Search Results

The tailpipe exhaust emissions were measured using a EURO4 emissions compliant SI car equipped with on-board measurement systems such as a FTIR system for gaseous emission, a differential GPS for velocity, altitude and position, thermal couples for temperatures, and a MAX fuel meter for transient fuel consumption. Various nitrogen species emissions (NO, NO2, NOx, NH3, HCN and N2O) were measured at 0.5 Hz. The tests were designed and employed using two real world driving cycles/routes representing a typical urban road network located in a densely populated area and main crowded road. Journeys at various times of the day were conducted to investigate traffic conditions impacts such as traffic and pedestrian lights, road congestion, grade and turning on emissions, engine thermal efficiency and fuel consumption. The time aligned vehicle moving parameters with Nitrogen pollutant emission data and fuel consumption enabled the micro-analysis of correlations between these parameters.

New EU environmental law requires 31 ozone precursor VOCs (Volatile Organic Compounds) to be measured for urban air quality control. In this study, 23 out of the 31 ozone precursor VOCs were measured at a rate of 0.5 HZ by an in-vehicle FTIR (Fourier Transform InfraRed) emission measurement system along with 15 other VOCs. The vehicle used was a EURO2 emission compliant SI car. The test vehicle was driven under real world urban driving conditions on the same route by the same driver on different days at different ambient temperatures. All the journeys were started from cold. The VOC emissions and OFP (Ozone Formation Potential) as a function of engine warm up and ambient temperatures during cold start were investigated. The exhaust temperatures were measured along with the exhaust emissions. The temperature and duration of light off of the catalyst for VOCs was monitored.

The emissions from vehicles in real world driving are of current concern, as they are often higher than on legislated test cycles and this may explain why air quality in cities has not improved in proportion to the reduction in automotive emissions. This has led to the Real Driving Emissions (RDE) legislation in Europe. RDE involves journeys of about 90km with roughly equal proportion of urban, rural and motorway driving. However, air quality exceedances occur in cities with urban congested traffic driving as the main source of the emissions that deteriorate the air quality. Thus, the emissions measured on RDE journeys may not be relevant to air quality in cities. A Temet FTIR and Horiba exhaust flow measurement system was used for the mass emissions measurements in a Euro 4 SI vehicle. A 5km urban journey on a very congested road was undertaken 29 times at various times so that different traffic congestion was encountered.

Different driving test cycles, the Leeds-West Park (LWP) loop and the Leeds-High Park (LHP) or HPL-A and B (Leeds-Hyde Park Loop-A or B, hereafter referred as HPL-A or B cycle) loop were selected for this urban intersection research and results are presented in this study. Different emissions-compliant petrol passenger cars (EURO 1, 2, 3 and 4) were compared for their real-world emissions. A reasonable distance of steady state speed was needed and for the analysis made in this paper were chosen vehicle speeds at ~20, ~30 and ~40 km/h. Specific spot of periods of driving at the speeds mentioned above were identified, then the starting and ending point was found and the total emissions in g for that period divided by the distance was calculated. A typical urban driving cycle including a loop and a section of straight road was used for the comparison test as it was similar to the legislative ECE15 urban driving cycle.

EU environmental law requires 30 ozone precursor volatile organic compounds (VOCs) to be measured for urban air quality control. In this study, 28 ozone precursor VOCs were measured at a rate of 0.5 Hz by an in-vehicle FTIR emission measurement system along with other VOCs. The vehicle used was a Euro 3 emission compliant diesel van. The test vehicle was started from a cold ambient temperature soak and driven under real world urban driving conditions. Diesel and B100 (100% Biodiesel) were compared using the same repeat journeys. The VOC emissions and OFP (ozone formation potential) were investigated as a function of engine warm up and ambient temperatures during cold start. The exhaust temperatures were measured along with the exhaust emissions. The temperature and duration of light off of the catalyst for VOC were monitored and showed a cold start period to catalyst light off that was considerably longer than would occur on the NEDC (New European Driving Cycle).

A cold start Euro 3 1.8 litre Diesel vehicle with an oxidation catalyst was used to investigate real world exhaust emissions over a driving cycle that included urban cold start congested traffic driving conditions. The aim was to identity those aspects of cold start real world driving responsible for higher emissions than in test cycles. Higher real world emissions may contribute to the problem of air quality in urban areas, which has not improved in quality in proportion to the reduced in vehicle exhaust emissions. Diesel, B50 and B100 fuel were compared to determine if real world driving effects were worse for B50 and B100 fuels due to their lower volatility and higher viscosity. The biofuel was WRME, derived from waste rape seed cooking oil. A multifunctional additive package was added to the biofuel at 800ppm to control fuel injector deposit formation. Gaseous emissions were monitored using an on-board heated Temet FTIR exhaust emission analyzer.

The tailpipe exhaust emissions were measured under real world urban driving conditions by using a EURO4 emissions compliant SI car equipped with an on-board heated FTIR for speciated gaseous emission measurements, a differential GPS for travel profiles, thermocouples for temperatures, and a MAX fuel meter for transient fuel consumption. Emissions species were measured at 0.5 Hz. The tests were designed to enable cold start to occur into congested traffic, typical of the situation of people living alongside congested roads into a large city. The cold start was monitored through temperature measurements of the TWC front and rear face temperatures and lubricating oil temperatures. The emissions are presented to the end of the cold start, defined when the downstream TWC face temperature is hotter than the front face which occurred at ∼350-400oC. Journeys at various times of the day were conducted to investigate traffic flow impacts on the cold start.