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Looking at this art, all I can think is "you wish":

The diagram shows only part of the story. Here's another part of the story:


Any bike is moving through a three-dimensional air mass. Addressing the "wingtip vortices" forming on the sides of the windscreen isn't waste of time. Here's the real deal:

But the VStream doesn't do anything for the air moving over the top of the windscreen. And it doesn't acknowledge the airflow coming under the FJR windscreen.

For the adventurous: Cut up some yarn (gotta be lightweight) into 6" pieces. Tape them in columns about 3" apart, and each yarn the in the column spaced vertically about 3" apart. Start in the middle of the windscreen and work to the left or right (covering only half the screen). To get really gee-whiz about this, try red yarn on the outside, and green yarn on the inside (opposite) half. Here's the hard part: recording the yarn's motion. The best bet is an action cam looking at the windscreen. The next best bet is a passenger taking pictures (or video) over the "pilot's" shoulder. Or just get riding and grabbing looks without getting stuffed into a car, truck or wall. Try different speeds, try being behind a car or truck as well as in free air. Try a cross wind, if possible. Try plugging the vent area at the bottom of the windscreen.

One crucial piece of advice: get your own yarn. Chopping up your SO's sweater project could be life threatening... :wink2:
 

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The pedantic part...

Yarn reading 101



Lots of smooth air in front of and and almost over the front wheel. The air flow basically matches the contour of the wheel arch - up and over. Near the top of the wheel arch, air flow has slowed down - the yarns are drooping. The yarns at and behind the scoop show show all it's doing is messing up air flow between the A pillar and the wheel arch. There's no air coming out of the scoop (yarns would be more or less straight back). Air flow over the hood is smooth (yarns straight back) and generally smooth along the door, except for a little burble near the door seam. Air is basically sliding over the roof and being pushed inwards by air coming up the side of the Trans-AM.

Compare any results from windscreen testing with this image. Tediously long discussion of the results available on request - or not. :wink2:
 

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Brian... the guy goes on worse than I do! A bit(!) of editing to get rid of the duplication and natter would help. Lots.

The yarns do show a good read on flow over the top of the windscreen. 'Course a simple "the wind hits me here. now the wind hits me there" does the same thing.

What started the business of air flow is the VStream and their concentration on tip vortices. My point is the vortices are only part of the picture. A low version of the VStream might push the vortices out of the way, but air coming over the top is still going hit a rider at point that leads to noise, etc.

The yarn will help visualize everything that's going on. A tank top camera, looking at the windscreen will show the whole picture without dealing with air messed by the camera.

I guess I know what I'll be doing in a couple of weeks...
 
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In the News today;

"the streets in SE Pennsylvania are littered with yarn, pedestrians are tripping and getting tangled in yarn, police are investigating....:grin2::grin2::grin2::grin2:"
Sigh... it appears the Phila. Inquirer has punted again. There's virtually no rigging done in the city except for the Gazela Primero at the maritime museum. They goofed on not only the town but the state! Mistaking PA for MD... :(
That should be "Annapolis - a drinking town with a sailing problem" (-- Numerous Annapolis T-shirts )

However my main source for the project is:



:razz:
 

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