Aerodynamics and light wieght TTT

[Sandy St. Louis]

I am looking for some thoughts on making our small trailers more fuel friendly. We all know wieght is a big factor making light is good and help fuel economy but what of shape and towing aids . An example , if one made the trailer reach ajustable bringing the trailer closer to the tow vehicle would this help? The reach could be shortened for highway driving and lengthened when tight turning is required city driving etc. The instailation of wind deflection devices as cambac's and foils . I hope an open discusion on this subject could help to give us more freedom in our camping passion .

[mezmo]

Hi Sandy,

Check this thread out - it'd apply to any TD/TT/TTT:

viewtopic.php?f=55&t=49036

Cheers,
Norm/mezmo

[angib]

Weight only becomes important in hilly country. On flat land, towing extra weight is not that significant.

The great problem with discussing aeros is that people think there are hard-and-fast rules, which there are not. We are looking at tow-vehicle-and-trailer combinations and it is the combination that matters, not just the trailer. So anything discussed has to say how it interacts with a particular tow vehicle.

Perhaps it is time to show again this photo of a trailer designed by Honda - when added to the Insight (with a stretchy flush elastomeric joint), it significantly reduced the car's drag! There is a little bit of cheating going on, as they did also add front wheel spats.

[Vedette]

I would focus on building it as light as you can without compromising the look you want and the creature features you think you will need while camping.
We sometimes tend to over think things.....which usually ends up with nothing getting done!
The amount you will save on gas probably won't amount to an extra beer a day while you are camping?
Good Roads
Brian & Sandi
PS
Are you interested in becoming a member of the B.C. Chapter of the Tear Jerkers?
It is FREE!

[Sandy St. Louis]

Actually The plan,for me , would be a Rimple style using the Pico building method and chassie pulled by a 1000cc tow vehicle. Matting the car , a hatchback style, to the trailer and getting the best bang for the buck. A few years ago Angib posted a picture and article on a multi use trailer called Shuttlecar by ACR engineering and it was very forward thinking maybe to forward for America but I'm hoping for a happy in between some of that could be tackling the air disturbance between the two vehicles. Yes what today we believe as overthinking may be the norm as auto manufacturers are grabing at less than a single digit improvement in fuel aconomy. This thread is for general ideas on making recreational travel less energy dependant and still affordable for the average population. We would even be greener at the same time. Off the wall ideas and remarks are very welcome

[rowerwet]

your TV will influence the best shape for a trailer to minimize drag. most modern sedans sweep the air down over the back window, and right into the flat area of a normal "benroy" type design. hatch backs, small SUV's and vans tend to not direct the air down as much. A small or large pickup truck will have a very different feel when towing, depending on the load in the bed, or if a cap is installed.
Mostly if you want good mileage towing, slow down, then design to keep the trailer inside the "hole" the TV punched, tongue box design, wings, foils, Vortex Generators will only do so much and the results will change with each combination.
While a teardrop may look aerodynamic, it actually generates a bunch of drag with the transition to the sides, and because the sides are plumb. This is by design, otherwise you loose storage, especially in the galley.
The most aerodyanamic looking teardrop I ever saw had a very distinct "wasp tail" shape to it. the whole tear was built in strip built fashion (think wooden canoe, kayak, or old wooden motorboat) and had a V to the whole roof just like an upside down boat hull would. It bulged at the front, and tapered down and in to the pointed tail. It was stunning, a work of art... and had a galley so small it was about useless. (they even had to come up with some fancy long arm hinges to allow a V shaped lid to open, further limiting internal space.

[angib]

A few years ago Angib posted a picture and article on a multi use trailer called Shuttlecar by ACR engineering and it was very forward thinking maybe to forward for America

Ah, I understand - you want aerodynamic styling/appearance not low drag! The Shuttlecar has some pretty glaring aerodynamic errors, but the long sloping nose makes people assume it is aerodynamic.

[michaelrsydney]

A few years ago Angib posted a picture and article on a multi use trailer called Shuttlecar by ACR engineering and it was very forward thinking maybe to forward for America

Ah, I understand - you want aerodynamic styling/appearance not low drag! The Shuttlecar has some pretty glaring aerodynamic errors, but the long sloping nose makes people assume it is aerodynamic.

Which raises the question (again!), what is a good compromise for usable volume in a Teardrop with optimised aerodynamics within the constraints of achievable build techniques?

Of course my question raises more questions as nothing is that simple. I assume one could envisage a sliding scale with a true teardrop (in all three dimensions) at one extreme to a box on wheels at the other. The former would be low drag but devilishly difficult to build and with poor interior space , and the latter a simple flat sheet build with the aerodynamics of a house brick.

As I understand it the original poster is looking for a compromise which will work in real world conditions using whatever techniques and detail changes will improve performance.

PS I know my TD is not a good example! It is a useful box on wheels but I would also like my next build to be more efficient.

[jstrubberg]

I would focus on building it as light as you can without compromising the look you want and the creature features you think you will need while camping.
We sometimes tend to over think things.....which usually ends up with nothing getting done!
The amount you will save on gas probably won't amount to an extra beer a day while you are camping?
Good Roads
Brian & Sandi
PS
Are you interested in becoming a member of the B.C. Chapter of the Tear Jerkers?
It is FREE!

It's surprising how many people will justify a $300 car payment by saving $30 a month in gas. Likewise, what's an extra $20 in gas on a vacation?

[rowerwet]

the real savings to a teardrop is the overall size. we don't need a big truck, don't see a huge drop in MPG towing, don't need a ton of space to store the tear. Unless you are living on the road in the tear, mileage isn't a big issue compared to a normal TT. I care more about comfort, space, and room to haul toys.
If you want the smallest loss of MPG take a tent.

[canned o minimum]

I am no engineer, but with a traditional teardrop ( 4 x 8 ) I would think that form AND function are about as good as it gits. We can tow em with small vehicles, and go darn near anywhere with em. The MPG and the wear and tear on the TV is pretty much minimal. When I first got into Teardroppin, sumbody said it all too well...KISS ! ( Keep it simple stupid ! ) Yes, there IS a certain amount of aerodynamics involved as well as light weight, but as previously stated... we do tend to over think these things .

[juanrc24]

Interesting idea with shortening the reach for highway travel. I like it.

[Roly Nelson]

I have designed my teardrop tongue lengths, to allow for a 90 degree back-up angle, before it crushes my rear fender. I really doubt that a few more inches between the hauler and the front of the TD, will be much of an advantage. I guess I don't even notice any additional drag behind my 4 banger Chevy Cruze, at the vehicle-in-tow, 55 MPH speed limit. I just like to keep it simple.
ff Roly, ~~

[cuyeda]

Roly... I was hoping you would post a photo of your stealth fighter teardrop as seen at Lake Perris! Surely that has to the best in aerodynamics!

[Roly Nelson]

Oh oh, I was hoping to keep it under my hat, until I take it to Shasta. There are many that will attend there, that didn't make it to Lake Perris. I had a great time there, but just couldn't find the landing strip anywhere in the campground. I actully met 2 guys that were involved in helping design parts of the fighter, how about that. No regrets, the 7 foot bed suits me and my 2 small dogs, the galley is just the right size, and is a surprise to most who see it.
Roly