Originally Posted by Cycle
It should move rearward and lower, given that we're taking some of the air that would otherwise be acting on the windward side of the bike and transferring it high on the opposite side of the bike.
*Only in a wind tunnel can the CP/CG relationship be verified
*As the symmetrical section encounters yaw,the forward stagnation point will also move (affecting your ability to harvest ram air)
I'm going to try to take as much of that out of the equation as possible by having the body faired. I'm thinking along the lines of some material that can bend outward when I put my feet out to balance, but it won't be allowed to bend inward due to air pressure. The rest would be fully faired up to shoulder
height.
*Only a rigid surface can overcome aeroelastic phenomena which occur as the angle of attack varies,and velocities/pressures with it
There should be no net effect on CoP in straight-line riding. But when riding into a side wind, I'm hoping to make it so the effect of that side loading is reduced.
*In crosswind,the windward stagnation point would be a moving target,and the leeward wake also,making it very challenging to vector your air discharge to control your roll moment.
Hadn't thought of that. Would it be a bad thing to 'rob' air from under the bike? It wouldn't be the totality of the air being pushed under the bike, but enough to lessen the moment of torque that tries to lift the front wheel. The scoop would also prevent that turbulent air being thrown off the front wheel from being sent under the bike, thus keeping what air does flow under there better attached. Wouldn't it?
*Any air you rob introduces a transverse contamination to the boundary layer which will affect an otherwise favorable pressure gradient (if you're gonna try a laminar profile).Once you reach the 1st minimum pressure,your at your point of BL transition to TBL and maximum lift
*If you'll spin your front wheel and observe its spin-down time profile,it will suggest it's ability as a prime mover/air handler.I believe that you'll be shocked at its inability to develop any meaningful static pressure.
*The scoop itself may trigger separation itself.
*In a crosswind environment,the leeward side of the front wheel will be in turbulence,offering no useful ram air to the scoop,and affecting the pressure of air entering on the windward side.
*NACA submerged inlets will convert velocity pressure to static pressure if you have an undisturbed pathway leading to the inlet.
*A Baumann scoop (NHRA Pro-Comp hood scoop) can reach outside the boundary layer and harvest the inviscid flow,with very low drag penalty,but needs an unimpeded approach for the air.
*As to the extractors,I recommend you look at Professor Alberto Morelli of Turin,Italy who was instrumental in the high-tech ducting of the 1978 Pininfarina CNR 'banana' car.He got the cooling system air to blend into the outer flow with zero turbulence.
*You will see that a reversed-NACA inlet is NOT ideal as an extractor.
The front wheel spinning will tend to act as that 'external power source' to ram air into the scoop, as will the forward motion of the bike. I intend to smoothly reintroduce the redirected air into the airstream higher and more rearward such that it doesn't create turbulence. Not quite sure how, though... do NACA ducts work well in reverse (air flowing out)?
Yeah, they'll have to be surfaced to prevent laminar flow along the duct walls. Something akin to Power Lynz or similar might do it.
*The walls should be as smooth as possible to delay TBL transition.After that we just pay the man for the surface friction.There's no avoiding it.
Definitely. I have no idea *how* I'll be reintroducing the redirected air smoothly back into the airstream rearward and higher on the bike, but there must be some way of doing it.
*The challenge is WHERE to cite the extractors,since you'll be riding in a fluid battlefield with the goal posts moving all the time.Georgia Tech has been battling this for decades now.
In the future we may have active morphing body capabilities in which active surface sensors talk to the CPU and alter the shape,or porosity to deal with transient pressure domains.
Thanks for the references. I'll check them out.
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