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Re: Wind Power Div. C
Posted: September 30th, 2008, 6:58 pm
by rocketman1555
If the rules for this event are the same in your state as they are here in TX, then they are exactly the same Physics Lab
Re: Wind Power Div. C
Posted: October 8th, 2008, 10:08 am
by carneyf1d
wind power is essentially building a propeller that generates energy from wind. the most important thing i can think of is making a windmill with blades having an airfoil designed to maximize efficiency. you can look up equations that correspond to power, P= T(Vinfinity + v) and thrust, T = 2(rho)A(Vinfinity+v)v and come up with a mathematical way to maximize the energy produced by the blades rotation.
Re: Wind Power Div. C
Posted: October 11th, 2008, 7:03 am
by vofbassist
man, and I thought physics was slightly challenging so far. could you give an equivalent to infinity?
Re: Wind Power Div. C
Posted: October 11th, 2008, 5:33 pm
by carneyf1d
Vinfinity is the same as the air velocity out in front of the propeller. As the air hits the propeller, the velocity changes to Vinfinity + v. Behind the propeller, the velocity is Vinfinity+ 2v. The v term is the accelerated air from the propeller. by definition T = momentum in-momentum out. Therefore, rho*A*V = rho*A*V...meaning Thrust = rho*A*(Vinfinity)(Vinfinity+ 2v) - rho*A(Vinfinity+v)(Vinfinity+2v)....by simplifying this you have T=2rho*A*(Vinfinity+v)v
now to find power you use the conservation of energy. Power= energy rate out- energy rate in. P = 1/2 mV^2 - 1/2mV^2. simplifying this you can find that Power= T(Vinfinity + v)
anyways. equations suck, but they are sort of important. if you have more questions just PM me or whatever.
Re: Wind Power Div. C
Posted: October 11th, 2008, 7:05 pm
by gh
Erm, I think he's just writing math incorrectly. I'm guessing "Vinfinity" means "V sub infinity" which would be written as V_infinity. "Vinfinity" as it is written would mean V*i*n*f*i*n*i*t*y.
Also, we can have a nice, informative discussion here on the issues, without having to make it private. Other users would then be able to benefit from the information and find it later using the search function, which will obviously not work with PMs. :)
Re: Wind Power Div. C
Posted: October 12th, 2008, 9:34 am
by vofbassist
wow...I was looking for a number I could punch into a calculator, but thanks for the equations. now I'm going to contemplate the answer to life. contact me in the next millenium...
Re: Wind Power Div. C
Posted: October 12th, 2008, 11:32 am
by carneyf1d
if you can find the speed of the wind they provide you...then you can go through a few equations to get some answers.
and besides, you cant always just punch something into the calculator and get a number for everything you want. you have to go through several things to get a calculation...remember, its science olympiad, not special olympics.
Re: Wind Power Div. C
Posted: October 12th, 2008, 11:35 am
by carneyf1d
Erm, I think he's just writing math incorrectly. I'm guessing "Vinfinity" means "V sub infinity" which would be written as V_infinity. "Vinfinity" as it is written would mean V*i*n*f*i*n*i*t*y.
sorry about the bad quotation. You got what i meant. if it doesnt make sense then its probably not what i was going for. its just easier to write it as one word instead of the whole underscore thing.
Re: Wind Power Div. C
Posted: October 12th, 2008, 2:08 pm
by gh
I was trying to clarify it for vofbassist, who thought it had something to do with the "number" infinity.
Re: Wind Power Div. C
Posted: November 16th, 2008, 7:50 pm
by Grace
rocketman1555 wrote:use the materials and build something that resembles a windmill, thats all i can think of
how are they going to measure how much power you generate?
you might want to ask someone thats good at mystery arch or another building event at your school for some help
They use a voltmeter. You have to create a windmill that can produce the most power at a strong and gentle breeze. I'd give some hints but seeing that we'll be competing with Boyceville, WI in 3 weeks...
I'll provide some hints in the near future, though.