Terminal velocity (THIS IS A TROLL THREAD)

[Christ]

If a tear drop is such a great aerodynamic shape:

Why does the rain drop have a terminal velocity of only 25f/s, compared to the outstretched human, with a tV of ~250f/s?!

Checkmate, aerodynamicists!

[Fat Charlie]

Density?

How about a thinner human will have a higher percentage of his weight made up of dense things like bone and muscle. Less surface area than water for a given amount of mass. Tubby McLardbutt will have a density more closely approaching that of water and will have a lot more surface area to act as a brake on his form, bringing him closer to the speed of a raindrop?

[meanjoe75fan]

1. Raindrops aren't "teardrop shaped," they're roughly spherical.

2. Raindrops fall slowly due to the "square/cube rule": as you scale up a design (like a raindrop) the force of gravity goes up by the cube, but drag is roughly proportionate to frontal area, and goes up by the square (ignoring Reynold's number.) A teardrop probably falls faster than a teardrop-sized person would.

[MetroMPG]

Partly because rain drops aren't actually teardrop shaped. :P

EDIT: Beat me by 2 minutes, meanjoe75fan!

[gone-ot]

...don't falling raindrops look more like blood platelets, ie: semi squished / flattened in their vertical plane due to air pressure against the center of its originally spherical shape?

...or, maybe, more like a clear Hersey "Kisses" chocolate drop falling with its "flat" bottom facing downward?

[mort]

Originally Posted by Christ

Checkmate, aerodynamicists!

Originally Posted by meanjoe75fan
1. Raindrops aren't "teardrop shaped," they're roughly spherical.

2. Raindrops fall slowly due to the "square/cube rule"

But don't ignore Reynolds number.
-m

[aerohead]

Originally Posted by Christ

If a tear drop is such a great aerodynamic shape:

Why does the rain drop have a terminal velocity of only 25f/s, compared to the outstretched human, with a tV of ~250f/s?!

Checkmate, aerodynamicists!

*Teardrop is not rain drop.
*rain drops alter their form continuously as they fall,as they are a deformable structure,yielding instantaneously to any stressor.
*A raindrops terminal velocity is meaningless unless its mass and time-averaged mean frontal area was specified as well as Reynolds number Same for human.
*The 'teardrop' is used in reference to streamline bodies of revolution of blunt nose and tapering tail.
*Streamline bodies are given the term due to the fact that they are 'streamlined',having no separated flow,and no appreciable turbulent wake.They are the lowest drag form for any structure tested.

[Christ]

I really tried to make it obvious with the "check mate" comment, but you guys are really easy to troll... LOL.

Thanks for making me giggle, though. It's been a long week.

[ecomodded]

[Regenerit]

I've got a good one: what's the difference between a tear dropped car and a fish shaped car without any fins?
And as a side note: its nice to see efficiency working superbly in nature with the low drag flow throughout the body of a fish with its beautifully tapered body (like the marlin).