So, got into serious thought about aero, the classic TD profiles are more eyeball aerodynamic than actually aerodynamic, oh they're better than a square box, but not really efficient. Like I said, sometime in the further future, like 5 years from now, I might want the compact hatchback towing this, and it needs all the help it can get.
This is very helpful... http://www.grandmarq.net/blaze/Blaze_Pi ... 0Autos.pdf
Now then what seems applicable in there is backlight angle at least to try and get rear profile right. Note also mention of boat tailing and radiused edges on the front for a bluff front. Seems somewhat unpossible to get front point of stagnation right, since most of the airflow is "delivered" off the roof and sides of the tow vehicle. I figure a good half of the front will be in the tow vehicle "dead water" so no need to go super pointy. Curved roof seems worth taking note of also.
So now I'm braining how to work such details into construction without costing myself too much time, effort, or money...
Think I could pinch the kitchen in 3" either side, pull the sides in a tad. Concern there is structural, do it building a plywood boat and you kinda don't mind the gunwhale splaying out a bit. So it seems to mean leaving the sides flopping at the back, until you've tied them at the top of main cabin with roof member structure. Then you can pull it in. Though, since there is not usually any structure across the middle of the tailgate opening, this leaves a concern about the sides splaying there, not remaining upright. Sure the countertop and cabinet framing provides some I guess. So maybe can do a slight boat tail.
"Backlight angle" seems like I could do a 1ft drop in 4ft for about 15 degrees or 1ft in 3ft for about 20 degrees. I think the 1ft in 3ft is going to win, keep more cabinet.
Front edge radiussing... I think I could rabbet the sides into a couple of light pine 4x4s, then radius those off... by the time it's all shaped, it's only like having 3ft of 2x4 there.... bonus is that it gains 2" in interior length over 8ft panel. The other bonus is you get a lot of knockproofing on those front corners. Difficulty is blending in the front roof curve, but I think I'll manage. Secondary worry about R value of wood vs the 1" insulation. Not sure if I'll use A/C in there but get weird temp inversions and humidity variations here, don't want to go creating wet spots. I am thinking there's not such a huge variance, plus if I'm worried about that, why amn't I worried about the walls where the sticks are between the styro? derp.
Roof curve.... well there's the front radius of about 2ft, but the roof roof was going to remain flattish.... however, the strongest structure is an arch, and flat roofs = standing water, so there's those other points for it. But cutting back my sides more and I may as well have built a 3 foot high, urgh. Solution? ... maybe use a 1 1/2 nominal plank, think that's 1.25 actual, again, rabbet the ply sides into it so it's flush and have x inches on top of the ply sides, may gain 3" headroom under the middle of the trailer, that sounds good, it's probably 2" more height in the interior cabs too, that would have been lost to the backlight cut. Not sure how high, is 4" enough? is 6" to much?... again, this sounds a bit weighty, half of it is gonna end up cut off, and 1x1 of it replaces the top side frame, so extra weight for both sides is of the order of an extra 2x4 in there somewhere.
I don't think I should worry about ply subskin to light pine transisition in "surface", since I am pretty much decided on some variety of PMF skin, and provided it's all level, should cover all the same and be protected.
Wheels???? They are buggers for drag, the well is an airscoop and the top of the tire is travelling 2x as fast as the rest of the surface making all sorts of vortices.... But, still lollygagging about my axle setup... on the popup frame the tiny wheels are inset a good 6" and I am not sure if they actually need wheel wells there, can't recall at the moment from last time I looked, and it might be just perched on top.... however, anything taller than a popup and those wheels look very silly... plus they need new tires all round. I have larger rims that should fit those hubs that I will probably want to use. I have to figure out whether the wheels will end up tucked in, tucked under or hanging out. Ultimately they will either get spats or arch covers or something, to expose only the bottom half of the wheel. This isn't as bad as you think for tire changing. If it sits at half the wheel when loaded, with a hub circle relief for bolt access, then by the time you jack it up, the axle drops such that the coverage is only to the edge of the rim, some tire still hidden, then when you loosen and pull the bottom of the tire out, you should have enough clearance to pull the wheel out, provided there's about 4" running clearance, or depth in well behind. Might have to design that in if you're doing it yourself... most cars though you could blank off most of the rear well and still change tire. However, mudguards that are spats could be a lot of fiddle, and it may get "rat rod" fenders initially... in the original definition of rat-rod, where you grab anything you can find and make it work, not the current poser definition, of spend weeks looking on ebay for some vintage thing to destroy by using as a car part just because it looks cooler than what's actually lying around in your garage. Then maybe later it will get "properly" formed fenders. I am pondering something like shaped out of hardware cloth on temporary wooden frame and covered with PMF on top, then take support out when dry and do inside too.
Oh btw, this fancy talk of rabetting etc, can do, have router, but these probably simple enough to do with a table saw... and I got one of those too.
Jack of all trades, Doctor of rocket surgery and fellow of the noble college of shadetree meddlers. "in argentum tenax vinculum speramus"