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Comparison of PM exhaust emissions measured at a chassis dynamometer and on-road chasing. Rainer Vogt, Volker Scheer, Roberto Casati Ford Forschungszentrum Aachen GmbH Barouch Giechaskiel, Zissis Samaras LAT, Aristotle University Thessaloniki. Overview. Objectives of the study
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Comparison of PM exhaust emissions measured at a chassis dynamometer and on-road chasing Rainer Vogt, Volker Scheer, Roberto Casati Ford Forschungszentrum Aachen GmbH Barouch Giechaskiel, Zissis Samaras LAT, Aristotle University Thessaloniki
Overview • Objectives of the study • On-road chasing method Results of on-road chasing • Laboratory experimental setup Results of chassis dyno work, comparison of instruments • Comparison of lab and chasing • Conclusions
Objectives • To measure the PM emissions of the VW TDI by chasing the exhaustplume with the Ford Mobile Laboratory (FML) at three constant speedsand fixed distance on a test trace • To measure the PM emissions of the VW TDI with the PARTICULATES dilution system at the FFA chassis dynamometer at the same constantspeeds and during the NEDC • To compare the results obtained with the PARTICULATES dilutionsystem with real-world dilution measured during chasing the exhaust plume with aspecial focus on nucleation particles
On-road chasing of exhaust plume Test vehicle: VW Golf TDI 1.9 l speed, fuel consumption EN590 diesel (280 ppm S) Ford Mobile Lab: SMPS, CPC, NOx, CO2 T and RH Test track: high speed oval, 4 km/lap 14 m distance: 0.4 s (120 km h-1) 1 s (50 km h-1)
In-let for on-road sampling • inlet: 4 mm (15 cm) • transfer line: 10.3 mm (420 cm) • total residence: 1.4 s
Constant speed tests • T= 3-6 °C, RH= 50 - 55 % (February 2003) • 10 min warm-up at 120 km h-1 • 8 min at 120, 100, 50 km h-1
Comparison: Lab & On-road chasing • 50km h-1 • PFSS: PDR: 12.5 DT: 32°C LR
Laboratory experimental setup - Makis part - Results of chassis dyno work comparison of instruments
Comparison: Lab & On-road chasing • 100km h-1
Comparison: Lab & On-road chasing • 120km h-1
Conclusions (1) • The PARTICULATES system is suitable to study the influence of the dilution parameters on nucleation • Longer residence time favours the growth of the nucleation particles and shifts the nucleation mode to larger diameters • Lower dilution air temperature enhances the formation of nucleation particles, with increased number and a distinct mode is formed at lower speed. • Chasing and lab experiments show that nucleation is not stable in a time scale of several minutes; dependent on vehicle history as shown in speed ramp tests
Conclusions (2) • The particle size distributions (only soot mode present) measured during chasing at 50 km/h were in very good agreement with dynamometer measurements • At about 100 km/h nucleation particles occur during the chasing experiment. The occurrence and in general the emission rate of these particles can be reproduced with the PARTICULATES system, if the dilution parameters are chosen in order to match the ambient conditions. • At 120 km/h a strong nucleation mode is observed in the exhaust plume. While the PARTICULATES system is capable to reproduce the soot mode very well, it shows a nucleation mode, which is somewhat lower in particle number, but larger in diameter.
Effect of chassis load • 100 km h-1 • simulated % grade
Effect of chassis load • 120 km h-1 • simulated % grade