Effects on the Flow around a Vehicle and Vehicle Dynamics Caused by Vehicle Electrification at Running

Kazuhiro Maeda･Mitsuru Sugimoto (Toyota Motor)･Noboru Maeda･Naohito Takasuka (SOKEN)

It is considered that the electrostatic charge generated on a vehicle during driving, combined with environmental conditions and vehicle behavior, affects the vehicle dynamic performance. Efforts are being made to improve this performance by suppressing such variations. Electrostatic effects influence various phenomena; however, this study focuses on countermeasures involving the airflow around the vehicle. By capturing the changes in airflow, motion, and electrostatic charge under these conditions, the effectiveness of the proposed measures was evaluated.

Effects of Electric Forces due to Vehicle Electrification and Air Ions on the Surrounding Flow

Naohito Takasuka (SOKEN)･Kazuhiro Maeda (Toyota Mortor)･Noboru Maeda (SOKEN)

It is considered that electrostatic charging of a vehicle during driving influences its dynamic performance. Improvements focusing on the airflow around the vehicle have revealed changes in its motion, airflow, and electrostatic charge. To understand the mechanism behind these effects, numerical simulations were conducted using a simplified geometry model based on the governing equations of three physical fields—fluid flow, electric field, and charge transport—to clarify how the electric force affects the airflow.

A Study on Quantitative Evaluation Methods for Assessing the Impact of Individual Vortical Flows around a Vehicle on Aerodynamic Drag

Taiga Nonaka･Takuji Nakashima (Hiroshima University)･Yusuke Nakamura (Mazda)･Shohei Imagawa (Hiroshima University)･Keigo Shimizu (Mazda)･Hidemi Mutsuda (Hiroshima University)

In vehicle aerodynamic design, it is desirable to identify and target vortices that have a significant influence on aerodynamic drag among the many vortical flows generated around a moving vehicle. This study combines existing vortex identification techniques with a method for evaluating drag induced by longitudinal vortices. A technique for quantitatively assessing the drag contribution of individual vortices is developed, and its performance is examined.

A Study on Performance Analysis of Active Aerodynamic System Combination

HONGHEUI LEE (Hyundai Motor)

We analyzed the performance of individual active aerodynamic systems and verified their aerodynamic improvement effects. Based on these results, we developed and assessed combinations of system locations and performance settings. The analysis confirmed that integrating multiple active aerodynamic systems significantly enhances aerodynamic efficiency and allows diverse operating conditions to improve driving stability. Furthermore, the study demonstrated that optimizing the interaction between systems can maximize overall performance. Using these verified effects, we completed the control logic that links system operation with driving modes, enabling practical application in mass-produced vehicles. This approach ensures improved aerodynamic performance, stability, and adaptability across driving scenarios.

Development of high cooling performance inverter cooler

Masafumi Saito (DENSO)

For expanding market for HEV and PHEV, we have developed an inverter cooler with high cooling performance that can handle the large current of power modules. The high-cooling performance fin shape contained within the inverter cooler was determined by extracting shapes related to cooling performance and pressure loss from the characteristics of the topology analysis flow, and taking into consideration high-speed press molding for mass production.