RChung wrote:
Tom A. wrote:
AndyF wrote:
RChung wrote:
OK, so since we're making admissions, what's the standard for positive and negative yaw? If you're on a bike and you've got a pure headwind, that's zero yaw. If you then turn slightly to the left so the wind is now slightly on your right, is that positive yaw or negative yaw? Is it the same if you're in an airplane (i.e., if you yaw to the right, is that positive yaw or negative yaw)?
Let's use this as a convention, at least in the Platypus thread:http://en.wikipedia.org/...ollpitchyawplain.png
Looks like bike convention follows airplane convention (IIRC), i.e. wind hitting the NDS of the bike corresponds to +ive yaw...
Here's a quote from the Cervelo S5 White paper: "The figure above is a yaw-drag chart, a typical way of comparing the aerodynamic drag forces of different bicycles with a rider. Less drag (lower on the chart) is better. The vertical axis shows the drag force in grams, measured along the axis of the bike (not wind axes). This is the opposing axial force the rider feels due to the wind. The horizontal axis shows the yaw angle, or crosswind angle, in degrees. This is the angle the net wind makes with the rider, including both the wind created by the rider’s motion along the riding direction, plus any atmospheric wind (cross wind). Positive yaw (right side of the horizontal axis) is with the oncoming wind on the rider’s right side; negative yaw (left side of the axis) is with the oncoming wind on the rider’s left side." Is that consistent with the airplane convention?
Nope. Perhaps I didn't remember correctly...I'm sure a search on Mark Cote's quotes (MITAerobike) might confirm Damon's statement above.
http://bikeblather.blogspot.com/