Introduction & Cross wind solutions to motorcycle Streamliners?

[P-hack]

yah, I think if the flaps were linked, and pivoted on the front, they would open naturally, with maybe a slight detent at center. I don't know if "scooping is helpful though, certainly putting more drag on the upwind side is good as you want to steer in that direction probably anyway, and more pronounced crossflow perhaps. there may be a "natural" pivot point that works well without computer intervention. This is so design specific though, I think you would want the ability to fine tune it that the controller provides...

[sendler]

This is fun to think about but in reality gets way too complicated. To quote a Vetterism:" Don't make it more trouble than it is worth".

[P-hack]

or just springs return it to closed, and you adjust the spring tension, or spring + cam maybe. Wish I were better at openfoam... I think it has promise, especially in regards to balancing side to side drag. Might need to cut some actual foam and plug in the leaf blower (via a dimmer)

[Michael Moore]

Originally Posted by sendler

This is fun to think about but in reality gets way too complicated. To quote a Vetterism:" Don't make it more trouble than it is worth".

A different version of that is "better is the enemy of good enough."



cheers,
Michael

[PeterS]

My version is "perfect is the enemy of good ".

[P-hack]

yes yes, I'm only entertaining this because you didn't think the nose fence was sufficient. So now you have another option

[godscountry]

It does sound like it meant it was flying,but no It is as if the streamliner is a a airfoil of a wing,but on its side[a vertical wing],depending on the speed and direction of the air moving down over the sides, will cause it to move in a horizontal plane[side to side,lateral movement]either right or left in relation to the roadway]So if we can change that movement of the air down the sides, in a strong crosswind,we can maybe reduce some of the horizontal movement,Peter said maybe a spoiler off the nose and on the side,and maybe in the future we could even alter the shape of the vehicle,just enough,so as not to upset the cd to much,but to reduce that high pressure and adverse movement.So alignment,wheelbase,balance etc and careful body design[aerodynamics] should make for a really nice ride.Thanks for helping me and i'm sure a few others break it down.

[freebeard]

Wow, made it to the end. I can't believe I read the whole thing. Teri_TX hasn't posted in his thread since April the 7th. I can only hope he gets email notifications. Because—

In all this discussion there was no mention of the difference between sit-on and sit-in two-wheelers. He should know about that.

There are techniques from other areas that may have application. I'm thinking of Development of Pneumatic Aerodynamic Devices to Improve the Performance, Economics, and Safety of Heavy Vehicles
Robert J. Englar
Georgia Tech Research Institute

I can't find an un-paywalled version of the paper. The original link 404's. The link I obtained from the SAE website appends a "/%E2%80%8E" to the URL and then can't find it . Just delete that and press return.

The potential of pneumatic aerodynamic devices applied to Heavy Vehicles can be summarized as:
• Pneumatic devices on back of trailer, blowing slots on all sides and/or front top can yield:
• Aerodynamic control of all three forces and all three moments plus boundary layer control
• Separation control and base pressure recovery =
drag reduction, or Base suction = drag increase
• Leading-edge (LE) suction on trailer = drag & tur- bulence reduction
• Additional lift for rolling resistance reduction (FRolling = μN, where N = Wt - Lift), or Reduced lift (increased download) for traction, braking and reduced hydroplaning
• Blowing locations instantaneously switchable • Partial slot blowing or differential blowing for roll con-
trol & lateral stability
• One-side blowing (LE or TE) for yaw control & directional stability
• No moving parts, small component drag
• Very short aft addition = no length limitation
• Splash, Spray & Turbulence reduction
• Use of existing on-board compressed air sources (exhaust, turbocharger, brake tank)
• Advanced Pneumatic Cooling Systems • Safety of Operation

Then there's semi-permeable membranes to relieve pressure differentials without impeding the overall air flow.

[Ironside]

Just a quick update on the 'storm strip' installed on the recumbent Honda.
I've recently returned from a trip to France for the D-day anniversary, we covered over a thousand miles, and I can report that the stability of the little Honda is acceptable.
It does squirm around when slipstreaming trucks, until a 'sweet spot' is found, but is no worse than a bike equipped with a conventional fairing, although the guys following said it looked a little scary.
At one point we were crossing a high bridge, the guy in front of me was riding a faired Honda 200 Benly and he said later that he had trouble keeping it within his lane, I had no real issues.
Ironside.

[minimac]

Originally Posted by sendler

I have actually thought about a similar concept before where you have flaps that are just barely held flush to the sir stream by magnets that are not quite touching so that the slightest pressure differential would sneak them open.

Think similar to flaps that N.A.S.C.A.R. now mandates on the roof and at the base of the windshield on the hood of their racecars to help keep the cars from taking off due to lift when they spin. They operate on wind differential. They should be easily adaptable to a streamliner.