Physics Project - Wind Turbine

[Flip_Willie]

Hello everyone,

I just thought I would show this off here. For my Physics semester project, my group decided to build a wind turbine. We built it for the specific purpose of demonstration, so using it for more practical applications would require modification. However, I think it turned out pretty well.

We got the basic plans for the wind turbine from this website. Although our final design doesn't look too much like his, we did take a good deal of information from the website. For example, the one thing that we did copy is the design for the blades.

Overall, we only worked on it for a couple of months. The design was pretty easy/clever. We constructed it primarily from 6" PVC pipe.

Anyway, here are some pictures and a video. It wasn't quite completed in the video; however, that is the only video I have uploaded.


EDIT: The video doesn't appear to load every time. You can click on the link if that is the case.

Flip_Willie

[JONTHEBOMB]

Cool Project!

How much did it cost to build the wind turbine?

[Flip_Willie]

Cool Project!

How much did it cost to build the wind turbine?

We spent around $80 on the project. However, we spent a lot of money on electronics that we didn't end up using. Also, we bought 10 ft of 6" PVC, and we only used 5 ft. In this regard, I am sure we could have saved some money if we better laid out what we would need.

That being said, we also saved a great deal of money. The motor was donated by our physics instructor. We also had machining done for the turbine. This would have cost us if we didn't know someone who could do it for us for free.

Flip_Willie

[RayB]

So how much power does it generate?

[Flip_Willie]

So how much power does it generate?

First off, I need to explain that a bit. We had hoped that we had a DC motor, but it turned out that the motor we got was actually AC. What we ended up doing was installing an AC to DC transformer in the turbine. This gave us an AC and a DC portion in the wind turbine.

Finding the power on the DC circuit is pretty easy. We installed 3 gauges on the wind turbine (AC volt Gauge, DC volt Gauge, and an DC Amp gauge). For the DC portion, you can simply multiply the values on the DC volt gauge and Amp gauge. When we conducted tests, we averaged around 20 mA and 8 V, so the power was around .16W (In fact, you can calculate this from the picture above).

Unfortunately, we never tested for power on the AC portion of the circuit. We wanted to install an AC amp gauge, but we couldn't find one locally, and because we worked on the project right up until it was due, we never got around to calculating the power. I am disappointed at this. I still have the turbine, so I may try and test for this later down the road. Really, all I would need to do is place a resistor in-line.

For additional information, I have included the wiring diagram we used and two graphs of some stats from the unit.

Flip_Willie

[Ummon]

So...what was the 'physics' portion of it. Looks like an engineering project to me.

[Flip_Willie]

So...what was the 'physics' portion of it. Looks like an engineering project to me.

Physics II: Electricity and Magnetism. Our semester project consisted of a 30-minute presentation and the actual project. During our presentation, we discussed the theories behind how a wind turbine works. For example, we talked about how the motor generates electricity.  Also, the course covers basic circuits, and we discussed this as well in our presentation.

Flip_Willie

[Level42]

So...what was the 'physics' portion of it. Looks like an engineering project to me.

For example, we talked about how the motor generates electricity.

If I had been your teacher, you would have got a F when I read that....


Cool project though.

[Flip_Willie]

If I had been your teacher, you would have got a F when I read that....

Wow, thank you very much. You made me feel really bad.

In fact, you made feel awful.

EDIT: Why would you say something like that? I mean, you didn't even point out what I said that was wrong in your opinion. The only logical conclusion I can come to is that you posted that simply to make me feel bad. Good sir, you have accomplished your task.

Flip_Willie

[Level42]

A motor does not generate electricity, a generator does. That's what I meant.

Lighten up 

[Flip_Willie]

A motor does not generate electricity, a generator does. That's what I meant.

Lighten up 

So because I got some terminology wrong, I should fail my presentation?

Flip_Willie

[Level42]

It is pretty essential yeah.

But don't get me wrong, a motor _can_ act as a generator and vice versa.

They're basically the same thing.

But when you do a presentation get the terms right.

But hey, it still IS a cool project, like I mentioned !

[Level42]

Afhhhghhhhhh forget it.

[Flip_Willie]

In fact, you made feel awful.

Man up.

Seriously.

EDIT:
You are right. I have a bad habit of taking things very personally and reacting before I have thought things out. That is my fault.

I invested a lot of time in the project. I thought forum members would find it interesting and not tell me that I should have failed for my efforts.

EDIT 2:
I predict now that I have killed the thread.

Flip_Willie

[Flip_Willie]

Please for the love of god tell me you're not a student at Texas A&M...

No, I am not. Why? I have already made a fool out of myself today, so go ahead and tell me what you think.

I feel like a moron for even responding to Level42's comment. I made a bad choice. I took myself too seriously, and I was offended at Level42's comment.

I regret the way I acted. You said "Man up," so I am taking your advice and admitting my error.

Flip_Willie

[protokatie]

When I saw the word motor I figured you had rigged a DC motor to act as a generator...     Then again you did say you could only find an AC one, so I was a bit perplexed...

[Flip_Willie]

When I saw the word motor I figured you had rigged a DC motor to act as a generator...     Then again you did say you could only find an AC one, so I was a bit perplexed...

We had wanted a DC motor to act as a generator; however, it turned out that we were donated an AC motor.

From my understanding, the only difference between a motor and a generator is where the work is being done. If you apply a current to a motor, the shaft rotates. If you manually rotate the shaft on a motor, it produces electricity. This is due to the principle of electromagnetic induction.

Flip_Willie

[RayB]

Hey --bags of cream-filled twinkies--, if he used a motor, then his terminology wasn't wrong. I can use a pencil to stab you in the eye, but that doesn't make it a "weapon". I still stabbed you with a PENCIL.

[Ond]

Hey --bags of cream-filled twinkies--, if he used a motor, then his terminology wasn't wrong. I can use a pencil to stab you in the eye, but that doesn't make it a "weapon". I still stabbed you with a PENCIL.

+1 (beautiful analogy) 

[Level42]

Hey --bags of cream-filled twinkies--, if he used a motor, then his terminology wasn't wrong. I can use a pencil to stab you in the eye, but that doesn't make it a "weapon". I still stabbed you with a PENCIL.

---smurf-poop---.  if you will go to court then in justice TERMS the pencil was the weapon that you committed the crime with.

The essence is this: Here we have a student who is doing an interesting project. He is trying to learn stuff and so it is important to get things right. If you would go to a electrical engineer and you talk about a motor that generates electricity, you will be laughed at. It's not a problem now, because he's a student and learns by mistakes. I tried to point him to that mistake in the hope he would accept it and learn from it, but instead he cries like a baby (not uncommon for today's youth).

He uses a motor to act as a generator. From the moment he uses the motor to transfer mechanical energy to electrical energy, it has become a generator.

I have a much better analogy for you guys: if he would apply electrical energy to the motor, he would have made a fan instead of a wind-turbine.

The point is that if you do a study project and you make a report or a presentation, and you will say that the electrical energy is produced by a motor it just sounds wrong.

The teacher should have at least pointed you to that.

[Ond]

yeah but RayB's analogy is funnier - so he wins.   

How bout this........AC Motor/DC Motor?   Many DC motor's are actually 'AC' anyway in operation (they generate an oscillating current within the rotor in order to turn).

My point?  None whatsoever.  Just fishing like you guys do.   

[ChadTower]

If you guys don't chill I will call MaximRecoil.  I mean it.

[Ummon]

If you guys don't chill I will call MaximRecoil.  I mean it.

Hnh hnh hnh hnh hnh.....


Yeah, it does help to have your terms and concepts laid out and straight.


And....

Hey --bags of cream-filled twinkies--, if he used a motor, then his terminology wasn't wrong. I can use a pencil to stab you in the eye, but that doesn't make it a "weapon". I still stabbed you with a PENCIL.

....um, just like the box cutters they used on the airplanes on 9/11. <chanting 'BOIL BOIL TOIL AND TROUBLE!'>

[ChadTower]

If you're going to go so far as to quote Shakespeare you could at least get the quotation right.   

[Ummon]

If you're going to go so far as to quote Shakespeare you could at least get the quotation right.  

Hey, man, I was going off of my sixth grade memory of three girls in my class doing it at Halloween. I don't recall knowing it was Shakespeare then.....though, your mention brings back some far more recent memories of that factoid....hmmm.

[Flip_Willie]

The essence is this: Here we have a student who is doing an interesting project. He is trying to learn stuff and so it is important to get things right. If you would go to a electrical engineer and you talk about a motor that generates electricity, you will be laughed at. It's not a problem now, because he's a student and learns by mistakes. I tried to point him to that mistake in the hope he would accept it and learn from it, but instead he cries like a baby (not uncommon for today's youth).

The only reason I reacted the way I did is because I do respect your opinion. I know I do not post much here, but I have frequented this forum nearly every day for almost 4 years. In that time, I have read a lot of posts and have come to respect several members on this forum. You are one of them.

That is why I reacted so strongly when you were so quick to condemn my project with an F due to fowled terminology. I am sorry. I don't have a heart of stone, and this project is something that I am proud of. One of the main functions of this board is for people to show off their work. I was showing off mine.

Imagine for a moment that you have a close friend or relative who is in the same position as I am. He is new to the field of physics and electrical engineering, but he is devoted to learning. This person has just finished a term project that he is very proud and is excited to show it to you. In process, he makes mistake in terminology -- a mistake that you even said yourself would be easy for a novice not to understand because a motor and generator are so similar. Would you say to this close friend the same thing you said to me, or would you say something like, "Hey, you better watch your terminology. In the real world, people will laugh at you for saying that"?

I cannot see why my position on this is so difficult to understand.

Flip_Willie

[SirPeale]

I cannot see why my position on this is so difficult to understand.

Because you're retarded.  And here's my basis for that assumption: you're arguing about something over the Internet.  Taking one anonymous guy's comments to heart.

Who cares what Level42 says about your project?

(no offense, Level42)

[Flip_Willie]

Because you're retarded.  

I am sorry you feel that way. It is my opinion that one should treat anonymous people with respect -- even if it is the internet.

And here's my basis for that assumption: you're arguing about something over the Internet.  Taking one anonymous guy's comments to heart.

I already admitted that I had a problem with this. I am not perfect. I already said I regretted what I said in the first place.

Come on, I simply want this conversation to end peacefully and without everyone thinking I am a complete fool. You cannot grant me even this?

EDIT: I wanted people to understand where I was coming from when I reacted the way I did. I never argued that Level42's opinion was wrong.

EDIT: Arg.. You are right, I have no idea why I care so much about this anyway. I am just going to drop this all now.

Flip_Willie

[shardian]

I think you did a great job. Kudos to whatever school you attend for actually making you all learn practical knowledge in physics classes. My physics classes were a joke. I didn't even take college Physics until my junior year, so I already had the practical engineering classes beforehand. I only attended for the tests and labs, and it was pretty pointless for me. At that point, mine and the colleges time would have been better spent just letting me test out, but they didn't allow that.

For most of the students though, it was a blood bath. I was the only A in Physics I. There were a few other A's in Physics II, but those I think were other engineering students who were taking it late like me.

[Kevin Mullins]

I was rather impressed that the floor standing fan was able to push the turbine so well.
I know those fans have a fair amount of force at that range, but still, when you throw in there the design of the blades, balance, pitch and tuning , etc, etc.....work out quite nicely.

If you ever go looking for a readily available small DC "generator" again, just grab an automotive alternator. Just about any these days are already internally rectified to output DC. (a single wire GM version would be a good choice)

[danny_galaga]

Nice project (",)

It's a pity you couldn't get a DC motor since at this sort of size, it would probably produce a lot more power. DC motor= almost exactly a DC generator. But an AC motor is not much like an alternator unfortunately. Then again, you aren't trying to power a house, just prove the concept so top marks!

@ Kevin. I think a car alternator would need much larger blades to drive at any sort of speed (we're talking over 1200W potential easy), so at that size you would definitely be better off using a basic dc motor as a generator. For instance, just spinning the shaft of a 540 motor with your fingers (the motors used in radio controlled cars) would produce more than .16W. I would predict something between the 540 and a car blower motor would work well with this sized turbine.

[Flip_Willie]

@ Shardian
Thank you, I appreciate it. I have certainly felt challenged by both courses at my college. Although I have been able to maintain an A so far, a lot of people struggle with both courses.

@ Keven
I was very surprised myself with the performance of the blades. I certainly did not expect some simple PVC blades to perform as well as they did. One thing to keep in mind though is that the turbine appears to be rotating faster than it is in the video because of the frame rate on the camera. Even considering this, they are moving quickly. You feel very uncomfortable if you stand close to the blades while they are rotating. It takes a while to gain momentum, but once it gets going it maintains its speed pretty well. It was also shockingly well balanced. While going, you can feel it shaking if you place your hand on it, but otherwise it is unnoticeable.

We took it outside one particularly windy day and it really got going. With the Floor fan, we were getting about 25 AC volts. During one particular gust outside, we reached around 50+ Volts.

Actually, several people suggested using an alternator. The reason why I initially avoided it is because this guy suggested not too use one. His reasoning is that is most car alternators work at much greater RPM than what the turbine would produce (as Danny has mentioned).

@ Danny
Yeah, I am certain that a DC motor would produced much more exciting results. I initially anticipated purchasing a motor off of Ebay, but in the end I decided to save money and shipping time and just take the freebie. The generator I used was rated for 230 AC V for 850 RPM. Which was much higher RPM than I had originally wanted, but it worked sufficiently for the demonstration.

I feel certain that with a little more work, the unit would have been much more practical.

Flip_Willie

[Ed_McCarron]

I was rather impressed that the floor standing fan was able to push the turbine so well.
I know those fans have a fair amount of force at that range, but still, when you throw in there the design of the blades, balance, pitch and tuning , etc, etc.....work out quite nicely.

If you ever go looking for a readily available small DC "generator" again, just grab an automotive alternator. Just about any these days are already internally rectified to output DC. (a single wire GM version would be a good choice)

Car alternators need to spin rather fast - in this application, not so good.  Ideally, you want a DC motor that will produce the voltage you want at much lower RPMs than its designed for.

IE, you want 12v at 200rpm, you need a motor thats spec'd at 120v, 2000rpm.  When it spins at 1/10 of its rated speed, you get 1/10 of the rated voltage.  Its not exact science, but this'll get you in the ballpark.

Motor, generator, who cares?  My question is what does a 'AC to DC transformer' do?

[Flip_Willie]

Motor, generator, who cares?  My question is what does a 'AC to DC transformer' do?

Ah, I was referring to a Wall Wart. In this case, it was one of those with the brick inline. We included it simply to run the DC LEDs.

Flip_Willie

[danny_galaga]

I was rather impressed that the floor standing fan was able to push the turbine so well.
I know those fans have a fair amount of force at that range, but still, when you throw in there the design of the blades, balance, pitch and tuning , etc, etc.....work out quite nicely.

If you ever go looking for a readily available small DC "generator" again, just grab an automotive alternator. Just about any these days are already internally rectified to output DC. (a single wire GM version would be a good choice)

Car alternators need to spin rather fast - in this application, not so good.  Ideally, you want a DC motor that will produce the voltage you want at much lower RPMs than its designed for.

IE, you want 12v at 200rpm, you need a motor thats spec'd at 120v, 2000rpm.  When it spins at 1/10 of its rated speed, you get 1/10 of the rated voltage.  Its not exact science, but this'll get you in the ballpark.

Motor, generator, who cares?  My question is what does a 'AC to DC transformer' do?

Generators like to spin fast too, more so than alternators. In fact, that's one of the reasons (as well as efficiency and cost) that they went to alternators in cars, trucks planes etc. At idle, most generators produce virtually no charge, aircraft were the worst- the battery would be slowly going flat when taxiing. Alternators are charging from the get-go and are up to full voltage at fairly low revs. Even though in general alternators are more efficient than generators, for something small like this  a generator would be the better choice, since you would be hard pressed to find an alternator small enough. Since DC motors are so similar to generators (there are subtle differences in design detail to optimise charging) you have a huge spectrum of choices, from slot car motors up. Most choices up to car blower motors will be dirt cheap too.

To get better efficiency out of either, you need to gear 'em up, like these bad boys. The blades spin at about 19 RPM. I don't have more specs, but i would guess the alternator would be spinning somewhere between 10-100 times the blade speed. Standing near them, you can hear the gearbox whining, even though it's 50 meters up!

It's all irrelevant now, since the project is done. Hindsight is always 20/20. Still fun to talk about though. Dragging up memories of things i learnt in trade school all those years ago  

[Kevin Mullins]

I had gear reduction in mind when I suggested using an alternator. (especially on a small scale project so to speak) Most wind turbines have some sort of gearbox and such in it as Danny mentioned. I guess I should have clarified that part.
Now finding a direct drive 1:1 motor/generator that would work sufficiently would indeed be tricky I think.

Another project on my long list that I've wanted to dabble in.

[Ed_McCarron]

Generators like to spin fast too, more so than alternators.

Just going off what I've read on DIY turbine sites.  They like old 30V tape drive motors - something goofy like 30v = 325rpm, so at 70-80 rpm they are cranking out 12-ish volts at halfway decent current.  Alternators seem to be not favored, and gearing up requires something a bit bigger than a 3' blade.

[DaOld Man]

Hmmm, well with generators or alternators, you need a supply current to get the thing started.
Field excitation I think is the term Im looking for.
It wont generate current unless there is a magnetic field to begin with it.
An automobile alternator must have the battery connected to begin generating, after that it can supply enough current to maintain the field.
A generator also has to have a maintained field.
Now you could use a DC motor with permanent magnets as the field, that would work nicely.
An AC motor can become a generator, as soon as the shaft of the motor is turning faster than the rated hertz of the supply current, it becomes a generator. (Dirty definition).
If you have a bench grinder with a lamp attached to it (lamp comes on when motor is turned on), then when you turn off the grinder, notice that the lamp slowly goes off as the motor is coasting down.

Anyway, nice project Flip_Willie, but I would give you a B, mainly because you couldnt explain how it works better.

[SirPeale]

Quite frankly, I'm rather impressed with your project.  I've been wanting to build one of these for a while.  You did an excellent job.

Just don't take random strangers comments to heart. 

[Flip_Willie]

Anyway, nice project Flip_Willie, but I would give you a B, mainly because you couldnt explain how it works better.

Ha, you should have seen the other projects. 

In some respects, I decided not to go to in-depth on this site to avoid confusion. However, it seems I did exactly the opposite. Obviously, I worked harder to make things sound more technical / knowledgeable in the actual presentation (Although, even that was probably lost due to my poor speaking skills).

Of course, I am not trying to imply that I understand how everything is working in the unit. I will admit that I could have put more research in every component. Some of that was due to time constraints, and some of it was due to the fact that I was embarrassed to ask how some of it was working.

If there is anything in particular that you believe I should have stated better, please let me know so that I can be knowledgeable later on.

Quite frankly, I'm rather impressed with your project.  I've been wanting to build one of these for a while.  You did an excellent job.

Just don't take random strangers comments to heart. 

Thank you. I have bad habit of taking other peoples thoughts / words too seriously. I have tried to correct this, but as with any habit correcting it is easier said than done.

Flip_Willie