Quote:
Originally Posted by freebeard
Really? The car rocks in roll instead of yaw, the Δ in closing speed halves. Fineness ratio and Reynolds number work the same.
A big dirty vehicle moving at high speed in a high crosswind might throw a lightweight vehicle into the ditch. I extrapolate from strings of boxcars blown off railroad trestles in high winds.
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1) waiting in a left turn lane, at a red light, other than for under-inflated tires, a car doesn't have any degree of freedom for yaw in its suspension.
2) in closing, the velocities are additive. In my case, we were both closing at 75-mph ( 150-mph relative motion ).
3) for standard SAE 'air', Reynolds number has only to do with vehicle length and velocity.
4) I've no personal knowledge of light vehicles sent into ditches in response to a commercial vehicle. Hucho devoted an entire chapter to concerns about this sort of thing. In 1990, the first time I went to Bonneville, about 10-miles east of the raceway, a triple-trailer rig was laying on it's side, west-bound on I-80. There's a price for load floors 48-inches off the ground and square-edged trailer sides. ( stupid American manufacturers )
5) empty boxcars would succumb the same way as an 18-wheeler. ( stupid American boxcar manufacturers )