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Old 11-02-2010, 04:03 PM   #5 (permalink)
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I've not yet seen any streamlined motorhomes except for earlier efforts by GMC and Airstream,plus one-off units built from aircraft fuselage.
The motorhome would benefit from anything which improves a typical van.Hucho's thing is to add length while carefully reducing the cross-section to maintain attached flow,which is the "boat tail."
If I had a motorhome,I'd construct a trailer which forms the boat tail,with complete gap-fillers.( the accordian-bellows material used with articulated buses would be a great way to go ).
I've had good success with a van,coupe,and pickup truck,using boat-tails.NASA has some images of their boat-tailed van research at Edward's Air Force Base.This is one of the 'bird-in-hand' low-drag technologies.
Last December I attempted a road test of a boat-tail trailer without the gap-fillers.I lost a wheel early on and had to abort the trip and limp home with my tail between my legs.
Considering that the trailer shouldn't work without the gap closed off,I was relatively pleased with the 30-mpg under the winter driving conditions and undercarriage damage.Until I can repair and re-test,she remains an unknown quantity,so I can't give you any 'real' numbers until then.On paper,the trailer will increase mpg.
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