NLR operates several facilities and the specific tunnel chosen was ideal for the task being capable of moving 371 cubic meters of air per second.
With the intention of increasing the aerodynamic efficiency of Ninja 400 riders in the WorldSSP300 Championship, the 22 old rider from Nijkerkerveen in the Netherlands had a full day of experiments mapped out for him in order to make best use of not just the facility but also the expert staff who have a wide experience of motorcycle aerodynamics as well as projects such as ice skating suits and even buildings.
Impressive from race one of the 2018 season, the Ninja 400 that succeeded the Ninja 300 of the previous year topped qualification time sheets and looked set to take a commanding position in the championship until the organisers introduced a series of rule changes across several race events in an attempt to reduce the performance of the Ninja to that of lower performing competitor machines. Now that the dust has settled on what was a complex and emotionally charged series of rule updates, the Ninja is performing well but the pressure is on Kawasaki to try to innovate further, such is the reality of racing.
As Fabien Raulo says, the idea to analyse and adjust the aerodynamic efficiency of the Ninja 400 for racing was occupying his mind for some time.
“Compared to something like MotoGP, our room for improvement in WorldSSP300 is much more limited, but in light of us operating with the severe limitation on our bike due to changes in the rules outside our control we've been thinking about some logical way to keep our bike competitive.
Considering the power range of this category, even small improvements can have a positive influence; for instance an improvement of less than 10% on the drag has the same effect of reducing the weight impact of the motorcycle by 10kg at 180km/h”
For Deroue this was his first visit to a wind tunnel, an experience he found fascinating.
“I had never been in a wind tunnel before and I was very excited about this. I wanted to find ways to make the Ninja 400 perform better in order to improve our times and ride faster. Being at the tunnel we tried to find out how to improve the overall process of riding.”
Using the NLR wind tunnel facility at Marknesse to the North East of Amsterdam, the Kawasaki group were advised to use the LST (low speed tunnel) for both its ability to accommodate a full size motorcycle but also the capacity to simulate speeds up to 200kph; a realistic top speed figure for a Ninja 400 in racing conditions.
With experience in both car and motorcycle aerodynamic testing Fabien Raulo had a planned approach to the day’s work which also accommodated input from the experts at NLR.
“I had quite precise idea of area I wanted to work on before starting this project but of course the experience of the wind tunnel staff was precious, sometimes to confirm the details of our plan, but also with new suggestions I hadn't thought of. As the time in tunnel was limited they were of a great help to focus on the most relevant parameters and optimize our testing time”
As always in a research environment there were surprises and these vindicated the flexible approach as Raulo continues.
“In aerodynamics you always have surprises, good or bad, that's why testing is so important. Some of the results were as expected; some others were surprisingly more efficient than we thought like edge covering (a NLR suggestion) and on the contrary others poor despite what we thought (e.g. changing the aspect of the wind screen)”
Quite apart from the wind tunnel itself, the sheer breadth of the staff knowledge at NLR allowed testing of the aerodynamics of an inanimate object (the motorcycle) and also the rider.
In the case of the rider, changes in posture and attitude were suggested, tested and added to the large database created during the test. Scott Deroue thinks the results may mean a fundamental change in his position on his Motoport Ninja.
“You have to think of a lot of things while riding, but again, if we see here that it makes sense I will try my best to change my riding style in order to have the best aerodynamics. The ultimate goal is more speed overall plus trying to increase our top speed on the straights”.
The signs are already encouraging with a goal according to Fabien Raulo of close to a 10% improvement in aerodynamic efficiency. This improvement can help not simply Deroue and the official Kawasaki team in WorldSSP300 but also other Kawasaki competitors who have been affected by the unexpected rule changes this season.
“One or two of the solutions we've found are already in place but we are still working to convert into practical solutions the positive results we've found in addition to these initial improvements” concluded a delighted and optimistic Raulo.