1. Brian, Mallory, Asghar, and Mohammad

2. Wind Turbine Wind energy is created when the atmosphere is heated unevenly by the sun, some patches of air become warmer than others. These warm patches of air rise, other air rushes in to replace them – thus, wind blows. A wind turbine extracts energy from moving air by slowing the wind down, and transferring this energy into a spinning shaft, which usually turns a generator to produce electricity.

3. Experiment Objective Our objective is to discover the most efficient turbine blade shape for wind turbines--the shape/size that generates the most electricity when the wind is at a constant speed. This relates to sustainability because it can be applied to real world wind turbines and help determine the best shape for generating the maximum amount of electricity

4. Experiment Description Materials: Heavy paper, popsicle sticks, clamp and axle, desktop fan set to a constant power level, strobe to measure the speed of the different blades After constructing three mini wind turbines, each with different blade shapes, fix the turbine to an axle and clamp, allowing it to spin freely

5. Experiment Description (Cont.) Position the desk fan and the strobe device in front of the turbine. Make sure the strobe doesn’t obstruct the fan’s path. Turn the fan to one of the power levels. Make sure the power level (low, medium, or high) remains constant throughout the experiment.

6. Experiment Description (Cont.) Turn the strobe on, making sure the light is reaching the mini turbine. Adjust the knobs on the strobe (speed of the flashing light/RPM) until the mini turbine blades appear to stand still. Record the data. Repeat these steps with the other two constructed turbines.

7. Experiment Description (Cont.) From there we will determine which blade shape had the highest RPM That will be the most efficient blade shape Blade ShapeSpeed (RPM) Turbine #1 Turbine #2 Turbine #3

8. Results We have not performed the experiment yet, but in general, rotor blades for wind turbines are always somewhat twisted The wind will be coming from a much steeper angle (more from the general wind direction in the landscape), as one moves towards the root of the blade, and the centre of the rotor. A rotor blade will stop giving lift if the blade is hit at an angle of attack which is too steep.

9. Conclusion We will make a conclusion once we perform the experiment, but based on current designs of wind turbines, it is safe to say that a blade that is at least slightly twisted will rotate the fastest and generate the most electricity