On-Road Measurements and Modelling of Disc Brake Temperatures and Brake Wear Particle Number Emissions on a Heavy-Duty Tractor Trailer

In this paper, results are presented for an on-road measurement campaign for measuring the brake wear particles of disc brakes on a heavy-duty tractor trailer during the EU P012101 Pilot Project funded by the European Parliament. A novel approach was adopted using a fully open sampling system with minimal influence on air flow around the brake and brake disc temperatures. Models for brake disc heating and cooling were developed, as well as a model for the particle number emissions. It was concluded that brake wear emissions per kilometre were the highest on urban roads and the lowest on the motorway. Furthermore, when modelling heating during braking actions, the best results were seen when introducing dependencies on both the braking work and initial brake temperatures. When modelling the brake cooling, a non-linear dependence on the difference between the brake disc temperature and ambient air temperature was empirically observed. For the particle number emissions, a relationship was established between the braking work applied to the disc during the braking action and the particle number emissions of the braking action.