[stillsearching]

How do you make best aero possible for articulated vehicles? Connect them with an accordion? Some kind of sliding scales? Or is there some kind of aero trick, like a lip on one that lets the airflow readily go over gaps of considerable size without causing additional drag?

At some future point i'm wanting to combine a slicked out tow vehicle design with.. a slicked down trailer! Yet the biggest problem is the normal gap of multiple FEET between the two. My assumption is that making each slick by itself but still having that gap will cause turbulence (I note how every semi trailer is like a vaccum you can draft) and it's quite possible that gap will cost more in drag than many other aero treatments with much work and expense create.

I don't know whether some kind of soft sided tarp equivalent (thats flexible) between the two would help the air flow better, or whether because it's not a hard piece, and could be flapped around by vaccum and stuff whether it would actually cause more drag than nothing at all. :P