دانلود رایگان مقاله انگلیسی تاثیر پارامترهای سیستم ترمز خودرو در تولید ذرات معلق - نشریه الزویر

ABSTRACT

The influence of car brake system parameters on particulate matter emissions was investigated using a pin-on-disc tribometer. Samples from a low-steel friction material and a cast iron disc were tested for different sliding velocities, nominal contact pressures and frictional powers. Disc temperatures were also measured. Their impact on total concentration, size distribution, particle coefficient and transition temperature was analysed. Results show that frictional power is the most significant brake system parameter. However, temperature, as a response parameter, is the most influential, inducing a shift towards the ultrafine particulate fraction and raising emissions. A transition temperature, independent of the system parameters, was identified.

7. CONCLUSIONS

A low-steel pad material was tested against a cast iron disc making use of a pin-on-disc tribometer specifically designed for particle measurements. Different nominal contact pressures and sliding velocities combinations were tested. The influence of the aforementioned parameters, the developed frictional power and the system temperature, on particle emissions was analysed. The results indicate that:

 System temperature is the most important factor affecting emissions due to the transition temperature which significantly affects the ultrafine levels. Transition temperature is not affected by the testing condition imposed here and lies in the range 170-190°C

 Among the typical brake system parameters, frictional power is the most important one. Similar frictional power can provide different outcomes regarding particle emissions in terms of total concentration, specific particle coefficient and size distribution, depending on the system temperature

 The specific particle coefficient for the ultrafine fraction is affected by frictional power and system temperature and increases as system temperatures rise

 The specific particle coefficient for the coarse and fine fraction is particularly affected by the sliding velocity and shows an increase when nominal contact pressure decreases