There will also be a difference based on the load and type of trailer. Am I
hauling round bales of hay, square bales of hay or a tractor? Am I pulling a
flatbed, enclosed, are the wheels under the trailer or exposed? Not all
trailers and loads are equal, so for a manufacturer to rate their vehicle, I
would suspect they would need a considerable number of different trailers and
loads to test. Once this was calculated, they would have to choose the number
to use; the worse, the average, the mean or some other number.
Or maybe they could test their vehicle with a trailer and load at a specific
weight that would cause the greatest drag. They could then rate the vehicle for
a specific weight with the disclaimer that range could be affected as much as
... let's say 50%. This would give the customer an idea of what they can expect
from the vehicle. EPA estimates of mileage for ICE vehicles are no different.
George Mullineaux
3rd Shift Wrench Monkey
Pinnacle Corrugated, Landis, N.C.
-----Original Message-----
From: EV <ev-boun...@lists.evdl.org> On Behalf Of Lee Hart via EV
Sent: Tuesday, August 18, 2020 14:44
To: Peri Hartman <pe...@kotatko.com>; Electric Vehicle Discussion List
<ev@lists.evdl.org>
Cc: Lee Hart <leeah...@earthlink.net>
Subject: [External] Re: [EVDL] [External] EVLN: Tesla-Y feels like it's not
towing anything
Peri Hartman via EV wrote:
> Won't it also make a large difference overall, depending on the tow
> vehicle? If the trailer fits in the trailing vacuum, I would think
> there would be less resistance than if it were punching a new hole. I
> suspect this could have a larger difference than the frontal area and Cd.
But of course! To find the difference, you would do the roll-down test with
just the tow vehicle, and then with the tow vehicle + trailer. Then you could
calculate the difference in drag coefficients.
Aerodynamics is complicated, and does not lend itself to intuitive guesses
(unless you are an aerodynamics expert). In special cases, a trailer can even
*reduce* the aerodynamic drag of a vehicle! For example, a teardrop trailer can
"fill in" the hole behind a truck or van with a squared-off back. But you still
consume more energy due to the trailer's weight and rolling resistance.
Lee Hart
--
A designer knows he has achieved perfection not when there is nothing left to
add, but when there is nothing left to take away.
-- Antoine de Saint Exupery
--
Lee Hart, 814 8th Ave N, Sartell MN 56377,
https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Furldefense.com%2Fv3%2F__http%3A%2F%2Fwww.sunrise-ev.com__%3B!!CvttNVKvMsQ7MGjF!vYdoHnuhKvfdDFTfTbzkiK_0l7DflMR82Ur0pptso69YawFxaKZoW8LWkpz2hHvEIHaiCEY7jtxVYo0%24&data=02%7C01%7Cgeorgemullineaux%40pinnaclecorrugated.com%7Caf99a3e947c54a4935f808d843a6458c%7C976178cc71b24588b870337d092cdfe3%7C0%7C0%7C637333728695511029&sdata=YrG38hP%2BsnJD8aNb2%2FfeMa0OA6eHCel9wUrS4KiPeww%3D&reserved=0
_______________________________________________
UNSUBSCRIBE:
https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Furldefense.com%2Fv3%2F__http%3A%2F%2Fwww.evdl.org%2Fhelp%2Findex.html*usub__%3BIw!!CvttNVKvMsQ7MGjF!vYdoHnuhKvfdDFTfTbzkiK_0l7DflMR82Ur0pptso69YawFxaKZoW8LWkpz2hHvEIHaiCEY7MtfjNuY%24&data=02%7C01%7Cgeorgemullineaux%40pinnaclecorrugated.com%7Caf99a3e947c54a4935f808d843a6458c%7C976178cc71b24588b870337d092cdfe3%7C0%7C0%7C637333728695511029&sdata=JpHDyWkdD%2F61wvYL%2FqpetPG3XmvHliM5Tiio59YJnaA%3D&reserved=0
ARCHIVE:
https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Furldefense.com%2Fv3%2F__http%3A%2F%2Fwww.evdl.org%2Farchive%2Findex.html__%3B!!CvttNVKvMsQ7MGjF!vYdoHnuhKvfdDFTfTbzkiK_0l7DflMR82Ur0pptso69YawFxaKZoW8LWkpz2hHvEIHaiCEY7SMKiMAE%24&data=02%7C01%7Cgeorgemullineaux%40pinnaclecorrugated.com%7Caf99a3e947c54a4935f808d843a6458c%7C976178cc71b24588b870337d092cdfe3%7C0%7C0%7C637333728695511029&sdata=1lMpheTVBhK7XyfkgpkzDLJtsdC0OOLfcb4oH3OHH34%3D&reserved=0
INFO:
https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Furldefense.com%2Fv3%2F__http%3A%2F%2Flists.evdl.org%2Flistinfo.cgi%2Fev-evdl.org__%3B!!CvttNVKvMsQ7MGjF!vYdoHnuhKvfdDFTfTbzkiK_0l7DflMR82Ur0pptso69YawFxaKZoW8LWkpz2hHvEIHaiCEY7m6r2D68%24&data=02%7C01%7Cgeorgemullineaux%40pinnaclecorrugated.com%7Caf99a3e947c54a4935f808d843a6458c%7C976178cc71b24588b870337d092cdfe3%7C0%7C0%7C637333728695511029&sdata=2W8SWijExERgOBMLsQg2yGAsGBicdEZEmWqERyMyK1U%3D&reserved=0
Please discuss EV drag racing at NEDRA
(https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Furldefense.com%2Fv3%2F__http%3A%2F%2Fgroups.yahoo.com%2Fgroup%2FNEDRA__%3B!!CvttNVKvMsQ7MGjF!vYdoHnuhKvfdDFTfTbzkiK_0l7DflMR82Ur0pptso69YawFxaKZoW8LWkpz2hHvEIHaiCEY7NC2eCTY%24&data=02%7C01%7Cgeorgemullineaux%40pinnaclecorrugated.com%7Caf99a3e947c54a4935f808d843a6458c%7C976178cc71b24588b870337d092cdfe3%7C0%7C0%7C637333728695516009&sdata=s1lwSCVtq3OO2AQUMFobZImY4v1AV420bp2vo3HvRbc%3D&reserved=0
)
_______________________________________________
UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
ARCHIVE: http://www.evdl.org/archive/index.html
INFO: http://lists.evdl.org/listinfo.cgi/ev-evdl.org
Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
