MotoGP aerodynamics

In the last test IRTA in Sepang, Yamaha showed the next step in MotoGP aerodynamics.

Fairing with ducted vanes

Technical regulation is forbidden aerodynamic appendices, therefore if you want to work with aerodynamic, only you have shape and ducts in the fairings.

Fairings are reason for aerodynamic existence, and the first goal is to down Cx in the motorbike.

Low Cx is less aerodynamic drag, and more top speed with same power, but this is dead end way when the top speed is all.

We take Honda RC213V values,

• width = 0.645m
• height = 1.110m
• Area = 0.562 m2 (Elipse área wuth height and width)
• Cx = unknow

However we have hayabusa Cx = 0.561, and could be estimate that the MotoGP more and less 0.5 and 0.6

	Cx	200 km/h	300 km/h	355 km/h
Hayabusa	0,561	45 HP	152 HP	252 HP
MotoGP	0,5	40 HP	136 HP	225 HP
	0,6	48 HP	163 HP	270 HP

We could see that the top speed is reachable by motoGP is the same that, but big part of circuit the power is superior than you need, the famous wheelie is this fact, engine to provide more power that bike could take to increase the speed.

Conclusion, top speed is only one point in track and more than 90% in the track, engine provides more power than motorbike can manage it.

Therefore, 90% in the track, we can power waste.

How? One way is aerodynamics effects, in the 2016 season we saw wings in all motorbikes, but in 2017 is forbidden wings, but wings are not all aerodynamics. we could explore two ways,

1. Slots and coanda effects
2. Lifting body

Yamaha show the first field, with ducted vanes to provide Coanda effect. is for air viscosity create boundary layer and air follow this profile meanwhile dont broke it, (stall effect).

Coanda effect follow the profile

But the coanda effect has other behaviour, and this could see in the Hunting H126 and it jet flaps.

jet stream drag the surrounding air in the same direction

Jet stream, deflect the air ans create lift

You could work with this effect, and create air paths in the surface, like diverterless, this effect could see in the F35 Lightning II engine intake.

This is DSI shape and it has other advantages in supersonic speeds

Lifting body create lift forces without wings, due to the body is a wing

With this effect and "dowforce" body, and ducted jet stream we could create down force, like the old wings.

Drag creates for in air intake is converted in downforce. Purple lines is air flow.

One point where could be create this effect is in the nose fairing

The nose is a big surface where Coanda effect works, and it begins the rest aerodynamic behaviour.

Sepang test,  M1 show this ducted

Yamaha M1 ducted vanes

If the make the first calculates with the effective vanes, and only the effect the flow deflection and Cx=1 (all air into the ducted is deflected).

• Intake width = 0.1m
• Intake height = 0.3m
• Intake area = 0.03 m2 

YZF-M1

200 km/h

300 km/h

350 km/h

2 Ducted vanes

11,6 kg

26,1 kg

36,5 kg