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A diverse range of sources like, domestic, industries and vehicles contribute to the airborne particulate matter observed in the urban atmosphere. Impact of growing number of vehicles, with a compounded annual growth rate of 15%, on air quality is evident. The particles in gasoline and diesel vehicle exhaust carry distinctive combinations of certain chemical compounds. The prominence of their chemical signature in ambient particulate matter is thus a qualitative but direct indication of gasoline and diesel vehicles' relative importance as sources of emissions. The vehicle emission profiles generated, by PM characterization together with the ambient particulate matter speciation data, could be a realistic input to the source apportionment study for identification of sources of air pollution.

In recent studies, the health implications of ultra fine particle emissions from vehicles have been investigated in a number of international studies. The adverse health effects are not only dependent on total particulate mass but also on other attributes including size, number and surface area of the particles. These ultra fine particles cause more adverse effect than larger particles. With this need UNECE GRPE had launched a Particulate Measurement Program (PMP) to formulate the regulation to control both particulate mass and number of ultra fine particles. These new regulations are applicable to the diesel and gasoline direct injection passenger cars and heavy duty engines of Euro-V/VI technology. However, at present the other vehicle categories and alternate fuels are not been covered. Limited experiments have been carried-out on the in-use vehicles which are with old technologies.

The paper deals with methodology for selection of Emission Control Devices (ECD), test matrix and evaluation procedure followed for vehicles, engines and analysis of test results. In the present scenario, it is always being discussed that how existing vehicles and engines manufactured in India complying to Euro I /Euro II standard will perform with different sulphur percentage fuel. The emission control device such as Oxidation Catalytic Converter (OCC) is not very commonly used on the Euro-II vehicle and heavy-duty commercial vehicles. The performance of diesel oxidation catalyst on different sulphur percentage is of vital importance in Indian scenario. The particulate matter is always a concern in diesel vehicles and engines and most of Indian vehicles are having very low margin for particulate matter vis-à-vis regulation.

Two-stroke engine two- and three-wheelers comprise over half of the total vehicle population in South Asia and, as such, are likely to be significant contributors to particulate air pollution in large cities. Because there are no standards for particulate emissions from two-stroke engine gasoline vehicles, there is very little data available quantifying their emission levels. This study examined the procedure for measuring particulate emissions from two-stroke engines which comprise predominantly liquid droplets, and measured mass emissions from in-use three-wheelers to examine the impact of the engine condition, lubricant type and quantity, and fuel quality. The results are compared to smoke emission levels.

Six-seater three-wheelers have gained popularity among the commuters especially for their point to point low fares and better frequency compared to Municipal buses. However, pressure is mounting from all the quarters to ban these vehicles or to drive them out of the municipal limits. These vehicles with maximum loading capacity of 550 kg employ diesel engines which emit high soot & particulate matter or 2-stroke petrol engines which emit carbon monoxide as high as 13 g/km and hydrocarbon as high as 8 g/km, alarmingly high above the 1996 emission norms of 6.75 g/km CO and 5.40 g/km HC. Also the noise levels were higher. Considering the above threat, the authors had taken up the challenge to investigate and curb the pollution by employing high durability metallic catalytic converters.

An experimental study was conducted on a carburetted 2-stroke gasoline, 3-wheeler engine for operating on Compressed Natural Gas (CNG) in bi-fuel mode and further to run on dedicated CNG. Work involved design and development of a gas-air mixer for CNG, pumpless lubrication system for engine, cylinder heads for higher compression ratio, etc. Moreover, the studies for optimising the spark timing for improving CNG engine performance and effect of higher compression ratio on CNG emission, BSFC, etc. was conducted. Performance tests regarding power, BSFC, emission, etc. were conducted on baseline gasoline, bi-fuel CNG and dedicated CNG mode. Engine test bed results show that, on bi-fuel mode power loss is around 14 to 19%, which can be reduced to 5 to 10% in dedicated mode.

At present most of the Indian vehicles are fitted with rigidly mounted bumpers without energy absorbing devices. An alternative to the rigidly mounted bumper is considered by designing and developing various energy absorbing devices and energy attenuators such as elastomers in various shapes and sizes, the collapsible, sheet metal fenders, metal flat springs and the ‘U’ type energy attenuator. The various factors such as aerodynamics, aesthetic, easy removal and mounting of the bumpers were also considered while designing and fabrication of the bumpers. The sheet metal and Fibre Reinforced Plastic (FRP) bumpers are designed and fabricated in four different types with various combinations of elastomers, energy absorbing devices and attenuators. A major emphasis is given on low cost fabrication of three dimensional bumper shell, dies, moulds, collapsible and energy absorbing device.