Since the emissions of particle number and mass from combustion engines have been reduced over the past years, the relative contribution from non-exhaust sources is gaining relevance to the total emission from vehicles. However, characterizations of other sources, like the brake system, are only at an early stage. Hence the presented study introduces results of a new housing for the specimen as a sampling concept. Several varying parameters, e.g. air flow rate, were considered in terms of their impact on brake particle emissions (BPE). Additionally, a direct comparison to measurements without the housing is presented and a recommendation for a suitable measurement setup is given. Another focal point is the analysis of particle size distributions. Results which show the variation of particle dimensions associated with the applied braking parameters are presented. Since an adequate testing method for BPE characterizations is introduced, the influence of vehicle peculiarities can be investigated. In a first step a brake system, based on AUDIs modular brake system architecture, was investigated. The abovementioned brake is used in different types of vehicles. This allows to understand the dependences of varying inertias and vehicle weights, respectively. In summary, it can be stated that the authors recommend a sophisticated test setup for brake particle emission measurements. Furthermore, the paper discusses the fundamental behaviour of particle size distributions for different brake application parameters. Last but not least, new findings on the impact of vehicle peculiarities on BPE are presented.
Sebastian Gramstat, André Cserhati, AUDI AG, Germany; Dmytro Lugovyy, Matthias Schröder; Horiba Europe GmbH, Germany.