Quote:
Originally Posted by aerohead
The concept of a streamlined spoke is kinda oxymoronish if you think about them.
*In a calm situation,the spokes are shielded inside the wheel from the oncoming flow.
*They are churning within an environment of sequestered air.
*Their boundary layers and individual wakes travel in a circular train with the wheel.
*If their next to an open engine bay,we'd probably have transverse flow,moving through the turning spokes,creating a pulsation perturbation which destroys the flow.
*If in a crosswind,some of the spokes may remain shielded,while others are attacked by the free-stream entering the void.
*If the spokes were airfoil sections,they'd perhaps have a minimum windage drag in the context of their peculiar flow,but it would still be intermittent flow.
*You can't model this in CFD yet.
*It would cost perhaps a $100,000 to experiment with them in a tunnel.
*Low drag concepts use full wheelcovers (or full disc wheels) inside a full skirt,if not with an inner fender as with Ford's Probe-IV.
*As far as aesthetics and aero go,the closer you get to a full disc the better the drag situation,but then you lose the 'look.'
*If you were to cover partially,you'd cover the center and leave your opening out close to the rim.
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Thanks for the insight.
Why would you want to cover the center with a partial cover though? I can't wrap my head around this...Aren't the spokes moving faster at the edge of the rim?
On the same note, I noticed that some cars have the wheels flush to the side of the car, but others (such as my car, and other Toyotas from the same time period) have the fender poking out more at the top of the wheel and receding towards the bottom, would this possibly "isolate" the air being churned by the wheels better?