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[Phys-L] A year late: Fwd: [Phys-l] Bernoulli, Coanda, or Lanchester-Prandtl

Terry replied to me and I didn't "follow up". (forward for further phys-l member comments)


Hi Bernard,
Thank you for bringing this to our attention.
We will update the idea sheet with other web references that address the issue of lift.
The new version of the idea sheet should be up by tomorrow.
Edith Barr
Educational Publications Manager
RAFT (Resource Area for Teaching)
1355 Ridder Park Dr.
San Jose, CA 95131
408-213-7202 (direct line)
408-451-1420 (main number)

Here's the (current) idea sheet:


Begin forwarded message:

From: "tmcolon" <>
Date: 2011, September 02, 08:45:01 PDT
To: Bernard Cleyet <>
Subject: Re: [Phys-l] Bernoulli, Coanda, or Lanchester-Prandtl
Reply-To: <>

My "How Planes Can Fly" article provides a general audience with a simplified, visual, fun explanation of how planes fly as per the Lanchester-Prandtl hypothesis.

The second article, "Bernoulli, Coanda and Lift" intended to show how some demonstrations of the Bernoulli principle supposedly creating lift are misleading, incomplete or mistaken. The intent was to support the first article, a sidebar for "How Planes Can Fly."

On both I think I did a pretty good, if imperfect job of it.

As I said, I'm not a fluid dynamics expert and relied on Terry Day's information and explanations. I am in no position to argue the details of fluid dynamics. Though it might not be scientific I have to rely on authority. Unless I'm mistaken, Terry Day has worked with NASA on Circulation Control applications of the Coanda effect, and so I have put my faith in him.

Perhaps he is wrong, perhaps I misunderstood his explanations. Still, I'm reluctant to change the article. For me, it's close enough for jazz, as my piano teacher used to say.

This may seem an inadequate reply, for which you can condemn me as you choose. When you do, perhaps you might also be generous enough to credit where I got it right. As I wrote at the end of the article, "If the only thing you take away from this is rejecting the old incorrect notion of lift being created by the Bernoulli principle or the wing's curve, then maybe I've done something worthwhile."

In other words, cut me some slack I'm only an illustrator. ;)

terry colon

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