Understanding Lift - As Non-technical as possible, Bottom-up

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AKar
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Re: Understanding Lift - As Non-technical as possible, Botto

Post by AKar »

No one's questioning anything, Dudley. :) That's never been my intention.

And yep - I'm familiar with this NASA site from where this paper appears to be, it contains quite a bit of good learning material. As said, highly recommended! I don't have the link to the main index atm unfortunately, but one can click back from the PDF as the links work.

Anyways, of course both of the theories are correct - they essentially must be, because they are highly related, as correctly noted in the article, and essentially need to co-exist: if one didn't hold in some circumstances, the other would be violated as well.

As the article states, one can calculate the lift from pressure distribution, from velocity distribution (as the two are connected via Bernoulli's), or from the net downwash - the basic argument is that all of these must co-exist to satisfy the conservation rules. However, it is obvious that none of the theories - on their own - really bring any light into the interaction itself. How an object displaces air, and why the air flows around it. How to arrive into that velocity field you can then use the Bernoulli's on to calculate the pressure and the lift (or equally to find its net downwash)? These are not trivial questions, and as the article puts it, "The real details of how an object generates lift are very complex and do not lend themselves to simplification." I don't find anything to disagree in that paper.

-Esa

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DHenriques_
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Re: Understanding Lift - As Non-technical as possible, Botto

Post by DHenriques_ »

AKar wrote: No one's questioning anything, Dudley. :) That's never been my intention. -Esa
Excuse me then, I must have misunderstood it when you said in your initial posting,
"the "complete explanations" based on "either" the Newton's or Bernoulli's principles are BS",
Dudley Henriques

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AKar
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Re: Understanding Lift - As Non-technical as possible, Botto

Post by AKar »

Ah, in that one...perhaps rather poorly put, but what the word "either" together with "complete" was my issue. For completeness, one needs...completeness. The "either-category" explanations I've ran into leave huge holes, perhaps that's why you strongly argued in favour of bringing the both explanations to the education. That said, either could be sufficient for a purpose, but that's my job to decide as a student. The lecturer has obviously a different, more responsible position. I've never been on one of your lectures, so I obviously that was never directed as a challenge, I'm sorry if it sounded that way.

-Esa
Last edited by AKar on 05 Sep 2016, 11:10, edited 2 times in total.

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ilya1502
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Re: Understanding Lift - As Non-technical as possible, Botto

Post by ilya1502 »

I'm sorry for raising this here, but are there any chances we see the second part of "Understanding autopilots"? :?

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AKar
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Re: Understanding Lift - As Non-technical as possible, Botto

Post by AKar »

Yes, sure! I dropped it in hold when I thought the changed simulation of the GTN's NAV was a bug. I had to alter the the topic a bit but didn't find any time to do it again back then, and I kind of forgot it. :)

I actually have an intention of remaining with S-TEC for the Pt.2 as it is often found unnecessarily primitive, while it actually is rather capable with a few common sense tricks.

-Esa

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DHenriques_
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Re: Understanding Lift - As Non-technical as possible, Botto

Post by DHenriques_ »

AKar wrote:Ah, in that one...perhaps rather poorly put, but what the word "either" together with "complete" was my issue. For completeness, one needs...completeness. The "either-category" explanations I've ran into leave huge holes, perhaps that's why you strongly argued in favour of bringing the both explanations to the education. That said, either could be sufficient for a purpose, but that's my job to decide. I've never been on one of your lectures, so I obviously that was never directed as a challenge, I'm sorry if it sounded that way.

-Esa
No problem at all. Let's drop this issue with a friendly departure and move on calling it a day shall we?
I think it's been covered from all sides of the aisle. So unless someone has something to add, I'll be moving on to other issues and leave any "last words" to others.
Dudley Henriques

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AKar
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Re: Understanding Lift - As Non-technical as possible, Botto

Post by AKar »

I agree with a handshake.

-Esa

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