Difference in drag from flat front to curved top front?

[Strop]

Bogo,

This is my tow vehicle. You can see by the rear wheels that I am use to having to move the car to get to the tyre valves.

ImageUploadedByTapatalk1369565028.354029.jpg (16.24 KiB) Viewed 242 times

Laurie

[mezmo]

Hi Strop/Laurie,

OOh ! A Citroen CX ! One of my dream cars. Unfortunately they don't
sell them here in the US. Once a vehicle is 25yrs old then they can be imported
the w/o needing to comply to US Specs...as they say, one of these days...

Now to the thread topic: Why is, or does the front of the proposed build have
to be, 7ftx7ft ?

From the reading I've done on the subject, the main/best way for "aero" help/aid
is to match the trailer front to the tow vehicle's either max cross-section or it's
'exit' cross-section. Gentle curves for transitions and radiused edges are also important.
Here's one location where some of the "aero" info on here has been gathered into one place:
http://tnttt.com/viewtopic.php?f=55&t=49036

One design philosophy that some off-roading RV mfrs in Australia use, that we can utilize
in our own builds, is to have the trailer fit/match the tow vehicle's profile/cross-section and
track, the reasoning being, that if the tow vehicle can make it through, then the trailer
should be able to do so too. 'Sounds reasonable to me.
Here's a 'cost-be-damned' - or - 'built to the highest performance standard' approach
[choose your viewpoint] that is pretty much a state-of-the-art as far as commercially
offered RVs [in the broadest sense of the term] go:
http://www.kimberleykaravans.com/

And here is a self-build prototype, meant for a touring motorcycle, that has great ideas and
method and execution, that'd be equally at home behind any tow vehicle:
http://www.goldbrand.info/

Every build's a juggle of multiple considerations and constraints. Why not skew some of
them toward aero design features that can have continual benefits over the life of the TD/TTT.

Cheers,
Norm/mezmo

[Bogo]

It is real balancing act and point you keep going over and over during the planning stage. At least I am. Do you go an extra 6" high or 6" wider. I just looked at some of the boxes on the front of the teardrops and they could obviously add to the drag or lessen it depending on their shape and size.

Going longer is also an option...

The tongue box can also be designed into the front of the main body. It doesn't need to be full interior height or width. The access hatch also doesn't need to be full width, just large enough for proper access for the uses planned. With the inclusion of the tongue box into frontal streamlining it should be possible to add allot of streamlining without impacting the interior much.

I decided with my hard sided pop ups to make the tongue box area a storage area accessible from inside, and lift it with the top. I went through a couple thought designs where I lifted a cover over the tongue box and rejected them for reasons of snow and ice freezing things together in the winter. I need for my camper to be fully winterized because that is the season I can most easily go camping. Plus I'd like to go Aurora hunting after I retire, and that is best done in the winter.