Foamie aerodynamics.

[loaderman]

When building a trailer not only does weight affect the tow vehicle but also aerodynmics.
Some interesting reading.
http://www.marama.org/diesel/frieght/conferencecalls/9_27_06/MADCAeroOvw2.pdf

A nice aerodynamic foamie!!!!http://www.roamingtimes.com/rvreports/5/heartland-edge-travel-trailer.aspx
Construction details http://www.roamingtimes.com/rvreports/5/heartland-travel-trailer-construction.html

[GPW]

L, aerodynamics is really everything ... The air is essentially a liquid and you can feel the effects just by sticking your hand out the window while driving ... the faster you go , the More drag you feel on the same area... Now multiply that times the frontal profile of your trailer .. Smoothing out the shape to better help the wind flow smoothly over the surfaces , really helps ... as you can see with modern fuel efficient cars which look like bullets ... Think about what airliners look like ... that’s a pretty optimum shape ... No reason a trailer can’t be similarly streamline (think Airstream) , especially easy with a Foamie ...

[loaderman]

What I found interesting was the back and side shape/fins.

[GPW]

Lots of little ways to reduce Drag ... and little things add up ... But the easiest way to reduce Drag is to just slow down ... True !!! Drag seems to increase exponentially with Speed ... Drag in water is just ridiculous ... nearly impossible to lessen ... Only way to reduce Drag on a boat is to get as much of it as possible OUT of the water ...

Actually the teardrop shape everybody loves in really not bad , we just need to find a better way to keep the flow attached off the back of the trailer which falls off a bit too sharply ... I’ve got some ideas from flying and designing planes all these years , but they would alter the basic TD shape considerably ... especially in the rear ...

Just for S&G, the basic TD shape stretched out would be even Better ... With TDs right now the flow detaches just about where the galley hatch starts... forming turbulence (low pressure) behind it ... the idea is to keep the flow of air attached till it just falls off the end of the trailer smoothly ... slipping through the air ... creating as little turbulence as possible ...

We might pay better attention to the undercarriage which as we’ve read, accounts for 40% of the overall trailer drag ... Air dams or smoothing the underneath would help , then some wheel pants ... all gets pretty complicated ...

[GPW]

Anyone SERIOUSLY interested in the airflow over their trailers , can just tape tufts of yarn all across the top and sides , affix a small camera to the roof and drive down the road videoing the action of the tufts at various speeds ... easy to see where the tufts lay down smoothly and where they flap about wildly in the turbulence , and where it starts ... Great way of testing , no myths ... Here’s a video of a plane airfoil being tested like this , one which keeps the flow attached across the whole wing ...(possibly an idea for a trailer ? ) http://www.youtube.com/watch?feature=pl ... RZBjUHoq7A Turn your speaker down , it does get irritatingly noisy , the whine of the motor and prop ...

[GPW]

Here’s a pic depicting what happens when the trailing edge starts to fall off rapidly , like a sphere ... sorta’ ... AND we may NOT want to make them Smooth ... http://www.aerospaceweb.org/question/ae ... 0215.shtml



Hey Eagle , what’s up with the loading picture [img] thing not working ???

[eaglesdare]

you have to add the img tags manually when loading from the albums. i'll do it for ya.

[GPW]

THANKS !!!

[loaderman]

INteresting thanks GPW.

Notice the #27 cupped hand shape is the worste for aerodynamics, as one would expect.


Read the full article and links.

[GPW]

L’ , boxy trailer’s Not much better eh ?? ... Looks like the clear winner is #2 with the squared off back ...

[angib]

Don't forget - almost none of this general information is terribly relevant to teardrops since:
a) none of those examples are vehicles travelling near the ground, and
b) none of those examples have a tow vehicle in front of them.

[GPW]

True , so True !!!

[loaderman]

Augh
Somebody had to point out that fat!

[GPW]

All is not Lost ! It would appear that streamlining would help Any trailer ... Gotta’ be better than just a box back there huh ??? We’ll never get absolutely Clean surfaces anyway ... so lessening any extra Drag sure would help ... a bit ... all that adds up to extra mileage ... so why not ? Besides it looks Cool !!

[linuxmanxxx]

Aero is relevant no matter if towed or not as if it didn't matter then you shouldn't lose any gas mileage towing your foamy but oh you do lose mileage and as these docs and pics have shown almost all to wind drag. Round up front edges and try and keep it within the tow vehicles profile as much as possible are your biggest gains for aero efficiency.