Every mechanical braking action creates particles through friction on the brake disc and brake pads. These particles contribute to the PM10 emissions of vehicles. Some get collected on the rims seen as grey dust, others are emitted to the ambient air. Thus there is a need for a brake dust particle filter. But first, measuring size and concentration of such brake dust is a quite challenging task. The particle generation happens in the short event of braking and depends on brake load and preconditioning of the brake (disc and pads), e.g. temperature, braking history, to name some. However, a defined way of testing brake dust particle emissions is the pre-requisite for later investigation of filtration performance.
For release of an automotive brake system specific standards are available regarding braking events. Furthermore a braking sequences can be based on standards like WLTP driving cycle. For particle measurement various techniques could be selected, e.g. DMA, impactor, particle counter. For reliable data, the integration of such equipment in the air flow through the brake testing chamber is crucial.
We are going to briefly review published activities regarding measuring brake dust particles. We will then focus on our own measurements and ongoing research. We will describe the challenges and discuss results. Thereby we will focus on the effect of specific braking events on particle emissions.
Session: G12 - Measurement Techniques I
Day: 24 October 2019
Time: 09:00 - 10:15 h