Aerodynamics and a Vardo

[Deryk the Pirate]

Ok I dont hide that I really would like the idea of a standie lol. Now I know traditional vardo's were hauled by horses and moved slow so drag coeficients and all that didn't apply so much. I have seen the bowtop style that on the tongue side it looked like an airstream trailer, but that skill in folding and shapeing metal is definatly out of my skill range.

I came across this pic yesterday and thought well its a sideways vardo. Seems in England there was a bunch of caravans built shaped like this. Well I came across this on etrailer not too long agohttp://www.etrailer.com/Trailer-Suspension/Timbren/A20RS545.html Timbren Axle-Less Trailer Suspension System with Hubs - 5 on 4-1/2 - Regular Tires - 2,000 lbs which if I installed it in my present vardo I could drop it about 6 inches lower then it is right now.

So I started thinking that if I built a trailer with the Timbren system and was able to get the sidewalls to 54" high (currently thats the inside height of my lil vardo and it is a little taller then the roof of my rav4, but if I were to reduce it 6" it would be shorter then my rav4) and had the roof curve up to say 76" center height would that give me less drag then I have now with the overhung roof that grabs the air as Im driving? Trying for some improved fuel efficiency or at least staying the same with a taller trailer.

thanks

deryk

[Shadow Catcher]

Aerodynamics of a Vardo are well, less good than a brick! Anything that rounds corners will be an improvement but unless you come up with something in the way of a truly aerodynamic shape it will be a matter of degree. Google Aerodynamic shapes and look at the images.
I have been thinking of ways to improve the aerodynamics of Compass Rose and the use of temporary shapes is wandering around in the back of my mind. Seeing what is being done in the trucking industry is an inspiration.

[Deryk the Pirate]

I have seen a few of the products they sell like those tabs you can add to the back of a trailer to hopefully improve fuel efficiency...and I agree the traditional shape of a vardo is so un aerodynamic its a joke lol but they didnt worry about it because it wasn't a problem, today we want to be hauling it at 65mph on the highway and fuel prices keep going up and up lol So its why I keep looking at shapes...sigh lol

[angib]

Consider the old clerestory roof idea with a centre strip that's higher than the rest - I think it was Doug H that said you call them trolley roofs. This can give you the same standing headroom without increasing the height of the trailer over its full width and so not increasing its frontal area and drag as much.

Combined with plenty of front-to-back curvature like in the old Brit 'caravan' below and you can have a trailer that's 4ft high at the ends but 6ft high in the middle. And do you really need the full headroom anywhere except in one spot?

[S. Heisley]

Now, that one is cool, Andrew!

[Greg M]

Hey Deryk, did you notice that Timbrem also makes a drop axle?

-Greg

[Deryk the Pirate]

So Greg, do you think the drop axle will lower the trailer about the same amount? It is a decent amount less then the other style lol.

thanks

deryk

[angib]

Will the Timbrens really help that much? You still need a cross-member to tie the two sides together and that needs to be fairly close to the suspension (ie, at the front and back ends isn't enough).

So you still need something like a 2" square tube to pass under the drop floor, even if it can then kick up either side to get to the main frame. That same 2" tube could be the axle tube of a torsion axle with an 'up' start angle to give a low ride height.

I think the description "Timbren Axle-Less" should really be changed to "Timbren - You Supply The Axle".

[droid_ca]

Hey Deryk here is some food for thought what about a poptop troll top so just the center of the trailer rises up instead of the whole roof I am just making coffee now hahahaha I am in the same situation with my cabin but I figure its the center area that I'll be standing and put my pants on ect ect ... so my side walls are only going to be 5 feet and I'm 5foot9 3/4s so there should be plenty of head space when I'm facing the wall. To make the most out of a dropped floor you could always raise the trailer somewhat so that you make he most out of your dropped floor......Sorry about the ramblings my coffee is ready now

[Deryk the Pirate]

Well Im trying to drop the trailer for sidewall height, so dropped floor is probably out lol. I was playing around with some sketches of the back wall tongue side at 5', and have it rise to the door side at 6.5' and put a wind deflector on my rav 4 roof. With a dropped axle I might be able to get away with that height, making it much more aerodynamic only an overhang on the roof on the door side, sort of like this http://paleotool.com/the-vardo/...if anyone ask why is the backside is shorter I can draw them to the door and say its a keystone effect lol


I have thought about a poptop but not sure with a curved roof...I could make the mollycroft permanent....so many ideas...I need to hit the lottery, get a woodshop and make a dozen different trailers to figure it out lol


deryk

[droid_ca]

What if you cut your door way into the arch you might have to thicken the arch up some but then you would have lower walls and head height in the center.... Or you could ask a gypsy???

[Deryk the Pirate]

well like i said I want to make it to look like george's vardo from paleotool's...Door on the back side the wall height will be lower, taller in the center at the top of the arch, but the tongue side arch will only be about 5' tall, door side a little over 6' tall... there will be purlens running front to back probably 1 3/4x 1 3/4". I want to do a metal roof this time so the roofing can screw down into the purlens, then cut foam to slide up between the purlens (probably about 12" on center) then either a 1/8th luan put up over the foam and use trim to hold it up and varnish it....I like the look of varnished wood. Im actually debateing if I can get unprimed palonia this time I might use cetol on the whole outside of the vardo and just paint the trim....the palonia is a japanese cedar very light and moisture/rot resistant

deryk

[Greg M]

Sorry, I meant to say that they make those "axle-less" units with a drop spindle. Andrew's right though, why not just use a torsion axle with the trailing arms set positive?