Researchers from Yokohama Rubber Co. Ltd. and the Japan Aerospace Exploration Agency (JAXA) have successfully simulated near real-scale flow structures (turbulence) around a tire rolling on a road surface -- and the acoustic waves (noise) generated from these structures.
The simulation opens up the potential for new technological breakthroughs that could lead to the following:
1. reduction of pass-by noise and
2. improvement of aerodynamic tire performance.
Conventional computational methods have limited accuracy in the vicinity of the tire's contact point with the road surface. The joint research team succeeded in increasing the accuracy of such computations by using both a supercomputer and a high-resolution computational method developed by Professor Kozo Fujii and his researchers at JAXA's Institute of Space and Astronautical Science.
By directly simulating a detailed tire model, the joint research team attained the computations of both of the air-flow field around a rolling tire at close to actual scale and its acoustic field. As a result, the researchers were able to demonstrate for the first time that the source of noise from tires is not only caused by the turbulence structure around a rolling tire but also from the compressed flow structures in front of a rolling tire caused by the air circulating around it.
In recent years, Yokohama Rubber has been active in the development of next-generation environmental technologies through the use of various simulations. In 2010, Yokohama established an aerodynamic simulation technique that enables simulation of air flow around tires under actual use conditions.
Yokohama says it will continue to support further research in these areas.
Using this technique in December 2012, Yokohama Rubber developed its fin tire design, which reduces aerodynamic drag on a vehicle by controlling the air flow in the wheel well. These fin tires have been featured at company displays at major motor shows around the world.
