Wind Turbine Blade Efficiency
Xhespina, Guillermo, Omar, Khalid
Wind turbines will transform the kinetic energy from the wind into electricity. The amount of power a wind turbine can produce depends on blade efficiency, the design of the blades will affect the power production. More efficient blades will use the wind and make the drag as small as possible as the blades spin around.The way the blades are designed and set up on the turbine will decide how fast they spin and therefore how much power is being created from that wind. The motor that the blades are attached to will convert mechanical energy to electrical energy as it is spinning.
The purpose of our experiment was to see which blade design is the most efficient. We had three different blade shapes as the variable and everything else was kept constant. The material that the blades were made up of were the same, the turbine they were put on were the same, and the wind speed was also kept constant.
The procedure for the experiment was to first estimate the area of each blade. We also had the exact area of the blade noted so we could tell the people if they were close so they could get a close number with the equation. Next, they had to pick one of the blades and put it on the turbine. We built the multimeter already connected on to the turbine so all they had to do was turn it to 20DC to get the voltage reading for the blade. Instead of using a fan to create the wind we decided to use a mini leaf blower because it was stronger and would give us a better result. The leaf blower was held about four feet from the windmill and they had to keep it on for 30 seconds. One person was watching the multimeter to get the highest voltage read. Another person held the wind speed monitor up to measure the wind.Next, they had to set the multimeter to 20K to get the resistance reading. All of these results were recorded on a table that was provided on the lab sheet. After following the same procedure for each of the blades the formulas provided had to be used to calculate both the expected wind turbine power and the actual wind turbine power that we measured.
This is the chart that was provided with the results that we got:
To make the wind turbine we used pvc pipes, a mini motor, and wires. Building the wind turbine was not too hard of a process. We had many difficulties with the experiment. The first difficulty was finding a motor that was not too hard to spin so that the blade would be able to spin it and we wo
uld get results. Our mini motor also burnt out twice, and we had to switch it out.The harder pro
cess was to get the blades to fit perfectly on the mini motor. If the blades did not fit perfectly on the mini motor the motor would not move and therefore we would
not get any results. We had to put glue on the part of the blade that connected to the mini motor let it dry just enough then put it on the mini motor to get the perfect shape on it. We chose to do a harder project because we were four team members and we felt it would be better to challenge ourselves.
Idea(link) on how to construct turbine
The white blade which we thought would be the most efficient and produce the most power was in fact the one that produced the most power. It produced 1.64 watts, the black was second producing 0.75 watts, and the blue (least surface area) was last producing 0.257 watts. The white had the most surface area which we think helped the most in reducing the drag of the wind. The numbers we expected using the formula were not close to the actual numbers that were measured by the turbine. We used the area of the blade for one of the parts because this is what we were told to use, but we were supposed to use the area that the blade covered instead.
We noticed that people got kind of annoyed doing the experiment because there were many things that they had to do. They had to measure a lot of different things and then use two formulas to do two separate calculations. Next time we might just include two blades or less things to measure in order to make the experiment less of a hassle for the people trying it out. Other than the detailed process people were very intrigued with how we built it and how the whole thing worked out. Even after working the formulas out they found it interesting to compare the expected and the actual results of the wind turbine.
We also enjoyed going around and seeing all of the other experiments that had been done. Everyone did a good job in constructing their projects and showing them to everyone else in the class. Some experiments were more time consuming and detailed when comparing them to others. Everyone had interesting topics and it was cool to see ideas we had spoken about in class be presented.