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Sjoberg
02-10-2013, 07:45 PM
Hi there.

I have been searching on the internet a couple of times for an aerodynamic: picture/drawing/diagram for a T1N sprinter.
I dont know if i am chasing something that cant be found but maybe someone knows somewhere to look for it.

A picture like this is would be supergreat:http://www.google.se/imgres?start=546&hl=sv&tbo=d&biw=1366&bih=667&tbm=isch&tbnid=KBvZeYOtKhpZ1M:&imgrefurl=http://ecomodder.com/forum/showthread.php/up-down-aerodynamics-another-way-look-perhaps-18692.html&docid=l0YxbQKfkcQ0cM&imgurl=http://ww1.prweb.com/prfiles/2009/01/20/1126544/JaguarExahighres15cropped.png&w=4000&h=2880&ei=WAQYUeO9POTa4QTO1IDADA&zoom=1&ved=1t:3588,r:53,s:500,i:163&iact=rc&dur=649&sig=108725957064860934725&page=26&tbnh=185&tbnw=258&ndsp=21&tx=146&ty=93 but if there is one to find is the question for me.

I think it could be great to now where the positive and negative pressures are on the vans body so that i can plan where to put the airvents and sunroof (? like fantastic vent)

best regards Jocke

Amboman
02-10-2013, 10:14 PM
Well going by the previous "Predator Vision" drawing it would have to be down the back end.

Altered Sprinter
02-11-2013, 02:46 AM
Hi there.

I have been searching on the internet a couple of times for an aerodynamic: picture/drawing/diagram for a T1N sprinter.
I dont know if i am chasing something that cant be found but maybe someone knows somewhere to look for it.

A picture like this is would be supergreat:http://www.google.se/imgres?start=546&hl=sv&tbo=d&biw=1366&bih=667&tbm=isch&tbnid=KBvZeYOtKhpZ1M:&imgrefurl=http://ecomodder.com/forum/showthread.php/up-down-aerodynamics-another-way-look-perhaps-18692.html&docid=l0YxbQKfkcQ0cM&imgurl=http://ww1.prweb.com/prfiles/2009/01/20/1126544/JaguarExahighres15cropped.png&w=4000&h=2880&ei=WAQYUeO9POTa4QTO1IDADA&zoom=1&ved=1t:3588,r:53,s:500,i:163&iact=rc&dur=649&sig=108725957064860934725&page=26&tbnh=185&tbnw=258&ndsp=21&tx=146&ty=93 but if there is one to find is the question for me.

I think it could be great to now where the positive and negative pressures are on the vans body so that i can plan where to put the airvents and sunroof (? like fantastic vent)

best regards Jocke Jocke I have ran this up direct from MB Germany several times,plus,plus,and plus I have deleted it on my mainframe since as to being old hat. but it can found again if time permits.
Wind tunnel tests for aerodynamics are quite interesting.
50312
Cheers Richard

Old Crows
02-11-2013, 04:26 PM
Jocke, Welcome! My Fantastic vent is located about .5 m behind the line of the front edge of the sliding door opening. In the center of the vehicle.

I'm taking a guess that like most vehicles, the Sprinter (when moving) has a low pressure area starting just behind the windshield and extending back over the top several meters. This would be the same area where you would place a sun/moon roof in a car. This is confirmed by my leaving the Fantastic vent open (not a cool idea!! More later!) when underway. Air is sucked out of the van through the open vent.

These vents, with the light plastic covers, are really not intended to be open when underway. On my van, having accidentally left it open, it was buffeted and beat about by the windstream quite badly even at low speed. The same on my old travel trailer!!! The result is a damaged or destroyed 'lid'. To be open when traveling you need something like a Maxxair cover over it for protection. http://www.etrailer.com/Enclosed-Trailer-Parts/MaxxAir/67277.html?feed=npn&gclid=CKTboPTgrrUCFQKoPAodUBgAlA That way you can leave it open while traveling.... although you risk sucking dirt, dust, and water into every opening you can not yet imagine. And you can't believe how much dust will infiltrate into a vehicle if it's under negative pressure by leaving a top vent open.


On the other hand when used sitting still, they are very effective. I have crank out windows in rear sides. The Fantastic vent is located forward and it creates a nice circulation through the van even without the fan turned on. So, consider putting the Fantastic vent toward the opposite end of the vehicle from the windows.

Deacon
02-18-2013, 03:51 AM
Being new to the Forum I may be replying to a posting that refers to a Sprinter NOT like mine, so here goes; my sprinter is a 2004 144 tall 10 passenger window van. What is the correct nomenclature for that?
On the my comment on this aerodynamic vent situation. Since any opening to a low pressure area will create an interior that is also lo pressure bringing with it dust etc into the cabin. What about installing a vent that opens into a higher pressure location then installing another vent as an outlet into a neutral pressure area, the latter being the flow controlling vent (actually either could be and no matter what was the decision the pressure would never go negative). At least that approach could have the possible benefit of decreasing the dust entry IF the inlet was chosen at a location higher on the body where the dust load should be lower. Disadvantage: must find 2 locations and in different pressure zones. Second; having the flow controlling vent in a place where it is easily managed.
Just some quick thoughts as the venting problem on US Sprinters is 1 on a scale of 10. I'd sure like to find a way to ventilate mine.
Lee

Colorado_Al
02-18-2013, 04:23 AM
If you intend to leave the vent open while underway, you should install a Maxxair vent.

autostaretx
02-18-2013, 04:23 PM
my sprinter is a 2004 144 tall 10 passenger window van. What is the correct nomenclature for that?
I liked the one you chose... everything is clear. Yours is generically a "T1N", but the "144" helps.
What you didn't specify was 2500 or 3500 (dual rear wheels). Putting a photo as your avatar (see mine) helps, too.

There are also two OEM vents located behind the lower rear quarter panels, hidden by the "bumper" wrap-around.
50482

--dick

Graphite Dave
02-18-2013, 04:41 PM
I have a Maxxair located about 3' forward of the rear doors. I leave it open most of the time including when driving. Only close it when sleeping in the van on cold nights. Have not noticed any dirt infiltration from fan. I also have a hole in the floor about half way between rear doors and drivers seat on the drivers side of van. I also have left it open most of the time. I have noticed dust around the floor opening after a year or so. Probably should close the hole when driving and use the front windows to obtain air flow. The floor hole should definitely be closed when driving on dirt roads. The combination of the open Maxxair and open floor hole provides airflow when stopped and Maxxair fan is not running. Acts just like a chimney. Hot air rises. You can put your hand near the floor opening and feel the airflow.

Sjoberg
02-18-2013, 06:34 PM
Thanks for all of your answers, now i have some real experience to listen to, instead of just take a guess and do it completely wrong,, like every other time!:smilewink:

My plan for the moment is to take two of this ventilators (http://www.google.se/imgres?hl=sv&sa=X&tbo=d&biw=1366&bih=667&tbm=isch&tbnid=oBnhT4cYB2PALM:&imgrefurl=http://www.timrafritid.se/sv/elektroluxdometic/reservkapa-elektroluxventil.html&docid=NPL8ADAgUier9M&itg=1&imgurl=http://www.timrafritid.se/shop/22668/art68/h8571/12518571-origpic-b22d6c.jpg&w=465&h=348&ei=RH0iUYPxIceJ4ATD6oHADw&zoom=1&ved=1t:3588,r:0,s:0,i:81&iact=rc&dur=754&sig=108725957064860934725&page=1&tbnh=183&tbnw=236&start=0&ndsp=18&tx=96&ty=93) and put them in the rear area of the van.
This ventilators is what is needed for the inspection but i will mount something more and i like the maxxair, dont now about spareparts for them here in sweden but thats a later problem.

This is my first step in planning the roof-area and i think the ventilators must be priority one, solarpanels second and if there is going to be anything more up there it comes in place three and for the moment i dont see any needs for storageboxes or something like that.

best regards jocke

d_bertko
02-18-2013, 07:38 PM
I am untutored in the field of aerodynamic but did look at this a while back.

Here is an excellent us epa pdf:
http://nepis.epa.gov/Adobe/PDF/9100WXMP.PDF

Lots to sink your teeth into.

The overwhelming majority of wind resistance is attributable to frontal area. The slant on the t1n must have been optimized with a lot of wind tunnel time. Body length is relatively unimportant if it is a relatively smooth continuation of the frontal area

Sprinter frontal area is almost 50 sq ft but the .36 coefficient reduces that to an effective 17.8 sq ft.

IIRC, it takes 1 hp to move 1 sq ft of frontal area at 50 mph. (The pdf will state this). Note how quickly that increases with velocity---8x the hp needed at 100 mph.

So solar panels are best mounted with narrower orientation to the front. Two aligned panels down the middle is roughly half the wind resistance of side-by-side crosswise.

Some car roofracks have removable crossbars because it will raise small car mpg by 3% at 70 mph. And running your a/c instead of opening your windows will yield better mpg at high speeds.

I'm guessing roof protrusions are relatively insensitive to placement away from the leading edge.

Frontal area of a low-profile fan enclosure (1/3 sq ft?) vs a higher box (2/3 sq ft?) might save about 1 hp at 70 mph.

And of course slowing down saves a lot!

Dan