Sumitomo Rubber develops tire aerodynamic simulator for EV tire development
Tokyo, Japan – Sumitomo Rubber Industries, Ltd. has developed a new simulation technique called “Tyre Aerodynamic Simulation” for use in EV tire development. To reduce energy consumption and increase the range of EVs, it is important to minimize both rolling resistance as well as air resistance around the tire. Sumitomo will pursue the development of a tire profile that optimizes aerodynamic performance. By visualizing the airflow around the tire of a moving vehicle through its own AI powered simulation, Sumitomo will use the findings to develop a low energy consumption next-generation tire to be launched in 2027.
In addition to measures already taken to reduce tire rolling resistance, Sumitomo will increase its focus on reducing air resistance, which is important to lower the energy consumption of an EV tire. With a rapid shift to EVs occurring today, the impact of air resistance is becoming increasingly important. Unlike internal combustion engine (ICE) vehicles, which lose over 50 percent of their energy due to heat, EVs suffer much less energy loss from heat. This means that air resistance accounts for a larger portion of the total energy loss. On a passenger car, the tires are exposed to the air that passes around the tires and flows out to the side and underside. As a result, 20 to 25 percent of the energy loss due to air resistance in a passenger car is related to the tires. In EVs, which have almost no energy loss due to heat, around 34 to 37 percent of the energy loss is attributed to the tires, when rolling resistance is included.
The newly-developed ‘Tyre Aerodynamic Simulation’ is a AI-powered tool that allows Sumitomo’s engineers to visualize air resistance around a tire. It uses actual vehicle data to calculate the aerodynamics of a rotating tire while simulating the tire pattern and analyzing results using AI. Tire Aerodynamic Simulation also accounts for the effect of tire deflection due to vehicle weight. Looking for every gain, it has developed a simulation that optimizes the shape of the lettering and fine texture on the sidewall while they are rotating. While it is important to have a smooth sidewall to reduce air resistance on EVs, Tire Aerodynamic will enable the development of a tire that achieves both design and aerodynamic performance targets.
Having used the results of a wind tunnel experiment to confirm the accuracy of the simulation, the new EV tire concept, with a decreased airflow behind the tire and greater evenness on the sidewall resulted in lower air resistance values than a standard tire. This confirmed the potential of the technology. Furthermore, the AI technology used in the simulation suggests that the sidewall plays a crucial role in air resistance reduction when the air resistance is higher, offering additional evidence of the effectiveness of the technology. Adopting this technique yields improved tire performance with maximized aerodynamic characteristics, leading to reduced aerodynamic drag and energy consumption.
Sumitomo unveiled its own unique Circular Economy Concept for the tire Industry, known as TOWANOWA, in March 2023. TOWANOWA features a two-ring structure, with a ‘Sustainable Ring’ comprising five processes in the value chain and a ‘Data Ring’ linking big data collected from each process. Sumitomo aims to create new value by sharing/using data between the two rings.
The newly developed Tire Aerodynamic Simulation technique will use simulation data obtained through the ‘Planning & Design’ process to reduce air resistance when the vehicle is running and thereby help lower EV energy consumption. Through TOWANOWA, the Sumitomo Rubber Group will further accelerate its efforts to promote and practice ESG Management and contribute to the achievement of carbon neutrality by 2050 and the development of a sustainable society.