Windmill Teaching Module
Let’s Talk About Windmills…
In the fall, have you ever seen helicopter seeds fall to the ground and make a spinning motion – kind of like a helicopter? It does this to travel farther from the tree to have its own space! Ever seen a boat use a sail on a windy day? Sailors use it to travel faster than simply paddling! These two things use what surrounds us every day – wind – to achieve something, such as survival and speed. But what about those big windmills that slowly spin in open fields? What do they do? Well, they turn free wind into power and electricity! In this project, you will be building your very own windmill, and seeing what exactly they do! You will even try to build the best windmill ever by changing certain things about it, such as how big the blades are, what shape they take, what they are made of, and how they orientate with the wind!
Windmills harness the kinetic energy of wind and convert it into mechanical and electrical energy. As the wind passes through the blades it hits the blades causing lift to take place. That lift causes the rotor or “shaft” to spin. The shaft spins a generator to create electricity. Wind power devices are commonly termed wind turbines. The power that a wind turbine can produce is proportional to the swept area, which is dictated by the shape and size of a wind turbine blade. In this project, the students will practice the design of the wind turbine blade with different shape and search for the optimized shape with the best efficiency.
High rotor efficiency is desired for increased wind energy conversion and should be maximized. The theoretical total power by the inflow is defined as follows: Pwind = 1/2*Rho*A*V^3
Where Rho is the air density, A is the area swept by the rotor, and V is the wind velocity. Therefore, in order to maximize the power one needs to increase the swept area. The swept area is related to the shape, size, angle, length of the arms, weight, and number of the wind blade. The students will learn through this project how to design the wind blade with optimized efficiency using the variables mentioned. They will determine which variables have the most impact. The quality of the designed wind blades will be measured by the power output at low and high wind speeds.
Science: Energy conversion (from kinetic energy to electrical energy) by a windmill
Technology: Materials choice for wind turbine
Engineering: Wind turbine design
Mathematics: size, shape, angle, length, area, measuring skills
Useful Information:
Credit: Kincaid Graff, Cyrus Koroni (EEML)