Quote:
Originally Posted by seuadr
i completely missed this reply, i apologize. i think the rounding would happen with the front... fairing?
here is my running list of potential ideas:
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Basically, you want to imagine an aerodynamic singularity. Not a tow vehicle and a trailer, but a single 'system', without kinks and mutilations.
Your tow vehicle will do the penetration, as with Lanchester's ( Entry ) 'head' and 'shoulder', and the gap-filler and trailer play the role of ( Run ) 'buttock' and 'tail'. Gaps are your enemy.
The flow remains attached over the entire length of the TV, then seamlessly transitions onto the gap-filler, then the trailer.
Whatever rear modification exists, it is there to allow the displaced streamlines to gently re-converge, back where they were before you ever came along.
Allowing for ground clearance, the belly and side of the RV should pick up on what the rear of the TV has, and just project that rearwards.
All the belly area should be as smooth as possible.
Rear wheel skirts are an insurance policy for clean onset flow to the tail.
There should not be a forwards 'diffuser,' just make the nose of the gap-filler level with the tail of the TV.
A rear diffuser on the TV would be great, but it won't do a thing for you without a complete belly pan ahead of it ( this isn't a race car on track day )
The roof should be 'naked', not a cemetery full of 'headstones'.
Let the Bowlus line of trailers and the new 'naked' Airstream be your guide.
If you choose a box-cavity, imagine a proper boat-tail, then position the rear of each step where they would intersect a 4-foot chopped truncation of the tail. It's going to contain the vortices within a region of no greater adverse pressure gradient than a proper tail would generate ( if you've got $ Millions, then head for Palo Alto California and blow it all at NASA Ames ).