Aerodynamic trailer plans

[jimbo69ny]

Anytime you put anything on the roof you take a 10-20% aero hit. If it was a tent then I would still have all of that set up to deal with, just like a tent, which I am trying to avoid by having a teardrop.

I havent mentioned this in this post but many others, part of my build is a range extending trailer. I built the first one in the world Feb - March of this year. Now I am building a second one. This time I am using a Tesla 85kwh battery pack (pictured in first post). I should come close to tripling my range. Check out my channel for more info if you are curious.

Setting up a tent does certainly take more time. But just curious: Do you think you'll do markedly better with a teardrop trailer compared to the 10-20% aerodynamic efficiency reduction of a roof-mounted tent?

Hmm: Is this you? https://insideevs.com/range-extender-te ... ler-video/
Apparently the big shots are interested in a similar concept: https://evobsession.com/electric-car-ba ... dic-power/

As I said: You're certainly in the "for the sake of science" category I'll be curious to see what you come up with.

Yup thats me.

A teardrop will be almost no deduction on the highway. Once you get all that weight moving for a 3 hour drive the car doesnt even know its there. Its in the slipstream of my car.

The battery is too heavy to put on top of the car.

Yeah I heard about that company. I bet they are years away. I could sell these now if I wanted to.

 

[timm-TNT]

For instance, with all respect to Timm's CAD mockup - which looks amazing! - I wouldn't want to spend a rainy afternoon in that thing.

Thank you, although it isn't as small as it appears. The top lifts up 18" with 4 pneumatic cylinders. This is a comparison between my current design and the Generic Benroy design you can find under "Design Resources".

The blue lines are the inside of my trailer and the black outline is the Benroy.

My door is slightly larger and my ceiling is a foot higher (50" vs. 38"). There's also a lot more room for storage inside the cabin.

 

[Andrew Herrick]

For instance, with all respect to Timm's CAD mockup - which looks amazing! - I wouldn't want to spend a rainy afternoon in that thing.

Thank you, although it isn't as small as it appears. The top lifts up 18" with 4 pneumatic cylinders. This is a comparison between my current design and the Generic Benroy design you can find under "Design Resources".

The blue lines are the inside of my trailer and the black outline is the Benroy.

My door is slightly larger and my ceiling is a foot higher (50" vs. 38"). There's also a lot more room for storage inside the cabin.

Timm ... I must have been looking at the wrong thing. I was referencing a different 3D solid mockup, an uber-aerodynamic mockup towed by the Honda Civic. Your camper looks substantially larger! So basically ignore what I said

 

[timm-TNT]

Nope, they are one and the same! The ultra-aerodynamic 3D model is the blue lines in that comparison.

Here's an animation of the top lifting up.
[youtube]sRWdZ4DMGN4[/youtube]

 

[Tomterrific-TNT]

I am convinced a pop-up roof is more aero than any full size tear. My trailer with only a plywood floor would pull effortlessly with two motorcycles or a tractor on it. Built the approximately 4 foot high camper and the extra wind resistance is quite noticable. Starting with a low raising roof design and then streamlining, that is the key.
So here is my plan for easy towing.
1. Design lifting roof.
2. Keep the trailer low. Like a Dexter axle rather than leaf springs. Small wheels.
3. Light weight. A underpowered vehicle will suffer as soon as the road goes from flat to up hill.

Tt

 

[Andrew Herrick]

Nope, they are one and the same! The ultra-aerodynamic 3D model is the blue lines in that comparison.

Here's an animation of the top lifting up.
[youtube]sRWdZ4DMGN4[/youtube]

 

[jimbo69ny]

My head is spinning after spending all day trying to use Sketchup. UGH! It drove me crazy.

After many hours this is the best I can show you.

I have tweaked my measurements a bit but this were my original sketches.

If anyone is fluent in Sketch up and wants to fix my mess let me know and I will send you the file.

 

[Xanthoman]

I also struggle with SketchUp as I learned parametric CAD (Solidworks) as my first CAD system. I really enjoy OnShape. It’s free and it’s nice that it’s all cloud based so you can work from anywhere with internet. And it functions like other parametric systems which is nice for me. I could build that design in about fifteen minutes in OnShape if you wanted.

 

[comp]

The tail design looks good, I like this idea a lot. The change I would do for a rear door is pivot the top/sides of the boat tail section up and maybe have the bottom section fold down as a ramp below the "umbrella shade" the upper 3/4 would provide. But I could see the side pivot being better for a rear galley design. Also I would look at some aero links before finalizing those angles for the tail, a few degrees can make a big difference to the air.

 

[comp]

Is this thread related to the t-rex on youtube!? Man that thing is so good. Sorry about bumping the old thread, I am newbs here, its like a maze of sub categories here.

I have always heard quoted 9-12 degrees was the ideal for a boat tail angle. To try to prevent flow separation.