Class a motorhomes aerodynamics

[sregord]

I made it to 15...
https://www.mk1autohaus.com/assets/images/251819015.png

[aerohead]

Looks good! The unit has a double squirrel-gage. ( twice the fun! )
What I experienced on the BOSCH, was that, as the envelope filled, and the fan was just dead-headed, no longer actually moving a volume of air, and just providing static pressure, the fan power draw fell off, kinda just 'cruising.'
And regardless of the constant electric load on the alternator, the T-100 went over 30-mpg for the 1st time.
Whatever you do, DO NOT use expandable Naugahyde automotive upholstery fabric. The envelope will not maintain its dimensions, wrecking the aerodynamics.
The advertising folks use a Hypalon-impregnated aerospace fabric. Rip-stop Nylon will work, but it needs UV protection. ( it can kill a perfectly good parachute ).

[sregord]

Originally Posted by aerohead

The advertising folks use a Hypalon-impregnated aerospace fabric.

Billboard covers?
I have alot of that.

[aerohead]

Originally Posted by sregord

Billboard covers?
I have alot of that.

Nice! You'd think it's engineered for exposure to the elements.
Marine-grade thread is also designed for the outdoors. You sure don't need seams ripping out on you.

[sregord]

Maybe I should start with a belly pan?
I have this ...tickle in the back of my neck about the future of this MH(Moby)... and its sell ability.
An improvement that doesn't effect the look.

Curious: I see many using coroplastic to smooth the underside... good because of weight, 9#s- 5/32"-4x8 sheet, but needs a fair bit of "structure" to rivet or screw to.
Has anyone used 21#s- .181" -4x8 plywood, sealed/painted with epoxy (Patio/concrete paint). It has alot of shear, and "twist" resistance. Neither belong near hot exhaust obviously, but 3 sheets under a Honda would equal a 36# difference, but would require less brackets, & frames. Moby would need ~7 sheets

[aerohead]

Originally Posted by sregord

Maybe I should start with a belly pan?
I have this ...tickle in the back of my neck about the future of this MH(Moby)... and its sell ability.
An improvement that doesn't effect the look.

Curious: I see many using coroplastic to smooth the underside... good because of weight, 9#s- 5/32"-4x8 sheet, but needs a fair bit of "structure" to rivet or screw to.
Has anyone used 21#s- .181" -4x8 plywood, sealed/painted with epoxy (Patio/concrete paint). It has alot of shear, and "twist" resistance. Neither belong near hot exhaust obviously, but 3 sheets under a Honda would equal a 36# difference, but would require less brackets, & frames. Moby would need ~7 sheets

If you can locate orbywan's old RV posts, you might find time-saving tricks he used. He got his Ford MH up to 14.5-mpg.

[ennored]

If it's been mentioned in this thread, I missed it.

A good example of a boat tail on a motorhome was done by user Orbywan a few years back. Did you review his build and results?

https://ecomodder.com/forum/showthre...d-e-18151.html

Imagine that. Both posted about it at the same time.....

[aerohead]

See if this is enough to locate Orbywan's RV mods.

[aerohead]

Originally Posted by ennored

If it's been mentioned in this thread, I missed it.

A good example of a boat tail on a motorhome was done by user Orbywan a few years back. Did you review his build and results?

https://ecomodder.com/forum/showthre...d-e-18151.html

Imagine that. Both posted about it at the same time.....

Yeah, 14.5-mpg got everyone's attention!
The rooftop fairing for the Colemen AC units are now used by Boeing Aircraft Corp. on their 737 MAX 800.

[sregord]

Originally Posted by aerohead

If you can locate orbywan's old RV posts, you might find time-saving tricks he used. He got his Ford MH up to 14.5-mpg.

WOW... 14.5MPG?
I did find the older thread :
https://ecomodder.com/forum/showthre...n-s-18427.html

More research