We learned from the expirement that the more wind blades there are, the more the wind blade's lifting capacity for washers (and, by extension, its energy use) will increase.
Our evidence for this claim is that the data and experiment shows that when the wind turbine had three wind blades made of three layers of soft paper, the turbine was only able to carry 12 washers up 30 centimeters (out of a possible 60 centimeters) before crashing in 11.2 seconds. The extra layers of paper on the single blade with craft popsicle sticks attached at an angle for curvature was affecting the turbine, causing it to weigh more and keeping the three wings from turning properly. Our group decided to adjust the layers and number of wings and reconstructed our turbine by turning it into a wind turbine of four wings that only had two layers of paper on each wing. Along with our new design, we kept our craft stick idea since we deemed it useful as the blade was easier to bend, unsing the sticks for certain curvatures. This new idea worked better because then our wind turbine was able to carry 19 washers (249 G) up the full 60 centimeters in 9.1 seconds.
We claimed that the more wind blades there are, the more washers the wind turbine will be able to carry. Here is our explanation for this claim, and the evidenceq we found while testing this claim! Adding more wind blades, as stated on page 6 of the Working With Wind packet, increases the turbine’s efficiency. More efficiency means more washers lifted, and faster! However, the efficiency gain does decrease with each blade added. In the wind packet, they found that going from a 1-bladed design to a 2-bladed design yielded a 6% gain in efficiency, but going from 2 to 3 only yielded 3%. This is, however, still a gain, just a smaller one, Because of this, when we changed the thickness of our blades and added one more, we gained efficiency and lifted 50% more washers (we lifted .249 KG!) over twice the distance (60 centimeters compared to 30) of before. This is our explanation for why adding more wind blades increases the amount of washers lifted.
One error that we encountered during our design process was our original model’s size. When we started out, we did not have an idea of how big or small we wanted our wind turbine to be and evidently, it turned out to be quite smaller than the average working wind turbine. We also used craft sticks to poke through the top and bottom parts of the wind turbine as it was difficult to curve the turbine normally due to its small size. We decided to go along with our first design but it failed to turn and cycle during our tests. This original model was not able to gather enough energy to turn or lift any washers. From this error and subsequent rethinking, we were able to get a better idea of what size our new design's blade sizes should be.
This was our final model and the blades were 37.8 cm long. We had 4 blades so that the blades captured more air instead of just letting it pass through. The curvature made it so the wind would be able to pass by and push it to turn. The curve helped it lift or take off and we knew this because of airplanes, and what it said in the Working With Wind packet. On the underside of an airplane the wing is curved. By adding another blade it took pressure off the others ones when it started to turn.
We made the blade large because our first design was small and the wind from the fan didn't pick it up. We approximately doubled the size of our model from the original. Our original model did not turn at all because it was being blown backwards instead of turning due to its small size and little curvature in the wind blades.