Project Research

The fundamental purpose of research was to gather technical documents and papers relevant to wind turbine technology, and the mathematics behind it. 

Newton's Third Law

The Bernoulli Effect

Wind Turbine Blade Design

Blade design and engineering is one of the most complicated and important aspects of current wind turbine technology. Engineers strive to design blades that extract as much energy from the wind as possible in a variety of wind speeds, while remaining durable, quiet and affordable. This engineering process requires a great deal of scientific experimentation, modeling, and testing.
There are two important reasons why wind turbine blades are able to spin in the wind: Newton’s Third Law and the Bernoulli Effect. 
​
Newton's Third Law
​
Newton’s Third Law states that for every action, there is an equal and opposite reaction. In the case of a wind turbine blade, the action of the wind pushing air against the blade causes the reaction of the blade being deflected, or pushed. If the blade has no pitch (or angle), the blade will simply be pushed backwards (downwind). But since wind turbine blades are set at an angle, the wind is deflected at an opposite angle, pushing the blades away from the deflected wind. This phenomenon can be viewed on a simple, flat blade set at an angle. If you push the blade with your finger from the direction of the oncoming wind, the blade will deflect away from your finger.
The Bernoulli Effect

The Bernoulli Effect tells us that faster moving air has lower pressure. Wind turbine blades are shaped so that the air molecules moving around the blade travel faster on the downwind side of the blade than those moving across the upwind side of the blade. This shape, known as an airfoil, is like an uneven teardrop. The downwind side of the blade has a large curve, while the upwind side is relatively flat. Since the air is moving faster on the curved, downwind side of the blade, there is less pressure on this side of the blade. This difference in pressure on the opposite sides of the blade causes the blade to be “lifted” towards the curve of the airfoil.

Wind & Wind Power

Quick Fact!

​The ratio between the speed of the blade tips and the speed of the wind is called tip speed ratio. High efficiency 3-blade-turbines have tip speed/wind speed ratios of 6 to 7. Modern wind turbines are designed to spin at varying speeds. Use of aluminum and composite materials in their blades has contributed to low rotational inertia, which means that newer wind turbines can accelerate quickly if the winds pick up, keeping the tip speed ratio more nearly constant. Operating closer to their optimal tip speed ratio during energetic gusts of wind allows wind turbines to improve energy capture from sudden gusts that are typical in urban settings.
Wind turbine blades must be optimized to efficiently convert oncoming winds into mechanical energy to rotate the main drive shaft. But when designing turbine blades, the real wind is only one part of a larger equation—good blades must also account for the apparent wind that is experienced as the blade passes through the air.
Imagine riding your bike on a day with a fresh breeze at your side. As you begin to ride and pick up speed, you feel this wind from the side, but also wind pushing back at you from the direction you are moving. When you stop riding, there is just the wind from the side again. This wind that is “created” as you are moving is known as headwind. The headwind, combined with the real wind, is known as apparent wind. A wind turbine blade experiences apparent wind as it passes through the air. This apparent wind is from a different direction than the “real” wind that has caused the blade to begin moving. Since the tips of large turbine blades may be moving through the air at speeds up to 322 km/h (200 mph), this apparent wind can be very significant.