Origin of downwash ducts in MotoGP
These so-called downwash ducts, also known as flow diverters, first appeared on the MotoGP stage in 2021 when Ducati presented the Desmosedici GP21 with downward-facing air ducts on both sides of the fairing at the pre-season tests in Qatar. Since then, these have been taken up by other manufacturers, and Yamaha introduced its own version of this design in 2024. The exact workings of the Ducts have often been the subject of speculation, but initial analysis shows interesting results.
At first glance, the ducts appear contradictory: they are located under the winglets, which are clearly designed to generate downforce when driving straight ahead. The ducts, on the other hand, absorb air from the sides of the motorcycle and deflect it downwards. Initially, one might assume that this would result in the front wheel of the motorcycle being lifted. However, studies such as the “Aerodynamic Study of MotoGP Motorcycle Flow Redirectors” suggest that this is not the case.
How the downwash ducts work
These air ducts apparently fulfill a dual function. When riding straight ahead, they suck up the “dirty” airflow behind the front wheel and fork and direct it under the motorcycle. This helps to reduce drag and generate some downforce. A different effect occurs when cornering: Air pressure is higher at the front and inside of the corner, where the fairing is close to the ground. This causes air to flow under the motorcycle at high speed and escape on the other side, where the pressure is lower. The downwash ducts amplify this effect and thus provide additional downforce.
Yamaha’s additional cooling benefits
Yamaha’s new patent application points to another advantage of the downwash ducts: improved cooling of the motorcycle. The turbulent airflow coming from the front wheel and hitting the front fairing edges is dissipated through the ducts, creating a low-pressure area behind the ducts. This is exactly where the outlets are located to remove the hot air that has passed through the radiator and oil cooler. The low-pressure area helps to draw the air through the radiators, allowing them to work more efficiently. This allows the radiators to be smaller and lighter, resulting in a sleeker motorcycle design.
Possible application on production motorcycles
Yamaha’s patent application could indicate that the company is planning to use similar Ducts on future production models. Patents for purely racing technologies are rather rare, as patents are usually intended to protect commercial innovations. Whether this idea is actually patentable, especially given the similar designs already used by Ducati and others, remains to be seen and is ultimately in the hands of the patent examiners.
Conclusion
With the downwash ducts, Yamaha could in future also incorporate an aerodynamic innovation from MotoGP into production motorcycles. This technology could both reduce drag and improve cooling, which could influence the design and performance of future models. It will be interesting to see how this idea develops, particularly with regard to commercial use and possible patent protection issues.
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