Ugly Hedgehog - Photography Forum
Home Active Topics Newest Pictures Search Login Register
Photo Gallery
Bernoulli's Effect
Page 1 of 2 next>
Mar 16, 2023 20:16:47   #
toxdoc42
 
I am really not sure where this posting belongs, but it started as an observation from my apartment window, then became a photographic effort, then an effort to explain the phenomenon I saw. The images are suboptimal, i was inside, not daring to go outside and the snow was really swirling around at high speeds.

I Lived my entire career in medicine, discovering things that were obvious, but that others missed. This included being the first to report a serial killer working in a hospital which ended up as the conviction of what some consider the most prolific serial murderer in the US history. If interested, see my book: Medical Toxicology, Antidotes and Anecdotes, published by Springer in 2017.

To make a long story short, there was a severe Nor-Eastern predicted for much of the country last week. In my area of NJ, Short Hills, we dodged the major bullet, with no real accumulation of snow. We did get the strong winds, allegedly gusting to in the 40 mph range. With it came swirling snow. When I looked out of my apartment window i was struck by something I had never seen before. The snow had accumulated on the vertical portion of every tree in sight, but, NOT ON THE NE side, in reality, the western side of the trees were accumulating the snow.

This made no sense to me at the time, if the winds were coming from the NE driving the snow, why did the snow not accumulate on that side. I looked up what the definition of a Nor-easter was to be sure that i was correct, that the winds come from the NE. Conforming that, I reached out to people I thought were smarter than me for help. There was silence from them all.

I postulated that perhaps, the tree trunk was acting like the leading edge of a wing and that the side opposite was developing a "vacuum effect" from the rapid rushing wind, the Bernoulli effect. I finally reached a meteorologist who said she had never been asked that question before, but felt that my explanation was probably sound.

https://www.khanacademy.org/science/physics/fluids/fluid-dynamics/a/what-is-bernoullis-equation

https://www.skybrary.aero/articles/bernoullis-principle


(Download)


(Download)


(Download)


(Download)

Reply
Mar 16, 2023 20:25:51   #
lukevaliant Loc: gloucester city,n. j.
 
this makes sense that's how a carburator introduces air to the system(venturi).

Reply
Mar 16, 2023 20:28:53   #
toxdoc42
 
Thanks for adding that. That is the way the hand held sprayers that attach to garden hoses to fertilize plants work. I bet only the older people on the Hog have even seen a carburetor, let along know what it does or how it does it! My 1963 Porsche 356B had dua carbs that constantly needed synching!@

Reply
 
 
Mar 16, 2023 21:06:12   #
lukevaliant Loc: gloucester city,n. j.
 
toxdoc42 wrote:
Thanks for adding that. That is the way the hand held sprayers that attach to garden hoses to fertilize plants work. I bet only the older people on the Hog have even seen a carburetor, let along know what it does or how it does it! My 1963 Porsche 356B had dua carbs that constantly needed synching!@


cool car

Reply
Mar 16, 2023 21:24:20   #
ELNikkor
 
Collected on the east side of our trees here in Rochester.

Reply
Mar 16, 2023 22:24:21   #
Architect1776 Loc: In my mind
 
toxdoc42 wrote:
I am really not sure where this posting belongs, but it started as an observation from my apartment window, then became a photographic effort, then an effort to explain the phenomenon I saw. The images are suboptimal, i was inside, not daring to go outside and the snow was really swirling around at high speeds.

I Lived my entire career in medicine, discovering things that were obvious, but that others missed. This included being the first to report a serial killer working in a hospital which ended up as the conviction of what some consider the most prolific serial murderer in the US history. If interested, see my book: Medical Toxicology, Antidotes and Anecdotes, published by Springer in 2017.

To make a long story short, there was a severe Nor-Eastern predicted for much of the country last week. In my area of NJ, Short Hills, we dodged the major bullet, with no real accumulation of snow. We did get the strong winds, allegedly gusting to in the 40 mph range. With it came swirling snow. When I looked out of my apartment window i was struck by something I had never seen before. The snow had accumulated on the vertical portion of every tree in sight, but, NOT ON THE NE side, in reality, the western side of the trees were accumulating the snow.

This made no sense to me at the time, if the winds were coming from the NE driving the snow, why did the snow not accumulate on that side. I looked up what the definition of a Nor-easter was to be sure that i was correct, that the winds come from the NE. Conforming that, I reached out to people I thought were smarter than me for help. There was silence from them all.

I postulated that perhaps, the tree trunk was acting like the leading edge of a wing and that the side opposite was developing a "vacuum effect" from the rapid rushing wind, the Bernoulli effect. I finally reached a meteorologist who said she had never been asked that question before, but felt that my explanation was probably sound.

https://www.khanacademy.org/science/physics/fluids/fluid-dynamics/a/what-is-bernoullis-equation

https://www.skybrary.aero/articles/bernoullis-principle
I am really not sure where this posting belongs, b... (show quote)


You are correct.
Living in various extreme climates over the years this is common.
Another place that it is frequently seen is on the leeward side of a parked automobile.
Snow loads at parapets is also another location such things happen.
Nice shots and good observation that many miss.

Reply
Mar 16, 2023 22:48:27   #
jimward Loc: Perth, Western Australia
 
The Bernoulli effect is why aircraft fly. The air passes faster over the curved upper wing surface, creating pressure lower than that on the lower wing surface.

Reply
 
 
Mar 17, 2023 00:12:30   #
flip1948 Loc: Hamden, CT
 
toxdoc42 wrote:
I am really not sure where this posting belongs, but it started as an observation from my apartment window, then became a photographic effort, then an effort to explain the phenomenon I saw. The images are suboptimal, i was inside, not daring to go outside and the snow was really swirling around at high speeds.

I Lived my entire career in medicine, discovering things that were obvious, but that others missed. This included being the first to report a serial killer working in a hospital which ended up as the conviction of what some consider the most prolific serial murderer in the US history. If interested, see my book: Medical Toxicology, Antidotes and Anecdotes, published by Springer in 2017.

To make a long story short, there was a severe Nor-Eastern predicted for much of the country last week. In my area of NJ, Short Hills, we dodged the major bullet, with no real accumulation of snow. We did get the strong winds, allegedly gusting to in the 40 mph range. With it came swirling snow. When I looked out of my apartment window i was struck by something I had never seen before. The snow had accumulated on the vertical portion of every tree in sight, but, NOT ON THE NE side, in reality, the western side of the trees were accumulating the snow.

This made no sense to me at the time, if the winds were coming from the NE driving the snow, why did the snow not accumulate on that side. I looked up what the definition of a Nor-easter was to be sure that i was correct, that the winds come from the NE. Conforming that, I reached out to people I thought were smarter than me for help. There was silence from them all.

I postulated that perhaps, the tree trunk was acting like the leading edge of a wing and that the side opposite was developing a "vacuum effect" from the rapid rushing wind, the Bernoulli effect. I finally reached a meteorologist who said she had never been asked that question before, but felt that my explanation was probably sound.

https://www.khanacademy.org/science/physics/fluids/fluid-dynamics/a/what-is-bernoullis-equation

https://www.skybrary.aero/articles/bernoullis-principle
I am really not sure where this posting belongs, b... (show quote)

The winds in a nor'easter circulate in a counter clockwise pattern around the center of low pressure.

The direction of winds you see in a given area will vary depending upon your location with respect to the center of the low.

The winds can come from the northeast, or from the northwest or even from the southwest as the center passes away from your location.

Reply
Mar 17, 2023 01:54:03   #
Wallen Loc: Middle Earth
 
toxdoc42 wrote:
I am really not sure where this posting belongs, but it started as an observation from my apartment window, then became a photographic effort, then an effort to explain the phenomenon I saw. The images are suboptimal, i was inside, not daring to go outside and the snow was really swirling around at high speeds.

I Lived my entire career in medicine, discovering things that were obvious, but that others missed. This included being the first to report a serial killer working in a hospital which ended up as the conviction of what some consider the most prolific serial murderer in the US history. If interested, see my book: Medical Toxicology, Antidotes and Anecdotes, published by Springer in 2017.

To make a long story short, there was a severe Nor-Eastern predicted for much of the country last week. In my area of NJ, Short Hills, we dodged the major bullet, with no real accumulation of snow. We did get the strong winds, allegedly gusting to in the 40 mph range. With it came swirling snow. When I looked out of my apartment window i was struck by something I had never seen before. The snow had accumulated on the vertical portion of every tree in sight, but, NOT ON THE NE side, in reality, the western side of the trees were accumulating the snow.

This made no sense to me at the time, if the winds were coming from the NE driving the snow, why did the snow not accumulate on that side. I looked up what the definition of a Nor-easter was to be sure that i was correct, that the winds come from the NE. Conforming that, I reached out to people I thought were smarter than me for help. There was silence from them all.

I postulated that perhaps, the tree trunk was acting like the leading edge of a wing and that the side opposite was developing a "vacuum effect" from the rapid rushing wind, the Bernoulli effect. I finally reached a meteorologist who said she had never been asked that question before, but felt that my explanation was probably sound.

https://www.khanacademy.org/science/physics/fluids/fluid-dynamics/a/what-is-bernoullis-equation

https://www.skybrary.aero/articles/bernoullis-principle
I am really not sure where this posting belongs, b... (show quote)


The Bernoulli's principle state that A change of velocity in a flowing fluid changes the fluid pressure.
Treating air as a flowing fluid, therefore: when the air speed go up, the air pressure goes down (vacuum) and when the it slows down, the pressure goes up. This effect only happens in a laminar flow. Turbulent air will have both slowing and speeding up elements blending within itself that it negates the principle leaving only drag.

Aside from that principle, other things affect air too. i.e. if the air pressure changes, its temperature also change. An increase of pressure will increase the temperature and vice versa.

By these two previous descriptions, I believe the Bernoulli's principle is either not involved in the phenomenon you saw, or has too little influence on the matter.

Not a vacuum effect produced by a fast moving laminar flow of air, rather the calmness of the air in the leeward/protected side, allows the snow/ice carried by the wind to fall and collect. More material is brought and fed to the wind protected space by the turbulent wind.
The collection of materials in the leeward side eventually create a more aerodynamic shape, which then limits the size and shape of the ice formation.

Note that there is also a small calm air pocket in the windward side too, but if the wind blowing keeps changing directions, this spot will keep changing location and the snow previously collected there will be blown off or kept to a minimum. This change of direction do not affect the leeward side as much because that is a bigger area, so a wind change within a front of 30 degrees or so will blow away what was collected in the front while still be depositing materials in the back.

Reply
Mar 17, 2023 07:03:54   #
Dannj
 
😂
I’ve noticed this effect many times under similar conditions generally with a “That’s weird” comment to myself attributing it to Bernoulli or Fibonaci or some other theory I have limited knowledge of…like the Gazinta theory…! I was right all the time😳😂

Reply
Mar 17, 2023 09:06:30   #
jaymatt Loc: Alexandria, Indiana
 
Snow on only one side of the trees happens all the time here in Indiana.

Reply
 
 
Mar 17, 2023 10:15:17   #
Dikdik Loc: Winnipeg, Canada
 
...very likely the case.

Reply
Mar 17, 2023 11:54:44   #
Toby
 
A lot of fancy descriptions and math. If you would like to see this principle in practice do the following. Cut a piece of paper about 1" wide and 6" long. Pinch the 1" end between your forefinger and thumb. Wrap the paper over the top of your fingers and the hold your forefinger up to your mouth with the top of the paper at the same level as the top of your bottom lip. What happens to the paper?? It is pulled up (lift) just like on the top surface of an airplane wing.

Reply
Mar 17, 2023 13:19:33   #
nervous2 Loc: Provo, Utah
 
While I don't need more education on the Bernoulli effect (studied that enough in high school and college), I am wild to read your Medical Toxicology, Antidotes and Anecdotes book. Apparently my library does not have a copy yet and my wife has placed a ban on my purchase of any more books (the shelves in our library, office and other rooms are over-stuffed). I may have to order a copy on Amazon and ask them to deliver it in a plain, brown wrapper. If you ever decided to post a summary of the case, I would love to read it.

Reply
Mar 17, 2023 13:42:11   #
toxdoc42
 
Thanks.

There are actually 14 stories of how an astute observation led to a diagnosis. It was written with both the lay public and science students as the target group. It is priced well, and many libraries can get it on loan from other libraries. It is also available online through many libraries that are on a subscription service with Springer, the publisher.

Reply
Page 1 of 2 next>
If you want to reply, then register here. Registration is free and your account is created instantly, so you can post right away.
Photo Gallery
UglyHedgehog.com - Forum
Copyright 2011-2024 Ugly Hedgehog, Inc.