Emissions of Nucleation Mode Brake Wear Particles on Real Urban Driving Cycles

HIROYUKI HAGINO, Japan Automobile Research Institute

     Abstract Number: 704
     Working Group: Urban Aerosols

Abstract
In recently, a standard test method for measuring brake wear emissions for passenger cars was developed by the Particle Measurement Programme (PMP). This aim is to reproduce in a laboratory experiment a driving cycle based on the worldwide average braking pattern, with PM sampling and particle number (PN) measurements according to generally accepted methodologies. Although this method is the basis for future regulations, it is important to evaluate the chemical composition and physical properties on wide range real urban driving condition in order to assess environmental effects and health risks. In this study, brake wear particles derived from passenger car brakes were measured by reproducing urban driving based on brake dynamometer experiments. A genuine front brake system complying with the ECE-R90 standard was used for the passenger car brakes. Realistic driving patterns were used to observe the characterization of emission levels, particle size according to driving style, using the California Brake Driving Cycle (CBDC) and the Los Angeles City Traffic (LACT). Real-time particle size distribution of the nanoparticles was measured using a Fast Mobility Particle Sizer (FMPS3091, TSI). In this study, the nucleation mode particles were observed in events of high brake angular velocity (speed [rpm] and torque [Nm]) (i.e. high friction work [J]) measured with an axial torque meter and may not necessarily be explained by only brake temperature.
This study presents the results of nucleation mode particle emissions from passenger car brakes on a real driving cycle. This work was supported by the Japan Society for the Promotion of Science (JSPS) KAKENHI Grant Number JP 22K03895.