Coanda Effect 

So glad my battle with pouring coffee has a name

This is the best explanation for Coanda Effect. Perfect.

What an incredibly enlightening vedio I found ! I've never fully understood the Bernoulli effect and Coanda effect until now. The explanation provided was so clear and easy to follow. Huge thanks to the teacher for making these concepts so accessible!

A perfectly clear demonstration of the Coanda Effect.

For those who don´t know , Henri Coandă was a Romanian inventor and aerodynamics pioneer.

The young romanian scientist/ genius observed this effect in 1910 when he was flying the first jet airplane in the world, that he designed at the age of 21. The engine was put in front of the pilot and in the flight he observed the jet of gas curving tovards the fuselage. It ignited it since it was made of ply-wood. He was lightly injured in the accident and he had some time to examine this effect of fluids.

On winter break and was trying to build an RC airplane from scratch. I was so confused while learning aerodynamics on why air would follow a wing. This summed it up perfectly, than you Harvard!

Thanks. Was reading about the Kings Cross fire in London in 1987 and noted this effect was significant in how the fire progressed so rapidly.

Excellent video about the Coanda effect!

I used to get free Public Library access to the Scientific American magazine back in the 60s. I have never forgotten the Coanda article. What a lucky and interested young fellow I was!

I was checking for a coanda nozzle used in a milk spray dryer .Now I understand .Thanks for saving my time .

I have always tried to understand the concept of this coanda effect and never managed to and then your video comes up and it's all crystal clear in just under 4 minutes. Awesomely done, great job.👍🏻

It was a really great explanation! Coanda effect is often mentioned during f1 car aerodynamics analysis but I really didn't understand very well what the phenomena was like. Thanks to you now I know so thank you very much! :)

I love how there are people like Wolfgang here, who go through the often difficult processes of learning or understanding something, and thinking "how can I make this easier for other people?". Thank you for the explanation!

You people are doing a great work by presenting the fascinating aspect of science ie practicals to students !!! Salute from India 🇮🇳🇮🇳🇮🇳

Its about dam time! This is awesome! how the hell did people expect others to like science if it wasn't explained as fast and striaght as this video! The guy just jumps right in with a visual and his explanation makes sence! Thank god!

Currently studying for a pilot exam. This demonstration helped a lot; so, thank you! 🙂

Proud to be a 🇷🇴 Romanian as Henri Coandã. The romanian inventor who discover the first jet engine.

So proud for me to be a Romanian at this moment,just like Henri Coanda…the inventor of jet airplane,smoke tunnel,airplane wing part that facilitates drag and lift,and….the Coanda Effect.

That was a cool demonstration of Conanda effect!

im glad this video exists its the perfect video for coanda effect i have been confused on it for years

This explanation here really flowed well

This is the greatest video on the conada effect that I've ever seen. Thank you, sir.

This is one of the best explanation of the Coanda effect. Thanks.

Wolfgang, thank you for making this so easy to understand. I've know about this effect for years and somewhat understood the science behind it.. Now I have a better grasp of what is going on. My motivation to revisit this stems from my building a small fume extractor to use when I am welding in my home workshop. I noticed that most of the professional fume extractors typically have a bell-mouth at the end of flexible duct on the suction side. Also, I have seen the same bell-mouth design on the suction side of fluid pumps and gas turbine engines. I am in the process of constructing a rectangular bell-mouth for my fume extractor. I went with this shape because it is the easiest to construct from 22 gauge sheet steel. A round bell-mouth would require special spinning machinery. I sized the small end to fit a standard 4" x 10" HVAC register boot that transitions from rectangular to 4" round. Hopefully, the Coanda effect will behave nicely with my custom bell-mouth.

Congratulations on the clarity of explanation. So brief and yet so accurate. Well done, Sir.

Looks like you foiled the Coanda's plans to drip in the end! Well done! xD

The last case (the bottle) is not because the Coanda effect, but the surface tension of the liquid. Think that if you pour the wine extremely slowly it will stick too and there is no speed for Coanda effect.

Explaining why there's a low pressure area and a high pressure area is the most important part of the video. It could have used more attention. So you're saying there's air being pulled into or with the main flow by friction, colliding with the air already in the flow. Normally this additional air enters the flow from all sides, so these collisions balance each other out and the flow remains straight. When a curved surface is introduced, air cannot enter from below because the surface is in the way, so air entering the flow from above knocks the whole flow down, following the curvature of the surface.

For the first time I understand the Coanda effect! Thank you!

Thank you. Exactly what i was looking for

Excellent! Within seconds I did understand what the Coanda Effect is, I did fast forward some seconds to the explanation of how it works and that was excellent. I read some text but didn't get it, but just after 20-ish seconds I got it from this video. Now I can perhaps read the articles and understand what they mean instead of getting headache

HAHAHA!! Thank you so much! Very good explanation! I avoid the Coanda effect in my wine bottle, drinking directly from the bottle!

日本の高校の理科教師です。発泡スチロール球を使って同じような実験を生徒たちと楽しみました。ピンポン球の実験は、5cmの発泡スチロール球を使うともっと上がって感動的です。

Can you share your Schlieren setup? Curious about the lighting and lens settings. I am trying to film Schlieren but I only get shadows. I can’t seem to get the subject in focus nor lit up.

Thanks for this lucid description.

what a great demonstration😍 Thank you so much❣

Awesome Explanation

Beautiful demonstration and explanation

The Coanda effect is used in the aerodymanics (engine-wing area) of Antonov An-72/-74 aircraft.

Thanks for the wonderful video. You couldn't have made it any clearer, sir.

Sir salute, finally i found this video

I mispelled Conan Grey's name to "Coan" and it recommends "Coanda effect" and now Im here learning new thing

Crystal explanation. Thanks.

Perfect introduction !

Coanda effect also important in high rise building fires as hot fire gases cling to the building exterior when venting from windows

Hey Wolfy, bet that's the only time your hairdryer see's the light of day.

Henri Coanda--way ahead of his time. Imagine if he had rolled out his aircraft in the late 30s when gearing up for WW2? Thanks!

I love your videos you explain so well!

Great video. 👍

Thank you! Instant sub. Looking forward to more.

Thanks! Now I can pour.

great explanation and great trick not to spil the wine...

Thank you!

very specified, very nice description

Brilliant demonstration.

If we define the Coanda effect as a jet of fluid following a convex surface, then indeed the coffee cup and wine bottle examples demonstrate the Coanda effect as well as the dryer plus circular object example does. However, from a physical perspective different phenomena are at play here. In the dryer example the deflection of the free jet of air is caused by entrainment of ambient air due to viscosity. The liquids follow the surface curvature due to adhesive intermolecular forces, since viscous air entrainment should be negligable.

What I also noticed with the ping pong ball demo was the ping pong ball axis didn't appear to change as the air flow tilted off C/L. I'm assuming gravity comes into play for that. It would be nice to see a F/U demo with a C/L scribed on the ping pong ball with a discussion relative to that. Keep up the good work.

Mas claro que esto; imposible! Gran aporte señor 👏🗿

Very nice visualization. I am confused though about the wine: is there really the Coanda effect that causes the wine to follow the bottle? isn't it mainly related to surface tension? just a quick search on wikipedia: A common misconception is that Coandă effect is demonstrated when a stream of tap water flows over the back of a spoon held lightly in the stream and the spoon is pulled into the stream (for example, Massey in "Mechanics of Fluids"[47] uses the Coandă effect to explain the deflection of water around a cylinder). While the flow looks very similar to the air flow over the ping pong ball above (if one could see the air flow), the cause is not really the Coandă effect. Here, because it is a flow of water into air, there is little entrainment of the surrounding fluid (the air) into the jet (the stream of water). This particular demonstration is dominated by surface tension. (McLean in "Understanding Aerodynamics"[48] states that the water deflection "actually demonstrates molecular attraction and surface tension.")" Thank you!

As the stream of air is forced around the curve of the ball in essence it is constricted therefore flows faster at the surface resulting in lower air pressure near the ball surface. The higher pressure of the stream at the top pushes the bottom stream downwards and thereby taking a longer path reduces its own pressure and is forced downward by ambient room pressure. Hence Bernouli and microscopic Magnus effect on air molecules are additional reasons.

Thank you for an Effective Explanation on Coanda.

Best explanation I loved!!!!

it's the Koalanda effect in Australia

Thank you sir!!!

excellent video! Thank you.

I’m here because of the new hair dryer from Dyson ahaha

Well done. Thank you.

Thank you for the wonderful explanation! Could the adhesion between the ball and the air also be one of the reasons for the Coanda effect?

Very well explained, thank you :)

Has this Coanda effect anything to do with wind travelling between two houses creating a differential air pressure thus the wind rushes around the back to equalise the difference? Thank you for video.

Simple and clear. Nice !

gravity and/or static cohesion, along with vacuum from the push, which then pulls from behind it

Nice explaination!

If you toss in the right ingredients -- Ivy League University + coffee + wine + great mind -- you'll end up with a good video. Cheers!

Great explanation with engeeniring solution :)

Very interesting! This reminds me of reading rivers to find gold. I wonder why light, air, water and magnetic forces bend and sound deflects at angles?

Thanks for crystal explanation.

He describes it so clearly and so simply. But we have to address the wider issue here and that is all these physics and mechanic website and blogs are written in such an overly complicated manner that is off putting. Like now I know the coanda effect I can describe it so easily to even a 10 year old but these websites make it so unnecessarily hard.

Now i can understand, or Coanderstand, the Coanda effect...

protect this man at all costs

Great work! Very easy to understand!

Great vid but how is this different that Bernoulli's principle? The Boston MOS used to have a demonstration installed of what this guy does with the hair dryer and ping pong ball, and it was credited to Bernoulli

Thank You sir

Henri Coanda (Coandă) was Romanian. He also invented the reaction engine. Just thought You should know.

Question: would having jet engine exhaust (or any form of propulsion really) distributed across the top of a wing produce greater lift at lower speeds as a result of this effect?

How does flow curve around a surface if viscosity is zero, such as potential flow around a transverse cylinder.?

When does coanda effect is eliminated? How it co related to the velocity or acceleration of liquid? Consider pouring wine from bottle with perfect angle or speed without observing coanda effect

Molecules that are dragged away can not be replaced as fast as the ones without an object to block incoming ones. I assume.

Levitating Hot Dog Cooker bring me here :)

And what about the boundary layer in the example with the basketball ball? Does is stick to the surface of the ball and then the rest of the airflow is pulled towards it, or is the whole airflow including boundary layer pulled towards the surface as a whole? Thank you.

Excellent Wolfgang! Are there limitations to the Coanda effect on something like a spiral shell? Say you take a sheet metal roll it into a spiral pattern with a few internal loops, would the air travel inside the spiral and come back out(like a smoke ring)?

I enjoy that the basketball has its weight marked on it. Ya know, in case you need to know how much it weighs, but don't have time to bust out the scale.

Effect Viscosity , boundary layer and no slip condition is effectively called coanda effect 👍

With the hair dryer you were creating a low pressure area behind the ball. When liquid follows the surface of a container when poured, defying gravity, I would think that would mostly be the surface tension of the liquid . ? Are they both the coanda effect? Is the coanda effect the direct result of Bernoulli's principle? Is the coanda effect and bernoulli's principle the same thing. Ah, maybe I'm confusing an effect and a principle.?

What is that thing in the background?

I just had someone dispute the coanda effect's relationship to airfoil lift, stating that coada applies only to jets of air ( like your hair dryer), not to larger air movement. But surely the entrainment principle still applies. True?

There is no friction, it is due to the vacuum that is formed, or not. As the air moves away there must be a continuous flow(the velocity cannot be zero for adjacent molecules. You could all this friction if you want but it is not due to forces but mathematics). This will create a vacuum in the cusp IF it was not filled with air. in fact, there is a sort of competition between a vacuum trying to form due to the escape of molecules and those coming in to fill the vacuum. So it is a network flow problem. But some of that air flowing away will swirl back around due to the forces of the vacuum(and so the isobars are concentric squashed circles radiating outward from the cusp). At all stems from trying to push molecules away(blow them away) which is impossible due to the conservation of energy/mass and this sets up a vacuum and anti-vacuum region around the object that is is constant tension(must balance out due the gas wanting to equalize out). The same thing happens with electricity and a liquid also experiences it since it is just a much denser gas(in this case though the variation is density is much less if almost non-existent so the flow will function somewhat differently due to the fluid mechanical differences).

Still don't know how to avoid the coanda effect while pouring coffee from one thick wall mug to another. Any ideas?

Thre is suddenly vacancy at the Curve surface of boll aside direct content line surface , So air goes down to fill the vacancy of air in that 90° angle gap