As per the European Environment Agency (EEA), air pollution is rated as the most significant environmental health risk in Europe. Traffic-related emissions are among the primary sources of fine particulate matter in urban areas and have become a global challenge. Already today non-exhaust emissions largely contribute to a vehicles PM10 and PM2.5 footprint. Furthermore, it is expected that due to the electrification of the vehicle fleet, in 2050 already 90% of traffic-related fine dust emissions will result from non-exhaust sources. Legislation has acknowledged this issue, and the European Commission proposed the EURO7 regulation in November 2022 to further reduce brake dust emissions from vehicles to mitigate the negative effects of traffic-induced fine dust emissions. The EURO7 regulation will limit the allowed brake dust particle PM10 emission for N1 and M1 vehicles to 7 mg/km effective 07/2025 and will further reduce to 3 mg/km from 2035 onwards. This regulation will apply to all vehicles, including electric ones. For most applications this target is only achievable by implementation of technical measures to actively reduce the brake dust emissions. Passive brake dust filtration in the vicinity of the emission source near the brake system has proven to be a promising solution for reduction in brake emissions. In this presentation we propose a new concept of an active brake dust particle filter concept. The concept consists of a suction nozzle and a subsequent filtration system for an efficient separation of the brake dust particles. Thereby the suction nozzle is in close vicinity to the emission source downstream of the brake pad and separates the particles directly after they become airborne. To maximize the separation efficiency, a CFD simulation model has been used to optimize the suction nozzle geometry and to understand the most influencing parameters. The simulation model is implemented in StarCCM and models the rotation of the inner-ventilated brake disc via a Moving Reference Frame combined with moving wall boundary conditions. Via a parametric optimization and a subsequent topology optimization the pressure drop at the nozzle as well as the flow distribution is optimized in order to achieve maximum suction efficiency, resulting in a maximum emission reduction. For the validation of the simulation model, prototypes have been built via rapid prototyping and have been tested. Experiments were conducted based on a chamber-in-chamber setup on an inertia brake dynamometer (LINK 3900). In addition, tests have been performed according to the GTR requirements and compared the previous measurements. It will be shown that significant PM10 reductions of up to 80% PM10 emission reduction over lifetime can be achieved by the proposed concept.

Dr. Florian Keller, Director Engineering Air Filter Elements & Simulation, MANN+HUMMEL GmbH; Mr. Tobias Wörz, Development Engineer Advanced Engineering, MANN+HUMMEL GmbH; Mr. Andreas Beck, Manager Engineering Air Filter Elements Validation, MANN+HUMMEL GmbH; Mr. Steffen Pfannkuch, Lead Product Engineer Development Air Filter Elements, MANN+HUMMEL GmbH; Mr. Martin Uhlir, Senior Simulation Engineer, MANN+HUMMEL GmbH