sph3u physics isu 2011

11 Physics ISU Bogdan Stanciu

SPH3U Physics ISU 2011

Wind Turbine Renewable

Energy Investigation


Purpose

The purpose of the wind turbine was to find out how efficient a turbine can be in making an

electric current from an outside force (In this case, a Fan)

Materials

The Materials used in making the turbine were the following:

Wooden dowel and wooden base which acted as the motor stand

Motor

Fan

Propeller 2 (Sarah)

- Red Hard plastic taken from cement container lid

Propeller 1 (Moi-Moi)

-Pipe Cleaners

-Construction Paper

-Toothpicks

-Paperclip

-Pen Refill

-Glue

-Masking Tape

-Metal Key ring

During Construction

-Phillips screwdrivers

-Power tools


Method

The stand with the motor was placed in front of the fan, and the height was adjusted so that

the propeller would be right in front of the fan. After the optimal height was attained, the

galvanometer was connected to the motor and the first propeller was attached to the motor,

and the fan switch was shifted to the first position (1 m/s). After gaining a reading, the switch

was shifted to the 2nd (2 m/s) position. After this was done and we had gotten a reading, the

switch was shifted to the final position (3 m/s).

When the first propeller was finished with testing, it was removed, and the 2nd propeller (Sarah)

was fitted onto the motor, and the same procedure as above was repeated.

Diagram


Observation Tables

Blade 1 (Moi-Moi) Blade 2 (Sarah)

Trial Speed 1 Speed 2 Speed 3 Speed 1 Speed 2 Speed 3

1 mA 12 mA 15 mA 20 mA 24 mA 48 mA 75 mA

2 mA 13 mA 14 mA 18 mA 22 mA 49 mA 65 mA

3 mA 11 mA 14.5 mA 19 mA 23 mA 48 mA 70 mA

Average 12 mA 14.5 mA 19 mA 23 mA 48.33 mA 70 mA

Analysis

Power of electricity

P=l2R

Moi-Moi

Speed One P= (12 mA) 2(2.3 Ω) = 3.3 x 10-4 W

Speed Two P= (14.5 mA) 2(2.3 Ω) = 4.8 x 10-4 W

Speed Three P= (19 mA) 2(2.3 Ω) = 8.3 x 10-4 W


Sarah

Speed One P= (23 mA) 2(2.3 Ω) = 12.2 x 10-4 W

Speed Two= (48.33 mA) 2(2.3 Ω) = 53.7 x 10-4 W

Speed Three= (70 mA) 2(2.3) = 112.7 x 10-4 W

Power of Wind

P=dAv3x ½

Moi-Moi

A= (pi) (radius) 2

R= 13.5 cm, or 0.135 m

A=0.0572 m2

Speed One= ½ (1.3 Kg/m3) (0.057m2) (13) = 3.7 x10-2W

Speed Two= ½ (1.3 Kg/m3) (0.057m2) (23) = 7.0 x 10-2W

Speed Three= ½ (1.3 Kg/m3) (0.057m2) (33) = 1 W

Sarah

R= 9 cm, or 0.09 m

A=0.0254 m2

Speed One= ½ (1.3 Kg/m3) (0.025m2) (13) = 1.6 x 10-2W

Speed Two= ½ (1.3 Kg/m3) (0.025m2) (23) =1.3 x 10-1 W

Speed Three= ½ (1.3 Kg/m3) (0.025m2) (33) =4.38 x 10-1 W


Efficiency

Pelec/Pwind x 100%

Moi-Moi

Efficency1= 3.3 x 10-4 W/ 3.7 x10-2W =0.08%

Efficency2=4.8 x 10-4 W/7.0 x 10-2W =0.06%

Efficency3=8.3 x 10-4 W/1 W =0.0083%

Sarah

Efficency1=12.2 x 10-4 W/1.6 x 10-2W X 100%=0.7 %

Efficency2=53.7 x 10-4 W/1.3 x 10-1 W X 100%=0.4 %

Efficency3=112.7 x 10-4 W/4.38 x 10-1 W X 100%=0.2 %


Discussion

1. When the speed produced by the generator increases, the output out of the motor will increase as well. Vice versa, when the speed produced by the fan decreased, so did the output of the motor. This can be easily seen in the power v. wind speed graph, as the power is in direct correlation to the wind speed.


2. The power that is available in the wind versus how much power is generated is quite a massive gap. None of our propellers reached even 1% efficiency, and as seen on the graphs, as the wind power increased, the efficiency plummeted for both propellers

3. As seen in the graphs and the data above, Sarah provided more overall efficiency and power. The 2 designs were almost radically different. While Sarah was made out of one solid piece of plastic, and with many flaws in her surface, Moi-Moi was made up of several materials, with precise measurements, and picture perfect aesthetic appeal. Design wise, Sarah mimicked a fan blade design, while Moi-Moi had a paddle/picturesque tear drop shape. The 2 different power efficiencies all stemmed from (obviously) the different designs. Things that might’ve helped Sarah in having a higher efficiency rating includes her less slanted surface, which contributed to air resistance, which in turn contributed to Sarah turning more as a result of more air on her blades.

Conclusion

In conclusion, when we set out at the beginning of this project to build the most efficient turbine, we had a competitive mind view set, but as we realized that it wasn’t a competition, we became more lax in building our turbine. We found that though a higher wind speed (input) resulted in a higher output (current), it also resulted in a loss of efficiency. We also found that the most important part of the blade was to have the largest area that the wind could hit possible, and as it would “slide” off the aerodynamic blade, its power output would greatly increase. Materials weren’t necessarily a problem; we had set on recycling things we already had, and to not buy anything extra. We realized that though the blades have to be light, they also had to be strong enough to not “flutter” when put up against the wind.

Error Analysis

There is no doubt this Entire experiment could’ve behaved better. One of the major sources of error would’ve been Sarah’s various cracks across her surface, a large one which stemmed from a preliminary testing where the fan was abruptly stopped, which applied too much force upon the blade, which nearly ripped it.

Another source of error would’ve been that the grips on the motors for both fans were both flawed; for Moi-Moi, the pen refill made it tilt slightly forwards, which decreased the amount of power it could generate greatly. For Sarah, the grip was too loose, and as such when it span, the air also pushed it backwards, until it would eventually actually touch the stand, which caused it make the base shudder erratically.

sph3u physics isu 2011

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