use the air we drive through

[talldudenumber5]

i was thinking if i have to let air in to cool my radiator why not put that air to use.
i have included a rough drawing to help illustrate my idea

i know we talk about solar to help top off batteries and to help in those who have performed an alternator delete but the other abundant reusable resource besides water ,which is not good for your car, is air or wind. not since the air blowing by your car is going at least as fast as you are moving then there is no shortage of wind when driving. so why not use a small scale wind generator (like this one i found on ebay, 12VDC 2400RPM MINI WIND GENERATOR TURBINE PROJECT MOTOR - eBay (item 250603606228 end time Oct-20-10 16:47:13 PDT) )

my thoughts was to make an inlet in the bumper for air possiblly an air intake velocity funnel ( Air intake velocity funnel image by almc2242 on Photobucket ) these can increase the amount of air taken in by up to 20 percent but it also does not increase the frontal area of the aerodynamics of drilling a 20 percent bigger hole. from this tubing which cold be intake tubing or just pvc pipe would be run to the radiator. inside the tubing i would place the mini wind turbine generator so it would look like a jet engine. the wind in the intake would create 12 volts in my experimental idea. which could be used to top off a battery if you had a voltage regulator ( Solar Charger Regulator Contoller LCD Panel 20A 12V/24V - eBay (item 270643685984 end time Oct-05-10 02:19:39 PDT) ) or could be used for other things i guess.

so what do you guys think would this idea create alot of drag or are there any down sides to an approach like this

[3-Wheeler]

Hi TallDude,

Sometimes for the sake of description, I like to take an example of an approach and size it large to an extreme, to see if the idea is worth pursuing or not.

In your example, we are using air that is passing by our vehicle to move another object, namely a fan blade.

Let's take this example to an extreme....

Picture a wind turbine mounted on top of our vehicle. We are moving through the air at let's say, 50 mph. The wind turbine on the top of our vehicle has three blades that are each 5 feet long, and will catch quite a bit of air while moving at this speed.

The blades will generate quite a bit of electricity for some type of use on our car, and this is the good part. However, those same blades will tend to make our motor in the car, work harder and use more gas to move the car forward.

Since we have not invented perpetual motion machines yet, the turbine mounted on the roof will always take more energy in, in the form of air drag, than it gives back out, in the form of electric energy.

Now we should mention that stationary wind generators that are mounted to the earth are useful, because even though they are not 100% energy efficient, they still take the free wind and convert some of that energy into electricity for our use later on.

Mounting this same wind generator on our car however does not give the same results that we are looking for in this case.

Thus we are better off making the air flow paths through and around our moving car bodies, as clean and efficient as possible.

Maybe you take some of your fan idea, and apply that to the free heat that is already in the engine compartment, and use that to propel the vehicle forward. And as you know, anytime there is excess heat, there is also expanded air that be used to make this happen. Just a thought for your next invention.

Jim.

[talldudenumber5]

i am not talking about diverting air anywhere i was talking about the front grill openings. there are already holes and air flowing through so that dynamic does not change it is just the addition of a small wind turbine. i am trying to make sure if i go alternator less that my battery stays charged. solar works only in the sun, and would forget to plug in a charger so i had this idea. would a wind turbine mounted in front of the radiator be more efficient than an alternator

[3-Wheeler]

Originally Posted by talldudenumber5

i am not talking about diverting air anywhere i was talking about the front grill openings. there are already holes and air flowing through so that dynamic does not change it is just the addition of a small wind turbine. i am trying to make sure if i go alternator less that my battery stays charged. solar works only in the sun, and would forget to plug in a charger so i had this idea. would a wind turbine mounted in front of the radiator be more efficient than an alternator

I think another question we can ask ourselves is this....

Why is there air entering into this area in the first place?

- Is it by design?
- Was this something overlooked by the manufacturer?
- Does this extra air serve a purpose?
- Can we simply shut off this air source and not let it be a form of drag on our moving vehicle?

Jim.

[Christ]

I can assure you, sir, there would be only a time or two that you would forget to plug in the charger.

[AeroModder]

I'm not sure about that, I've forgotten to turn off my headlights quite a few times (mostly because by the time I park, the sun comes out and I can't tell they're on).


My thoughts on this are like electric superchargers- You're not going to produce enough energy from it to make a difference.

[3-Wheeler]

I do like your enthusiasm about how to make extra energy work to propel our vehicles.

Do not give up too easily on just how to extract extra energy out of the fuel we use to move our cars.

Since the engine does create extra heat in areas that need to be cooled, such as the exhaust system, there is free lunch here concerning excess energy can can be harnessed in some way.

Using a turbine in this area to generate electricity would indeed provide a net gain in energy efficiency.

Just don't try to harness this energy from the cooler, moving air. The goal to high efficiency here, is to present the air with the least amount of drag as possible, and this includes turning fan blades.

Jim.

[Patrick]

I think that you might be able to gain a few watts from this idea if you changed it so that the turbines were in the airflow after the radiator. This air has already been heated by the radiator and if you expand it properly you might be able to recover some of that energy that would have been dumped overboard.

[Otto]

You can't get energy for free, as noted by others above.

That said, you can save some energy otherwise wasted. I don't know if you'd have a net improvement or not, but suspect not.

That said, let's look at tweaking your idea: Instead of using intake air from off to the sides, how about using intake air where it's best, i.e., at the highest pressure stagnation point of flow at the nose centerline. Now, let's release that air back into the slipstream where pressure is lowest, i.e., maybe 1' back from the nose on the forward surface of the hood, or at the known low pressure zones on the sides just forward of the front wheels. Look at any fast fish mouth and gill placement, and you'll get the idea--inflow at highest pressure point and outflow at lowest pressure points. So, take a tuna and lie it on its side, add faired wheels, and now you have probably the world's most streamlined car.

Back to your ducted windmill idea: If you put the ducted windmill in an efficient duct that goes from highest pressure nose stagnation point to lowest pressure hood or fender or undertray point, then you can extract the most through-flow energy to turn the fan. Whether this makes more electrical juice at less cost than running the belt-driven alternator remains to be seen. Maybe, using little fans like in computers and installing them in the ducting, you'd get trickle flow of juice to top off the battery. Or not.

[Cd]

Popular Science did a very small writeup circa 1999 - 2000 on a company that was experimenting with a large fan mounted horizontally on the roof of a van. As the van moved forward through the air, the blades would turn and charge the batteries. ( it was an EV )
What made it all work, was that the fan blades were geared to fold flush past a certain point. This reduced the drag that the blades would normally cause.
I don't have the magazine anymore, but if you were wondering, it had a story titled " Detroits new 80 mph cars ".
Much like the ' new 80mpg' cars, I never heard anything from that experimental van .