Travel Trailer/Camper help

[Blu3Z3rg]

Ok guys... this one may be a bit trickier, BUT, after reading and such, I don't really know where to head with this thing. Here is a link to someone selling a camper just like mine:
2005 Kz Sportsmen 2404 BUNKHOUSE, Travel Trailers RV For Sale in Canton, Michigan | HW Motor Homes | RVT.com - 70317

My truck is a Dakota, as listed in my information. Pulling it is no problem weight wise, but the aerodynamics KILL me when up at speed. Especially last year, when there was a wind storm. I was fighting 50 mph wind gusts that I was headed straight into. My truck was brought down to a crawl on any hills. It wasn't good at all. I"m still working on the truck, and it shouldn't have a problem pulling, BUT, the aero on the camper can obviously be improved.

My thoughts: Some sort of boat tail, even minor should be a huge improvement. There is some damage and leaks to the roof, so this may actually prove to be beneficial. If not the whole way around, perhaps a little "wing" type as you see on some SUV's and such. QUESTION: Is there an optimal angle/length etc. for this and how do i find it?

The underbody will be smoothed, as it is already most of the way.

Anything else I could work on while i'm hacking it away?
I will be redoing the flooring and the master bedroom as well, mattress and all that got wet as well. Roof is now a single roll of sheet with some tar around all the stuff sticking out like the A/C etc.

Thanks for the help guys! I can use any improvment that would be worth the time and effort, and I promise to document!!!!

(Also revising my grille block and air dam on my truck to write up quickly for ya'll)

[slowmover]

Mechanical baseline is critical. And, while an aid to mpg, it is central to vehicle performance and component life.

Combined Rig RV MPG

Orbywan's threads are to the point:

Aero RV Boattail

Aero RV Bellypan

And Skyking's design underway:

5th Wheel Design

I'd have a long look at how many miles per year, and expected lifetime use (number of nights of use) to see what benefit aero changes will make. A few thousand miles per year may make it more of a demonstration versus a $$ savings.

I believe you'll want to conduct some tests on road horsepower demand (coastdown, etc) as your trucklet is hard pressed to pull that square white box.

The best TT's are aero in shape, but also feature low ground clearance, low center-of-gravity and torsion arm suspension (independent). A sway-eliminating hitch (such as Pro Pride) is also going to be a help from the aspect of control, and from reduction of steering inputs.

.

[drmiller100]

10 degrees is great. air will reattach if it gets tripped.

apparently 20 degrees is livable, but about the upper limit.

[aerohead]

The boat tail probably won't help until the nose of the trailer is corrected.
The lack of side radius is costing you up to 18% mpg,and the gap between trailer and truck another 8% mpg.
If she had a nose like the early Airstreams you'd see up to a 26% improvement.
The 'Bullet' trailer was compared to one like yours,behind a Town and Country minivan.
A 16',2,990-lb trailer like your's got 11.8 mpg @ 60 mph.
The 32',5820-lb 'Bullet' returned 13.2 mpg at same speed,same tug.
And the 'Bullet' nose is in no way ideal.
The side radius has been reported as a source of sway.Fibrelock Fabric Ltd.,England,who marketed an inflatable 'Airstream' nose (trailer dome) in 1982 claimed that their unit reduced pitching and snaking.
The worst part is that your trailer nose will exhibit the highest drag increase in a crosswind,whereas an Airstream will exhibit the lowest.And it's windy most days.

[slowmover]

Aerohead, do you mean to indicate the postwar Curtiss-Wright Clipper nosed vehicles (shared by both Silver Streak and Airstream)?

1953 Silver Streak "Clipper" (More images in link).





Or, as with the later 1959 Airstream "Overlander":



Also, does The side radius has been reported as a source of sway need to be corrected to the lack of . . .?

Thanks

.

[Blu3Z3rg]

SlowMover: Thanks for the good insight! I don't believe i'm going to be doing a full boattail. As for the amount of use, we just bought the camper, but the idea is to go a minimum of 3 trips a year. Our typical spot is a 4-5 hour drive. Last time we took this trip, my basic stock combo got 12+ mpg there, and 9+ mpg on the way home. Why so much worse coming home? Wind storm. One that had a lot of tornadoes in the mid west. We didn't know it, but we were driving right into them on our way home.
Now, I have a Cold air/hot air intake (switchable setup for purposefull driving) a grille block during the wintertime, and a chin spoiler. Hopefully an electric fan coming soon as well, but I have a boat i'm trying to work on and sell.
As for the camper itself, I'm going to repair the things that need to be repaired, and if in doing so I can improve slightly, I will.

drmiller: Thank you for that. I am thinking of simply doing something along the top and perhaps the sides on the back for 6-8 inches. Similar to the mercedes trailer.
Mercedes Trailer tail

AeroHead: When you said, "The side radius has been reported as a source of sway.Fibrelock Fabric Ltd.,England,who marketed an inflatable 'Airstream' nose (trailer dome) in 1982 claimed that their unit reduced pitching and snaking." did you mean that MY camper is prone to sway, or the airstream is? It is worded that a side radius creates sway, which you have also told me improves mpgs. Then you tell me that this company claimed to reduce it? I'm confused.

On another note, my propane IS in a nose cone, not like the one shown there. I'm sure it improves slightly, but I can't find a picture of it. I really need to go through and find some pictures because due to work I can't get over there in daylight to take one of the real thing.

So... If I made a front for my camper such as this:
Camper Link here would that be much of a help, or would that not really be enough. Anything more than that I probably wouldn't do it as it would be really hacking into this thing. If a project takes a month or long to do, I can do it during the winter inside my friends shop, but I would need to do that next year.

Also, moving the camper closer to the truck you said would improve mpgs by 8%. I don't know where you got that number, but are we talking an inch or two, or like, a lot? I don't think there is a lot of flexibility there, sadly, even if i drilled another hole into the hitch. It would be about a 2" closer max and then I would be afraid of hitting things anyways.

Thanks again guys!

[aerohead]

Originally Posted by slowmover

Aerohead, do you mean to indicate the postwar Curtiss-Wright Clipper nosed vehicles (shared by both Silver Streak and Airstream)?

1953 Silver Streak "Clipper" (More images in link).





Or, as with the later 1959 Airstream "Overlander":



Also, does The side radius has been reported as a source of sway need to be corrected to the lack of . . .?

Thanks

.

Yep.They have some advantage at zero-yaw,but from graphs Hucho published in his book(s) they really dominate low drag under crosswind conditions,which is what we have much of the time.
If the gap can be closed as well(which is responsible for almost all crosswind drag) we pick up even more savings.
The 1982 'trailer dome' by Fibrelock Ltd. did both operations and was credited with up to a 26% fuel savings.After working with Hucho's material on trailers and commercial vehicles I believe it.
As to crosswind stability,Fibrelock claimed that their unit actually reduced pitching and snaking.
If the gap is closed off the yawing moment will be killed.You'd feel some 'push' but that's to be expected when you are pushed from the side.
If we watch our load distribution and tongue weights we ought to be okay.

[Blu3Z3rg]

Here is a picture of my actual camper front
I attatched it - front of my trailer. I don't know how good it is, but it's better than the one I actually posted. You can see a little bit of the damage up top. It's not significant, but if i do nothing, the water keeps coming in. It currently isn't leaking due a bunch of tar but needs to be actually fixed.

As for the back, i will probably do something like the mercedes trailer listed above previously just to help. i would think that it actually helps in the way of stability as well, AND, i am thinking of making it some sort of storage. I don't use the shower outside attachment that is there, so i plan on eliminating that and reworking that. We will see how projects advance. It may end up being more of a back end than I had thought before!

found the links for a boattail on an rv as well. i only wonder if doing something like that is even legal because it goes over and past the bumper.

[KamperBob]

Blu3Z3rg, see if you can get a copy of Hucho's book. If not for purchase maybe borrow from your local branch via inter library program. That's what I did last year. The section on trailers compiles data from others and connects some dots. For example, the effect of nose slope on sway is covered; think face pressure and tongue weight. Of course Cd reduction and hence MPG gain. From the wind tunnel pix a big win came from taming bow wave splash from trailer with too blunt a leading edge. There is also some data showing effect of edge radii including rear not just front. Roof deflector too. It will be time well spent I'm sure if you can get a copy. Good luck!

[aerohead]

Originally Posted by Blu3Z3rg

SlowMover: Thanks for the good insight! I don't believe i'm going to be doing a full boattail. As for the amount of use, we just bought the camper, but the idea is to go a minimum of 3 trips a year. Our typical spot is a 4-5 hour drive. Last time we took this trip, my basic stock combo got 12+ mpg there, and 9+ mpg on the way home. Why so much worse coming home? Wind storm. One that had a lot of tornadoes in the mid west. We didn't know it, but we were driving right into them on our way home.
Now, I have a Cold air/hot air intake (switchable setup for purposefull driving) a grille block during the wintertime, and a chin spoiler. Hopefully an electric fan coming soon as well, but I have a boat i'm trying to work on and sell.
As for the camper itself, I'm going to repair the things that need to be repaired, and if in doing so I can improve slightly, I will.

drmiller: Thank you for that. I am thinking of simply doing something along the top and perhaps the sides on the back for 6-8 inches. Similar to the mercedes trailer.
Mercedes Trailer tail

AeroHead: When you said, "The side radius has been reported as a source of sway.Fibrelock Fabric Ltd.,England,who marketed an inflatable 'Airstream' nose (trailer dome) in 1982 claimed that their unit reduced pitching and snaking." did you mean that MY camper is prone to sway, or the airstream is? It is worded that a side radius creates sway, which you have also told me improves mpgs. Then you tell me that this company claimed to reduce it? I'm confused.

On another note, my propane IS in a nose cone, not like the one shown there. I'm sure it improves slightly, but I can't find a picture of it. I really need to go through and find some pictures because due to work I can't get over there in daylight to take one of the real thing.

So... If I made a front for my camper such as this:
Camper Link here would that be much of a help, or would that not really be enough. Anything more than that I probably wouldn't do it as it would be really hacking into this thing. If a project takes a month or long to do, I can do it during the winter inside my friends shop, but I would need to do that next year.

Also, moving the camper closer to the truck you said would improve mpgs by 8%. I don't know where you got that number, but are we talking an inch or two, or like, a lot? I don't think there is a lot of flexibility there, sadly, even if i drilled another hole into the hitch. It would be about a 2" closer max and then I would be afraid of hitting things anyways.

Thanks again guys!

It is confusing.Hucho will have a drag table showing the lowest drag with a semicircular plan form ( like AIRSTREAM),but then warn that these are subject to yawing forces when in a crosswind.
Then Fibrelock advertises that when you install their trailer dome, that the trailer is more stable.
Your trailer nose should not create the effects that Hucho's mentions.
Personally,I would be willing to see.
If the gap is closed off so is the cross-flow which would create the potential yawing moment.
The gap is dead,you've got the bulbous nose,and at the gas station 26% less often.
I looked at a CM Trailer Co. rig last night.It is 94.5" wide with a 19-inch radius on the vertical leading edges of the nose.8" radius @ top edge.