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For a long time I thought it was the raindrop, but it turns out that raindrops aren't raindrop shaped
https://youtube.com/shorts/Ko02mUWhItA?feature=share
Raindrops are almost perfectly spherical I think aren't they?
Doesn't mean that the teardrop shape isn't the most aerodynamic shape though just that water being a fluid can't sustain that shape.
It's probably some sort of ellipsem
Subsonic it's close to a teardrop.
Supersonic, the shapes become a bit strange.
Depends what for doesn’t it?
In the superman position.
With puppy paws.
The most aerodynamic shape can mean many things. If we consider most aerodynamic to mean minimum drag with zero lift then artillery rounds wilth slightly longer tails will be pretty close. Or sears-haack bodies which are essentially pointy teardrops. Generally long things with smallest cross sections are best i e. Slender things. But not to long or skin friction increases more than the pressure drag reduces.
"Raindrops are almost perfectly spherical I think aren’t they?"
Yep, turns out they are!
"Depends what for doesn’t it?"
To be more aerodynamic
what range of angles of attack will this shape have to operate at?
A Liz Truss premiership in freefall must be a pretty aerodynamic shape.
To be more aerodynamic
I don't think aerodynamic means what you think it means.
Making a wing lift an aeroplane is aerodynamics
Making a car stick to the ground is also aerodynamics
Reducing the drag on the bove two examples is also aerodynamics.
What if the raindrop is on a treadmill?
But not too long or skin friction increases more than the pressure drag reduces.
Hence the development of the Kammback or Kamm-tail on racing cars, and sports cars.
https://en.wikipedia.org/wiki/Kammback
Half a house brick.
Is it aerodynamic ?. Certainly felt like it when one hit me on the head, but to be honest I wasn't giving that point much consideration at the time.
Aerodynamics is fun. It is so easy and obvious that a child can see it and designers just used their 'eye'. and then you try to study it and quantify it and everything goes pear shape and it is really difficult.
What most people mean by aerodynamic : Least drag when moving at a constant speed in a constant direction, possibly with the addition of a flat plane (the ground) on one side - less technically described as which is the slippyest shape. Then the 'clever people in white coats' come along and start talking about Aerodynamic Center<span style="background-color: #d5d5d5;">, </span>Airfoil<span style="background-color: #d5d5d5;">, </span>Angle of Attack, Center of Pressure, Chord, Circulation<span style="background-color: #d5d5d5;">, </span>Computational Fluid Dynamics (CFD)<span style="background-color: #d5d5d5;">, </span>Density, Drag Drag Coefficient, Dynamic Pressure, Flap Deflection Angle, Lift, Lift Coefficient, Mean aerodynamic chord etc and everyone gets confused.
When you start looking closely and applying real world factors, material used to make the thing affects the aerodynamics and the surface texture of the material impacts the boundary layer. I know this is the 'shape' really but when drawing a teardrop people rarely draw the detail so you can compare one made of water with one made from molten lead for example.
Not sure if this helps but it has taken up 5 minutes of my time while no-one bothered turning up to the morning Teams call so I can crack on with some real work now.
Raindrops stretch as they fall due to acceleration. The lower part is faster so it splits away when the surface tension can't hold it together.
Graeme Obree
everything goes pear shape
That's an improvement then, right?
Hence the development of the Kammback or Kamm-tail on racing cars, and sports cars.
Different effect.
A high aspect ratio aerofoil like a glider wing has less drag per surface area than the shorter aspect ratio of an airliner. Up to a point, you first hit a practical limit as high aspect ratio foils will stall at shallower angles of attack, and beyond that you hit a point where making the foil longer and thinner adds more drag due to the the leading and tailing edges.
Kammtails are a way of minimizing wake drag when your shape has other constraints (i.e. your car still needed to be car shaped, bikes need to be a balanced tube shape etc) where adding a tail twice as long as the body would just add skin drag and weight. It's still more drag than a NACA foil. Piush bikes being the exception that proves the rule, because we don't move any quicker than a moderate breeze a NACA foil doesn't work because almost all the time it's aligned the wrong way.