Ram Air Wind Alternator

[ketel0ne]

So here's the concept a, 6-8" Ram air tube from the grill to an 6-8" blade assembly with a larger pulley to a half sized pully on one of these alternators. I have several hundred pages of alternator documentation(zip file) of how to pull this off. Looking for your thoughts. Also thinking that a solar panel could be rigged into the setup as well against the battery.

http://cgi.ebay.com/Permanent-Magnet...QQcmdZViewItem

[omgwtfbyobbq]

The only problem I can think of is efficiency. According to wikipedia (maybe?) the best (small) permanent magnet generators are ~60% efficient while most new alternators are ~55% efficient (bosch PR), and circa 2004, ~70% efficiency for the best bosch versions. Since the energy you gain from the generator spinning must result in some proportional increase in drag, I'm not sure it would help with auto efficiency at all. I think the best bet would be minimizing electrical consumption, disconnecting the alt, dropping in a couple deep cycle LA batts, and using the solar panel as much as possible.

[FormulaTwo]

before everyone here tells you not to do it.

just go freaking do it.
then tell us how it works out!

but seriously tho, only charging while moving etc....
the ram air will mess up your aerodynamics....


run it like this.... Put it in your back bumper, with a hole cutt for the fan, whatever u use to spin. make a scoop to it. THEN, have it so that it will capture the exhaust gas blowing onto it, as well as, the air you are generating while the car is moving.

[DracoFelis]

I would think your idea would just be trading direct alternator drag on the engine (the normal case), for aerodynamic drag on the car itself (since I would think the wind ram would cause additional aerodynamic drag, proportional to the power generated). This isn't exactly a win.

However, if you add an active shutter system (at the grill, in front of your "ram"), you could then use the system like this:

1) When the car is tuned off or stopped, the shutter opens, and therefore any wind blowing into the grill will generate some electrical power. If you live in a windy area, this would be a great way to top off a deep-cycle battery when you park somewhere.

2) And you might want the shutters to also open, when the break lights come on (i.e. when you step on the breaks, even very gently). This will allow you to usefully use the aerodynamic drag this "ram" produces to assist with breaking (and generate a little electrical power in the bargain).

3) If you don't have any other charging circuit (i.e. you have disconnected the main alternator of the car), and the battery is getting low, you might want an override switch to open the shutter and therefore have your ram start charging things (albeit at the cost of more aerodynamic drag, while charging).

4) At all other times, I would leave the shutter closed (this system turned off), to avoid the aerodynamic drag on the car.

NOTE: I don't see any reason you couldn't do both this and a solar panel. If you used deep cycle batteries, the combo might very well let you disconnect the normal alternator from your car, thereby lowering that electrical drag on the car. You would then be running mostly off of the deep cycle battery (or batteries), with the solar and wind power (and your idea is essentially a clever way to hide a wind turbine in your car) when you are parking. And you would even get a little "while you are driving" assist from the solar cell (if the sun was out), and the wind ram (if/when you are slowing down or stopped).

[JanGeo]

not enough air flow to make any power - small boat generators I have worked with have three 2 foot radius blades and only produce 10-15 amps in 20-25 mph winds . . . maybe at higher speeds with ducted air flow would work . . . extra battery means extra weight

[rh77]

Originally Posted by JanGeo

extra battery means extra weight

I'm thinking that if it's remotely possible, that it would be a supplement to the alternator. If it proves effective, a clutch mechanism similar to that of the magnetic A/C engagement, could cut the load from the alternator and use the wind. If this second step proves effective, a simple electronic system could be setup to engage/disengage the clutch, based on electrical load/wind generation.

No idea is too crazy here

Scientific testing can only determine effectiveness.

RH77

[Matt Timion]

It would work wonderfully at highway speeds IMHO, but what about city driving?

I still think that finding a way to do this with the exhaust gases would be the best bet. If you could rig it up to capture both exhaust and wind that would be the best.

[rh77]

Originally Posted by Matt Timion

I still think that finding a way to do this with the exhaust gases would be the best bet.

Agreed. A turbo could do a variety of things aside from just pumping more air into the engine. If you somehow hook it to a gearset to step-down the RPMs of the output, it could easily be an alternator or more. Due to the high speeds, precision crafting would be essential.

RH77

[JanGeo]

Anyway you do it, all you have to do is pump the current into the battery and the engine alternator will automatically not charge if the battery voltage is already high enough. The only thing you may want to do is let the battery run down a little if you know that wind power is coming down the road when you are heading for highway. An extra battery is also possible if you get a voltage booster you can pump the additional battery 12 volts up to 14 volts and feed it to the main vehicle battery you should be all set. I have a simple way of doing it with an inverter and a 35 amp switcher charger - might be interesting to give it a try then get something setup that will just boost the voltage directly like a beefed up hobby charger that operates off a 12 volt battery.

[DracoFelis]

Originally Posted by theclencher

I proposed such a thing to my engineer uncle when I was about 12. He said the extra aero load would negate the proposed engine drag reduction "benefits". There ain't no free lunch.

Which is why I was proposing that the OP use an active shutter system, so that the unit is only engaged (i.e. only have the shutter open) when:

A) You want regen braking. As you can easily get more aero drag, simply by opening the shutter. And all that aero drag/braking, generates "free" power for the car.

or B) You are already stopped. In which case the only power you will get out of the thing is on a windy day (when the wind blows into the unit). But such power (even when you are parked with the engine off) would occasionally come (more so in windy areas, less so if you park in a garage).

or C) Your battery is low enough, that you really need the extra power, and you are therefor willing to put up with the drag.


In case A&B (above) the power is "a free lunch" (beyond the extra weight of this contraption). And in case C, you will "pay the price", but you at least have an option to get the power if/when you really need it...

[DracoFelis]

Originally Posted by theclencher

Would it even turn over when the vehicle is stopped, only by wind speed? I think it would generate little, if any, under that condition.

I would suspect that would depend upon how strong the wind is hitting the grill. And that will depend upon how windy the area you live in is.

[ketel0ne]

With a wind gauge in a duct tube behind the grill 8 inches, I have the following data:

Top wind speed 78mph (top speed for commute was 75mph coasting down mountain)
Avg wind speed 37mph (avg speed for commute was 42mph)

I have no instaneous yet as I could not be under the hood and see the gauge. This was data from my daily commute this morning. Trying the lower grill on the way home.

[ketel0ne]

Further research, the max speed of the wind gauge I am using is 78mph. So the avg is affected as well. No complete data yet. Looking to borrow a higher power wind gauge. Possibly one with a remote data display. Oh how has the scangauge spoiled me.


ETA: The wind data is also not time specific over the commute. So no way to know how much time there was no wind to make the average.

[AlexK]

JanGeo mentioned there will not be enough power available, based on his experience with boat wind turbines. Actually it's a simple calculation to see how much power is available. A pretty good wind turbine would capture 1/3 of the available kinetic energy of the wind. At sea level, 78 mph, 8" diameter turbine, 33% efficiency, the available power would be 524W. That would be 37A (assume 14VDC) at perfect conversion to electrical power. Available power is proportional to wind speed cubed so slowing down really hurts performance. For example at 25 mph, current would drop to 1.2A.

I can't prove it, but it seems to me that covering the hole (to improve aerodynamics) and running the alternator from the engine instead would be more efficient. It's just a matter of conservation of energy. The power has to come from somewhere, and the inefficiency of the wind turbine would be wasted energy. Seems like the old grill block is a pretty good idea.

[Ryland]

what is the average electrical draw on a car? around 80-90 watts for engine electrical, 20-50 watts for radio, 200 watts for all the lights that come on with the head lights, am I missing anything?
now the Air 403 wind generator's specs are as fallow:
Rotor Diameter: 46" (1.14 meters)
Weight: 13 lbs (6 kg)
Start up wind speed: 7 mph (3 m/s)
Voltage: 12, 24 and 48 volts (Inquire for others.)
Output: 400 watts at 28 mph (12.5 m/s)

average vehicle speed is what, around 25mph? so unless you do alot of highway driving you might end up needing a prop close to that size if you are going to do any driving at night, or in the rain (head lights on), now of corse if you were running a race car without any other electrical loads, you could get by with a much smaller prop and generator.

[cfg83]

Hello -

There is a website with a Honda Insight that uses a "drop down" 5th wheel for starting the car. This is the closest I could find (search for Mike Dabrowski) :

http://www.greencarcongress.com/2006...our_de_so.html

How about a drop down wheel for regen breaking? I did some calcs on the item in question :

Assume : 10" diameter 5th wheel = 5" Radius
Circumfernce = 2*PI*R => 31.4" => 2.61 feet
Max RPMs for this alternator = 18,000

18,000 * 2.61 feet => 46,980 feet per minute maximum for alternator

60 MPH => 1 Mile Per Minute => 5,280 feet per minute

5280 / 46,980 = .11 => 11% => At 60 MPH, when the altenator connects to the road, it will only be at 11% of it's maximum design load.

With a clever design, you should be able to create a regenerative break system. When you hit the break, the wheel goes down. If you keep it inline with one of the wheels, you should be able to reduce the drag penalty.

I don't know how to achieve the "clever", part, however .

CarloSW2

[JanGeo]

Don't think in terms of max rpm for max output - it can output a lot of power at lower rpms also. You should belt couple it to the wheel anyway and gear it up - be good to spin up the tire however or there will be a lot squeeling tires.

[red91sit]

Originally Posted by cfg83

Hello -

There is a website with a Honda Insight that uses a "drop down" 5th wheel for starting the car. This is the closest I could find (search for Mike Dabrowski) :

http://www.greencarcongress.com/2006...our_de_so.html

How about a drop down wheel for regen breaking? I did some calcs on the item in question :

Assume : 10" diameter 5th wheel = 5" Radius
Circumfernce = 2*PI*R => 31.4" => 2.61 feet
Max RPMs for this alternator = 18,000

18,000 * 2.61 feet => 46,980 feet per minute maximum for alternator

60 MPH => 1 Mile Per Minute => 5,280 feet per minute

5280 / 46,980 = .11 => 11% => At 60 MPH, when the altenator connects to the road, it will only be at 11% of it's maximum design load.

With a clever design, you should be able to create a regenerative break system. When you hit the break, the wheel goes down. If you keep it inline with one of the wheels, you should be able to reduce the drag penalty.

I don't know how to achieve the "clever", part, however .

CarloSW2

Hmm very intersting, i was considering a very similar system, however mine will use a small motorcycle rear end, (powered 5th wheel) for highway cruising.

[cfg83]

red91sit -

Originally Posted by red91sit

Hmm very intersting, i was considering a very similar system, however mine will use a small motorcycle rear end, (powered 5th wheel) for highway cruising.

Ok, I found the Insight 5th wheel guy on another GasSavers posting, so you can have his tech solution for reference :

http://www.99mpg.com/mikesinsight/

CarloSW2

[MetroMPG]

Somehow I missed this thread...

Originally Posted by omgwtfbyobbq

The only problem I can think of is efficiency. According to wikipedia (maybe?) the best (small) permanent magnet generators are ~60% efficient while most new alternators are ~55% efficient (bosch PR), and circa 2004, ~70% efficiency for the best bosch versions.

Can you point to a source for that info? Wikipedia (all of which is true, btw) claims 90% alternator efficiency:
http://en.wikipedia.org/wiki/Alterna...harging_system

[MetroMPG]

Originally Posted by theclencher

For anyone bound and determined to capture some wind energy, I'd suggest getting one of those boat windgen units and coming up with some sort of telescoping pole and folding blades so you can unfurl it when you park and capture wind energy WHILE THE VEHICLE IS PARKED.

Like this:

http://solarvan.co.uk/wind.htm

[Brock]

Looks like an Air 403 to me.

[onegammyleg]

Its just like this but runs on solar...

[MetroMPG]

Too funny. There are some short videos on the solarvan site (last time I looked) which show him setting up the mast & generator, etc.

[JanGeo]

That looks like the one on my buddy's boat that I saw putting out 20 amps into the 12 volt batteries in a 29mph wind and his blades looks about the same size - supposed to be a 600 watt wind generator on his boat.

[omgwtfbyobbq]

Originally Posted by MetroMPG

Can you point to a source for that info? Wikipedia (all of which is true, btw) claims 90% alternator efficiency:
http://en.wikipedia.org/wiki/Alterna...harging_system

From that same page

Originally Posted by Wikipedia

In comparison, the best permanent magnet generators, such as those used for bicycle lighting systems, achieve an efficiency of around only 60%.

In terms of alternator efficiency, the conversion of mechanical to electrical may be very efficient, but it still goes into charging a battery which loses some efficiency, the laternator may only reach peak efficiency at a certain engine speed, so overall efficiency may be mucn lower than peak efficiency, etc... The alt efficiency clip was based off this blurb on diesel alternators. I'm guessing normal auto alts are the same or worse in terms of efficiency. 100% pure truth.

[BuffaloChips]

I haven't read all the responses here at the moment. But, to JanGeo, The idea of a clutching system was to alleviate the horsepower drain not stop the engine alt. from producing power. As for increasing the ram air system discussed. Have you thought about, or tried some type of funneling device to catch more air and accelerate it into a smaller more compressed area? I doubt the issue of extra drag from a system like this would truly be significant. I know a guy that drives his truck everywhere with the hood popped to the safety latch. This lets the hood sit up at least an inch. He claims he gets about a 3mpg boost on the highway just doing that. He hauls granite loads a lot and doesn't seem to thing there is significant drag.

[Ted Hart]

Originally Posted by FormulaTwo

before everyone here tells you not to do it.

just go freaking do it.
then tell us how it works out!

but seriously tho, only charging while moving etc....
the ram air will mess up your aerodynamics....


run it like this.... Put it in your back bumper, with a hole cutt for the fan, whatever u use to spin. make a scoop to it. THEN, have it so that it will capture the exhaust gas blowing onto it, as well as, the air you are generating while the car is moving.

Hmmm.... Isn't this called a turbo turbine???

[Ted Hart]

Originally Posted by ketel0ne

So here's the concept a, 6-8" Ram air tube from the grill to an 6-8" blade assembly with a larger pulley to a half sized pully on one of these alternators. I have several hundred pages of alternator documentation(zip file) of how to pull this off. Looking for your thoughts. Also thinking that a solar panel could be rigged into the setup as well against the battery.

http://cgi.ebay.com/Permanent-Magnet...QQcmdZViewItem

Interesting! Have you considered the power req'ts of spinning this alternetor assembly at some (lower?) RPM? Nothing is free...not even power-making devices; ie, it takes power to make (less) power! The law of conservation of energy prevails....And, have you considered the square footage involved with the solar collector...just to generate the current required to charge / partially charge the battery while "motoring" down the road? Wow! If it were feasible, the aftermarket would have scooped this up !

[FX Flyboy]

Originally Posted by Matt Timion

It would work wonderfully at highway speeds IMHO, but what about city driving?

I still think that finding a way to do this with the exhaust gases would be the best bet. If you could rig it up to capture both exhaust and wind that would be the best.

KetelOne, I have to agree with Matt here. I've only started on this forum, so don't take my word for it, but here's the logic:

Alternator belt on the engine driveshaft produces drag on the engine, and your idea will simply move that drag to the aerodynamics side of things.

However, the combined heat and kinetic energy of exhaust gases is higher than that on the wheels of your car (SIC!). Therefore combining a modified turbocharger and alternator/powersteering/AC/etc. would logically make more sense.

Here is where I got the inspiration from:

YouTube vid explaining the energy in exhaust gasses

Then I googled "connect turbine to an alternator" and one of the first results is this patent website:

EXHAUST-DRIVEN TURBINE-POWERED ALTERNATOR

After I saw this I started a search on here and found your thread.
Might save a few HP and not produce ANY additional drag. What do you think? I'd be interested to see this.

I've also started looking at ebay listings for turbocharges that I could get cheaply and start modifying.