A Study on A-PLR Side Flow Noise Reduction According to Windshield Side Molding

Nak Kyung Kong･Kyunghwan Kim･Heung Gi Kim･Byung Woo Lee (Hyundai Motor)

The flow that flows around the vehicle while driving can be divided into a Center Flow that flows through the center of the vehicle and a Side Flow that flows toward the A-PLR. The side flow accelerates past the A-PLR during vehicle driving and is divided into a main branch flow that flows through the bottom of the door glass and a vortex flow that flows toward the top of the door glass. Through the flow guide structure of A-PLR molding and the shape change of the molding, the change of the flow flowing around the door glass was investigated. As a result, as the R value of the side molding decreased, the flow speed of the wind flowing through the A-PLR was accelerated, and it was confirmed that the vortex of the top of the door glass was weakened.

Investigation on the Multidisciplinary Design for Simultaneous Reduction of Wind Noise and Squeak of the Door Inner Belt Weatherstrip in Electric Vehicles

Sang Hyun Lee (Hyundai Motor/Sungkyunkwan University)･Seunghyun Cho (Sungkyunkwan University/Samsung Electronics)･Bumyong Yoon (Samsung Electronics)･Sanghyun Lee･Kyoung Min Hong (Hwaseung Material)･Jonghwan Suhr (Sungkyunkwan University)

NVH are becoming crucial performances in EVs, particularly wind noise. A high initial contact load of the door inner belt weatherstrip should be applied to prevent the wind noise from entering the interior of the vehicle. This in turn may cause a squeaking noise at the glass/weatherstrip interface. Thus, this study demonstrates a multidisciplinary design of the weatherstrip to simultaneously reduce wind noise and squeak by designing TPE material properties and structural geometry of the weatherstrip. By adjusting the TPE material recipe, flock coating compression set, damping, friction properties were improved, Vehicle level evaluated to confirm that the performance was verified

Effect of Turbulence Intensity on the Aerodynamic Performance of Test Specimens in Wind Tunnel Testing

Ken Terakawa･Satoshi Inazumi (Japan Wind Tunnel Testing)

Wind Tunnels used in automotive aerodynamic testing typically have different design geometries and various levels of uniformity and turbulence intensity. Typically, these differences are accounted for by applying correction factors. In this presentation, the effect of turbulence intensity is evaluated using Ahmed body and NACA aerofoil specimens measured using the same wind tunnel and wind speeds.

PHEV Thermal Management System of Fast Charging Time Reduction
-Utilizing Engine Coolant Heat Loss and Cabin High Voltage Heater for Battery Heating System-

Takayuki Shimauchi･Hidekazu Hirabayashi (Toyota Motor)

TMC is developing PHEV for EV distance improvement and fast charging time reduction. We think about adoption of fast charging to improve EV distance. The problem of fast charging is long time in winter. The key of development is to reduce fast charging time. In this paper, we propose the world’s first battery heating system. It is a new battery heating system using Engine coolant loss and Cabin high voltage heater to reduce fast charging time.

Development of Aerodynamics Noise Prediction System using Generative AI for Vehicle Body Shape Flow

Yuta Ito･Kohei Shintani･Yohei Morikuni･Tomotaka Sugai･Shiro Yasuoka (Toyota Motor)

Aerodynamic noise is the mechanism by which pressure fluctuations caused by turbulent flow generate sound waves that penetrate and propagate into the vehicle cabin. Among them, for aerodynamic noise originating from the vehicle body shape (exterior noise), a predictive method using Computational Fluid Dynamics (CFD) has been established. While the introduction of CFD has shortened the development time for exterior noise in automotive development, it still requires considerable computational time whenever changes are made to the exterior shape. Therefore, as a new method to solve this issue, we report a case where an AI model was created using CFD results as training data, and a method to predict exterior noise without conducting CFD was established, significantly reducing the output time.

Effect of Bulk Viscosity Coefficient on Vehicle Aerodynamic Noise Analysis by using LBM

Akiyoshi Iida (Toyohashi University of Technology)･Yoshinobu Yamade (Mizuho Research & Technologies)･Masashi Miyazawa (Honda R&D)･Tsukasa Yoshinaga (Osaka University)･Chisachi Kato (The University of Tokyo)

The bulk viscosity used in LBM analysis is larger than that of actual value, and the aerodynamic sound attenuation rate obtained by LBM analysis is larger than the solution of the NS equation. The problems of aerodynamic sound analysis for automobiles are discussed.