Enclosed trailer NOSE - suggestions?
 

I am building my own enclosed trailer.
(Images are photoshopped of what I am about to do..., not mine, and not to scale, but the drawings and measurements are the intent of my outcome).

Overall Dimension: Basically 20 feet long, 8 feet wide, and 5 feet tall.

Looking for "interface" aero thoughts between F150 and trailer.
Is the front edge height of trailer okay...? Opinions...?

Good question.

Just going off the fundamentals I would say more bang for the buck (and fabrication time wise) going a little higher than 48" and allowing a gentle 5-10 degree receding roof slope is going to do more than anything else.

EDIT:

While looking for a proper image I found a related thread in another forum that may be of interest.

https://www.dieselbombers.com/towing...o-trailer.html
https://www.dieselbombers.com/attach...iler-vnose.jpg
Again, if you follow the fundamentals, an aero-cap on the pick-up truck is going to do more.

Are you at least planning on using a tonneau cover?

EDIT-2:

Looking at the original images I was assuming there was a roof, but if so - how does it open? Will sloping such a roof pose as an issue for hinges and air-springs?

We need to more about this proposed design, just have front and sides, no info on top, bottom and rear where a box cavity may be of use.

Is the F-150 tow vehicle stock?

I decided to go full V-nose (and remove my toolbox).

Reasoning for overall shape is dictated by aluminum pieces:
1. The 48" x 96" diamondplate will be the hinged lid access to the nose.
2. The 60"tall x 144"long x .050"thick will be the maximum wall height.

Guestimating that the interface between the vinyl-covered bed, and the beginning of the trailer is about the only factor I can "adjust". That is the part I am trying to maximize effort. Cannot reduce/taper/round/Kammback any of the rest of the trailer, due to constraints of cargo, and/or welding the aluminum structure complexity.

Here is my cargo:

Here is an alternative for your consideration - see attached.

The front can be as blunt as you want, although rounded corners certainly help.

It is the tapering of the form that punches a smaller hole through the air.

Visualize a rain drop as the perfect shape, which scheme looks more like a rain drop, or even a half rain drop?

Bonus: You can now stand up at the tall end.

GREAT DISCUSSION!!! (this is what I was hoping for). ;)

Given the ORANGE line, seems like adding a significant amount of complexity to raise it some 18" (over 60" base). Which only comes to about a 5-degree slope.
To get a PURPLE 10-degree slope, you need to add nearly 3 FEET of height? Wouldnt all that frontal area, negate any effect of a more streamline flow?


What about option #4, "diamond" shaped front and roofline (pseudo-round) ?
Still with only a 5 degree slope. Yeah - that is significantly more complexity and welding time...
Is it even worth trying to get that 5-degree slope...?

You waited until now to ask the question?

....

My first thought before I scrolled down was to fair in between the back of the fender and the front of the tail light and add a collapsible trailer tail.

Permalink #3 adds the pertinent information — the use case. I'm surprised that kach22i suggests adding frontal area. :confused:

The gold standard in these-here parts is Thee Holy Template. If you abstract it down to simple curves and add it to a trailer frame you get this:

https://ecomodder.com/forum/member-f...17-trdrp1a.jpg

It has the correct taper on the front and sides but not the top, which is the biggest deviation from the template to accommodate a rear entrance.

Just starting with a rolled face on the trailer sides would have helped. Is that race car's wing demountable?

edit:
Okay, changed my mind already. Follow Mair:

https://i.imgur.com/UxyoQ4q.png

Back to a collapsible tail, but the curved nose is instructive.

> Waiting till now...
Clarification, I am ENCLOSING an already existing trailer, and none of the existing trailer dimensions are alterable.

Here is a Googled example of the NOSE that I wish to emulate (jut found this).
Materials must be from 2x2" aluminum tubing, and sheet aluminum, cause that is what I have access to purchasing.

No, the wing is part of the carbon fiber decklid (and framing support underneath), yes - removable, but not storable elsewhere during hauling... So no, it stays on vehicle.

So I appreciate discussions, theories, suggestions... but I am extremely limited to fabricating anything extraordinary...
Mostly looking for discussions on the FRONT NOSE (entry height , angle of attack from behind F150, angle of slope, angle of V-nose...). that type of discussions.

Might add boat tail flaps on rear, once the body of the trailer is finished (dont have the rear door/ramp thought out yet).

I was thinking of it as adding useful interior space (Bonus) and saving one's neck and back from excessive crouching.

The tidbits about a collapsible tail are good, and think that I already mentioned a box cavity tail in passing.

Another route (Alternate-2) could be build your simple box (not even with the front nose complexity you have expressed a desire for), but radius the front and side corners.

Using this approach you will not be adding any "frontal area" and will have taken steps to tame vortexes created by differing air pressure at 90 degree plane intersections (corners).

Oh, and of course add a box cavity similar to a tractor trailer.

I've posted where to source these curved trailer parts at least one other time in the forum, let me see if I can find it again.

EDIT: Here we go, used phrase "curve box trailer".


Fiberglass Roof Caps, V-Nose Enclosed Trailers
http://www.mirageinc.com/trailer-roofs
http://www.mirageinc.com/content/ima...orque_360.jpeg

http://www.mirageinc.com/content/ima...-trailers.jpeg

Looks like closing up that tow vehicle to trailer gap is beneficial.

https://ecomodder.com/forum/showthre...van-35515.html
The below is flawed in that the wheels are not fully enclosed and no evidence of a box cavity similar to tractor trailers, but close to my most recent Alternative-2. Yours would be shorter, are you flexible enough to hunch it all the way down? Perhaps a front hatch would prevent some grief.

https://www.doolittletrailers.com/tr...sed/doolittle/
https://www.doolittletrailers.com/wp...-doolittle.jpg

Got it.

The problem becomes defined by the back end. How much could you nip off the rear corners of a rectangular bed? Maybe use a perforated ramp instead of a solid one and leave the wing standing proud?

A lot depends on loading and unloading. Do you need access through the driver door?

You can have slab sides and put the radius in the cap. kach22i's two examples are good.

edit:
Some argumentation here about this design (the old faster backwards conundrum):
http://www.bre2.net/mm5/graphics/000...railer_lgt.jpg

Or go with a homebuilt version of the boxtails that 18 wheelers have been using for years.

https://www.fleetequipmentmag.com/wp...iler-Tails.png

Overall I think there is a consensus of concentrating efforts on the tail, not the nose.

Causes of aerodynamic drag
https://www.sciencelearn.org.nz/reso...rodynamic-drag
https://static.sciencelearn.org.nz/i...jpg?1522302539

Ovoid forms aren't pertinent to the rectilinear construction. Follow Mair or Ahmed

https://media.springernature.com/ori..._Fig5_HTML.gif
ecomodder.com/forum/.../random-aerodynamic-oddity-day-thread...#post610679

Typical trailer aero considerations would be having a radius at the leading edges of the box, not sharp corners. A V nose may reduce the need for this, but I would be inclined to curve the front edges to some extent.

I would recommend you create a rear door that was a several feet deep boat tail, hinged to one side. That gives you the taper, but the door opening would still be 100% of the width, as only the section past the door opening would be tapered. Think of the typical trailer tail, except as an enclosed door. Then either continue to use the ramps that you would use now, or build/buy removable ramps.

I couldn't find it, but in this site (else my imagination) there was a post about a full height box trailer with a clamshell boat tail.

The one I'm thinking of was an RV way back in 2011.

https://ecomodder.com/forum/showthre...d-e-18151.html
https://ecomodder.com/forum/attachme...p;d=1310601634

Not a tractor trailer style baffle box cavity, but similar results I assume.

First found it here while doing a search:
https://www.buildagreenrv.com/new-ideas/

Yea, I posted several images in that other thread with this thread in mind. Wasn't quite sure how to introduce or implement it here without scaring people off.

Too much information and all that.

Good post. :)

https://ecomodder.com/forum/showthre...tml#post436708

Photobucket has eaten the images a bit. But I think this would be the trailer you were thinking of. I never heard any more about it at the website I saw it at. Maybe I'll ask there. Ought to either have a few miles, or a lot dust on it, by now.

Thanks. That's the one. Photobucketsucks.

close the gap between truck and trailer as much as possible (preventing cross-flow)
it's where the V-nose will help, and a vertical baffle plate along the centreline, too - allowing for vertical articulation


Consider rounding off corners, if possible

but NO semi-circular rounding off on the rear (in plan view)
It'll make the trailer sway : Coanda-effect working sideways, aft of axle/pivot -> sway

Vortex street.
https://upload.wikimedia.org/wikiped...-animation.gif

I once was interested in buying a travel trailer with a V-nose. After all, such a nose configuration works for boats in water; why not trailers in air?

After looking into it, I decided against the trailer because owners reported no perceptible economy gain, and some said that it didn't handle as well in side-winds.

I ultimately decided against it, mostly because the trailer's design had the tongue weight too heavy for my tastes.

At a hovercraft rally I had an opportunity to witness a triangular style hovercraft yawing back and forth unable to fly in a straight line. I was positioned well in front of the craft on shore and the struggle was memorable to say the least.

Similar to this:

Yellow Jacket Hovercraft
http://kevinthewise.com/hover/pics/1strunup.jpg

The side wind was very gentle, other craft with rounded bows had no such issues.

Crosswinds are what matter. Low ground clearance on independent suspension. All edges radiused. Full-enclosed. FE will follow.

Not owning one at present isn’t any bar to start testing:

1). TARE weight of tow vehicle. This can be combined with;

2). Highway FE test of tow vehicle.

— A CAT Scale 45-50/miles from home out on Interstate. Obtain weight after topping fuel tank to auto shutoff. Correct tire pressure to spec (cold read at home).

— On a loop back to the same location, 100% use of cruise control at your choice of 62,3, or 4-mph. Same as when towing. As you know, keeps you right below commercial traffic. The catbird seat. (I’d note accel/decel events plus forced pass).

This is the optimum MPG. Can be reproduced by anyone. Changes are only temps, winds and traffic volume.

Engine hours against average MPH is the data desired to make judgments.

If you have — or have had — another travel trailer, then the tow vehicle loaded to the same weight value, but unhitched is the real number wanted.

A). What is the percentage drop from the previous? Against what weight increase (per axle)? (Assumes tires are again optimized. Numbers on the book).

B). As TT Towing FE is more about mechanical deficiencies against an almost universal 40% towing penalty, getting a baseline on:

1]. TV wheel alignment, steering slop, brake drag and engine air handling (is where to concentrate). Verify.

2]. The (not previously discussed) TRIP PLAN. Where to stop (location in same lane of travel) Where to park & how to park. (Easiest egress).

All familiar with your commercial driver experience. Choices all made in advance.

The familiarization loop can be used with stops each time. A rest area. A travel center. A KOA Campground. A WallyWorld truck-friendly (Trucker Path). A 200-mile total loop for testing incorporating these stops. Refining the how-to. As it’s never obvious until one does it.

Drive one trip leg at a time. Only. (Kills anxiety).

The ideal is steady-state cruise. Any deviation is what kills FE with a heavy (relative) rig. Accel & decel count total per trip. Laid-back attitude. Get there when you get there.

— If a gasser, a vacuum gauge dash mount (time manual control of downshifts versus using rpm).

— A feedback gauge showing percent of engine load. (Least isn’t best overall, but an acceleration strategy is). Otherwise, keep load under 80%.

Obviously, some of this needs a trailer. But the first two scale tickets and two loops won’t. Nor will attending to TV mechanical.

Gear wanted:

— Brake controller. A TUSON DIREC-LINK is current state of the art. It’s better than the ones integrated with today’s vehicles.

— A Hensley-patent hitch. (Hensley brand or improved Pro Pride). Cheap at twice the price for what it does.

— Budget item to convert TT to DEXTER TOR-FLEX axles with disc brakes.

— Budget item to use TUSON Trailer Brake Actuator for Antilock.

The transitions are what matter (accel/decel). Thus the need for average mph against engine hours for a trip. Total Time Steady State is far less than people expect. Even after cutting idle time, the need to minimize energy use in transitions are the killer.

One can cut the number & degree of steering inputs to a minimum. Same for use of throttle and brakes.

But where the TT design/equipment is obsolete (leaf springs plus drum brakes) there’s a minimum to accommodate them which isn’t THE TRUE MINIMUM.

AFTER these comes aerodynamic considerations. The above are safety-related (loss of control accidents lead the pack for all RVs), as familiarization can be a painful process. Takes 10k-plus miles over a wide variety of year-round conditions encountered.

Commercial driving is a help. A step up. But it isn’t enough to cover the twins of Safety & FE.

Test, and record. Most FE gains around here aren’t being subjected to noise-elimination. Mechanical deficiencies addressed. Baseline performance improvement (the TV can also be improved via wheels/tires, shocks, anti-roll bars, etc).

I “know” what I should be averaging with my rig. And isn’t the 15-mpg average for which I’m called dishonest using a one ton to pull a 35’. It’s 17+. All of the above applies.

You can start today if you desire.

.

MG, the “goal” (as you’ve seen me say) is being happy with the per nights aboard cost of an RV. How many years & miles expected. Finance, insurance, maintenance factored. It’s often $350-$400 the way most people do it.

One trailer TYPE is the longevity king. And the family vehicle properly-spec’d for that, FIRST, is the tow king. It won’t be a pickup unless one is a farmer or a contractor as minuses far outweigh pluses.

One trailer DESIGN is the FE King (as it’s optimized for safe handling: crosswinds). Happily, these two are the same.

The lowest cost per mile (and per night aboard) is also the lowest risk per mile.

But only if properly-mated to the right family vehicle.

1). From the annual nights aboard number (5k miles annually), what percent of those daily hours is spent at steady-state cruise? (As you’ve broken it out). How has this changed travel plans? Real numbers. Not feels good stuff.

2). What is the cost reduction per night of FE maximization in this approach? As the other costs (mainly depreciation) outweigh it? (Costs above and beyond initial purchase. Will spending to save work?).

3). Versus having a tight-spec family vehicle (Safety & FE), what was the Tow Vehicle penalty for owning a less efficient vehicle (cpm)?

It’s not just the trailer, in other words. The best outcome IS the trailer-first approach. All else follows, is where savings are most obvious.

The last item is also a budget set aside. A hard-surface, covered parking spot on your property with 30A (minimum) electrical plus water & sewer.


Use a clean sheet of paper.
Sharpen several new pencils.

.

All good advise of course, but it's a toy hauler.

https://ecomodder.com/forum/attachme...p;d=1572363700

Most of that addressed to MeteorGray.

Crosswinds are still what matter. A V-nose is wasted space. Needs a Trailer Tail.

RV Nomenclature: a toyhauler is living quarters with enclosed toy space. Usually a fifth wheel pulled by Baby Daddy in a jacked up 4WD.

gap
 

Testing has shown a 16% drag increase associated with the gap.:(

the British option
 

Decades ago,an English company offered an inflatable bulbous nose for caravan trailers,which would convert a 'shoebox' into an 'Airstream.'(at least at front)
If memory serves me,it was good for a 28% drag reduction.I had a graphic,but lost it in the PhotoBucket takeover.:o
A study of contemporary inflatable advertising (recently Halloween pumpkins) will illustrate the concept.And any 12-VDC automotive HVAC blower fan would be adequate for inflation.Gentlemen,Start Your Sewing Machines!

https://ecomodder.com/forum/member-f...01-2-04-41.png

This one is in my Photoshops album. Rather than an inflatable, a virtual bubble. I learned this from you years ago, showed Hersbird this pic, and he implemented on his Hi-Lo. I forget his results.

Well I don't know if it worked but it looked dang cool! Seriously that trailer did get really good MPG but I didn't have a lot of before testing and did everything at once so I didn't know if any one thing helped more than others, or if it just did good the way it came from the factory. I could get over 15 mpg towing with a rig I seldom got better than 17 mpg not towing.

I'm now back in the idea of planning a ground up build again now that I have the TDI and the tongue weight on my big camper is really over the hitch rating although the overall weight is within the tow rating. I could probably ditch 1 of 2 propane tanks and switch in Li-ion batteries and move them inside and get it under the 615 pound limit. That wouldn't get me that sweet 15 mpg again though, and I think I can beat 20 mpg with a ground up build.

https://ecomodder.com/forum/member-h...117-154543.jpg

see how it faced the air in relation to the tow rig.
https://ecomodder.com/forum/member-h...1-imag0253.jpg

also notice the factory trailer is "shark nosed". I don't know if that helped in any way either but as the back of the Aspen sloped in a parallel manner I can't imagine it hurt.
https://ecomodder.com/forum/member-h...1-imag0247.jpg

I always thought those forward facing radii should be perforated wit RGB-LEDs inside and a plasma globe in the cap. Sort of a Dekotora/Wurlitzer trailer.

https://ecomodder.com/forum/member-h...1-imag0253.jpg

If you do a ground-up rebuild consider a trolley top. It could match the crown of the tow vehicle's roof.