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Advances in renewable energy sources and impact of green house gases on climate change have led intense research in the area of renewable energy for transport and power generation sectors. All over the world gaseous fuels have gained momentum as an ideal alternative fuel for meeting future energy needs. Hydrogen enriched compressed natural gas (HCNG) may be considered as an alternative automotive fuel which does not require any major modification in the existing CNG engine and infrastructure. Several studies of HCNG fuel were reported on small and light duty engines / vehicles, but limited reports are available on heavy duty engines. In this study, experimental investigations were carried out on a 6 cylinder heavy duty CNG engine which has been optimized for 18 percent HCNG. Initial performance of the engine on HCNG was compared vis-à-vis CNG and, thereafter, the engine was subjected to endurance test as per BIS 10000 norms for 100 hours (severe cycle) with HCNG.

Use of biofuels derived from biomass, bioethanol, biodiesel, etc., are being seriously viewed from multidimensional perspective of depleting fossil fuel resources, environmental health, energy security, agrarian economy and new avenues of gainful employment. For the best use of available biofuels in diesel, a new blend was prepared which constituted 85% diesel + 5% ethanol + 10% biodiesel and was evaluated on Light Commercial Vehicle. This paper discusses the systematic performance evaluation of blended fuels and is compared with neat diesel with respect to lubricity, fuel economy in the steady speed ranges of 40 - 70 km/hr, driving cycle fuel economy, exhaust emissions like CO, HC, CO₂, O₂, NOx, smoke and characterization of particulates including particle size distribution. Synergy of 5% ethanol + 10% biodiesel in diesel was compared with diesel when the fuel was used as individual blends.

Gasoline components play a prime role in the formation of deposits on engine components. In order to reduce the deposit forming tendency of fuels, oil marketing companies dope the multi functional additives in gasoline for trouble free operation over a longer period of time. For assessing intake valve deposits and combustion chamber deposits forming tendency of gasoline/additised gasoline, Coordination European Council (CEC) has established the engine test method CEC F-20-A-98 on Mercedes Benz M 111 gasoline engine. The above test method is able to discriminate IVD and CCD formation tendency with neat fuel and additised fuel. In the present work, an effort has been made to discriminate between the additives and an attempt has also been made to understand their impact on emission characteristics.

Though there are different chemicals used in oxygenated diesels, their high level blending has its own disadvantages. For this investigation, three compounds were selected on the basis of their oxygen level and flash point [1]. These low level blends are tested in a single cylinder naturally aspirated direct injection diesel engine. Performance of the blended diesel compared with the performance of pure diesel. The influence of the blended diesel on power, brake thermal efficiency, cylinder peak pressure, smoke level and particulate matter are studied. From the tests it was concluded that 2-Ethoxy Ethanol performs better in terms of both emission and efficiency.

Part substitution of alcohol in gasoline alters the composition and combustion characteristics leading to different particulates as emitted by individual fuel. This paper presents the test work done on characterisation of particulate number concentration emitted from four stroke engine powered two wheeler with neat Euro III gasoline and its blend with ethanol (5, 10, 20 & 30 %) using Electrical Low Pressure Impactor (ELPI). The characterisation of particulates was carried out under different operating conditions viz. Indian Driving Cycle (IDC), Road Load Simulation (RLS) and Wide Open Throttle (WOT) conditions on Chassis Dynamometer with the test fuels. It was observed from the study that for all the test fuels, the number concentration increases as the particulate size reduces. Further, it was observed that addition of ethanol in neat Euro III gasoline has reduced the particulate number concentration both in transient and steady speed conditions.

An experimental study was conducted on in-use and new, Indian two-wheelers to study the effect of gasoline composition (olefins, aromatics and benzene) on exhaust mass emissions. Exhaust emissions of benzene were also measured. The study was conducted on six makes of new and in-use, two-wheelers consisting of popular 2-stroke and 4-stroke, mopeds, scooters and motorcycles. Three test fuels, a high olefin gasoline, a high aromatic gasoline and a Euro-III equivalent gasoline were used for the study. High olefin test gasoline contained 26.5% olefins, 10.3% aromatics and 0.3% benzene. High aromatic test gasoline contained 0.9% olefins, 61.9% aromatics and 1.5% benzene. Euro-III test gasoline contained 15.9% olefins, 37.4% aromatics and 0.9% benzene. Intake system deposit study was also conducted on 4-stroke motorcycles and two-stroke scooters having separate lubrication, using two fuels, i.e. high olefin gasoline and Euro-III gasoline, with and without the use of multi-function additives.

Field trials were conducted on two-stroke engine powered two-wheelers with 5%, 10 % ethanol and 3 % methanol. The performance and emissions of vehicles operating on these fuels were compared to those with neat gasoline up to 20,000 km. No significant change in fuel economy was observed with 5 % ethanol and 3 % methanol, however about 1.1 % loss was observed with 10 % ethanol. Emission test conducted after mileage build-up showed reduction of carbon monoxide (CO) with 5 % and 10 % ethanol, while increase of CO was observed with 3% methanol. Total hydrocarbon emissions increased on mileage build-up with all the test fuels. Merit rating of engine components after 20,000 km indicated that the ratings were better for 5 % ethanol blended gasoline. Startability and drivability problems were observed with 3% methanol after completing 10,000 km.

Optimization of catalytic converter related to flow improvements, cost and conversion of pollutants using computational model and computational fluid dynamics (CFD) are described in this paper. A computational model is developed for predicting the performance of Pd/Rh catalytic converter at wide range of operating conditions. An experimental investigation was done on Pd/Rh catalytic converter for validating the model. Optimization of the catalytic converter was carried out based on three parameters namely catalytic converter length, cell densities and typical metal loading. The cell densities varied from 200 cpi to 1200 cpi. The length of the catalytic converter varied from 70 mm to 180 mm. About 8 patterns were studied on Pd/Rh catalytic converter. The predicted patterns show that about 48 percent precious metal can be saved by proposed metal loading patterns.

Biofuels derived from renewable plant sources (tree borne vegetable oil) hold immense potential for meeting India's future energy needs. The pure vegetable oils need chemical treatment to be ready as engine fuel. This chemically treated vegetable oil is called Biodiesel. This paper investigates vehicle performance of different blends of biodiesel as engine fuel. Biodiesel used for these studies was derived from Jatropha curcus. Blends of Biodiesel upto 15% did not affect the engine power while blends with higher proportion of Biodiesel showed tendency to decrease the engine power. Best fuel economy was observed with 10% biodiesel blended fuel. Oxides of Nitrogen (NOx) emissions, increased under different operating conditions while smoke was reduced at all speed ranges in Road Load Simulation and Wide Open Throttle test modes.

In an earlier paper[1] we had emphasized the need for diesel engine lubricants meeting specific built-in specifications to combat the stress emanating out of the geographical, operational and engine design requirements in Indian subcontinent for heavy duty sectors. In this paper we present our work in identical domains for a segment utilizing passenger car and/or utility vehicles. This paper presents our work on development of a diesel engine oil to meet the specific requirements of a thermally-stressed IDI engine with respect to key performance attributes. The laboratory optimization for thermo-oxidative stability typical of requirements for IDI engines coupled with higher level of dispersancy and wear inhibition that are identified with current generation lube oils have further been established in engine test programs. The superior performance has been established in endurance test on a representative engine.

The investigations relating to the evaluation of an automobile catalytic converter are reported in this paper. These investigations are aimed at arriving at a data that would pave the way for the optimization of a catalytic converter by experimental and computer simulation at steady and transient operating conditions The converter used in the present study contains Pd, Rh binary catalyst (10:1) impregnated on ultra thin ceramic substrate. Characterization of catalytic converter was done for its compositions using Inductively Coupled Argon Plasma (ICAP) and Scanning Electron Microscope (SEM). The necessary instrumentation developed, which include pre and post converter emissions, backpressure and exhaust gas temperature are described for both steady and transient conditions. The experimental setup has been designed for assessing the performance of a catalytic converter on a passenger car at different operating conditions.

Performance of a Current generation catalytic converter using Pd/Rh (10:1) as binary catalyst impeded on an ultra thin ceramic substrate and alumina wash coat is modeled for performance prediction and parametric optimization. Kinetic rates for the catalyst are reduced after conducting series of experiments on a passenger car engine. A new concept in mass transfer coefficient is introduced for improving accuracy of the model prediction. In order to take care of the precious metal resources and to become independent of precious metal price fluctuation, a new pattern of loading of precious metal is suggested for optimum performance and metal savings about 46 percent was observed. Experimental investigations were carried out to validate the established kinetic rates over a wide range operation of the engine and for the model validation. Satisfactory agreements are observed for the model prediction and experimental results.

Current generation of metal monolith using binary catalysts Pt/Rh (5:1) is simulated for transient temperature and conversion inside a catalytic converter during warm-up. A new concept in mass transfer on a catalytic combustion is introduced in this model for improving accuracy is known as Reynolds analogy. Design parameters and operating conditions are investigated for its influence on solid temperature and conversion of species. New patterns of precious metal loading have been investigated for metal savings and maximum conversion efficiency. Satisfactory validation of computed data was observed.