It’s here! Aviator90 Episode 1- Lift
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Excellent work Chris! Enjoyed it and I will be looking forward to the next lesson.
Bman.
Thanks Ben!
Awesome. I will looking forward to the next video as well.
Cesar
KDAB
Thanks Cesar!
Great video. Can’t wait for the rest of the series.
-Jason
Thanks Jason.
There isn’t much more you can say about the first lesson that Benjamin hasn’t said.
Very good work and the graphics are excellent.
Bob Ski
Thanks! More to come, of course
Just a question on push lift. Just to make sure what i understand is true. When the air plane is pitching up, the relative wind attacks the lower surface of the wing and pushes the air down,which pushes the wing up.Is this true? BTW awesome vid
Cheers
Alex
Actually, it’s more like the wing is ‘forcing down’ the air underneath it. In this theory is less about the angle and more about the force of the wing pushing down the air (and then getting the opposite reaction of lift).
But yes, I guess you could also explain it that way.
Ahhh, that explains it Chris! I’m a slow learner, it takes me a while to get used to new things. But i’m glad that the new info is sinking into my brain. BTW, previously I was actually talking about impact/barndoor lift,is this the same as push lift?
Cheers
Alex
I’ve never heard of the barn door theory! Do you have a link to that?
I like to this of lift in simple terms. The push theory is good enough for me. You were close enough to have a good understanding of it.
Excellent job on the video. But did you know the air on the top does not in fact catch up to the air going across the bottom? (after all, why should it?)
I’m an airline pilot, and I produce a podcast about the airline life from my vantage point in the cockpit. In my latest episode I tackled the question of lift with the help of a PhD who works at the Institute for Aero and Gas Dynamics at the University of Stuttgart. If you are interested in a deeper discussion on this, then check it out here: http://joepodcaster.libsyn.com/index.php?post_id=574110
Joe, first of all, thanks for all the great work you do with your podcast.
I am very aware that the air doesn’t actually ‘catch up’. The whole ‘equal time distance’ theory was something new to me, but I thought it did go well with the bernoulli principle.
For me, I’m simple. The push theory works just fine for me.
A great honor to have you chime in. I’m going to listen to this particular podcast and then I’ll report back.
Thanks Joe!
Joe,
I’ve always loved your podcasts. You have an uncanny way of bringing along us non ‘PhD’s. This was a very interesting conversation.
As a side note, I’m always impressed with how dang smart Germans are. Something about the people from that culture, and their minds, has always impressed me.
Great podcast.
Would you mind sending our users a link to the podcast (and how to follow it) you are currently working on? I know a lot of them would love this.
Great start, thanks for putting the time in Chris!
Thanks Mark!
thx for this. i felt it was fantastic. it may be useful for some of the “viewers” to remember that this is for newbies! just like me.and
It’s great for me to go back and look at these things too! I actually learned a lot in making this one that I didn’t know before, believe it or not.
This is brilliant thanks for this great resource!
Are you using the HDR light dll?
If so would you mind posting your settings? Looks great!
Thanks
This guy has some comments on this youtube video that I used. It works really well.
http://www.youtube.com/watch?v=7gCX269Tlh8
Chris and the AOA team, Great first lesson. Good info and timing. Well done production.
One every other day, Wow.
Thanks you for promoting Flight Sim,
Tom
kb1tom
Thanks, Tom! Glad you enjoyed it.
Good job Chris, just when I was having fun with the theory it ends leaving me wanting more…I’ll keep tuned for sure…liked the mountains under the Piper also.
Thanks Carlos! That’s from the up and coming Pacific Northwest from ORBX (www.fullterrain.com)
Thanks Chris ! A great start to this project offered free to all flight simmers. Both the content and the presentation was excellent ! Looking forward to all upcoming lessons.
ernie
Thanks for the comment, Ernie. Great to have you around!
hello chris!
good first episode. as i’m an engineer, i like how you explain it correctly and simple, as that’s not always easy to find the right amount of technical depth without being talking about it too long.
the bernoulli effect is well a bit simple explained but true and does the trick.
one little thing, higher pressure doesn’t WANT to go to lower pressure, it HAS TO, as the lower pressure’s force is well less than the higher pressure, law of static/dynamics for simple.
nevertheless, i didn’t read/see that in any other tutorial yet, so that’s a thing how i could imagine “lift” way more vividly than only with the standard diagrams shown in every other tuts.
so far, good start, for explaining lift a very compact, detailed and reasonable lesson. hope this stays the same with the other lessons.
good thing is one can look and scroll through the vids to hear/see it again.
regards
patrick
Thanks for the detailed comment, Pat.
In a comment above there’s a podcast that explains lift even further and is pretty dang interesting!
I like to keep things very simple, especially for flight simmers. There’s not reason to get too complicated and start getting into rotational flows and all the complex equal time distance (which isn’t actually equal).
With that said, we hope to give flight simmers a taste of real world knowledge with what we’re doing here.
So far, we feel we have done just that.
Dear Chris.
Once again you performed “The Excellence” bravo
Christian
Chris, first of all, beautifully done video! If this is the level of explanation and graphics we can expect from Aviator90, then it will be a valuable resource indeed.
Now, something that’s always puzzled me slightly about lift and airfoil shapes: if the wing is specifically designed to push air down while being sucked upward (a gross oversimplification of push and Bernoulli), how can some planes fly happily when inverted? It seems like they’d be forever being pulled toward the ground by the same forces that make them fly so well when right side up.
the forces of the world won’t invert. it’s just another airfoil profile you sent through the air, it also lifts depending on angel of attack, but the aerodynamic design is of course not designed for that.
A very valid point, Bill.
This is where if you really start looking into it the theories start to fall apart. There’s a great podcast link above that I think you’d enjoy.
Here’s another point from a pilots perspective… The aircraft was made to do certain things, and within those parameters it will fly correctly and fly well. One of them, at least for me, doesn’t include flying inverted. I just know I’m not supposed to (and it’s dumb to do that in an aircraft that isn’t designed for it) so I don’t.
The push theory better explains inverted flight compared to the equal time distance+bernoulli, for sure.
Nice to see you around!
Airplanes that fly upside down use an airfoil with zero camber and a zero native angle of attack. When the plane flies right-side up, the pilot has to pitch the plane to a positive angle of attack just to get lift to equal weight. When the plane flies upside down, the pilot has to pitch the plane to a negative angle of attack so the lift will be out the bottom of the plane, opposite the gravity.
Chris, Great job and I look forward to the rest of the videos.
Thanks Mike! Great ot have you around.
Great video, and a very good thing you are the first to explain lift with Newton.
Forget Bernoulli, since this effect is a result (and not a cause) of bending the airflow downwards. (action equals opposite reaction , as Newton expains).
With Newton you can also easily explain how aircraft can fly upside down. With Bernoulli, this can’t be explained. Besides, it sais that air catches up? Well, it doesn’t, and in reality the air travalling above the wing will end up a lot farther behind the training edge than the air coming from below the wing. AoA is everything in an airplane, and Bernoulli does not help virtual pilots think in terms of bending air down. (lift versus drag).
Looking forward to the next video in the series.
Agreed, Eric. Funny thing is, this is EXACTLY how lift is taught at flight school. In fact, I learned the Push theory from a book called Stick and Rudder, not in flight school.
Hallo Chris,
Thank you, it’s great.
Henk
Excellent start to what looks like a great series Chris. Well done!
Thanks Ken!
Thanks Chris for this great and excellent project.
Great start Chris! Nicely done!
Cheers, great video! Love the graphics =]
Hello Chris, well done on the first lesson. A fantastic and inviting visual approach to explaining the ‘mysteries’ of flight. I can see from some contributors you’ve sparked a good deal of interest and discussion. You’ve certainly taken on a very big task here. Well done! Keep it up. No doubt it will promote many to seek even more knowledge.
Thanks for the encouragement, Paul! Every little bit helps.
Lift is a combination of a myriad of forces that can all be partially explained by a few basic principles, the lift you see in any individual flying machine is a mixture of the various principles, the ratio of which normally vary depending on the speed of the aircraft.
Consider a 747. In order to lift off and climb, the wings rely mostly on the push principle, the equal and opposite reaction caused by moving vast amounts of air downwards. The flaps function mostly as extra pushers. However, during the cruise part of the flight, there is much less air being pushed downwards, and a greater reliance on the Bernoulli effect, as the lift generated by the effect generates much less drag and is therefore more efficient in terms of aircraft speed for a given thrust.
There’s nothing to stop an aircraft manufacturer developing a large plank with control surfaces and a suitably powerful engine, such a machine would fly, without even a hint of an airfoil. However, the efficiency and stability of its flight would be abysmal.
So don’t think of lift as being generated by just one force, push or Bernoulli, rather, think of it as a constantly changing combination of the two, plus other forces, that depend on angle of attack and speed through the air to come into play.
Thanks for the very detailed post, John. And yes, you are exactly right. It’s more about a combination of many different forces.
Chris,
Very clear and simply explained. I look forward to your other lessons, being an retired pilot, always interesting to renew knowledge.
Thanks, Geoff. Great to have you around.
Chris
Many thanks for the excellent video, very informative, looking forward to the next.
George
Thanks George! Throttle On.
Love it. I’d never heard of the push theory of lift. Makes a lot of sense. Looking forward to the next episode.
Thanks Simon!
For all those interested, Simon is an aviation nut and professional musician. He designed the great bumper music at the beginning of every episode.
Check out his site if you’re interested in his work.
Thanks for promoting FlightSim. I’m sure a lot of people will follow your blog.
I also listened on the podcast by Joy d’Eon and for all flight simmers that find it difficult to follow the technical discussion about Lift I would recommend to also have a look at this site, which give an easy to understand physical description of lift.
http://www.allstar.fiu.edu/aero/airflylvl3.htm
Cheers,
Bert
Hey Bert,
Not a problem! We’re enjoying this series so far.
Great link you have there. I would say it explains it in more detail rather than gives an easy understanding. But, regardless, thanks for that!
Throttle on.
Luvly … great fun to hear a comfortable lecturer! But let me jump in:
I was /fascinated/ by fluid dynamics as a kid. (L.A.S.E.R. and “valence” in chem made perfect sense to me in grade 3. Go figure.)
So I figured it this way: 1) sure … “push” … but also 2) “pull”; the air has momentum, so the air passing over the top edge of the chord keeps going straight, but *cue drum roll* there’s angle of attack, so the space “behind” the chord is, well, kinda empty. And the empty space creates “pull”. Cuz heh we all know that Mother Nature abhors a vacuum!
Sure, Bernoulli … he was a grown up. I thought up my theory when I was 9. *shrug*
cheers!
Wow! The only thing I was thinking about at 9 years old was action figures! Wasn’t even into flying yet!
The Bernoulli effect and the push effect both act concurrently. At any instant, air is being “thrust” downward, while at the same time the air pressure across the top of the wing drops due to a reduction in the cross-sectional area available for the air to flow through. (This is how wind tunnels can achieve high velocities at their narrow test sections.) The notion that air on top has to catch up to air on the bottom is justifiably crude, although in a bigger picture, the same mass of air must flow over the top of the wing as the bottom of the wing. (If mass flow were not equal for the top and bottom of the wing, then air would endlessly accumulate on top of the wing, which doesn’t happen).
It is fascinating! Many, many thanks for the absorbing video. It is realy clearly and interestingly explained.
Great Video and theory lesson. Look forward to more
I don’t understand why everyone slams the Bernoulli effect. Hold a piece of paper against your lower lip, and blow across the top of it. The airflow over the paper lifts the paper, with no downward thrust occurring at all. Also, a wing with convex curvature on both the upper side and the lower side will produce little downward thrust or “push”, but will nevertheless carry a massive aircraft through the air.
Everyone loves to portray engineers as being mechanics with maniacal egos. If you don’t understand how surgery works, you don’t negate the knowledge and value of a surgeon. Engineering is the same way.
Thanks Chris!
I am recommending Aviator 90 to as many simmers as possible. I hope that it continues to benefit all who participate. Thank You for sharing your passion and knowledge of the with all.
Best Regards,
Bruce
Bruce,
Thanks a ton! Glad to know your’e sharing.
Even more importantly, we’re glad you’re enjoying it.
Nice to have you around. See you next episode
Hey Chris, great video and useful even for real pilots . Just a question about the Cessna, is it normal procedure to take off on long runways without flaps?
Certainly is. In fact, the only time you really need to use flaps it for shortfield and softfield takeoffs, which we will be teaching you guys soon. Only jets really use flaps for takeoff on a long runway. You don’t see that on a little buy like a cennsa 152.
yeah softfield takeoffs are amazing! took a little getting used to at first in the cessna 172. pull the yoke all the way aft, 10 degrees of flaps, apply full power and rotate with the stall warning horn screaming at you
lower the nose slightly to remain in ground effect to build airspeed before continuing the climb! a lot of fun…lol.
BTW nice video Chris.
My take on it – The air molecules are squeezed apart in the upper side of the camper. Now there is less matter in that the volume of air above the airfoil, less mass equals less pressure. That’s what creates the low pressure on top of the airfoil. Now impact pressure can now push the airfoil into this semi void.
Very cool explanation here. Amazing what a different perspective on the words can bring. Thanks for sharing your thoughts!