Here is the Building Windmill Method No One Will Tell you About

Let’s first start with the prior knowledge. There are many observations done by the students about the wind. You have to focus on their attention on the ability of the wind to make the objects move.

This what the wind does because of the kinetic energy or the energy of the movement. When the wind blows faster, there is more kinetic energy. The energy is transformed when the wind strikes an object and makes this object move.

There are many things that are built to catch the kinetic energy from the wind. Such are sailboats, kites, windsocks, gliders, pinwheels, windmills.

There are some questions about how the windmills work and their ability to catch atmospheric motion and make their blades spin. There are many windmill designs known to the students. In the journals students may draw their own conception of windmill.

Let’s now continue with the exploration. Windmills are designed so as to extract as much as possible energy from the wind. Windmills catch the energy from the wind by moving their blades or rotor. The effective windmill should capture the wind energy.

What you can do is to build a K’Next tower for each group of students. You can design each group a fan and let them make the best blades for catching the wind’s kinetic energy. Students should think about what the best windmill can do.

This could be a windmill which blades move faster or blades that can catch even the slightest wind.

You can use materials from the old windbag or any other materials that you can assemble to make windmill blades. Students should have the opportunity to describe their trial designs, record the criteria that classifies the best windmill, gives evidence for their selections and test their hypothesis. They have to keep records of their observations.

Here comes the explanation. There are two types of windmill designs and these are horizontal axes and vertical axes. The conventional windmills like the K’Next tower spin on a horizontal axis. The spinning part of the windmill is the rotor and it is very important because it states how much wind energy is needed that will transform it to some other energy.

The rotating blades depend on two aerodynamic principles and their derive power from the wind by dragging or lifting. Drag devices can be categorized like simple wind machines using flat, curved or cup-shaped blades that turn the rotor.

In such cases the wind pushes the cup or the blade and forces the rotor to spin.

Lift devices are using airflow like the wing of an airplane to propel the rotor. The airflow over the blade uses both the lift and drag. Some objects like the airplane wings move through the air and the air resists them. This is what is called drag.

Lift represents moving the wind at different speeds all around the wing. Faster moving air usually has lower pressure than slow moving air.

Slower air moves under the wing and pushes it upward as lift. These two forces generate a thrust that pulls the blade on its journey through the air, just like pulling a sailboat thought the water. The thrust is greater when the blade is slicing the wind. Airfoil performance is usually determined by the ration of lift and drag.

Here are some examples from the everyday life.
One example is the cut-type anemometer. This represents four hemispherical cups that are attached to radial arms that spin about a vertical shaft. The anemometers measure the wind for each revolution per minute. The devices work on the basis of the aerodynamic drag.