Search Results

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.

Today's automotive exhaust systems are developed to deliver minimum noise, emissions and maximum durability based on the legislative and performance requirements. In addition, they must also meet requirements of packaging, safety, flow rates, lower system restriction, high temperature compatibility, corrosion resistance, easy serviceability and cost effectiveness. These challenging requirements cannot be met effectively without a systems approach. The exhaust system development process starts with selection of design methodology and evolution of checklists for system design specifications and definition of targets. System design specifications are elaborated with reference to performance, durability, legislation, installation, manufacturing / assembly / service considerations, etc. Checklists for exhaust system clearance and design review are given.

In this work a simple 1-D model for the macro kinetic conversion behaviour of a commercial automotive Three-way-exhaust catalyst for a Turbocharged DI-Gasoline-Engine is realized using GT-Power. A detailed reaction kinetic model to predict the activity of the commercial three way catalyst has been adopted from Young-Deuk [1], considering all possible reactions in the catalytic converter based upon the Langmuir-Hinshelwood mechanism. 1D model was later modified for the laboratory scale catalyst and validated against synthetic gas test bench data.

Application of Diesel Particulate Filter (DPF) will become necessary for trapping diesel particulate matter especially with stringent Emission Legislation of Euro IV and beyond. While developing a DPF, conflicting requirements like low-pressure drop, high thermal durability, high compressive strength, high trapping efficiency and practical regeneration needs to be considered. This paper focuses on the development and optimization of cost effective ceramic based DPFs for a diesel utility vehicle. The effect of DPF diameter, length, cell density and wall thickness on the pressure drop in fresh as well as soot laden conditions are evaluated, based on which the final size of DPF is determined. Special attention to substrate making, coating, canning, temperature and pressure feedback is given. Strategies for DPF regeneration like catalyzed and additive regeneration are evaluated.