User:Pjmarsden/enes100/My Work

Link to team page.

Write problem/project Goal
To design and construct a wind turbine.

My First Task
Get a car 12 volt DC 110 volt AC inverter and locate a suitable motor to use as generator.

Summary of actual work over first weekend
I planned on coming up with a full design of our wind turbine. It turns out I had a lot more research ahead of me before i could do that. So I started experimenting with different motors to be used as a generator. I determined that I was going to need to find a much bigger motor then was available in the shop. The plan over the weekend was to go to a junk yard and utilize the motor from a radiator fan.

Week1 Narrative
Over the weekend my group and I went to the junk yard and found a radiator fan the would make a great foundation for our wind turbine. The motor in the fan was able to generate 4 volts from just blowing air at it with an air compressor under no load. So I believe there will be some useable energy to harness here.

My Second Task
In the second week of the project I want to develop a way to charge a cell phone with the radiator fan by blowing air at the fan blades and causing it to spin.

Summary of actual work over second weekend
In week two i wanted to go bigger scale then what i was working with in week one. In week 2 I wanted to take the radiator fan and motor to charge a cell phone. In this week I discovered that there are a lot more problems to look over such as adding resistors to the circuit to regulate the power being produced. So in this week I decided to scale down the wind turbine to a smaller motor with smaller fan.

Week2 Narrative
In week 2 I decided I needed to start much smaller then was i was dreaming up in my head. So I begun to design a much smaller prototype. Instead of setting an unachievable goal for myself I decided to light up a single LED light. The first design I build was a small motor with a small fan on the motor shaft. I wired and LED directly to the motor in a simple series circuit. The problem I faced was that there was nothing to regulate the power to the LED to I was over powering the LED and burning it out. So next instead of just playing around trying to light up the LED I started to record data of the voltage and current outputs of the wind turbine. After that I used an online calculator to calculate the kind of resistor I would need to protect the LED. Now my circuit was a series circuit with a 2 volt LED and a 100 ohm resister. Next I wanted to built a mount and base to hold the wind turbine so I didn't have to hold it with my hand anymore. I took a cat litter box and mounted a PVC pipe with the wind turbine on top into the box.

My Third task
Record what you are planning on doing for the team during the third weekend.

Summary of actual work over third weekend
In week three I planned on doing small scale testing. throughout the week I started small but moved my way up to full scale. This week mainly for md consisted of myself building the wind turbine and blades and my other two team members working on test circuits.

Week3 Narrative
I did a lot of work in week three I worked three days for about 4 hours each, so I am going to break down what I did in week 3 day by day.



3/7/12 I started off this day by checking on an epoxy bond I made on a bigger fan that was to be mounted on our prototype motor. The biggest challenge I faced with getting the bigger fan on the motor was to make sure I get in on straight so that it spins balanced. So I had a hole in the center on the fan that was slightly smaller then the motor shaft, so I heated the motor shaft with a torch so it would melt the plastic to slide on and make a perfect fit. however this did not work as well as I hoped and the fan was very unbalanced, but being impatience I decided to test it like that any way instead of making it better. As I begun to test the voltage output of the motor with the bigger fan the voltage output was very low only .5 volts because the bigger fan does not spin as fast. So since this voltage was not suffecient enough to light an LED I decided to scale up to using a radiator fan motor as a generator. the first thing I did with the bigger motor was find a new way to mount it. In the shop there was a metal pipe in a concrete base that would work perfectly so I went to work mounting the motor to the top of it. After spending about a half an hour mounting it on top I was very excited to mount the fan to it. I then became very frustrated when I found that I had not measured correctly and it would not fit so I have to spend another half an hour remounting the motor so the fan would fit. Next just out of curoscity I wanted to see if the bigger fan from the radiator would spin in natural wind. The fan was however was to small to generate the torque needed to spin the motor. for testing purposes I used a leaf blower to generate a higher voltage this bigger wind turbine with the leaf blower was able to generate 7.9 volts. Pretty impressive I thought enough to light a couple LEDs or to charge the battery in a cell phone.



3/8/12 While my other group members worked with test circuits to collect more data from the wind turbine I came up with a task for myself. I really wanted much bigger blades that would spin in real natural wind. So I made blades that were 2.5 ft long in order to make a 5 ft diameter fan. I developed a very simple way of doing this by cutting a cardboard tube into froths so they could be mounted in opposite directions on a hub. My plan for the next day was to make a hub to mount them to.





3/9/12 The last day of the week I spent all my time making the bigger fan. I needed to make a hub to mount the blades to. I started to look around the shop for something that was a circle that would work. I couldn't find anything so I decided a square piece of wood would work. I mounted all four of my blades to the hub then drilled a hole in the center of the hub for the bolt on the motor to go through. After that I took it outside to see if it would spin and to my surprise it spun relatively fast in very low wind speeds. I wanted to make it spin faster by blowing the leaf blower at it but the fan blades flexed to much causing them to hit the pole.

Videos
 * http://www.youtube.com/watch?v=yN47dCX5pm0 ← large wind turbine spinning in natural wind
 * http://www.youtube.com/watch?v=UgX1Dug8Wmk ← small wind turbine over powering LED
 * http://www.youtube.com/watch?v=twKCa1b8o-U ← small wind turbine powering LED

My Fourth task
In week four I will continue work with larger wind turbine blades to try and produce useable power with natural wind.

Summary of actual work over fourth weekend
In week four I planned on harnessing natural wind to generate useable power. This is the same as what I actually did however I side not succeed in my goal.

Week4 Narrative
In week four I sought to accomplish my goal by making more efficient wind turbine blades that would spin faster in natural wind.

The first step in making the new blades was that I needed to come up with a design the would work better then the first ones I made in week 3. The first problem I addressed is that the bigger blades although were very large and spun in very low wind speeds the speed of them was limited due to their size and that they were too flexible because of there length. I decided not only do I need to rethink the length but also the material. So I decided make them half the length then the previous design and out of PVC instead of cardboard. Since I wes making this change I had another problem and that was how can I get the blades to generate enough torque to spin in low speed wind just like the larger ones. I came up with two solutions the first would be that I would double the amount of blades so instead of 4 blades on a square hub I was gonna have 8 blades on an octagonal shaped hub. Next I needed a way to make the smaller blades generate the same torque as the bigger blades. So I came up with a way to do this which seemed counter intuitive at first because it involved decreasing the surface area of the blades. But what this design did actually allowed me to do is harness a mechanical advantage by funneling the wind to the tips of the blades furthest from the center of rotation. The way I achieved this was by cutting a diagonal line across the blade so the wind would funnel down to the tip. This was different from the bigger blades that had the same curve the whole way along them.

The beginning preliminary cut on the new blades.

After diagonal cut was made.

Full blade assembly

Full blade assembly.

Blade assembly mounted on motor

Video of the new blades spinning http://www.youtube.com/watch?v=74-k8h8T634&feature=youtu.be

After having the new blades assembled I needed to test them in natural wind. The problem I had though was the day I was working on it there was no wind outside so to simulate the wind I went indoors and resorted to using the leaf blower, although the leaf blower only simulates very high rates of wind. After testing and finding that these new blades only generated 6.5volts I needed to rethink the generator I was using. Throughout this whole project I have been fighting one major problem. That is that I have been attempting to generate power but the motor I have been using to generate power is designed to work at high RPM low voltage. So in order to actually make this work I need a better motor that is designed to work with a high voltage and low RPM. So for the next 4 week project I will continue to focus on wind turbine but my main goal will be to find a motor that will work well as a generator.

Complete Project Page
Follow the "project done" format.