The objective of this study was to design, develop and qualify the Compact Mobile Emissions Measurement System (CMEMS) for real-time on-board measurement of exhaust emissions from heavy-duty diesel vehicles. This study was aimed at developing a system more compact and lighter with respect to the existing Mobile Emissions Measurement System (MEMS), so that the entire system could be mounted on the tail pipe of the test vehicle in order to reduce installation time, power requirements and manpower requirements. This was achieved by judicious selection of commercially available compact solid-state gas analyzers, and development of a sampling system which was significantly smaller than the existing system in the MEMS. Accuracy, linearity, repeatability, interference and response time tests were conducted on all analyzers and components of the sampling system. Pressure and flow rate variation, vibration and inclination tests were also conducted to qualify the system for harsh on-board conditions. Components of the sampling system were selected based on several criteria, such as size, weight, power consumption, robustness and cost. After complete integration, the system was tested on the tail pipe of a Ford F450 Pickup truck and also in an engine laboratory on a DDC series 60 engine to document the system's performance against the MEMS and the laboratory. On a concentration basis, the CMEMS reported a maximum percentage difference of 5.18% for NO x and 3.10% for CO 2 against the MEMS in two on-road tests, which were conducted on a Ford F450 pickup truck. In addition, the CMEMS also reported a difference of 2.36% for NO x and 2.69% for CO 2 measured on the g/s basis against laboratory grade analyzers on seven FTP runs on a 1992 DDC series 60 engine. Differences of 1.87% for NO x and 1.51% for CO 2 were reported on the g/s basis against the laboratory grade analyzers when the series 60 engine was exercised on a simulated on-road cycle. iii Acknowledgment I always thank God for any good thing that takes place in my life. This document is one such good thing for which I cannot thank him enough. There are many more people to whom; I owe many special thanks and sincere gratitude in trying this pursuit of education and learning. However, one person to whom I cannot thank enough is Dr. Gautam. He is a special friend with many; including my family; great advisor to some of the best products of the research arena, and immense support for his family. I was privileged to have him as all. Therefore, waiting no longer, I owe this thesis and a greater part of my personal development to Dr. Gautam. But for him, this pursuit would have never come into existence. I also thank Dr. Clark and Dr. Shade for presiding over the defense committee for this thesis document. Family always stays to my heart's closest. I love my parents and my younger brother and therefore, thank them all for every thing. At this point, I desire to thank Gurudutt for all the professional and emotional support. He inspired me to look beyond my own aspirations and foc...
Evolution of automotive air conditioning was a remarkable milestone in the history of mankind. It has played an important role in human comfort and to some extent in human safety during vehicle driving in varied atmospheric conditions. This research focuses on providing comfort conditioning of a tractor cab which is a key factor in ensuring optimum working performance of the driver. A closed tractor cab acts like a greenhouse and its interior could become unbearable and sometimes even dangerous. Conventionally, vapor-compression refrigeration systems are standard for air conditioning in automobiles and account for up to 25 % of fuel consumption in the cooling season. Apart from conventional vapor-compression technology, this paper explores applicability of evaporative cooling in comfort conditioning of a tractor cabin which is an economical and eco-friendly alternative. The prototype performance lowered cabin temperature close to acceptable limit with less than 10 % of energy consumption compared to vapor-compression units when tested under similar hot-dry conditions. Keywords Automotive air conditioning Á Evaporative cooling Á Cabin cooler Á Tractor cabin cooler List of symbols A Area (m 2) h o Specific enthalpy of air in the cabin at steady state (kJ/kg) h o 0 Specific enthalpy of air at fan exit (kJ/kg) M air Mass flow rate of air (kg/s) M w Water consumption rate (kg/h) RH Relative humidity Ti dbt Inlet air dry-bulb temperature (ambient) To 0 dbt Dry-bulb temperature of air at fan exit V air Volume flow rate of air (m 3 /s) v Velocity of air (m/s) w i Humidity ratio of inlet air (kg moisture/kg dry air) w o Humidity ratio of air at fan exit (kg moisture/kg dry air) Greek symbols l Effectiveness q Density of air (kg/m 3
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