[FireCrow]

Originally Posted by EVEngineeer

I don't know how helicopters fly, why don't you explain it. Helicopters do not have a wind turbine that allows wind to push it, like a windmill. They use gas to power the turbine to move it fast to push against the atmosphere. That's what I think.

Why don't you just change your nick to something more suitable? Sorry man, no one here is trying to spoil your dream... We're just trying to take you back to the reality!

[EVEngineeer]

Originally Posted by Brute Force

Try this simple thought experiment (analogy):

1. Open your wallet.

2. Take out a dollar bill.

3. Put the dollar bill in your front pocket.

Now a multiple choice test about the results of the experiment.

Did you just:

A. Earn a dollar.

B. Spend a dollar.

C. Break even.

Now imagine the Universe is the government, and wants to tax the proceeds of the transaction.

Thanks for the sarcasm jerk. I am simply trying to understand why wind turbines do not exist for cars. I legitimately do not know and am trying to understand, but I feel like even with all of the negativity there just has to be a way and I plan on trying to find that way. It may take my entire lifetime and I may never find the answer, but I would like to at least find all the ways that it does not work. Then others can see my real findings of data that I physically tested and then others can learn from it. Maybe I will write a book on what not to do. Benjamin Franklin states" I didn't fail, I just found 100 ways of doing it wrong"

[EVEngineeer]

Originally Posted by FireCrow

Why don't you just change your nick to something more suitable? Sorry man, no one here is trying to spoil your dream... We're just trying to take you back to the reality!

I know what you mean and I did not know some of the things that were mentioned to me on this forum, but I just know there is a way. Scientists and Engineers are people who create, discover, etc. the impossible or as most of you would probably rather say the improbable.

[EVEngineeer]

So to summarize, what has been said to me is that the wind turbine adds drag, because of the extra surface area. Is this part correct so far? Also, some of the energy that is lost is through heat. Is that part true? If so, where does the heat come from and where does it go exactly? My thoughts are that couldn't someone design a turbine so that it is aerodynamic for an automobile? Also, couldn't someone find a way to capture that heat and use it in a different way? I'm really just trying to understand this, in it's complete entirety with the math, laws, etc.

[TigerNut]

Originally Posted by EVEngineeer

So to summarize, what has been said to me is that the wind turbine adds drag, because of the extra surface area. Is this part correct so far? Also, some of the energy that is lost is through heat. Is that part true? If so, where does the heat come from and where does it go exactly? My thoughts are that couldn't someone design a turbine so that it is aerodynamic for an automobile? Also, couldn't someone find a way to capture that heat and use it in a different way? I'm really just trying to understand this, in it's complete entirety with the math, laws, etc.

You get heat loss because you add turbulence to the air; the local compression around the turbine blades raises the air temperature, and you don't get that back. Then, the electrical components (generator, wires, battery) all have internal resistance and you lose power according to Ohm's law: P = I^2 * R. That power loss shows up as the components getting warm, and the excess heat is generally radiated away. If your components get extremely hot, then you can try to recover this energy by capturing the heat and building a heat engine... but it will have an efficiency that is proportional to the temperature difference between the hot and cold parts, divided by the absolute temperature. For most electronics you'll fry them before that efficiency becomes high enough to pursue.

A different look at things: The turbine does work (as in the classical physics definition of work) on the air. Work equals force times distance, and the SI units for work are Joules. Energy is work. Power is work divided by time. If you hold a turbine up into an airstream then it does work on the air, and you'll note it takes a certain amount of force F to hold that turbine against the wind. Suppose you travel a distance d, you'll extract F*d of energy from the air (maximum, in an ideal world).

You can look at the power used by a car in a similar way. If my car requires 15kW to travel down the road at (say) 33 meters per second (roughly 70 mph), then it will take me 30 seconds to cover 1 kilometer.
In that kilometer, I'll have done 15000*30 = 450,000 Joules of work. The equivalent average opposing force for that kilometer is 450 Newtons, which works out to near enough 100 pounds.

So, if I wanted to re-generate 10% of the power required to move my car, so as to increase its range, I would necessarily have to hold my turbine up with 10 pounds of force against the oncoming wind. But that 10 pounds of force is added to the average opposing force that the car experiences, and so there is no net gain. And in the real world, we'd experience additional drag force by sticking the turbine in the wind, and we'd lose power through the wiring resistance of the generator.

This is why wind-powered generators cannot extend the range of a moving vehicle while the vehicle is moving. Reducing the vehicle's aerodynamic drag force is the cheapest and most effective way to increase a car's range at highway speeds.

[Dicey]

Just wanted to jump in here after reading this. Where I work, we've received patents people have filled out for just the type of thing that EVEngineer is talking about. The whole problem is, as many of you have pointed out, you end up increasing the drag on the vehicle by incorporating a wind turbine to try and harness energy. Even if you mount the turbine in the middle of the car, you will increase the energy it requires for you to move forward. You can get significantly better benefits by simply streamlining the vehicle. As to why not everyone does that? Not many people want to drive cars with flat bottoms, covered wheels, and a variety of other rather unsightly drag reducing techniques.

EVEngineer,

The heat comes from the operation of the generator, which you need to convert the energy from the rotating blades to electricity. There is no getting rid of those losses in the system as heat is basically a byproduct of every system. Even the blades on a wind turbine heat up during to frictional losses on the blade as they spin. Trying to capture that heat would lead to know losses. Essentially, there is no easy, or even difficult way, to get 100% efficiency from a system. When I get home, I'll pull out my heat transfer book and reference a couple problems for you if you'd like that cover heat loss over a wind turbine blade. This really isn't an idea you should try to proceed with.

[somanywelps]

Originally Posted by EVEngineeer

Since Florida is the sunshine state, would it be beneficial and efficient to recess a solar panel on the hood of the car? how much money would it cost and how much power would I get?

No, it wouldn't be worth the cost.

Also to the turbine question, remember your 4th grade science classes.

"Conservation of energy"

[aeroscott]

Wind generators or sailboats build pressure bubble in front of them , it becomes a slightly slower moving teardrop of air . This slower moving teardrop on a sail boat is huge , starting well infront of the object , engulfing the entire object and ending more then a boat length behind it.This monster airfoil or teardrop would make you think the boat couldn't ever sail with this blimp over it .But this is only slightly slower moving air ,but accounts for rather large loses to our boats ,wind machines or our cars . Wind generators are about 50% eff. back in 1979 I saw in Popular mechanics or Science A wind generator that tried to lesson this bubble by stacking the turbine disks (3 or 4) in front of each other with 10 to 15 deg. advance on each preceding disk . these were all fixed on a long shaft (horizontal shaft machine ) they claimed it was the most efficient wind generator in the world . I never saw anything more about it.

[ricklearned]

Originally Posted by Ziggythewiz

You can break your city's laws. You can break your state's laws. You can break Federal laws. You cannot break the laws of physics...that's why they are called laws, as opposed to theories.

Aaaahhh, the immutable laws of nature.

Back to reality again. This is some thread.

[Brute Force]

No sarcasm was intended. The analogy stands. You can't pay yourself and come out ahead, there has to be an external input. Similarly, you can't use the energy your car is consuming to make energy for your car to consume, there has to be an external input.

No matter how perfect of a turbine you come up with, even one that is 100% efficient, it still requires energy to turn the generator the turbine is driving. That energy will come from the motor pushing the car down the road.

Your missing a very important concept: conservation of energy. Every one of us engineers and scientists are well acquainted with it. Its been proven over and over again for centuries now. You'll get to know it too.