Sumitomo Rubber develops simulation technique for development of next-generation EV tires
07 March 2024
Sumitomo Rubber has developed a new simulation technique called Tire Aerodynamic Simulation,which is used in the process of tire development. In order to reduce the electricity consumption of electric vehicles (EVs), it is important to minimize tire rolling resistance as well as air resistance around the tire.
Sumitomo is pursuing the development of a tire shape that optimizes aerodynamic performance by visualizing the airflow around the tire of a running vehicle through its own simulation using AI, and aims to develop a tire that further contributes to lowering the electricity consumption of an EV in a next-generation EV tire to be launched in 2027.
One important element of the petformance of an EV tire is to achieve low electricity consumption in order to maximize the range. In addition to various measures Sumitomo has already taken to reduce tire rolling resistance, the company will focus on decreasing air resistance, which is important to lower the electricity consumption of an EV tire.
The simulation technology will help accomplish this goal.
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; as a result, 20% to 25% of the energy loss due to air resistance in a passenger car is related to the tires. In EVs, which cause 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.
Comparison of energy loss at a speed of 100 kilometers per hour between ICE vehicle and EV
The newly developed simulation technique that allows the visualization of the 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 through the use of AI technology.
The simulation technique accounts for the effect of tire deflection due to vehicle weight. In addition, Sumitomo had newly developed a simulation technique that changes the shapes of the lettering and fine texture on the sidewall while they are rotating in the same way as the pattern. While it is important to smoothen the sidewall to reduce air resistance in EVs, using the newly developed simulation technique will enable the development of a tire that achieves both design and aerodynamic performance at higher levels.
Sidewall aerodynamic simulation that can accommodate the lettering and fine texture on the sidewall.
In comparison with the results of a wind tunnel experiment, which was conducted with an actual vehicle to confirm the accuracy of the simulation, 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.
This confirmed the potential of the newly developed simulation technique. 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 high, 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 electricity consumption for an EV.
Concerns about tire wear particles indicate that we need to rethink how they work, including not only airflows but gathereing and containing them.
Here is one approach which seeks to contain them electrostatically:
https://www.jamesdysonaward.org/2020/project/the-tyre-collective/
They only managed 60%, but it is early days and other approaches may be possible.
The problem is not as great as it might appear, as tire wear raises drastically with increased weight and acceleration, and so initially some device on heavy freight vehicles and buses would counter a great deal of the problem,
It is about time those insisting on driving fat, heavy, fast cars actually contributed to something other than road fatalities too! :-0
Posted by: Davemart | 07 March 2024 at 02:45 AM
Who would have though that the wind resistance of tires would have such an effect on EV performance. Once you know this, you can work on smoothing the surfaces and also working on an aerodynamic wheel in total (like Tesla claims to do).
+ it would also work (a little) on ICE vehicles as well.
You have nothing to lose but your embossed logos.
Posted by: mahonj | 07 March 2024 at 11:15 AM