Go Back   EcoModder Forum > EcoModding > DIY / How-to
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 06-14-2009, 07:04 PM   #41 (permalink)
EcoModding Lurker
 
Join Date: Jun 2009
Location: brum
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by ShadeTreeMech View Post

If you want to reduce the alternator load, put in a bunch of solar panels on the roof and dashboard.
yeh, rip out the sunroof and fit a 30w panel, and run the alternator at 1/2 speed (and a fraction of the belt tension too).
i ran without the belt on too, during some sunny spells last summer
http://ecomodder.com/forum/attachmen...1&d=1245020633
http://ecomodder.com/forum/attachmen...1&d=1245020633

Attached Thumbnails
Click image for larger version

Name:	35242.JPG
Views:	174
Size:	105.2 KB
ID:	3703   Click image for larger version

Name:	35243.JPG
Views:	111
Size:	110.2 KB
ID:	3704  
  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 07-12-2009, 10:42 AM   #42 (permalink)
EcoModding Lurker
 
Join Date: Jul 2009
Location: 30728
Posts: 1
Thanks: 0
Thanked 0 Times in 0 Posts
wind driven alternator

I have a 2004 dodge ram PU the alternator is wind driven. using a small squirrel cage fan ducted to the fog light mount in the bumper.naturally it only charges while in motion. still using factory installed battery now almost 6 years old.
  Reply With Quote
Old 07-14-2009, 04:06 PM   #43 (permalink)
UberNaut
 
metalshark's Avatar
 
Join Date: Nov 2008
Location: where the wind blows
Posts: 21

Verna - '01 Hyundai Accent GS
Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by kr4ua View Post
I have a 2004 dodge ram PU the alternator is wind driven. using a small squirrel cage fan ducted to the fog light mount in the bumper.naturally it only charges while in motion. still using factory installed battery now almost 6 years old.
that sounds interesting I would love to see pictures
  Reply With Quote
Old 07-15-2009, 04:58 AM   #44 (permalink)
Master EcoModder
 
orange4boy's Avatar
 
Join Date: Aug 2008
Location: The Wet Coast, Kanuckistan.
Posts: 1,275

The Golden Egg - '93 Toyota Previa DX
90 day: 31.91 mpg (US)

Chewie - '03 Toyota Prius
90 day: 57 mpg (US)

The Spaceship - '00 Honda Insight
Thanks: 100
Thanked 306 Times in 178 Posts
I've been alternator free for about a year now. I'm getting at least 10% better FE.

My current set up is a 12V costco deep cycle that I got for $49 at the end of season clearance and a used 6V trojan t-105 that I got free. I have them set up in series for 18V. Assuming a 10% improvement that battery was paid for after 10 $60 fill ups. The battery is only discharged about 10% for each trip I make and should last for over 1000 cycles. I already had an automatic battery charger but you can pick them up for $30 if you look for deals.

I am running at 18V to keep the spark nice and hot and the fuel pump at max pressure.

FE gains from alternator disconnect have been shown on this site by metro mpg and others to give 10% better mpg. That ranks up there as one of the biggest single gains in the ecomod list. And that gain was at 12V. They would probably get a bigger gain at 14.5+V.

A deep cycle battery that is only discharged 50% should last well over 1000 cycles. Chart of Depth of cycles vs life.

Alternators are at best 40-50% efficient so for every watt produced the engine has to produce more than double the watts not including the belt friction.

Just to keep the average car running +/- 18A turns into about one HP when you do the math which is drawn at all engine speeds including idle. Idle happens to be the most inefficient engine speed. Remember too, you have to replace the energy lost to starting: 300+ amps at the best of times.

Once you learn how to figure out your amp draw you can estimate your battery life just like with gas. You can even get a battery gauge just like a fuel gauge showing % discharge. Or keep the original starting battery in the car as a spare. I have never run out of battery juice myself.

The best thing is I get to say I have a hybrid.
__________________
Vortex generators are old tech. My new and improved vortex alternators are unstoppable.

"It’s easy to explain how rockets work but explaining the aerodynamics of a wing takes a rocket scientist.


  Reply With Quote
Old 07-16-2009, 12:29 PM   #45 (permalink)
UberNaut
 
metalshark's Avatar
 
Join Date: Nov 2008
Location: where the wind blows
Posts: 21

Verna - '01 Hyundai Accent GS
Thanks: 0
Thanked 0 Times in 0 Posts
I still like the idea of a solar panel and a wind powered alternator.

both of those sound like easy solutions without costing a ton for batteries.
  Reply With Quote
Old 07-16-2009, 12:34 PM   #46 (permalink)
Moderate your Moderation.
 
Join Date: Nov 2008
Location: Troy, Pa.
Posts: 8,919

Pasta - '96 Volkswagen Passat TDi
90 day: 45.22 mpg (US)
Thanks: 1,369
Thanked 430 Times in 353 Posts
Quote:
Originally Posted by metalshark View Post
I still like the idea of a solar panel and a wind powered alternator.

both of those sound like easy solutions without costing a ton for batteries.
I'd like to see pictures and some non-biased data from anyone who claims FE improvements from a wind-driven alternator operating while they're driving.

*Maybe* just *maybe* it would work out in a normally high-turbulence area like the fog light holes, but I still have my doubts.

Then, when you consider how much "power" wind contains at speed and density, vs the amount of "power" it takes to spin the alternator under load, I'm almost sure it just won't work with such a small area for the air to act upon.

In fact, I'm calling BS until there's evidence otherwise.
__________________
"¿ʞɐǝɹɟ ɐ ǝɹ,noʎ uǝɥʍ 'ʇı ʇ,usı 'ʎlǝuol s,ʇı"

  Reply With Quote
Old 07-16-2009, 01:09 PM   #47 (permalink)
UberNaut
 
metalshark's Avatar
 
Join Date: Nov 2008
Location: where the wind blows
Posts: 21

Verna - '01 Hyundai Accent GS
Thanks: 0
Thanked 0 Times in 0 Posts
Im not saying Ive done it but kr4ua said he did. like I said before I would love to see pictures of it working.

It sounds like it would be plausible at speed over 50 with a big enough turbine.

I once had an idea of an alternator driven by exhaust force.. using a turbo exhaust housing and make custom fittings for an alternator to be place at a cool distance.
  Reply With Quote
Old 07-16-2009, 02:14 PM   #48 (permalink)
Moderate your Moderation.
 
Join Date: Nov 2008
Location: Troy, Pa.
Posts: 8,919

Pasta - '96 Volkswagen Passat TDi
90 day: 45.22 mpg (US)
Thanks: 1,369
Thanked 430 Times in 353 Posts
Quote:
Originally Posted by metalshark View Post
Im not saying Ive done it but kr4ua said he did. like I said before I would love to see pictures of it working.

It sounds like it would be plausible at speed over 50 with a big enough turbine.

I once had an idea of an alternator driven by exhaust force.. using a turbo exhaust housing and make custom fittings for an alternator to be place at a cool distance.
What would actually happen is that (possibly unless it's in a place of high turbulence already) the blades of the turbine or cage fan would just increase the overall drag coefficient, which would make the speed at which drag becomes an issue even lower than ~45mph.

The exhaust driven turbine-alternator has been done by a company... we're awaiting mass production or ultimate failure.

Regarding the wind-driven alternator -

Here's the formula you need to determine that it will or won't work:

P = 0.5 x rho x A x Cp x V3 x Ng x Nb

where:
P = power in watts (746 watts = 1 hp) (1,000 watts = 1 kilowatt)
rho = air density (about 1.225 kg/m3 at sea level, less higher up)
A = rotor swept area, exposed to the wind (m2)
Cp = Coefficient of performance (.59 {Betz limit} is the maximum thoretically possible, .35 for a good design)
V = wind speed in meters/sec (20 mph = 9 m/s)
Ng = generator efficiency (50% for car alternator, 80% or possibly more for a permanent magnet generator or grid-connected induction generator)
Nb = gearbox/bearings efficiency (depends, could be as high as 95% if good)


Assuming the best possible circumstances, and 100% of the Betz Limit -

(Work the formula from left to right)

0.5*RHO(1.225) = .6125
(That foglight hole isn't even .5M^2, but we'll use it anyway, since there are turbine designs that have more than "face value" for their area)
.6125*A(.5M^2) = .6125*0.25 = 0.153125

0.153125 * Cp(.59) (Using Betz Limit) = 0.09034375

0.09034375*V3(WindSpeed, or Vehicle speed, in this case, in M/S) (45mph = 20.1168 meters / second) (20.1168 meters / second * 3 = 60.4m/s

0.09034375*60.4 = 5.4567625

5.4567625*Ng (we'll assume the alternator is replaced with a permanent magnet generator, at 80% efficiency)

5.4567625*0.8 = 4.36541

4.36541*Nb (again, assume space age efficiency here)

4.36541*0.95 = 4.1471395

So P = 4.1471395, or about 4.15 watts.

4.15 WATTS!, and that's assuming the best case scenario.

I'm reasonably satisfied to say that this claim is COMPLETELY false, unless I've overlooked something.
__________________
"¿ʞɐǝɹɟ ɐ ǝɹ,noʎ uǝɥʍ 'ʇı ʇ,usı 'ʎlǝuol s,ʇı"

  Reply With Quote
Old 07-16-2009, 05:40 PM   #49 (permalink)
Master Novice
 
elhigh's Avatar
 
Join Date: Jan 2008
Location: SE USA - East Tennessee
Posts: 2,314

Josie - '87 Toyota Pickup
90 day: 40.02 mpg (US)

Felicia - '09 Toyota Prius Base
90 day: 49 mpg (US)
Thanks: 427
Thanked 616 Times in 450 Posts
You gave the foglight hole half a square meter!?

Oh, you so crazy. Or generous. Or - and this isn't completely outside the realm of possibility (though it is making an escape attempt) - that really is one mother of a foglight.

Any turbine that claims more than its face area is working from the maxim regarding fools and their money.
__________________




Lead or follow. Either is fine.
  Reply With Quote
Old 07-16-2009, 09:27 PM   #50 (permalink)
Master EcoModder
 
McTimson's Avatar
 
Join Date: Sep 2008
Location: Nyack, NY
Posts: 310

Maverick - '22 Ford Maverick XLT
90 day: 38.61 mpg (US)
Thanks: 1
Thanked 5 Times in 5 Posts
If the air-driven turbine was enough to do anything useful, the performance-oriented crowd would already be using it to force air into the engine. You'd have cold air intakes that stick out from the grille if that really worked. Sure, it might provide a little extra, but it's minimal at most.

The exhaust-powered alternator is being developed by ThinGap, and is definitely a great idea - but it will probably cost too much to be worth the MPG gains, unless it starts coming as a standard option as new vehicles.

The wind-driven alternator that was posted definitely sounds bogus. And the battery lasting 6 years is cool, but probably has nothing to do with a little fan in the fog light hole.

__________________
  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com