Effects of braking conditions on nanoparticle emissions from passenger car friction brakes

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985858%3A_____%2F21%3A00559337" target="_blank" >RIV/67985858:_____/21:00559337 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/68407700:21220/21:00350512 RIV/60461373:22310/21:43923436 RIV/60460709:41310/21:85731 RIV/61989100:27640/21:10247503 RIV/61989100:27650/21:10247503

Výsledek na webu

<a href="https://hdl.handle.net/11104/0332667" target="_blank" >https://hdl.handle.net/11104/0332667</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.scitotenv.2021.147779" target="_blank" >10.1016/j.scitotenv.2021.147779</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Effects of braking conditions on nanoparticle emissions from passenger car friction brakes

Popis výsledku v původním jazyce

Automobile friction brakes generate, in addition to coarse particles generated by mechanical processes, highly variable amount of nanoparticles from high temperature processes. The effects of braking conditions – speed, deceleration rate, brake rotor temperatures – on nanoparticle production were investigated here, aiming to provide practical guidance for reducing emissions through driving style and traffic management. Typical brake pads and a rotor from a common passenger car were subjected, on a brake dynamometer, to three runs of the WLTP brake cycle developed for brake wear particle measurements. Additionally, four sets of common brake pads were subjected to those parts of standardized brake performance tests believed to be reasonably realistic for common driving. Particle size distributions (5.6–560 nm electric mobility diameter, without removal of volatiles) show a dominant peak at 10 nm commensurate to the severity of braking and a non-linear increase of the total particle number at higher braking powers and higher total energy dissipated. The average emissions for three runs of the WLTP brake cycle were 3.3 × 1010 particles/km, while the harshest deceleration, 175–100 km/h at 5.28 m·s−2, has produced 8.4 to 38 × 1013 particles, corresponding to 2.5–11.5 thousands of km of WLTP-like driving. While previous studies have correlated higher PN production with higher average brake rotor temperature, a more complex relationship between nanoparticle emissions and a combination of initial rotor temperature, total energy dissipated and braking power has been observed here. From a driver behavior and regulatory perspective, it appears limiting harsh braking and braking from high speeds, possibly through improved driving practices, road design and traffic management, may potentially reduce brake wear nanoparticles. From the measurement perspective, it appears that off-cycle braking, even if relatively infrequent, may be associated with exponentially higher emissions and non-negligible share of the total emissions, and therefore should not be neglected.

Název v anglickém jazyce

Effects of braking conditions on nanoparticle emissions from passenger car friction brakes

Popis výsledku anglicky

Automobile friction brakes generate, in addition to coarse particles generated by mechanical processes, highly variable amount of nanoparticles from high temperature processes. The effects of braking conditions – speed, deceleration rate, brake rotor temperatures – on nanoparticle production were investigated here, aiming to provide practical guidance for reducing emissions through driving style and traffic management. Typical brake pads and a rotor from a common passenger car were subjected, on a brake dynamometer, to three runs of the WLTP brake cycle developed for brake wear particle measurements. Additionally, four sets of common brake pads were subjected to those parts of standardized brake performance tests believed to be reasonably realistic for common driving. Particle size distributions (5.6–560 nm electric mobility diameter, without removal of volatiles) show a dominant peak at 10 nm commensurate to the severity of braking and a non-linear increase of the total particle number at higher braking powers and higher total energy dissipated. The average emissions for three runs of the WLTP brake cycle were 3.3 × 1010 particles/km, while the harshest deceleration, 175–100 km/h at 5.28 m·s−2, has produced 8.4 to 38 × 1013 particles, corresponding to 2.5–11.5 thousands of km of WLTP-like driving. While previous studies have correlated higher PN production with higher average brake rotor temperature, a more complex relationship between nanoparticle emissions and a combination of initial rotor temperature, total energy dissipated and braking power has been observed here. From a driver behavior and regulatory perspective, it appears limiting harsh braking and braking from high speeds, possibly through improved driving practices, road design and traffic management, may potentially reduce brake wear nanoparticles. From the measurement perspective, it appears that off-cycle braking, even if relatively infrequent, may be associated with exponentially higher emissions and non-negligible share of the total emissions, and therefore should not be neglected.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10511 - Environmental sciences (social aspects to be 5.7)

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2021

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Science of the Total Environment

ISSN

0048-9697

e-ISSN

1879-1026

Svazek periodika

788

Číslo periodika v rámci svazku

SEP 20

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

10

Strana od-do

147779

Kód UT WoS článku

000662648800007

EID výsledku v databázi Scopus

2-s2.0-85106349084