aeromods for trailer?

[mpg_numbers_guy]

The angle would need to be a curve that ends flat for best airflow IMO, kind of like the way the streamlining template shows.

[Daschicken]

From the speed discussions, trailer tires are rated for 65 mph unless otherwise noted. That is really not fast. Some may be M rated for 81 mph. If the trailer is near max load for the tires, I would try to stick to 60 mph. I used to work at a tire shop, and probably 70% of trailer tires that we replaced(the ones coming off, not going on!) had a tread separation or catastrophic failure from underinflation/excessive age. Treat them as you would with car tires, replace if 6 years or older, or if cracking badly/out of round, etc.

Originally Posted by justinooo9

Does anyone have any data on those roof mounted wind deflectors? see them on big rigs but rarely on trucks pulling 5th wheels. I could fabricate one pretty easily and anyone can ask my wife I don't give a rats butt about what others think my truck looks like lol. shes nearly pristine for 20 yrs old.

I was thinking the wind deflector on my roof because the side my side may sit 1.5 higher on even my new trailer etc.

I didn't know how valid the picture attachment really was etc.

The problem with the truck mounted wing is that it increases lift at the front of the trailer, less stability. I think hucho’s book has lift measurements. I’ll have to check.

Originally Posted by aerohead

The original source included the drag coefficients for each configuration.I have it at PhotoBucket,but can no longer access any of it.
As to the deflectors,they need to be tuned,and do not lend themselves to just shooting from the hip.

I’ve got hucho’s book on road vehicle aerodynamics, pretty sure it’s in there. I could look, but not until tomorrow.

[Angel And The Wolf]

Originally Posted by mpg_numbers_guy

The angle would need to be a curve that ends flat for best airflow IMO, kind of like the way the streamlining template shows.

Yes, the Curve would be best, but hard to make. The forward mounted vee would be an improvement over your sketch, and could house tools and maybe a spare tire.Acone mounted to the back of your cargo would help cut drag.

[freebeard]

I'm reserving judgment until we see the UTV and trailer together. Those side view don't say anything.

[MeteorGray]

I've been running a '96 7.3 F250 automatic since I bought it new 20 years ago. When I towed a 1967 27-foot aerodynamic Airstream travel trailer with the truck, I could get 15 - 17 mpg running at 55-60 mph. In 2006, I sold the Airstream and bought a new but squarish 27-foot Jayco travel trailer, and with it I average 14 mpg. I sold the Airstream even though it was more economic to pull because it was aging out and needed a lot of work. So, I bought a new Jayco for about a quarter of the price of a new Airstream because it was new and smelled good and most important, made the wifey happy. Since I don't pull the thing that much anyway, the tradeoff was well worth it to me.

To help with the fuel economy when pulling the squared-off Jayco, I did put a set of vortex generators (AirTabs) on the back of the trailer. However, I cannot certify any fuel savings. I can say the back of the trailer is cleaner with the AirTabs, and the trailer seems a little bit more stable in the wind and among the big trucks. In addition, I also attached a wing on the back of a campertop on the F250. Again, I can't certify whether there is any fuel savings or not. There may be some improvements over the long haul, but the difference is certainly not stark like there is between pulling the rounded Airstream compared to the squared Jayco.

I used to be proud that my big ole F250 diesel was among the most fuel efficient travel-trailer-hauling trucks out there loaded to the gills with camping junk. Then came the little diesels on the market that can achieve maybe 20 mpg towing, and my vanity has dissipated accordingly.

[Joenavy85]

Originally Posted by freebeard

I'm reserving judgment until we see the UTV and trailer together. Those side view don't say anything.

Yep, gotta have all the factors in place before making calculations.

[aerohead]

Originally Posted by Angel And The Wolf

Perhaps:

Really can't tell.They're both extremely mutilated forms as a unit.I'd be going with an inflated,bulbous nose ahead of the cargo.I might even enclose the cargo in a zippered,inflated envelope.boat-tailed if possible.

[Hersbird]

I do have this thing sitting beside the house my wife is THRILLED about. My buddy took it off the semi truck he is using to tow a big 5th wheel around the country as it made his truck too tall and the 5th wheel had it's own nicely shaped front anyway. It is 8' wide and would make a great aero nose for a ATV or snowmobile trailer assuming it was 8' wide.

I'm not far away in Missoula if you wanted to come and get it, I'm not going to be able to use it anytime soon.

[Joenavy85]

Originally Posted by Hersbird

I do have this thing sitting beside the house my wife is THRILLED about. My buddy took it off the semi truck he is using to tow a big 5th wheel around the country as it made his truck too tall and the 5th wheel had it's own nicely shaped front anyway. It is 8' wide and would make a great aero nose for a ATV or snowmobile trailer assuming it was 8' wide.

I'm not far away in Missoula if you wanted to come and get it, I'm not going to be able to use it anytime soon.

His trailer it probably close to that width. He could mount it so it partially overhangs the trailer tongue and have a covered from support structure to provide some storage and a nice smooth bulbous nose to get some amount of attached airflow.

I remember you posting this picture a while back (a few years ago I think) on another thread, but couldn't remember your name. I'm kinda surprised you stil have it, figured the wife would have made you toss it by now.

[Hersbird]

I only got it this spring. My utility trailer is only 5' wide, I think it would hurt more than help unless 8' wide or you could probably cut a section out of the middle to make it narrower. I also figured put it as close to the hitch as possible while still allowing turning and then skin the bottom. If it's not tall enough then build up a box to put it on, it would actually be perfect for sleds with the skis slid up underneath. You could also add hinged panels to the top and sides that form a kham back but move out of the way for loading.