" the direct high pressure under the wing is where most of the lift comes from" The lift comes from a solid's shape, asymmetrically oriented to the relative wind (from any cambered shape asymmetry plus angle of attack asymmetry). This creates a force in the vertical direction from the reaction to turning the wind. All the lift from this condition comes from conservation of mass, momentum and energy. Bernoulli is simply shorthand for these conservation relationships. Bernoulli in the above sense, is applicable to all air and liquid flow dynamics. It is universally present, because it represents the most fundamental physical principles.

@@davetime5234 Dave, How many readers are going to understand that explanation? Most of us are not physicists, certainly not I, but I did get an "A" in high school physics. And kites fly without a chambered shape, especially a box kite. Basically it's not the cambered surface above the wing created a low pressure area that creates all the lift to float say a 1,000,000 pound 747-8, it's the direct pressure below the wing. Although wings with lift devices such as flaps and slats adding (and lengthening) more camber do add to lift which lowers stall speed during takeoff and landing. Just as vortex generators lower stall speeds by preventing separation of the air flow over the top of the wing. It's all good. But then again how do laminar flow wings work with the same or similar camber above and below the wing?

@@larryweitzman5163 "How many readers are going to understand that explanation?" I would think a fair few would understand it because the outline is simple: Asymmetry of a solid object moving through air, turns the air. Lift is the resulting reaction force. So, two simple things for the essence of lift: 1)asymmetry 2)turns the air "kites fly without a chambered shape, especially a box kite. Basically, it's not the cambered surface" Lift is caused by "1)", asymmetry. You could have no camber, lots of camber, upside down camber. Camber by itself says nothing about lift. Lift is caused by asymmetry. If camber is asymmetrical, that adds to lift. But angle of attack is always either adding to any asymmetry caused by camber, or subtracting from it. So, you don't need camber at all for asymmetry. Which explains box kites and paper airplanes. "it's the direct pressure below the wing. Although wings with lift devices such as flaps and slats.." Actual pressure diagrams, widely available, show the pressure decrease on top is mostly responsible for the lifting force. Any consideration of wings, camber, flaps, etc., all work the same in terms of the pressure drop on top being the heavy lifter in making lift. But, the wind does confront the front of the wing. And there is a pressure disruption around the wing that results. So, the different pressure that result around the wind need to be justified: There is a competition for space between the relative wind that would be moving through without the wing, and the decreased shared spaced imposed by the wing. The earlier mentioned conservation of mass flow rate, momentum and energy, set the ground rules for how this pressure difference profile develops around the airfoil. As complex as that may sound, the overriding concept is also simple: The competition for space between the air and solid object forces a pressure reaction because air mass cannot stagnate. The "self-forming" pressure distribution is the one that expedites the mass through the restricted space such that mass does not accumulate anywhere. So, we could say lift is from: 1)asymmetry 2)turning the air 3)from a competition for space caused pressure response 4)which accelerates the air mass sufficiently to prevent flow disruption.

@@davetime5234 In defining asymmetry you are referring to the relative wind I presume. That could also be defined as angle off attack. Gotta to have some angle of attack and usually angle of incidence and enough airspeed. I would presume that you have a physics/engineering background.

It had 3 blades on early versions actually. As they made the engine more powerful on later versions, they could increase propeller power absorbtion by making the blade chord wider, or by adding another blade. Adding another blade was more efficient. As it already had the longest possible blades for the prop rpm, it couldn't be made any longer.

This video's only purpose is to assert that an upside down wing will still have a longer flow path over the top due to the stagnation point. I certainly dont have the means to prove it experimentally, and I'm not clever enough to do the maths 🙂 Either way it's not required as any fluid dymamic theory proves it, Euler's equations for example perfectly proves it. Note that the longer path isn't responsible for lift and isn't meant to describe lift, it only enables lift.

It's easy for us to get mixed up about what we mean by "path" and attempt to use one word to make all sorts of arguments. In a venturi tube for example, which path are we talking about?: the mean path of the entire flow, or the path only at the edge of the flow close to the curved contour etc.? If you say the mean path of the entire flow from local to extended, then no alteration in path length occurs, yet we get a pressure drop. If on the other hand if you say the path of the air nearest the curve, then of course, it has to be longer for any pressure drop to occur. The completely flat plate produces a local air path difference simply due to angle of attack, but the broader path of the overall relative wind doesn't change. So, that's already two different path meanings for the flat plate. And then you are adding a third definition for path: the geometry of the airfoil's shape irrespective of any orientation effects. In the venturi's case, we're implying one path that hugs the curve; in the completely flat plate, we have to look further out a bit from the surface to make sense of the local path, because the average local path is the smoothed-out journey around the sharp and abrupt edges, around which the air cannot turn perfectly fast. The notion of path is a mix basket of fruit. Exact definition is everything. As far as Nasa and tying those pieces together: Air forced down does create an upward reaction. That air is forced down by a pressure difference. That pressure difference results from a solid with an asymmetrical orientation producing an asymmetrical "path" challenge to the oncoming relative wind: Static pressure (potential energy contained within the affected block of air mass) is consumed equal to the dynamic pressure (kinetic energy) increase compelled by "equal transit time" of the entire wider air mass (a condition from, as NASA lists, the Navier-Stokes continuity equation, considered in aggregate). So, the above invokes the other big terminology mix-up: "equal transit time" Because mass transit time through the vicinity of the wing's effect has to result in the same mass out equal to mass in as before, it means an asymmetry in the path requires local transit time also be asymmetric, that is unequal (for mass out to be equal to mass in, and at the same level as without the wing). In other words, equal transit time through the system means that within the system, a certain definition of relative path distance being different, is absolutely necessary for the condition of lift. And this is true whether a wing is a completely flat plate or not.

The "hand out the window" is incredibly lacking as an explanation and forms in incomplete unerstanding of lift. For one, the path over the top if your hand would absolutely be longer, see from around 7:44 in the video if you missed the part around the formation of the stagnation point. Mind you, the path length difference doesn't create lift, it only enables it to be created. Not sure what the outside loop proves. It sounds like the main argument that I disproved in the video. The path of air over the upside down wing (the side that is pointing up, now the bottom) is longer than the path below (which is now the upper surface) as explained from about 9:00 in the video. The confusion is created by camber/upper surface shape. It's not the camber that creates the longer path over the wing, it's the angle of attack. And as long as a positive angle of attack exists on a wing, you hand, or a flat plank, path over the top will be longer. It's all well proven and documented in fluid dynamics.

@@LetsGoAviate Pretty sure the length of the wing on the top and the bottom does not change... dynamically depending on its orientation. At least not according to my non-magic tape measure. Outside loop, you're always flying the wing, upside down, irrespective of gravity's direction. Quad pilots like me... fly with no wings... at all. When you've got enough engine, you don't need... wings. My 5v DC computer fan will flow the same amount of air pretty much... forwards or backwards... As long as you can shove enough air out of the way in one direction, you'll go the other... aka a rocket. Spewing baseballs out one end to go the other. Or, a sailboat tacking into the wind. Or a girl on the ice on a secretary roller chair, getting hit by a baseball cannon, and deflecting them with a board... Something about Newton's Third Law... push a lot of air molecules downward, you'll go.. upward.

@@choppergirl Based on what you say, I think we are more ore less in agreement, but getting stuck on terminology and basic principles. The outside loop is simply flying upside down in a loop. The length over and under the wing doesn't change when upside down, but the distance of the airflow does. The stagnation point that separates the air over and under cannot be ignored. As long as it has a positive AoA, the path over the upside down wing will now be longer. Don't take this as me saying the path length difference creates lift, it doesn't without at least applying one other lift creation theory. Newton's 3rd law is a valid way to describe lift. But it's not just the bottom of the wing shoving air down. How does a wing stall then? We know the stall happens on top of the wing. Think about it, if bottom of the wing shoves air down, regardless of what happens on top, where is the air over the top going? Does it create a vacuum between the down shoved air and the air over the top? No, it's all differences in pressure and the air over the top has to be displaced downwards too, and this simply debunks the air being shoved down by the bottom of the wing theories. NASA insists lift cannot be correctly understood by ignoring what happens with the air going over the top of the wing, i.e. low pressure and air speeding up, and I agree. You used a sailboat as an example. I sailed Hobie 14's inland and 24 footers to big Catamarans on the ocean long before I became a pilot. When sailing let's say 45°-30° upwind on a tack, the wind doesn't push the inside of the sail, it cant. The forces at an angle doesn't resolve forward, but approx 90° sideways of forward. Instead, low pressure "pulls" the outside of the sail. I'm not saying this carries over 100% to airplane wings, or that there is no pushing on the bottom surface happening, but the "hand out of the car window" arguments simply isn't enough, and apart from being partially true, it creates a wrong idea of lift.

@@LetsGoAviate Does a Manta Ray swimming through the water, stall? Delete gravity out of the equation, and there is no stall. Even if you increase angle of attack to 89.99999 percent, there is still lift upward... albeit, past 45 degrees is more drag than lift. I could argue there is no drag at all, but rather, that drag is just lift in a different directional vector. kzfaq.info/get/bejne/qbh3Zayn05jYj4E.html

Thanks, I think you mistook the topic video. I did not explain, or attempt to explain lift. If simply took the upside down argument, and explained why it's false. That's it. The point I made about the loop - as you said - that the wing doesn't create upside down lift at any point, assuming it's done properly, is valid. I'm surface level familiar with Euler's equasions, as it can be used to mathematically explain the stagnation point, the whole concept this video is based on 😉

You may be thinking about blade pitch. Blade twist is not really relevant in this discussion, and I covered it in depth in another video. Blade twist is needed because the blade speed is higher at the tip than the root, meaning different parts of the blade hits air at different angle of attack. Thus the blade need to be twisted so that all portions of the blade hits air at the same angle of attack. So blade twist is irrelevant to aircraft speed but directly related to blade speed. Here is the video, blade twist covered at the 10 minutes mark. kzfaq.info/get/bejne/ntySosxn3Je-aXU.htmlsi=EApVDHlhRRZ2vAXB

@LetsGoAviate the twist is different according to the plane speed , just think about it when the plane travels at over 300kts vs 125kts , that's why all propellers are not suited to all planes even with the same power and diameter , a propeller made for 125 kts will not be efficient on a plane that travels at 300kts even with the right pitch.

No Wankel engine has ever been reliable enough to pass airworthiness certification for passenger aircraft, the Apex seals have a MTBF that is too low. The primary failure mode of all Wankel engines is compression loss due to ablative and high brisance damage to the apex seals, this scenario is not related to lubrication and there is absolutely no evidence that pre-mix fuel w/ 2-stroke oil has any beneficial effects, Mazda used metered oil injection because research has shown that pre-mix fuel and oil reduces reliability. Mistral is defunct, they went bankrupt after repeatedly failing FAA and EASA _PFTR_ tests for airworthiness certification. No aircraft engine manufacturer has ever developed a Wankel engine reliable enough for passenger aircraft. Rob Dahm is not a professional expert on aviation or engineering, he is not a qualified engineer or certified AMT, he is not even a certified automotive mechanic. You lost any shred of credibility when you listed Rob Dahm as a reference source... Dahm, who is neither an engineer or a certified technician has had his KZfaq account suspended for posted videos extolling the virtues of the recreational use of Adderall and cocaine. Please do your proper due diligence before posting bad advice to others that could result is serious injury or death.

That isn't how a radial engine exhaust tone sounds. They make a low-pitch rumbling/gargling sound, not a high pitch "screaming" noise like in the clip in the video. When the T6 is in cruise, and the propeller pitch is set coarser, i.e. slowing down the propeller speed and thus the tip speed, it doesn't make that sound anymore.

Thanks. Yeah blade thickness is the least changable parameter (relatively speaking). Changing thickness changes camber, and that changes lift/drag ratio of the blade (which changes more things down the line, like optimum lift/thrust spinning speed). There's is not a whole lot of room to "play" with thickness and camber to cater for more or less horsepower.

How then would you explain a wing stalling though? A wing stalls when the boundary layer of air on top of the wing is no longer sufficiently attached and creating insufficient lift...well known and well documented. If a wing is just pushed into the air and it's all about the bottom of the wing, why does what happens on top of the wing matter? And if the answer is it stall because of increased drag of the high AoA, how do you explain accelerated stalls?