Tuesday, April 24, 2012

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.

Monday, April 23, 2012

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

Sunday, April 22, 2012

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

Wednesday, April 18, 2012

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.

Tuesday, April 17, 2012

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.