Go Back   EcoModder Forum > EcoModding > Aerodynamics
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 01-09-2009, 03:27 PM   #1 (permalink)
EcoModding Lurker
 
Join Date: May 2008
Location: Edmonton, Alberta
Posts: 32
Thanks: 0
Thanked 0 Times in 0 Posts
Why can't radiators be moved under the body?

I'm thinking of larger vehicles like pickups and SUVs here... (for improved fuel economy AND reduced emissions.)

To improve the front end aerodynamics on the bigger boxier vehicles why don't they cut the rad requirements into two - place a small wide radiator up front and then put a secondary backup radiator under the body of the vehicle? (It could easily be protected / armored to prevent rocks etc. from doing any damage. Maybe even laid inside the box frames on the heavier duty vehicles. Maybe the whole rad could go under some vehicles!!!)

Alternatively, they could go to LED headlights that span across the whole the front end and then stretch the radiator from fender to fender thus substantially cutting down on the required height.

  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 01-09-2009, 03:59 PM   #2 (permalink)
(:
 
Frank Lee's Avatar
 
Join Date: Jan 2008
Location: up north
Posts: 12,762

Blue - '93 Ford Tempo
Last 3: 27.29 mpg (US)

F150 - '94 Ford F150 XLT 4x4
90 day: 18.5 mpg (US)

Sport Coupe - '92 Ford Tempo GL
Last 3: 69.62 mpg (US)

ShWing! - '82 honda gold wing Interstate
90 day: 33.65 mpg (US)

Moon Unit - '98 Mercury Sable LX Wagon
90 day: 21.24 mpg (US)
Thanks: 1,585
Thanked 3,555 Times in 2,218 Posts
1. Cost
2. Vulnerability
3. Value added to consumer greater than 1 and 2?
__________________


  Reply With Quote
Old 01-09-2009, 05:32 PM   #3 (permalink)
Legend in my own mind
 
trikkonceptz's Avatar
 
Join Date: Apr 2008
Location: Homestead, Fl.
Posts: 927

Evil Pumpkin - '08 Scion xD RS 1.0 #1633
90 day: 35.45 mpg (US)

Silent Silver Killer - '10 Honda Insight EX
90 day: 51.5 mpg (US)
Thanks: 2
Thanked 14 Times in 13 Posts
Plus underneath a vehicle like a truck, you have exhaust to contend with. It's proximity to said exhaust could heat the engine more.

In addition, you would have to engineer a way to get the air to pass through it to cool as a traditional radiator does which could make the airflow under the vehicle more turbulent that it already is perhaps hurting FE.

This is all speculation of course ...
__________________
Thx NoCO2; "The biggest FE mod you can make is to adjust the nut behind the wheel"

I am a precisional instrument of speed and aeromatics
If your knees bent in the opposite direction......what would a chair look like???





  Reply With Quote
Old 01-09-2009, 06:59 PM   #4 (permalink)
EcoModding Lurker
 
Join Date: Jul 2008
Location: Fargo, ND
Posts: 45

MarzyPan - '95 Honda Civic 2000 Si Running Gear
Thanks: 1
Thanked 0 Times in 0 Posts
seriuos off road trucks usually run fans in the pickup bed, but I fail to see the benefits on a road going vehicle. Since the radiator needs airflow, might as well bleed a little off the high pressure area on the front of the vehicle. It's the extra air that hurts the aerodynamics. Standard radiator placement usually also minimizes the radiator hose run.

Old Saab 92b's run radiators behind their 2 cycle 2 cylinder engine. This is vented to the cab as the heater core.
  Reply With Quote
Old 01-09-2009, 11:00 PM   #5 (permalink)
Master EcoModder
 
Join Date: Jan 2009
Location: Maui, Hawaii
Posts: 813
Thanks: 5
Thanked 34 Times in 26 Posts
How about instead of a radiator that air flows through, they use a radiator that air flows OVER, with thin fins sticking up into the airflow?
  Reply With Quote
Old 01-10-2009, 01:59 AM   #6 (permalink)
EcoModding Apprentice
 
Bicycle Bob's Avatar
 
Join Date: May 2008
Location: N. Saskatchewan, CA
Posts: 1,803

Appliance White - '93 Geo Metro 4-Dr. Auto
Last 3: 42.35 mpg (US)

Stealth RV - '91 Chevy Sprint Base
Thanks: 91
Thanked 459 Times in 327 Posts
Moving a standard rad to another location is not usually recommended, because it needs air flowing through it. A surface radiator, with air just flowing over it, has to duplicate the surface area of the regular one, which is considerable. If you are able to have true laminar flow over it, you need far more area. However, the usual case is a turbulent, but attached boundary layer. So, how to produce a large, contoured heat exchanger, able to contain pressurized fluid? The tube and panel solar collectors are a good model. It should be possible to make a composite panel using aluminized fiberglass (40% by weight) to improve heat conduction, and mold in coolant ducts that double as panel stiffeners. Vulnerability to damage is certainly an issue, as is weight, however, the potential savings are about 20% of the total drag. Perhaps a combined radiator/belly pan would make a good add-on, for more combined savings.
__________________
There is no excuse for a land vehicle to weigh more than its average payload.
  Reply With Quote
Old 01-10-2009, 02:06 AM   #7 (permalink)
Master EcoModder
 
Join Date: Jan 2009
Location: Maui, Hawaii
Posts: 813
Thanks: 5
Thanked 34 Times in 26 Posts
Bob, what about a radiator with fins sticking into the airflow like a heatsink?

http://www.epiacenter.com/pictures/r...atsink_800.jpg
  Reply With Quote
Old 01-10-2009, 02:27 AM   #8 (permalink)
EcoModding Apprentice
 
Bicycle Bob's Avatar
 
Join Date: May 2008
Location: N. Saskatchewan, CA
Posts: 1,803

Appliance White - '93 Geo Metro 4-Dr. Auto
Last 3: 42.35 mpg (US)

Stealth RV - '91 Chevy Sprint Base
Thanks: 91
Thanked 459 Times in 327 Posts
Fins add surface area to the car overall, but they can keep the cooler more compact. That would be a compromise between the two designs. The 1911 Napier had external tubes, resembling fins on a surface.
__________________
There is no excuse for a land vehicle to weigh more than its average payload.
  Reply With Quote
Old 01-10-2009, 03:50 AM   #9 (permalink)
NightKnight
 
NachtRitter's Avatar
 
Join Date: Dec 2008
Location: Placerville, CA
Posts: 1,594

RippinRoo - '05 Subaru Legacy Wagon 2.5 GT
Subaru
90 day: 21.16 mpg (US)

Helga - '00 Volkswagen Jetta TDI
TEAM VW AUDI Group
Diesel
90 day: 53.91 mpg (US)

Olga - '03 Volkswagen Jetta Wagon
90 day: 46.24 mpg (US)
Thanks: 303
Thanked 311 Times in 186 Posts
It's probably not something that "can't" be done (or, said more correctly, it's probably something that "can" be done)... But I agree with Frank Lee... there is additional cost, there is additional vulnerability... and the consumer is the one that will pay for that... what is the benefit for the consumer? If the consumer is looking to buy a truck or SUV, then the consumer will have specific reasons for making that choice and it's unlikely that fuel efficiency and lower emissions are going to rank very high on that list. I would not want to pay extra for something that I don't even want.

Last edited by NachtRitter; 01-10-2009 at 03:57 AM..
  Reply With Quote
Old 01-10-2009, 06:41 AM   #10 (permalink)
Master EcoModder
 
Join Date: Feb 2008
Location: belgium
Posts: 663

vectra a - '95 Opel Vectra GLS
90 day: 37.51 mpg (US)
Thanks: 14
Thanked 61 Times in 44 Posts
i'd rather recommend a more ducted radiator, like in the p51 mustang fighter plane for example. i've noticed if you compare a modern engine bay is full to the brim, modern computer design to place all the components probably has to do with it... this means the average engine bay is almost 50% smaller than lets say that on a 60's or 70's car.

now modern cars make good use of this extra space to produce more interior space, but in theory one could have a reasonably dimentioned car with quite some space for ducting up front

a well designed ducts could lead to a smaller radiator and that could be placed lower underneath the car, the bottom of the duct being integrated in the undertray

__________________
aer·o·dy·nam·ics: the science of passing gass

*i can coast for miles and miles and miles*
  Reply With Quote
Reply  Post New Thread


Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
The Mechanism Behind Flow Separation LostCause Aerodynamics 46 07-15-2010 07:38 AM
why do builders put radiators under windows? modmonster Saving@Home 16 01-13-2009 09:33 PM
rear-mounted radiators and ballast tanks aspera Aerodynamics 19 11-10-2008 08:08 AM



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