air flow

[Greg Barrick]

Ok, I have a fairly quick question for anyone.
I am planning on building a standee. I would love to have a rear door and deck if possible. But that kinda throws me into a Vardo, which I love, but kill gas mileage. I realize a "rounded" front will help with mileage, but what about the rear? Will a vertical rear act like a parachute? Would a slopped rear, like a rear door scotty be beneficial for mileage? Must I angle my roof down toward the rear wall?
Just how much will these items affect towability?
Thanks for any input. I'm older (retired) and don't travel so far any more, but may still take a couple longer trips as kids are in Montana, I havn"t taken the wife to the "big Texan" yet. And neither of us have been to the Grand Canyon, yet.

[bobhenry]

My barn is about as aerodynamic as a ah ah BARN !

I have no problem towing even with a 1200 cc Suzuki Esteem at state highway speeds. My answer is build what you want and take the scenic roads less traveled at a more enjoyable speed.

[rowerwet]

At highway speed the airflow tends to detatch from the skin just after the widest/tallest point, a flat back end will not create a huge drag like you imagine, though you could experiment with vortex generators around the aft perimeter, there is plenty of talk and advertising hype, but as far as I know, the best research on this was done by NASA.
For a trailer like you are talking about look for the foamstream built by GPW, he recently had it on the highway and said it felt like it wasn't there.

[BrwBier]

As far as I know a flat back does cause drag and the best research on this was done by nascar.

[48Rob]

Greg,

No doubt you could make it "better" but for the amount of camping you'll do, it probably isn't a big deal.

As a motorcycle rider who, on a big bike with a big shield and fairing has experienced the worst of turbulence behind semi trucks, I can tell you that the new improvements/equipment some of the trucks have installed; namely the skirts and rear deflectors, have calmed the air to the point you can hardly tell you are passing anyone.
This from the previous experience of having to hold on tight and be buffeted back and forth in a dangerous turbulence that could easily cause a crash in bad weather.

Rob