I started in this direction of thought in another thread then realized it probably needs it's own discussion...
In a situation of say an aeromodded front with a pickup... and an aeromodded trailer with a boat tail... how important is the in-between area? I know people talk about trying to blend/connect the tow vehicle to the trailer, but I was also wondering how the aero of the open pickup bed and such affects it. Some tests have shown that under some conditions having the pickup tailgate up instead of down is better aero.
Driving With Tailgate Up Is Fuel Efficient : Discovery Channel I am curious whether the "separated bubble" is the same FE as say, a topper connected to a trailer of similar profile.. whether it's only the laminar flow that matters, or whether the 'bubble' still causes some drag even if less drag than you think because of smooth flow.
What i'm wondering is whether you might be able to use some kind of similar 'trick' on say the front edge of one body like a bit of a lip to kick the airflow out slightly, to get the airflow to go right to the trailer, without actually being physically connected and without any real increase in drag...