Wind Power ~ Speed Cubed

One reason to avoid Cat. 5 hurricanes.

Bret Cahill

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Bret Cahill
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what do you mean? That the power of the winds is equal to the speed of those winds cubed? How does that work out?

power, in W, or in J/s......speed cubed, m^3/s^3 ?

even reduced to essential units, power is (N *m)/s

which is then [(kg * m/s^2) *m]/s which will simplify to

(kg * m^2) / s^3 ... not equal to m^3/s^3.

there's a mass unit on one side and a length unit on the other that won't resolve, as far as I know.

did I misunderstand what you're saying?

regards, k wallace

Reply to
k wallace

The kinetic energy of any moving mass m is equal to 1/2 m v^2. In a fluid the amount of mass also increases with velocity you pick up another v term.

If they know the wind speed they know the momentum transfered to the water in a hurricane so they know how high the storm surge will be.

They also know how high the levees are.

They were first predicting a 9' wall of water coming over the levees.

When you think about the difficulty in shutting down and evacuating a large city it will be surprising if more than 10,000 didn't die.

Galveston still holds the record for number of deaths and they rebuilt on a lot of fill.

They also built a 15' high sea wall right on the beach.

I'm betting not just N.O. but a lot of port cities start working on their levees and sea walls.

Bret Cahill

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Bret Cahill

yes. I didn't think farther than 'power ~ wind speed', but I understand what you are saying below. N.O. has been dodging this particular bullet since it's been there.

regards, k wallace

Reply to
k wallace

//

Hold onto that force times distance for energy, and force times speed for power.

The force a wind can provide is air drag drag

The force due to drag is 1/2 rho Cd A V^2

So if power is force times speed, then it's proportional to A V^2 times V - the cross section area times wind speed cubed.

Brian Whatcott

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Brian Whatcott

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