Vehicle Electrification Effects on the Flow around a Vehicle and Vehicle Dynamics in 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 Motor)･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.

Development of the Double-Sided Cooler for the Inverter

Masafumi Saito･Yuya Saito･Ryohei Tomita･Tomohiro Shimazu (DENSO)･Yosuke Hasegawa (The University of Tokyo)

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.