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Coanda effect Vs Bernoulli

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Coanda effect Vs Bernoulli

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Old 23rd Jun 2013, 14:25
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Where does Coanda come in to this or have I not been paying attention ? Isn't that what makes my teapot drip ?

Equal transit time is clear and present : only used to fob off 10 year olds in school.

Circulation is bernoulli isn't it; speed of flow difference generator.

From memory, no viscosity (inviscid flow) denies lift and drag, but I am with the accelerate the air downwards school and tire of the details of 2D potential flow which again is only a model................
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Old 23rd Jun 2013, 16:50
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Originally Posted by Mr Optimistic
Where does Coanda come in to this or have I not been paying attention ? Isn't that what makes my teapot drip ?
Coanda makes sure the air follows closely the curved surface of the airfoil and leaves the TE in the desired direction....
No Coanda => No Newton (and no Bernoulli/Circulation either)
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Old 23rd Jun 2013, 19:23
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Ah, best get a new teapot then I suppose.
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Old 23rd Jun 2013, 20:03
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Or fit an 'exhaust mixer' that mixes the spout boundary layer with the main stream.
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Old 24th Jun 2013, 20:16
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Originally Posted by Mr Optimistic
Ah, best get a new teapot then I suppose.
Alternatively you might want to try and sharpen the TE of your teapot...
In contrast to an airfoil this will also help reducing the starting vortex
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Old 24th Jun 2013, 20:20
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seems that the leading edge of the spout would influence the rollup of the vortex.

we have done some very, very interesting things messing with vortex creation in water systems, especially dams.

Last edited by FlightPathOBN; 24th Jun 2013 at 20:22.
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