The top surface of the helmet used while driving high speed vehicle is provided with two ducts and two ripple strips on each side. Why?

Explanation

If ordinary helmet is used having no ducts and strips, then on increasing the speed of vehicles, the air streams set up on the upper surface of helmet will have quite high speed than that on the lower surface of helmet. Ac cording to Bernolli's principle, the pressure becomes less on the upper surface than on the lower surface of hlemet. As a result of it, a lift acts on the helmet, pushing it upwards. Due to it, sometimes, the head of the driver is buffeted severely and frontvision is obstructed. To solve these problems , two gill-like ducts and two ripple strips are provided on each side of the top surface of helmet. The ducts allow low energy air flow out of the helmet to mix with the faster moving air over the upper surface of helmet and the ripple strips enhance the mixing process. This will be reducing the lift on the helmet. Such helmets will not obstruct the front vision of the driver at high speeds and driving becomes safer.