Go Back   EcoModder Forum > EcoModding > Aerodynamics
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 10-01-2018, 01:40 PM   #11 (permalink)
Somewhat crazed
 
Piotrsko's Avatar
 
Join Date: Sep 2013
Location: 1826 miles WSW of Normal
Posts: 2,248
Thanks: 216
Thanked 620 Times in 533 Posts
The popup tent camper people have a 4 post lid lift system that operates off a single crank which so could be electric. We were going to make hard folding sides for bear country and cold weather camping before we bought the casita. I don't do stairs or ladders at 2 am potty runs anymore, falling down with full bladder is highly annoying.

__________________
casual notes from the underground:There are some "experts" out there that in reality don't have a clue as to what they are doing.
  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 10-01-2018, 06:55 PM   #12 (permalink)
Master EcoModder
 
freebeard's Avatar
 
Join Date: Aug 2012
Location: northwest of normal
Posts: 20,209
Thanks: 5,670
Thanked 6,609 Times in 5,328 Posts
This will have to do:*



Differing curves in the forward and aft sections might need to be reconciled. No headroom problems if you don't want them.
_______

Quote:
Part of that dream as I understand it is retiring and traveling the country (USA only) in an RV.


I bought into the dream but I couldn't afford to even take it on the road.

*Back to doing graphics by hanging a transparency over the monitor, just like the 19080s, before I got a Thunderscanner.
__________________

."Once men turned their thinking over to machines thinking this would set them free. This only allowed other men with machines to enslave them." Frank Herbert
____________________

Sadhguru: Yesterday isn't good or bad, it's gone.
____________________

Last edited by freebeard; 10-01-2018 at 07:01 PM..
  Reply With Quote
The Following User Says Thank You to freebeard For This Useful Post:
oldtamiyaphile (10-02-2018)
Old 10-01-2018, 08:23 PM   #13 (permalink)
Master EcoModder
 
kach22i's Avatar
 
Join Date: Jul 2011
Location: Ann Arbor, Michigan
Posts: 3,878
Thanks: 52
Thanked 2,589 Times in 1,814 Posts
Quote:
Originally Posted by freebeard View Post
Differing curves in the forward and aft sections might need to be reconciled. No headroom problems if you don't want them....
One could just start with a taller front cabin and then taper down, but the end result would still be a larger hole in the air compared to a collapsible version.

I did not see any tall caps on just the front end cabs, but one could always create their own. I mean if you have the skill to make a huge top, why not a mini top for the cab?

Perhaps they could be one in the same.

EDIT:
Scheme-3
Added a non-moving shell, simple as can be. Bed at short tail end, forces the toilet/shower location to middle or front for headroom. No back door on this one.

Quote:
Originally Posted by freebeard View Post
I bought into the dream but I couldn't afford to even take it on the road.
I like it, what is it?

Corvair based?
Attached Thumbnails
Click image for larger version

Name:	Tall-Caps.jpg
Views:	16
Size:	64.5 KB
ID:	24970   Click image for larger version

Name:	RAM3-composite-sheet-kach22i.jpg
Views:	27
Size:	73.6 KB
ID:	24971  
__________________
George
Architect, Artist and Designer of Objects

1977 Porsche 911s Targa
1998 Chevy S-10 Pick-Up truck
1989 Scat II HP Hovercraft

Chin Spoiler:
http://forums.pelicanparts.com/off-t...effective.html

Rear Spoiler Pick Up Truck
http://forums.pelicanparts.com/off-t...xperiment.html

Roof Wing
http://ecomodder.com/forum/showthrea...1-a-19525.html

Last edited by kach22i; 10-01-2018 at 09:04 PM..
  Reply With Quote
Old 10-01-2018, 09:28 PM   #14 (permalink)
Master EcoModder
 
freebeard's Avatar
 
Join Date: Aug 2012
Location: northwest of normal
Posts: 20,209
Thanks: 5,670
Thanked 6,609 Times in 5,328 Posts
All that work and no Thanks?

Why not start with a top chop?

It was a 1964 Clark Cortez. I held it 10 years and never got ahead of the maintenance.
__________________

."Once men turned their thinking over to machines thinking this would set them free. This only allowed other men with machines to enslave them." Frank Herbert
____________________

Sadhguru: Yesterday isn't good or bad, it's gone.
____________________
  Reply With Quote
Old 10-02-2018, 12:23 AM   #15 (permalink)
Master EcoModder
 
Join Date: Nov 2013
Location: Texas
Posts: 676
Thanks: 20
Thanked 145 Times in 129 Posts
Quote:
Originally Posted by freebeard View Post
Why not start with a top chop?
Start with the extended van, and build a profile cap to mount on the chopped cargo box. Hinge it so you can flip the cap up. You already have 76 inches of height at the hinge.
Attached Thumbnails
Click image for larger version

Name:	long ram.jpg
Views:	47
Size:	46.2 KB
ID:	24972  
  Reply With Quote
Old 10-02-2018, 03:06 AM   #16 (permalink)
EcoModding Lurker
 
Join Date: Dec 2011
Location: Poland
Posts: 56

Renault - '06 Renault Megane II
90 day: 38.41 mpg (US)
Thanks: 0
Thanked 8 Times in 7 Posts
Hello, in Europe there are several models Fiat ducato camping, max cemping, 4x4 etc. eg:
Fiat Ducato 4x4: https://www.carscoops.com/2015/08/fi...n-looks-ready/
Fiat ducato camping: Reprogrammation moteur Camping car Fiat Ducato 2,3l jtdm 130 | Digiservices Troyes
Fiat ducato camping max: https://www.kampery-pruszcz.pl/katal...cato-baron-26g

And burning fuel burns almost as much as a small truck.
  Reply With Quote
Old 10-02-2018, 10:22 AM   #17 (permalink)
Master EcoModder
 
kach22i's Avatar
 
Join Date: Jul 2011
Location: Ann Arbor, Michigan
Posts: 3,878
Thanks: 52
Thanked 2,589 Times in 1,814 Posts
Quote:
Originally Posted by freebeard View Post
All that work and no Thanks?
Delayed thank you, your comments led to the creation of Scheme-3 FYI.

To clarify, the roof on your overlay scheme is intended to be a two-piece clam-shell that gets lifted up, right?

Quote:
Originally Posted by Angel And The Wolf View Post
Start with the extended van, and build a profile cap to mount on the chopped cargo box. Hinge it so you can flip the cap up. You already have 76 inches of height at the hinge.
That works for me as I'm short and my wife is even shorter, we may not need to raise the roof cap mechanically at all with those dimensions. Again this is a "just a for fun" study, a musing of daydreams. Nice work, thank you for putting that together for us all.


Quote:
Originally Posted by airbiteses View Post
Hello, in Europe there are several models Fiat ducato camping, max cemping, 4x4 etc. eg:
Fiat Ducato 4x4:
Nice links, thanks.

It's like designs that initially appear to address aerodynamic concerns end up failing or surrendering to some mundane practicality of function.

What this tells me is that aerodynamic design is still a fashion statement hired out to some stylist for marketing concerns and fails to get faithfully executed due to poor hand offs and delegation to others that do not embrace the concept and just want to retire early themselves.
__________________
George
Architect, Artist and Designer of Objects

1977 Porsche 911s Targa
1998 Chevy S-10 Pick-Up truck
1989 Scat II HP Hovercraft

Chin Spoiler:
http://forums.pelicanparts.com/off-t...effective.html

Rear Spoiler Pick Up Truck
http://forums.pelicanparts.com/off-t...xperiment.html

Roof Wing
http://ecomodder.com/forum/showthrea...1-a-19525.html

Last edited by kach22i; 10-02-2018 at 10:35 AM..
  Reply With Quote
Old 10-02-2018, 11:47 AM   #18 (permalink)
Master EcoModder
 
Join Date: Sep 2012
Location: Motor City
Posts: 261
Thanks: 0
Thanked 192 Times in 123 Posts
Quote:
Originally Posted by kach22i View Post
What this tells me is that aerodynamic design is still a fashion statement hired out to some stylist for marketing concerns and fails to get faithfully executed due to poor hand offs and delegation to others that do not embrace the concept and just want to retire early themselves.
While I agree with your statement, also remember it doesn't have to sacrifice much to be quite aerodynamic, nor does it have to "look" aerodynamic.

Best example of this is the Vixen motorhome. It had an actual Cd around .30. But, to most folks, it is still a box.

And boy do I wish Navistar published a Cd for the Monaco Vesta / Holiday Rambler Trip. I bet it was similar. And again, very few folks would ever really think it's much more than a big box.

Both these examples follow the simple method of rounding the front corners until the aero doesn't get any better, than taper the rear as much as you can. Didn't take much taper (which is loss of interior space) to get pretty good.

That said, if you don't consider low .30 as good (you didn't really say), getting it lower would indeed require more sacrifice. Being that my own motorhome is probably over .5 (data suggests it's almost .6), I'd take .3 any day.

(Images attached to save anyone who isn't familiar with these the search time.)
Attached Thumbnails
Click image for larger version

Name:	meet-the-vixen-rv-bmw-2-series-active-tourers-american-ancestor-86050-7[1].jpg
Views:	47
Size:	69.9 KB
ID:	24973   Click image for larger version

Name:	2011_Monaco_Vesta.jpg
Views:	38
Size:	11.3 KB
ID:	24974  

Last edited by ennored; 10-02-2018 at 11:56 AM..
  Reply With Quote
Old 10-02-2018, 12:31 PM   #19 (permalink)
Master EcoModder
 
kach22i's Avatar
 
Join Date: Jul 2011
Location: Ann Arbor, Michigan
Posts: 3,878
Thanks: 52
Thanked 2,589 Times in 1,814 Posts
Quote:
Originally Posted by ennored View Post
While I agree with your statement, also remember it doesn't have to sacrifice much to be quite aerodynamic, nor does it have to "look" aerodynamic.

Best example of this is the Vixen motorhome. It had an actual Cd around .30. But, to most folks, it is still a box. ..............
Thanks for posting the Cd, did you reference a source or just go off memory?

The roof taper is appearing on many vehicles today without much fanfare or acknowledgement to aerodynamics, this somewhat stealth introductory of aerodynamic design will eventually mark flat roofs as antiquated I suspect.

We are not seeing a lot of tapering in plan outside of hatchback and crossover greenhouses, and you really have to look for it. The smaller Volvo's and the Juke come to mind.

The Vixen and other larger RV's benefit from a longer length ratio to lower their Cd as much as anything else going on.

However, what we are studying here and I suspect will be seeing more of in the future is taller height to length ratios that will have to resort to tapered roof profiles to maintain any kind of fuel efficiency.

The hinged and telescoping roof schemes are an attempt to skirt around the height issue and get a more friendly length ratio.
__________________
George
Architect, Artist and Designer of Objects

1977 Porsche 911s Targa
1998 Chevy S-10 Pick-Up truck
1989 Scat II HP Hovercraft

Chin Spoiler:
http://forums.pelicanparts.com/off-t...effective.html

Rear Spoiler Pick Up Truck
http://forums.pelicanparts.com/off-t...xperiment.html

Roof Wing
http://ecomodder.com/forum/showthrea...1-a-19525.html
  Reply With Quote
Old 10-02-2018, 02:47 PM   #20 (permalink)
Master EcoModder
 
Join Date: Sep 2012
Location: Motor City
Posts: 261
Thanks: 0
Thanked 192 Times in 123 Posts
Quote:
Originally Posted by kach22i View Post
Thanks for posting the Cd, did you reference a source or just go off memory?
There's sources quoting "<.30". But as I recall, Bill Collins did extensive testing in a wind tunnel (U of M in Ann Arbor?) and later sent a full size vehicle for testing (at the Bendix Proving Grounds) which came in a bit higher than the model (as happens). Somewhere online is a complete history written by Bob, which he presented at an owners convention or something like that. I'll google that a bit more...

Also recall that the Vixen had a pop up roof, later replaced with a fixed, higher, roof, but that version wasn't aero tested.

So long as the front contours result in laminar flow along the top and sides, the length isn't as important. I bet a Vixen could be shortened quite a bit before the aero got worse. I think long bodies benefit from the air getting reattached along the length of the body. If it never detaches, it could be shorter.

  Reply With Quote
Reply  Post New Thread


Thread Tools




Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com