Sumitomo Rubber taps AI for tire aerodynamic simulation

Kobe, Japan - Sumitomo Rubber Industries (SRI) has developed a new simulation technique which is aimed at enhancing aerodynamic characteristics of tires of electric vehicles (EVs).

The newly developed "tire aerodynamic simulation" technology uses artificial intelligence (AI) to visualise the airflow around the tire of a running vehicle, the Japanese group announced 7 Feb.

The process uses actual vehicle data to calculate the aerodynamics of a rotating tire while simulating the tire pattern and analysing results through the use of AI technology.

The technique accounts for the effect of tire deflection due to vehicle weight.

As part of the project, SRI developed a simulation technique that changes the shapes of the lettering and fine texture on the tire sidewalls, while they are rotating in the same way as the pattern.

According to the group, the simulation has so far established the importance of 'smooth' sidewalls for the reduction of air resistance in EVs.

To confirm the results of the simulation, the Kobe-based group said it carried out an actual wind tunnel experiment.

The process revealed that "the EV tire with a decreased airflow trend behind the tire and less unevenness on the sidewall showed lower air resistance values than the standard tire”.

“Adopting this technique yields improved tire performance with maximised aerodynamic characteristics, leading to reduced aerodynamic drag and electricity consumption for an EV,” SRI added.

Air resistance, SRI noted, is important for lowering the electricity consumption of an EV tire and will thereby extend the car’s range.

Unlike internal combustion engine (ICE) vehicles, which lose over 50% 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 total energy loss in EVs.

“The tires are exposed to the outside of the vehicle body, and the air that passes around the tires flows out to the underside and side of the vehicle,” SRI explained

In ICE passenger cars, tires generally account for 20% to 25% of the energy loss caused by air resistance, SRI explained. 

In EVs, which incur almost no energy loss due to heat, around 34% to 37% of the energy loss is attributed to the tires, if rolling resistance is included, the group added.

SRI said it intended to use the simulation technique in developing its ‘next-generation EV tires’ to be launched in 2027.

The ‘next-gen’ tires, it added, will offer lower rolling resistance and improved fuel efficiency compared to existing tires.

“In addition to various measures we have already taken to reduce tire rolling resistance, we will focus on decreasing air resistance,” said SRI.