency boost. However, I did not see what the actual net improvement was. When they talk percentages, they are talking only about "in the transition zone". They say the coefficient improves throughout, but in theory, it could…

Based on the mechanism of flow attachment in the transition zone it seems like the overall airfoil profile would likely have to change to take full advantage of the reduced friction. I think its much more likely to see this technique played with somewhere like Formula 1, if it hasnt been already.

Re: A fundamental principle of aeronautical engineering has been overturned

#20

Post by wafflemaker »

6stringmerc wrote: post #11

I wrote about this ages ago, in that shark skin is an evolutionary adaptation worth study because water is thicker than air, but when air compounds, blah blah blah. Basically think of making a composite mold with directional tiny tiny dorsal fin looking surface. If you rub your hand on it the wrong way it cuts you open. Could even be scaled for large cargo ship hulls. Next up: my personal wing invention which uses le…

Why wait for heaven. There probably are mods for Kerbal Space Program with exactly that parts. Create your wingsuit there.
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