The static pitch angle of the 1903 props was just above 27°. If that number were all that mattered, it would be above stall angle in still air. It's not all that matters. The Wright's props were very long, wooden, high-aspect-ratio affairs. Under load, they'd tend to flatten in pitch as the airfoil wants to turn nose-down.* Under load, the effective pitch would be quite different than the static pitch, even in still air. The Wrights were taking this into account, after their 1902 research showed that the 15° pitch test prop flattened out too much and didn't produce the expected thrust.Here's a good picture of the 1903 Flyer showing the blade angles. I can't say whether the angle is above stalling with no wind velocity.
Don't know about that, but the Wrights were constantly working on their props, just like the rest of their aircraft. The 1904 props were different than the 1903 ones, and there were further improvements in 1905. The 1908 designs were quite a bit different than the 1903 props, as a result.Wasn't there a story that the 1908 Flyer took off using only its skids?
Yep, and I wish the people who research these things would work with conventional nomenclature. The 27° figure I got from here: Wright propellers (rev3) It's an interesting bit of study, but they also overlook the aeroelastic effects on the prop just like the replica makers, and their thrust margin figures at lower airspeeds are almost certainly too low by a wide margin....Prop pitch: Like any modern propeller, the Wright's blade were twisted. Speaking of "27° pitch angle" is meaningless unless you specify where along the blade it's measured."
Well said. The Flyer had a "design" airspeed of about 24-30mph. In ultralight territory, by modern standards.Spin a prop in static air and the inner portion will be stalled, yes, while the outer portions will be not so much so. Furthermore, even a stalled airfoil generates considerable lift; the drag increases rapidly but while the lift (i.e. thrust) drops off it doesn't suddenly go to zero. There's also induced inflow, so no prop is ever operating in really static air. Thrust may be diminished at lower speed, perhaps not even enough to fly, but it will be enough to start it moving; the faster it goes the more thrust it makes until it reaches its design airspeed... which wasn't all that high anyway.
Very few, if any, innovations come completely out of the blue (pun not intended). Instead they are the result of a series of developments punctuated with gifted insight. Perhaps the Wright's biggest contribution was that they used good engineering practice---study what others had done, identify problems, solve the problems, keep improving the product. Yes, their 1903 flyer wasn't all that good, but they kept at it and eventually 'got it right'.Certainly the Wrights "stood on the shoulders of giants." Much of what they did was refinement of others' previous work, though they did it more scientifically than most others had before them.
Hence the quote form Santos-Dumont in my previous post: "To them we are as children." He was admitting that the Wrights were far ahead of any development in Europe.Several years later, when the Wrights came out of seclusion and demonstrated their airplane in Europe, while others had gotten airborne, none had achieved the level of control (and controlability) that the Wrights had acheived several years earlier.
You mean Charles Manly's remarkable engine. This engine was literally decades ahead of its time, and he's one of the unsung heroes of engineering of the period. The fact that Langley's Aerodrome was incapable of controlled flight in its original configuration (the 1911 tests were with a radically modified variant) had nothing to do with the engine developed by Manly. There is little chance of understating how advanced this powerplant was for the period. The power-to-weight ratio, for example, wasn't exceeded until WWI....the full size drawings of his remarkable engine...
Yes, that was a common hobby-horse of the period. Maxim hoped his dynamite and machine-gun would do the same, as did Gattling, et al.Chanute hoped that flight would be so disuptive to normal military operations as to bring warfare to an end as the final page in his book of 1894 states.
Marine propeller "theory" at the time was confined to tables of empiric measurement, not theory as we conceive it today. One could not design a propeller to specification and expect it to perform according to design at the time. The Wrights were the first to develop a rational theory and design methodology for propellers in any medium. Their development of an early form of blade-element theory was, perhaps, their greatest contribution to science and engineering, but perhaps their least-recognized.Marine propeller theory was well established by 1900 just not in inland Dayton I guess - windmills also knew about helical pitch and camber etc.
Exactly the latter case. Their theory held up, but didn't acknowledge the realities of aeroelasticity in their real-world propeller designs. This is why they increased the pitch between their 1902 test propeller designs and the design used on the 1903 Flyer. They realized that the reason the thrust developed by their 1902 test prop was less than their theory specified was because the thing was twisting and reducing the effective pitch. They compensated by increasing the static pitch of their propeller designs. It wasn't based upon theory (aeroelastic theory was decades in the future at the time), but they were aware of the results and what, pragmatically, needed to be done about it.--I would need convincing that the Wright's props were aeroisoclonic or aeroelastic by design but the effect might have been known to them by trial and error...
OK. I think we can all agree that the 1903 Flyer wasn't a practical airplane... by any objective standard it was a horrible airplane... underpowered, unstable, and fragile. But it did fly.No one is saying the Wright Flyer of 1903 was not a real aeroplane but simply not a practical one...So too the Wright Flyer had relatively low power and the Wrights did not attempt any flights from level ground in low wind. They had plenty of space to increase the take of distance but used a slope instead for ATO for their test on 14th December 1903, because of low wind.
I'm finding mixed references on the construction of the Wright's 1903 props. Certainly some of the ones from later years were laminated. The historians who research this stuff seem to care so little for such technical details. However, even if the 1903 props were laminated, my point still stands - a replica would need to copy the aeroelastic behavior of the originals in addition to their shape. Simply having laminated props doesn't mean that the blades weren't twisting, it simply is a matter of degree. From their wind-tunnel testing on scale prototypes (mostly 1902) the Wrights knew their blades were twisting, and they were trying to compensate for it.Topaz says the 1903 Flyer had propellers carved from solid wood. All the references I have seen say they were laminated. So the flexing issue is not clear. The idea for Langley's engine was probably influenced by Hargrave's design as he allowed free use of his designs. Interestingly on the two occasions that I visited the Power House museum Hargrave's display was not available for the public to see. It seems that Australian's do not appreciate the pioneer that was in their own backyard. Is that because he was an ex pat Brit?