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This paper presents three main topics which proved useful during the systematic resolution and testing program to confirm the ability of the proposed friction material to conform to the performance requirements indicated on the TP-121D [1] dynamometer test. Initially, the paper presents some commonalities and differences between the vehicle FMVSS 121[2], the dynamometer TP-121D and the SAE J2115-06 [3] test protocols. The second part of the paper elaborates on the implementation of the methodology established on the ASTM E1169-07 [4]. This standard relies on Design of Experiments (DOE) methods to assess the robustness of a given test method when testing on the extreme values allowed for key test conditions. The DOE used a three-factor, two-level, fractional factorial design to investigate the influence of (a) cooling air speed, (b) brake power as the combination of test inertia and deceleration settings, and (c) brake adjustment method.

The investigation and measurement of particle emissions from foundation brakes require the use of a special adaptation of inertia dynamometer test systems. To have proper measurements for particle mass and particle number, the sampling system needs to minimize transport losses and reduce residence times inside the brake enclosure. Existing models and spreadsheets estimate key transport losses (diffusion, turbophoretic, contractions, gravitational, bends, and sampling isokinetics). A significant limitation of such models is that they cannot assess the turbulent flow and associated particle dynamics inside the brake enclosure; which are anticipated to be important. This paper presents a Design of Experiments (DOE) approach using Computational Fluid Dynamics (CFD) to predict the flow within a dynamometer enclosure under relevant operating conditions. The systematic approach allows the quantification of turbulence intensity, mean velocity profiles, and residence times.

Emissions of particulate matter, or PM, due to brake wear, are not well quantified in current air pollutant emission inventories. Current emission factor models need to be updated to reflect new technologies and materials and to incorporate the effects of changing driving habits and speeds. While emission regulations drive technical innovations that are significantly reducing PM emissions in vehicle exhaust, non-exhaust automotive emissions remain unregulated. Current emission factor models need to be updated to reflect the changes caused by new technologies, materials, and speed-dependent vehicle usage. Most research regarding brake emissions relies on a laboratory setting. Laboratory testing has allowed researchers, application engineers, data modeling engineers, and environmental agencies to generate large datasets for multiple vehicle configurations and friction couple designs.