Quote:
Originally Posted by godscountry
I'm a little confused, so is the streamlined body, acting like a big wing on its side,with the top of the body[canopy,roof area] acting like the leading edge of a aircraft wing. The reason I say that,is looking at the early testing of the Ecomobile in crosswinds,the bike moved into the wind,as if it was providing lateral lift instead of vertical lift like a aircraft wing would do, if it were in a horizontal plane..So what your saying is the shape of the side panels[maybe the open cockpit] of his body design,is changing the airflow and reducing that lateral movement?Sorry guys,but I'm not too well versed in aerodynamics,but after reading about Rogers crash,I want to learn a little more .Thanks for your time
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Hi godscountry,
I'll leave the explanation of the Ecomobile moving into the wind to the motorcycle gearheads which I am NOT!.
As I understand it, the trail of a motorcycle's front wheel causes it to move into the wind when pushed by it. My theory is based on the idea that a streamlined motorcycle body behaves as a wing which in a cross wind develops lateral lift in the downwind direction. This is a good thing as the opposite is bad. However, too much can be
BAD if it moves you right into an oncoming vehicle or off the road.
My theory of having "stall strips" is to ruin the downwind lateral lift by spoiling the wing effect. Vetter's open sided streamliner is one way to minimize lateral lift in a cross wind situation. However, the big gap causes more drag and thus lower fuel efficiency (we're here for FE). All previous fully streamlined 2 wheeled vehicles suffer from cross wind sensitivity to the point of causing them to crash. Videos of streamlined HPV's show some spectacular crashes from cross winds. HPV's are especially sensitive because of their light weight.
Motorcycles are heavier and the Ecomobile's weight (1000+ lb) and wheelbase (3m) make them less sensitive but still vulnerable. Roger's crash is because his vehicle is light and is vulnerable to cross winds because of his aerodynamics.
I hope stall strips will become a defacto part of the bodies of streamlined 2 wheelers. I say "largely prevent cross wind sensitivities" because there is always the simple bluff body wind forces of cross winds. Traditional kites have simple flat planes for lift but still fly as they always have.
Hope this clears up your confusion.
-- Teri