ZRXDean
Needs a job
Posts: 2225
|
posted April 22, 2011 07:40 AM
OT: Trailer aero
I just picked up a 2003 Wells Cargo 6x10 trailer to haul my bike and gear. It has a flat front. It pulls nicely, torsion axle, only weighs 1000lbs. I'm pulling it with a older Tundra pickup with no bed cap. The trailer height is about 90". Lately I've been towing around 10K miles a year.
I noticed a lot of cheap trailers on the market with V-nose fronts. Also Wells Cargo sells a version of the 6x10 with a fiberglass nose cone that looks like the rounded front of a streamliner. These nosecones are available as an add-on. Neat before / after video here;
http://www.nosecone.com/aepull.htm
Some forum posts claim 1 mpg savings. Costs about $500, which buys a lot of gas. Maybe 20,000 miles of towing to break even.
I've also read about vortex generators placed on the rear of trailers to reduce drag. About $150 to cover the rear edges. This could pay off sooner, if it works. I can't find any info on drag reduction.
http://www.buyairtab.com/shop/individual-airtabs/
So what do folks think? Could I expect to see a measurable drag reduction from the nosecone or 'airtabs' ? Or should I just pump up the tires and slow down.
  
|
tcchin
Zone Head
Posts: 867
|
posted April 22, 2011 08:18 AM
 Edited By: tcchin on 22 Apr 2011 16:36
I worked with an aerodynamicist that developed and patented add-on rounded edges for the leading edges of trailers and box vans. He claimed that smoothing the air flow around the edges to avoid flow separation was just as beneficial as adding a full nosecone-style fairing to the trailer. The reductions in drag were significant - on the order of 3-5%.
I can't seem to find a link to his stuff, but it was a lot like the device in the image below.
|
VincentHill
Needs a life
Posts: 6520
|
posted April 22, 2011 08:52 AM
Have youi noticed the back of some car transports lately? They are totally rounded, The back is as or more important than the front As tcchin said, the rounded corners (SIdes and top) should seriously reduce drag. a 10% increase in fuel mileage from 15 to 17 at $5 per gallons would mean instead of 150 miles for 10 gallons you would get 170 miles or 20 more miles / or save about $6.50 per 150 miles or in 15,000 miles vs the 17,000 miles the 2,000 miles difference = at least $666 savings Per year in the future or $500 right now. The only question is "How Long" do you plan to use the trailer because anything over 2 years you MUST do something.
I would first put a straight cap or even slightly up sweapt at the rear on the Trunda (Even Borrow one) and see what the difference is. Use the front of your truck as the Aero part and blend in the trailer in back to it! This would help you even when NOT towing the trailer
____________
Made History @ Daytona and still one fast old man!!
|
tcchin
Zone Head
Posts: 867
|
posted April 22, 2011 10:18 AM
I agree that significant gains can be made by controlling the air flow around the rear of the trailer. The problem is that, unlike the leading edge which is being forced through the air, the trailing edge is passive, and the it must be faired in a way that allows the flow to stick together at roughly one atmosphere of pressure. This means a much longer and more gradual fairing for the trailing edge. Also, trailers have doors on the rear, meaning that any fairing devices would need to accommodate the doors by moving out of the way. I have seen some inflatable devices that attach to the rear of the trailer. At least those devices are collapsible for storage. I think the one that Karl uses has a permanent look of surprise on its face, and possibly an internal heating element.
|
ZRXDean
Needs a job
Posts: 2225
|
posted April 22, 2011 11:19 AM
Great suggestions guys. I might be able to mimic that rounded edge with a big piece of PVC.
|
entropy
Moderator
Posts: 8671
|
posted April 23, 2011 05:35 AM
cool topic, Dean.
my new rig gets 6mpg at 80mph, 9mpg at 60mph.
i should look into some of the stuff like you are doing, but have my hands full getting both my bikes running.
Tim,
" I have seen some inflatable devices that attach to the rear of the trailer. At least those devices are collapsible for storage. I think the one that Karl uses has a permanent look of surprise on its face, and possibly an internal heating element"
good observation, see the thread on lube squirters.
____________
This moderator uses moderation in moderation
|
oldkawboy
Needs a job
Posts: 2125
|
posted April 23, 2011 06:32 AM
quote:
cool topic, Dean.
my new rig gets 6mpg at 80mph, 9mpg at 60mph.
Karl,
Osti & I want to know what yer rig gets at 100mph since that's what you usually cruise at!
The only time you see 60 or 80 is on your way to 100.
Dean,
I've often wondered how much even a V-nose helps. We've got a 20' toy hauler that has a flat nose and my truck gets the same mileage as when I'm pulling our 18' V-nosed enclosed with four bikes.......they weigh within 200 pounds when loaded.
I'd probably spend a little experimenting but Im not sure if you'd get your money back if the cost is high.
Dan
|
osti33
Needs a job
Posts: 2973
|
posted April 23, 2011 06:55 AM
Edited By: osti33 on 23 Apr 2011 14:57
quote:
quote:
cool topic, Dean.
my new rig gets 6mpg at 80mph, 9mpg at 60mph.
Karl,
Osti & I want to know what yer rig gets at 100mph since that's what you usually cruise at!
The only time you see 60 or 80 is on your way to 100.
Dan
Dan,
 Or on his way back down from 100mph!
I could barely keep up with him going to and from the track. I had the diesel soot rolling out of the truck more than once.
I'm pretty sure my mileage suffered a great deal following Karl.
Best quote of the weekend was yours Dan. This was on the morning of the last day of racing. This might not be word for word but it's pretty close.
Ryan: "Dan, where's Karl?"
Dan: "He already left. I told him go ahead without me. I don't think my truck can handle another midnight drag race to the track."
|
osti33
Needs a job
Posts: 2973
|
posted April 23, 2011 07:00 AM
Edited By: osti33 on 23 Apr 2011 15:01
quote:
I think the one that Karl uses has a permanent look of surprise on its face, and possibly an internal heating element.
I think I saw this one is his garage!
Sorry Dean.
Back to trailer aero...
|
entropy
Moderator
Posts: 8671
|
posted April 23, 2011 08:59 AM
the whole point of buying a big vehicle is to burn as much fuel as possible!
Dan does very well, Ryan does better, i'm just trying to follow your good example.
Dean seems to be going in the wrong direction.
____________
This moderator uses moderation in moderation
|
tcchin
Zone Head
Posts: 867
|
posted April 23, 2011 09:04 AM
Sounds like Karl is advocating reducing trailer aerodynamic drag by pre-heating of the air itself with the tow vehicle. Always thinking outside the, uh, box.
|
VincentHill
Needs a life
Posts: 6520
|
posted April 23, 2011 04:35 PM
quote:
Sounds like Karl is advocating reducing trailer aerodynamic drag by pre-heating of the air itself with the tow vehicle. Always thinking outside the, uh, box.
Good one!! Are any of you forgetting where Karl Works??
____________
Made History @ Daytona and still one fast old man!!
|
Ozonkiller
Expert Class
Posts: 350
|
posted April 23, 2011 09:28 PM
I bought a trailer from LOOK trailers here in Phoenix. I asked about the v nose saving gas and, despite the opportunity of selling me the more expensive v nose, they told me that they had spent a bunch of money researching aero and the v nose was negligable in gains aero wise. They found adding a v in the rear was the ticket
Think about it, the blunt edge of an airplane wing is the leading edge.
I get a couple mpg more when I have the camper shell on my truck while pulling over towing without the shell. Closing up that gap between the two seems to help.
|
entropy
Moderator
Posts: 8671
|
posted April 24, 2011 03:27 PM
quote:
quote:
Sounds like Karl is advocating reducing trailer aerodynamic drag by pre-heating of the air itself with the tow vehicle. Always thinking outside the, uh, box.
Good one!! Are any of you forgetting where Karl Works??
How many of you guys have actually touched crude oil????
huh????
I have touched it on many occaisons and i'm telling you that crude is nasty, sticky shit.
Smells not too bad, but tastes horrible.
I say BURN it and all it's environmentally dangerous byproducts like gasoline and diesel!
Lets have a clean environment, burn the gasoline!!!!
____________
This moderator uses moderation in moderation
|
ZRXDean
Needs a job
Posts: 2225
|
posted April 24, 2011 04:02 PM
Now now Karl, I know you harbor secret Al Gore love. Don't try to cover it up with over-the-top consumption.
Thanks for the info folks, I'm going to get a baseline mileage estimate pulling the trailer to Tejas next month, then add some airtabs and nose coping and see if it makes any difference.
Put down a new layer of flooring and built some shelving, the trailer is ready to roll. Gonna bring my spare motor, so if I need a place to work, I'm all set. It's a nice little trailer, Wells Cargo makes a good product.
|
oldkawboy
Needs a job
Posts: 2125
|
posted April 24, 2011 05:28 PM
I solved my poor fuel mileage problem in a different way.
I get 11 mpg pulling our 18' enclosed which is fine when it's loaded with the boys and my bikes along with our pit scooter but since I had plans on making a few events alone ( 'cept for momma ) this year I had a small 5x8 V-nose enclosed built down in south Georgia and it works fine for one bike.......just ain't gonna be working outta it!
Out in Texas where it was flat I averaged almost 15.5 mpg which is affordable. Got between 14 & 14.5 for 2,500 miles.
Granted it don't have much room but there's enough for my bike, riding gear & a tool box.
Now if I had my bike and a spare motor plus a boat load of tools I'd definately want/need more room especially if work needed to be done. Since I just run a streetbike, usually a sprocket change is the most work required........I'm just not gonna run very fast!
Just hate pulling the big enclosed for one bike.
Dan
|
VincentHill
Needs a life
Posts: 6520
|
posted April 25, 2011 08:38 AM
Karl, I like what Jay Leno says, Let everyone get clean energy vehicles so that the gasoline can be saved for everyone wanting to enjoy their Gas Guzzlers from the past on the Weekends!
I have not touched it but I have seen it and the difference between what comes from the Middle East and Alaska. What you described was closer to ALaska than the Middle East where it is less Sticky and Nasty. I also know that it is the Middle Distillates that make Diesel and the Middle East Oil is Better for Gasoline than Diesel.
Also the Prius gets worst Mileage than a BMW M3 when Pushed Hard so it is all more about HOW we drive than What we drive!
____________
Made History @ Daytona and still one fast old man!!
|
|
|
HOME
NEW TOPIC