Windmill Results

Mass    Height   Energy   Power   Time
7.83g   .7874m  60.54j     1.06w    20s
14.7g   .884m    128.85j   7.336w  20s

• Which rotor has the most power? Why? The second one because it was wasn't too light and wasn't too heavy.
• What was the different  from the design with the most output? It had longer wings.
• What are the limitations to the model? We could've made it bigger and maybe try to get more weights to be lifted.
• How do airplanes and windmills compare? They use their wings to move.
• Why did we twist the rotor blades at an angel to grab the wind? So that it would spin easier and faster.
• Explain how windmills and sailboats use the sane principles. When the wind hits from a distance it seems to move faster, you don't want to be right up close to the windmills and sailboats because it will slow it down or won't even move at all.

rotor

Results:

Mass	Height	Time	Power
8.6 g	92 cm	15 sec.	5.2 watts
27.34 g	92 cm	36.84 sec.	6.70468 watts
30.66 g	92 cm	27.6 sec.	10.33 watts

1.) Which rotor had a better design? why?
Our second rotor had the best design, it was lightweight but long and it produced a decent amount of energy
2.) what is different about the design with the MOST output from yours?


3.) What were the limitations of your model?
Our model was limited to a mediocre amount of weight because it had a rough design and was pretty heavy.

Time Mass Height Energy Power
76 seconds 8.84g .13m 11.285144 .15 Watts

Our Turbine that had the most power was our small one made out of cut up pop cans with a small dowel. It had the most power by default. The other didn't work. Ours was short and thin, looked like it could have been a scale model. The limitations of our model were that it wasn't heavy enough to support itself, and slid around. The other just wasn't glued well and had a smaller blade than the others. Airplanes and Windmills work by a change in air pressure. Airplanes also have small blades that come off of the end that catch the wind at a proper angle to cause lift. That same property can be applied to windmills. It has a slant on one side of the blade, which allows it to catch wind and not lose a lot of air. That is why it is necessary to have the rotor blades at an angle. The sail on a sailboat is long and thin, just like a successful rotor. It also has a slight angle, and catches the wind. On the correct angle, it is caught by the wind and moves, just as a windmill catches the wind and spins.

Windmill Results

Windmill Type	Length of String	Mass	Time	Power	Energy
Pop can	85 cm	8.8 grams	12 seconds	73.45 joules	6.121 watts
Paper	85 cm	8.8 grams	10 seconds	73.45 joules	7.345 watts
Paper (test 2)	85 cm	13.77 grams	12 seconds	114.94 joules	9.578 watts

1.) Our paper rotor had the most output because the rotor was more reliable when it was spinning. It didn't stop and start as much as the other one so it gained more momentum.

2.) The paper rotor had more surface area and a greater angle on the blades.

3.) Some limitations to our rotor are that the blades are not very long so they won't be able to use as much air to spin.

4.) When the wind hits the edge of the blade, it splits the wind in two. One way goes above and has no effect. The other goes down and gets pushed down by the angle of the wing. The wind then pushes the plane up. The same basic effect goes for the windmills.

5.) It is necessary to twist the rotor blades in order for it to be able to catch and redirect the airflow to one side in order for it to spin.

6.) The rotors of a windmill and the sail on a sail boat both catch the air in order to move. The rotor moves the air to one side to spin and the sail catches the wind and holds it to move straight forward.

Wind Energy

Wind Energy

Wind Energy	Mass in grams	Height in cm	Time in seconds	Energy in jewels	Power in watts
Playing Cards 1	8.83	76	104	65.90	0.63
Playing Cards 2	34.54	76	77	257.78	3.35
Feathers 1	7.06	76	49	52.69	1.08

1. The one of our windmills that worked the best was the playing card version (as opposed to the turkey feather version). Both of the turbines were built with a base of foam and had three blades in the foam at an angle. However, the playing card blades caught the wind better than the feather blades did. This was because the cards were uniform,rigid, and held their shape while the feathers varied in size, were easily broken, and were more flimsy. The design worked both times, but the cards were a lightweight and sturdy material, proving more efficient than the feathers.

2. The one of our classes that worked the best was the one that Miranda and Kelsey made(16.69 w). However, they did not have a picture, so I'm not sure why it worked better. The second best was made by Nate, Mike, and Evan, (10.03 w) but they also didn't have a picture. The third best was made by Jacob and Tyler(9.85w) who also didn't have a picture. (I'm sensing a pattern here.) The fourth best was made by Sofia, Jessica, and Samantha (6.5 w). Luckily, they did have a picture. Their design included slightly cupped blades that were taped to the dowel using masking tape. The blades were about six inches long and three or four inches tall. I think that the reason theirs worked better than ours was because their blades, made of cardboard, were sturdier and heavier than ours. They were all of a uniform size, kept their shape, and caught the wind easily. They were attached to the dowel in a sturdy way and were able to turn and lift weight.
3. Some limitations on our model were the size, design, and materials. Since we used playing cards and feathers for our blades, they weren't able to lift much due to their light weight. Our blades were also rather short; longer blades output more energy. The feathers especially were somewhat flimsy. Due to the work we did with them, they began to tear and not catch the wind as well. We used foam to hold the blades in place, which was not the firmest. The blades were also not all at the exact same angle of tilt, making them less efficient. The playing cards did not have any curve in them, and were only tilted, making them less aerodynamic and less functional. Since the blades were not all uniform (mainly the feathers) the wind did not catch them all the same. It would have worked better to have slightly stronger and better attached blades that were all uniform, longer, and more curved.

4. Both airplanes and windmills are affected by Bernoulli's Principle: as velocity of a fluid increases, pressure decreases. Airplanes use this change in pressure to fly; as they go faster, there is less pressure above the plane and more beneath it, creating lift so they can stay in the air. As a windmill begins to turn faster, there is less pressure beneath the blades and more above them, causing it to continue the turning motion. Much of this is due to curvature and tilting of the blades/wings, since the wind moves faster over a curved surface.

5. It is necessary to twist the rotor blades at an angle so they can catch the wind. If you have flat blades, wind blown on them will just be stopped. If the blades are at an angle, they have the opportunity to catch the wind and turn, giving off energy. Rounded or cupped blades also don't work, since the wind will fill up the blade and not move anything; tilted blades catch and spin.

6. Rotors on a windmill and the sail of a sailboat are both designed to catch the wind and move forward. A sail is tilted so when the wind catches it, the boat is moved in that direction. The blades of a windmill are tilted to catch the wind and turn in that direction. The tilt and turning factors show how windmills and sailboats operate on the same principle.

Rotor Questions

Results
Mass Height Time Energy Power
8.84g .13m 76 sec 11.29 .15 watts

Which rotor had the most power? Why?

We only had one rotor because it was dropped and broke and we didn't have enough time to make another. It didn't work because it short and wide rather than long and thin. Also, one blade was heavier than the others.

What was different about the design with the most output?

Our design was different from others because it was made from aluminum pop cans. Most of the other designs were cardboard. Ours was also a lot smaller than the other windmills.

What are some limitations of your design?

One limitation of our design is the weight. The windmill was very small and lightweight. One of the blades was heavier than the others too so it when it got to the bottom it would stop rotating.

Another limitation is the blade angle. The blades were not twisted so the wind just ran into the blade without turning it.

How do an airplane and a windmill use air pressure to fly and rotate?

The sail of a windmill and the blade of a windmill are a lot alike. They both use a twisted shape. This makes the air push on it and create a change in air pressure which causes the windmill to turn and the sail to carry the boat with it.

Why do you have to twist the blades on the windmill?

Twisting the blades makes the air push off it. Without twisting the blades, the wind just runs into the blade without pushing the blade.

How does a windmill rotor and a sailboat have the same principle?

They both use air pressure to move by being pushed by wind.

Wind Turbines

1. Which windmill had the most power? Our purple windmill had more power because the wings let the air to push them around.

2. What was different about the design with the most power? The blades in the less affective one didn't have enough space in them to make the wind hit it and make the turbine turn. In the one that worked, the rotors were cupped, which allowed the air to go in and hit the side, making it turn.

3. What are the limitations of the model?

One of the limitations was the blades were too caved in and air would get trapped in, sometimes causing the windmill to slow down. We also could have tilted the blades a little bit more and make them longer so the air would pass through more easily.

4. How do airplanes and windmills use air pressure to fly or rotate? The blades are set at an angle and have a curve to them so that the air pressure pushes them.

5. Why is it necessary to twist the rotor blades at an angle? So that the air doesn't hit the blade evenly, because then it wont be able to push and put pressure on it and it wont rotate.

6.  Explain how the rotors of a windmill and sailboat illustrate the same principle? They both use Burnellies principle because the blades have a curve in them.

Mass           Height     Energy   Power
7.5g            .95m        69.96      6.5w

Wind Turbines

1. Which rotor had the most power and why?
My 3 bladed turbine worked the best.  It worked best because it had more wings to catch the wind and create more power.
2. What is the difference in the design that had the most outout?
 The wind turbine that had the most output had long and skinny blades. My blades were short and fat.
3. What are the limitations to your model?
My blades were short and fat so they lost alot of energy and did not catch as much wind as the others.
4. How do an airplane and windmill use air pressure to fly and rotate?
Both blades have a angle to them that when the wind catches the curve it creates lift.
5. Why was it necessary to twist the rotor blades at an angle?
So that the blades can catch the wind and make them move.
6. Explain how the rotors on a windmill and the sail of a sailboat illustrate the same principle?
The blades and sail both have a curve/ angle to it so that it can catch the wind.  They both use lift to move.

Mass	Height	Energy	Power	Time
40 grams	.085 meters	33.38	16.69 watts	2 seconds

Windmills

1. Which roder had the most power and why?- The purple roder with four sides had the most power because it had more room for the wind to hit it and push it. 2. What was different about the design that had the most output?- it was shorter but wide on the inside. It had more space for the wind to go in and push it. 3. What are the limitations or model?- the model is roud and deep inside. Some limitations of our windmill are we could made the windmill longer instead of it being short. 4. How does an airplain and a windmill use pressure to fly?- a windmill has a smooth but roudish figure when the wind hits the widmill the wind will go smoothly over the mill and get caught in the curves which pushes it around. 5. Why is it necessary to twist the roder blades at an angle?- so the wind can fly smoothly over and around the windmill while still pushing the windmill. 6. Explain how roders of a windmill and the sail of a sailboat have the same principle.- They bothe are tilted to catch the wind to make the objects move. Power of our windmill- 6.5 High Energy- 69.96 Mass- 7.5 Time- 41 sec.

Windmill Questions

1. Which rotor had the most power and why?
The rotor that worked the best for us was our one made out of milk jugs.  It worked well because it was a hard plastic and had the curves so that the wind hit it just right to get it to move.  Our other one didn't have the bend and didn't move as well.
2.What was different about the design with the most out put?
I noticed that the designs that worked the best were long and slender compared to our design. I think that that probably helped it catch the wind better.
3.What are the limitations of the model?
Looking at the other models I would say that a limitation of ours is that it was not as long and skinny as the ones that worked well.
4.How do airplanes and windmill use air pressure to rotate. 
If you look closely the wings on a plane and on a windmill have a slight curve in the wing.  This helps so that when the air pressure hits it the wind will flow right over the wing causing it to spin/lift the wing.
5.Why was it necessary to twist the blades?
By twisting the blades all the same direction the air pressure will hit them just right making the air go over the blade which causes it to spin.
6.How do rotors of a windmill and the sail of a sailboat illustrate the same principles?
They illustrate the same principle because they both have slight curves in the sail/wing that cause the air pressure to hit it and go over it causing it to move.



               Mass               Height                Energy                 Power             Time
                7.83g                .7874m              60.54J                   1.06w             20s
                14.7g                .889m                128.85J                 7.336w           30s

Windmills

1.I made two rotors and the only difference was how they were connected to the dowel. One was connected by three vertically slanted craft sticks on the dowel, the other was three craft sticks connected to two pyramids that surrounded the dowel. The one with the two pyramids had a shorter base then the three craft sticks directly connected to the dowel, since I had cut the craft sticks. The pyramid windmill worked better, probably because it had more room for the string to move by itself, which meant I had to touch it (and cause friction) less often.
2.The difference between most of the turbines and the most powerful one was that the most powerful one had long and thin turbines and most of the others were short and wide. The most powerful one also looked like it had sturdy turbines, unlike the other turbines that were long and thin, which looked flexible. If the turbines were flexible, the wind wouldn't be able to apply as much pressure.
3.Some limitations to my design could be that the turbines aren't slanted. Because of the turbines not being slanted very much, the wind hit the turbines at an equal force, not allowing for rotation to happen. Also, with my triangle rotor, I think one of my turbines was heavier then the others, so that it wasn't able to spin easily.
4.An airplane uses air pressure by making the wind going over the top of the wing go faster then the wind going under the wing, causing lift and pushing up on the wings, which lifts the airplane into the sky. A turbine uses air pressure by having the air pressure slide by the slanted wing, which means when the air pushes off to one side so that the air can continue it's forward momentum. When the air does this, it pushes on the wing so that the wing spins in the other direction, causing rotation.
5.It is necessary to put the turbine wings at a slant so that the air doesn't evenly hit the wings, because if the air hit the wings evenly, there would be no rotation.
6.A turbine and a sail on a sailboat both use air pressure to push the sail or wing forward. When a sail is used going with the wind, the wind is pushing against the sail, which moves it forward. When the sailboat is going against the wind, what happens is the sail goes at a back and forth slant. When the sail is at a slant, an area of low pressure is made at the front side of the sail because of the wind going to the back of the sail, according to Newton's Third Law. This creates an opposite push. This happens with a wind turbine also.
                               time                       height (meters)                          mass (grams)
triangle (test 1)        2:28                          0.86                                        29.55
triangle (test 2)        1:36                          0.67                                        35.58
slant                        0:00                          1.10                                         0

Wind

What Are The Limitations Of The Model?
My model could hold three weights which is equil to 22.31 grams. When I added the fourth weight it couldnt quite spin all the way. The blades would slightly turn but could not completely go around. My model could also only spin with three weights if the fan was on high. Without that amount of wind my model failed to spin fluently.
How Do An Airplane And A Windmeal Use Air To Rotate?
They both have an air foil that creates pressure causing rotation within the blades.
Why Was It Necessary To Twist The Rodar Blades At An Angle?
Twisting the blades allowed it to have a resistance against the wind or the air flow. When there is resistance it helps the blades rotate with the wind direction.

Wind

Which Rotor Had More Power?

I was told to test just one of mine due to time issues, but the one that was tested was made out of poster board cut into four blades that each intersect eachother. At the ends of each blade is a cup like figure to help catch the wind drifting from the fan.

Why Was It Necasary To Twist The Rotor Blades at an Angle?

Twisting the blades helped them move with the wind or to help it catch wind without it like this, its likely that it wont spin.

Explain How The Rotors On a Wind Windmill and The Sail of a Sailboat Illistrate The Same Principle.

Withput a sail on a sailboat it wouldnt be able o move as fast, it would only be able to move by the push of the waves. When the wind catches the sail or a blade catches the wind it helps push forward or backwards depending on the set up of the wind and the sail.