Quote:
Originally Posted by euromodder
If it manages to reduce the drag coefficient more than it increases area, it works ...
Thos bumps are found on small European vans, busses seen above, trains, ...
Don-Bur trailers work
Despite the added area - c an't reduce internal trailer height
Aerodynamic Teardrop Trailer |
There is a simple diagram from the late 1970's (
I presume) that I find once in a while on the Internet. It shows a boxy sedan with a 90 degree angle between radiator and hood and some rotational arrows illustrating turbulence at the plane change. This is not a real life condition found in the last 30 years on vehicle design but even back then I suspect it was a misrepresentation because the high pressure wave in front of the vehicle directs air flow just above it up and over the hood.
I think you are right that it comes down to in field or in lab testing of individual conditions, and no two will be the same.
In the link below "
radius of curvature of a fairing sitting on top of the caravan" seems to be an important element in the CFD studies. maybe there is something in the article that sheds light on our related topic.
Posted By LEAP CFD Team on Jun 21, 2017 | 0 comments
https://www.computationalfluiddynami...l-consumption/
Quote:
The Findings
The most dominant factor that contributes to drag and fuel consumption on a caravan is the speed at which it is driven. This follows from basic aerodynamics theory which states that the drag goes up four-fold, for a two-fold increase in speed. Put another way, the drag you experience at 30kmph is a quarter of the drag that hits you at 60kmph. So unfortunately, speed will eat into your fuel economy and holiday budget.
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The Don-Bur Aerodynamic Teardrop™
Aerodynamic Teardrop Trailer
Of course there can be other problems with going higher, like not fitting into your garage, or worse.
http://forums.pelicanparts.com/off-t...pics-4597.html
