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Outstanding aerodynamics derived from work in a wind tunnel Scene of development at one of the leading wind tunnel experimental facilities in Japan, located in Tochigi Prefecture.
In this huge wind tunnel, a rider actually straddles a machine, and the air flow due to the helmet form is analyzed using various data. |
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The participant in our wind tunnel experiments was Takeshi Tsujimura, an OGK KABUTO contract rider in the All- Japan JSB Class, who was also Suzuka 8-hours winner in 2006.
In 2007, he is wearing the FF-5. |
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| Air flow can be analyzed from the movement of threads called “tufts”which are affixed to the helmet surface. Verification of experimental results showed that, with a conventional helmet, large differences arise in air flow at the back part of the helmet when the rider is facing forward, versus when the rider is facing sideways. Thus, OGK KABUTO developed a design to make the air flow as close to uniform as possible, no matter what the angle, by boldly attaching a part which disturbs the flow at the back of the head part. This is the Wake Stabilizer. |
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Akira Azuma
Professor Emeritus of Tokyo University |
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Professor Emeritus of Tokyo University.
Specialist knowledgeable in all fields, including aircraft and bio-flight. Had a tremendous impact on the development of the FF-5. |
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Nagakatsu Kawahata
Professor, Nihon University |
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Professor, College of Science and Technology,
Department at Precision Machinery Engineering.
Specialist knowledgeable in fields such as flight dynamics and control. Father of the new devices and Wake Stabilizer provided at the buck of the FF-5. |
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Kunio Yasuda
Professor, Nihon University |
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Professor, College of Science and Technology,
Department of Aerospace Engineering.
Specialist in rotary wings; famous for research on flight of plant seeds by autorotation, and on bio-flight. Supervised wind tunnel experiments in development of the FF-5. |
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Yuichiro Yamawaki
OGK KABUTO Development
Design Consultant
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Specialist in the field of design, and an industrial designer,
who also works as an instructor at the Osaka University of
Arts.
Devised OGK KABUTO’s Top Aero-Ventilation (a ventilation system which actively uses the negative pressure produced on the shell surface).
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The main stage for development of the aerodynamic surface of the FF-5 was a huge wind tunnel for aircraft development, of the horizontal circuit Gottingen type. Wind tunnel experiments were necessary and indispensable for the FF-5, which uses a newly conceived aerodynamic device called “Wake Stabilizer”.
There were mainly two purposes to these experiments. One was visualization of the viscous fluid which cannot be seen with the eye. Another was numerical quantification -- i.e. measurement of lift, drag and surface pressure.
In visualization experiments, a thin line of smoke is introduced into the flow, and the flow of air streaming around the helmet is observed. Details of the flow near the surface are determined by the movement of small threads called "tufts" which are attached in large numbers to the surface of the helmet. In experiments for numerical quantification, a precision measuring device called a "6-component balance" is fastened to the helmet, and researchers measure the drug ( ≒ resistance), lift (force which tries to float up) and lateral forces (forces to the left and right) experienced the surface pressure distribution using a helmet number of holes have been opened in the surface.
These measurements are performed in multiple speed ranges, and in all conceivable positions -- i.e. under all elevation angle and direction conditions with respect to the flow of air -- and thus there is a very large amount of data. Under the guidance of Akira Azuma (Professor Emeritus of Tokyo University) and Nagakatsu Kawahata (Professor of Nihon University), and with review and proposals provided by Kunio Yasuda of Nihon University (Professor, College of Science and Technology, Department of Aerospace Engineering), the FF-5 was steadily evolved without fighting against nature, aerodynamics.
Takeshi Tsujimura, the OGK KABUTO contract rider, participated in wind tunnel testing (which constitutes final finishing of the design), and actually straddled a motorcycle in the wind tunnel. When the switch of the wind tunnel was turned on, Tsujimura became one with the motorcycle with his beautiful form, and a line of smoke flowed in a beautiful curve over the FF-5. Immediately, spectators burst into spontaneous applause. It took over 3 years from the conceptualization stage. This moment marked the birth of 0GK KABUTO Helmet's FF-5, a helmet which brings together the very best aerodynamic innovations. |
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