Wind Power B/C

[daydreamer0023]

What kind of shapes are you using for your blades? We are using airfoil and we aren't getting past 600 mV no matter hwo much we change the design. Do we need to use a different material? Please respond quickly. We have states in less than a week.

What material are you using now? If you haven't tested paper, balsa or basswood, give one of those a shot. Try changing blade shape if you haven't already.

Also, do you mean 600 mV for high speed? With or without resistance? I would say that for Division C on high speed without resistance, it's not bad. For improving the design, what have you tried so far?

[Sakura Panda]

This year, are you allowed to tap the blades to get them going? In one of the invitationals I went to, the proctors let the competitors tap their blades. I thought you weren't allowed to, though?

[maxxxxx]

This year, are you allowed to tap the blades to get them going? In one of the invitationals I went to, the proctors let the competitors tap their blades. I thought you weren't allowed to, though?

As long as it's before the 30 second timing period starts it's fine.

[tyasasvi]

I got 600mV on high speed with no resistance. However, we are only using 14 cm blades. Whenever we increase the blade length, it becomes slower. We are thinking it is because of the added weight longer blades bring to us, but I am hearing from other teams that the longer the blade the better. Can someone tell me if I should try longer blades or just keep it around 14 cm?

[tyasasvi]

Also, I am in division B which means that our length could go to 20 cm.

[Alex-RCHS]

You should keep testing variables! For example, you could make the same blade design at 20, 17, 14, and 11 cm and see which does best.

[ashmmohan]

I got 600mV on high speed with no resistance. However, we are only using 14 cm blades. Whenever we increase the blade length, it becomes slower. We are thinking it is because of the added weight longer blades bring to us, but I am hearing from other teams that the longer the blade the better. Can someone tell me if I should try longer blades or just keep it around 14 cm?

Although we are division C and can only go to 14cm max, I find that having longer blades generates higher results than shorter blades for sure.

[Xuax]

I got 600mV on high speed with no resistance. However, we are only using 14 cm blades. Whenever we increase the blade length, it becomes slower. We are thinking it is because of the added weight longer blades bring to us, but I am hearing from other teams that the longer the blade the better. Can someone tell me if I should try longer blades or just keep it around 14 cm?

Although we are division C and can only go to 14cm max, I find that having longer blades generates higher results than shorter blades for sure.

Cp=0.5 rho * av^3

[Tesel]

I got 600mV on high speed with no resistance. However, we are only using 14 cm blades. Whenever we increase the blade length, it becomes slower. We are thinking it is because of the added weight longer blades bring to us, but I am hearing from other teams that the longer the blade the better. Can someone tell me if I should try longer blades or just keep it around 14 cm?

Although we are division C and can only go to 14cm max, I find that having longer blades generates higher results than shorter blades for sure.

Cp=0.5 rho * av^3

Yes, the easiest way to max out your speed would be to do longer blades due to the equation above.
However, that equation is mostly useless once you realize that almost everyone is testing on the same setup with same air density, velocity, and sweep area. You didn't include the efficiency, which is what Wind Power is all about. You are trying to find the most efficient blade design since everyone has the same theoretical limit.

[Xuax]

Although we are division C and can only go to 14cm max, I find that having longer blades generates higher results than shorter blades for sure.

Cp=0.5 rho * av^3

Yes, the easiest way to max out your speed would be to do longer blades due to the equation above.
However, that equation is mostly useless once you realize that almost everyone is testing on the same setup with same air density, velocity, and sweep area. You didn't include the efficiency, which is what Wind Power is all about. You are trying to find the most efficient blade design since everyone has the same theoretical limit.

I know, I'm just saying why making blades longer would increase power.