To contribute to the understanding of the test cycle influence on brake emissions, the present study investigates the differences between the novel WLTP-based brake emission test cycle and several commonly used real-world test cycles in terms of characteristic parameters like kinetic energy and disc temperature. Building on this comparison, the effects of those differences on brake emissions are shown based on a direct comparison of three cycles on a brake emission dynamometer. The dynamometer setup includes a climate-controlled environment as well as a brake emission enclosure with a filtered incoming airflow. Using particle sampling and downstream PM measurement it is shown that the used test cycle has a significant impact on brake emissions. This fact makes clear the necessity of using realistic and representative test procedures when aiming at the evaluation of PM10 brake emissions in a reproducible and conclusive manner. The novel WLTP-based brake emission test cycle provides such a procedure and is widely accepted as standard procedure to measure brake emissions.

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Dr.-Ing. Andreas Paulus, Development Engineer, TMD Friction Services GmbH; Mr. Matthias Kloda, TMD Friction Services GmbH