Reducing Brake Particle Emissions from Commercial Vehicles

Particle emissions from automotive friction brakes are a recognised source of air pollution, with potential health implications for the urban population. The increasing number of delivery vehicles and buses on our roads exacerbates this problem due to their weight and repetitive braking duty cycles. The overall aim of this project is to investigate alternative brake materials in order to reduce the quantity of micron-sized debris released into the environment from such vehicles which operate mainly within an urban environment.

The main equipment used at Leeds will be a fully-instrumented small-scale tribometer and comparisons will be made against results from full-size brake dynamometer tests.

During the early stages of the project, the student will conduct an in-depth literature review and will also become familiar with the existing experimental equipment at Leeds which may need some updating. They may also spend up to 3 months at Cummins-Meritor's Cwmbran site becoming familiar with the company's business priorities and design/development procedures.

The experimental work at Leeds will measure friction performance and particulate emissions for a range of potential lightweight and/or coated rotor materials. In each case, compatible friction materials will need to be specified and sourced. Tests will be conducted according to the WLTP driving cycle specified in the proposed new EURO7 standard regulation for vehicle emissions, before and after exposing the braking materials to a severe corrosion cycle designed to replicate winter driving conditions in the UK; such conditions are known to exacerbate wear emissions especially for uncoated cast iron rotors.

The overall outcomes of the project will be improved understanding of the factors that affect emissions from large friction brakes as well as detailed data of how the different alternative rotor materials perform with respect to each other and to the existing uncoated grey cast iron.