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Hello,

I'm a CAD Designer at GM working at the GM Technical Center. I asked to work on the Volt and they gave it to me. I'm so excited to be working on this vehicle. Its the coolest car I've ever done. Anyways, I have a question. Does anyone have any information on Vehicular Wind Turbines? I've been told that it doesn't work. I'd like to know if the idea has been tested?
 

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designer or engineer

In this house we obey the laws of physics

Seriousely a turbine on a car. to what? power the batteries as its moving on battery power.

Jenkies, you'd never have to stop. Perpetual motion here at last. Why didnt anybody think of this earlier. Who needs battiers at all. Just push start the thing and let all that endless wind power work for you.
 

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Yeah, what the poster above said. People just love this concept but I'm afraid the only way it will work for you is the following setup (the car is stopped and you pull out the turbine from the trunk and set it up). The guy in the video is a few years ahead of everyone in terms of thinking. I won't even mention that the video is quite old! Enjoy.

http://www.youtube.com/watch?v=raLgNo0jhys
 

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I know, I know. Everybody makes fun of me when I bring it up but I think its one of these things that "everybody" knows won't work but has never been tested. I was talking to one guy who made this wind buggy thing and he said that when the impellars are up to speed there is no resistance. And I also just saw a Mitsubishi i MiEV concept car with Vehicular Wind Turbines right up front mounted in the fascia. I don't know... It seems to me that you could use some of the energy(wind resistance) that you have already overcome to spin a couple of small generators and send a small charge back to the batteries. I wonder if its ever been tested.
 

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fourflush,

Designer. But we do plenty of Engineering in our group. We end up engineering alot of these parts ourselve because the engineers are so busy. Those guys are overworked.
 

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fourflush,

Designer. But we do plenty of Engineering in our group. We end up engineering alot of these parts ourselve because the engineers are so busy. Those guys are overworked.
 

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Volt Designer,

I have always wondered the same thing. Besides the whole we obey the laws of physics here argument against, I think the practical problems boil down to if you can access the power of the wind without messing with the aerodynamics to the point where you are using more energy to overcome the drag than you have originally. There is probably an equilibrium point where you can generate a certain amount of energy from excess wind on the vehicle, but it doesn't increase the drag too much, and thus you can extend the range of the vehicle. There is air coming into the vehicle through the front grill. There is air flowing under the bottom of the vehicle. So if I was designing the vehicle I would ask, is there anywhere already where there is air flowing through or over the vehicle where we can capture energy without causing a disruption in the aerodynamics. I would think that at the front grill would be a good location. Take a look at http://www.humdingerwind.com/. If you incorporated some of these low cost wind generators into the grill, then you could capture energy from the air flowing into the engine compartment and use it to charge the batteries a little more. The air is already going to be flowing there, so there is no breaking any laws of physics, there is minimal increase in drag, and the cost of the technology is low, making for a trifecta of reason.
 

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BigRedFed,

Exactly...There has to be a point where the electricity generated overcomes the drag. I know areodynamics are real finicky. I've worked on programs where they changed the studio surface ever so slightly and got an extra 1 MPG from it. But I think you can make a small generator with some low friction bearings and mount it behind the front fascia. Have a snorkel tube feed it some air throuh a hole in the fascia and have it charge the battery for those long trips.

I just want GM to be ahead of the curve instead of playing catch-up on this one. They have the resoures to study something like this.
 

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I checked out that site....Yeah those rotating wind turbines wouldn't cause much drag at all....thats pretty cool.
Yea, I've been waiting for the Developer kits to come out. I want to get one and see how much enery it creates. I think it would be cool to install them along the edges of my roofline to catch the wind that flows over the house. Then couple that with some solar panels on the roof and maybe go Grid Free down the line.
 

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Designer,

Ok, maybe i was a little harsh in my first post. Its been a long week.

Let me try and explain where i'm coming from. Imagine a calm day, no wind. Your in your Volt driving down the highway at 70 mph. Realative to you there is a 70mph headwind which you have "created" by moving your vehicle through a stationary air mass. So what energy was used to create this wind? for the volt it would be electrical power from the battery pack or gen-set.

So now you want to use a turbine to extract work from the wind you created. At 100% efficiency in the turbine. you could get exactly as much power from the turbine as it took to create the bit of wind to turn it. Since nothing operates at 100% efficiency the turbine will cost you energy depending on how efficient it is. IF its 90% efficient you lost 0.1 kw for every 1 kw generated. Meaning it takes 1 kw of power to push the car through the wind enough to generate 0.9 kw of energy. that 1kw of power would not have to be spent if the the turbine was not on the car.

I understand what your trying to do and its great to think outside the box. but careful that your mind is so open that your brains fall out. There is no free energy. The only way the turbine could be a net positive is if, instead of a calm day, you where driving into a strong headwind. And I would imagine for a normal person that would be a very unlikely scenerio and would not compensate for the additional weight and cost.

Think about it this way. If i put a fan on one end of a tube (blowing into the tube) and a generate on the other. would it run forever? For wind turbines on cars not only would it have to run forever (generate enough power to offset what it takes to create the power. but it would have to convert more than 100% of the energy in the wind so that there is some extra to power the batteries.

Wind turbine on house, good idea. Wind turbine on something you are using energy to move. bad idea.
 

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Sorry guys, I know you love the idea but you can't get something for nothing. Impossible. You just have to trust the engineers, physicists, and scientists on this one. You didn't like the wind turbine setup on the video? I thought that would satisfy you.

Ponder this: Put a 2 foot wind turbine on a very light carbon fiber skate board with a super efficient electric motor on it. There is no wind and the road is flat. The turbine output is directly connected to the electric motor. You spin the turbine by hand to get things started. The generated electricity starts to move the turbine foward and thus the turbine will spin more from the movement though the air. The spinning turbine will provide more electricity to propel the cart forward. If your theories are correct the vehicle will continue to move forward for as long as the road is. Correct? What do you think will happen? Please post your answer and I will give you the correct answer after that. Good Luck!
 

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I agree with Texas on this one. Aircraft, such as the 757 have a RAM air turbine (RAT) that is deploy in the event of loss of power (say running out of fuel at 30K ft, which happened in the late 80s). The RAT turns a generator to send emergency power to the cockpit, so the pilot can get vital info like altitude, airspeed, etc. (Turns out pilots get real upset when their cockpit goes black at 30K ft) The RAT is deployed into to the slip stream and creates a lot of drag, that drag is what turns the turbine and the electric load connected to the generator. Under normal operating conditions power is generated using a PTO shaft from the main engines, or with an APU. Why, because they consume less fuel than using a RAT to generate the power, which would increase drag and cause more fuel to be consumed to maintain cruise airspeed.

If you want to increase the electrical efficiency of the Volt, add a conformal solar panel the roof. When the sun is shining, it will add X amount of current to the system with no increase in drag. This will have the net effect of increasing the electrical efficiency of the system by X%, thus extending range. Of course, that X% increase in efficiency will come with added cost.
 

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Excess Energy

I agree with you Rooster.

The only excess energy that can be recaptured is from the intertia created once the vehicle is in motion. This is already being done with regenerative breaking.

Even if some energy can be harnessed with wind it would likely not be enough to offset the costs. As Rooster point out, solar cells produce energy without any sacrifice to drag and continue to work when the vehicle is at a stop...but again the costs outway the benefit. With the advances in photovoltaics (www.nanosolar.com), we may see them on the rooftops of the Volt eventually.

Lastly, photovoltaic cells actually work surprisingly well in cloudy conditions because they use the entire light spectrum. It is thermal solar generation that suffers almost complete shut down during cloudy days because of its total reliance on infrared light only from the sun.
 

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Sorry, you aren't getting the picture

Sorry guys, I know you love the idea but you can't get something for nothing. Impossible. You just have to trust the engineers, physicists, and scientists on this one. You didn't like the wind turbine setup on the video? I thought that would satisfy you.

Ponder this: Put a 2 foot wind turbine on a very light carbon fiber skate board with a super efficient electric motor on it. There is no wind and the road is flat. The turbine output is directly connected to the electric motor. You spin the turbine by hand to get things started. The generated electricity starts to move the turbine foward and thus the turbine will spin more from the movement though the air. The spinning turbine will provide more electricity to propel the cart forward. If your theories are correct the vehicle will continue to move forward for as long as the road is. Correct? What do you think will happen? Please post your answer and I will give you the correct answer after that. Good Luck!
What I think will happen, is that eventually the skateboard will stop. Why? Simple, the amount of energy put into the system is never more than the original amount. However, my question to you is, will the skateboard go further with the turbine than without. The answer to that is, it depends. If the initial energy generated is enough to overcome the weight of the turbine, then the skateboard will probably go further with the turbine running than with the same aerodynamic profile/weight and no turbine running. Take your skateboard, place it going downhill and a slight incline then with the correct size motor and aerodynamic profile, you will not only go all the way down the hill, but generate enough energy to go up the next hill. No one here thinks that they can get anything for free and for the man who loves to expose solar panels on the roof, despite all the inefficiencies, I expect more of an open mind from you.

If you have a small generator, that has a low cost of development, such as that I linked to in my previous post at humdinger, can you recapture enough energy from the wind, say moving through the grill into the engine compartment or going out the exhaust pipe, to overcome the small cost of installing it in the car to the point where the cost is recouped from a few extra miles able to be reached by the electricity generated/recaptured?

That is the question, not can we add something to the car generate perpetual motion. If you don't have an answer to the question, even if it is no, then give the answer and if you know why not, then it would be nice of you to say so. I'm sorry, but just trusting the "engineers, physicists and scientists" is just not within me, especially since the answer "they" just gave, doesn't even begin to address the actual question.
 

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Sorry, You just cannot generate more energy through the grill than it would take to overcome the drag from the turbine. I'm sorry you don't understand the difference between this and a solar panel. I'm trying to come up with an explanation that is good enough for you to believe. Very difficult. Perhaps you think you can make the turbine so slippery that it will have no resistance. Even if that was the case you have the resistance in the generator. Understand? You don't just spin a generator freely and energy comes out. It will have a resistance greater than the energy it produces (the amount greater is it's efficiency) If it was 100% efficient (does not exist) then it would produce the same amount of energy that it took to spin the shaft.

Now I know you are going to hold on to this argument and change it so you don't feel bad and I understand. Unfortunately, many people make this mistake and also there are many people in this world that take advantage of people who don't understand physics. The water powered car comes to mind. Anyway, since you are so passionate about the idea I think the best way to spend your time is to get a good education on how things work. Go to the MIT site and you can actually get free lessons on all related subjects. It
 

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"If you have a small generator, that has a low cost of development, such as that I linked to in my previous post at humdinger, can you recapture enough energy from the wind, say moving through the grill into the engine compartment or going out the exhaust pipe, to overcome the small cost of installing it in the car to the point where the cost is recouped from a few extra miles able to be reached by the electricity generated/recaptured?"​

The answer is no.

The quest for perpetual motion will never die, but what few realize is that we already have it.

Anytime you see a perpetual motion machine, it is always, well, a machine. Are machines free? I think not. Can anyone think of a machine, or device, that we already have, which will produce energy without a fuel cost?

I thought you might.
 

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Texas, FourFlush,

I've had a few engineers at GM explain it the same way. Basically if you have energy over here, and energy over there, and you put a system in between them, you are going to lose energy in through system. But like BigRedFed said, I'm not thinking about perpetual motion, just an auxillary generator. If I read your posts right you say that the drag that the tubine would cause would overide any energy created by the turbine. The 757 RAT analogy was pretty convincing. I don't know. I don't want to give up on it just yet but I find your reasoning hard to aurgue with. And I can relate back to my experiences in the wind tunnel on the last program I was working on. They changes the surface ever so slightly and got an extra 1 MPG out of the car. Anyways. Thanks for the dicussion that was helpul.
 

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This has got to be the most civil group of people on any discussion site I've ever visited. PERIOD.:)
 
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