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This paper is focused on the prediction of in-cylinder pressure, temperatures and engine-out NOx. One of the important factors influencing engine output parameters is the rate of heat release, which affects the in-cylinder pressure, temperature and engine out emissions. A single-zone model is formulated for prediction of heat release and in-cylinder pressure. Being a predictive model, this model does not required cylinder pressure as an input. Combustion pressure is predicted by modeling compression pressure, ignition delay, heat release, and heat loss. Required Sub-models have been obtained from the literatures. Fuel burning rate is predicted using Watson model. To retain the computational efficiency and better prediction accuracy a two-zone model has been formulated to predict NOx emissions. Flame temperatures are predicted by enthalpy balance. Thermal NO concentration is predicted by using basic Zeldovich mechanism.

Natural gas engines are finding wider applications in automobiles due to environmental and operating economics reasons. These applications include add on fitment in gasoline vehicles as well as replacement of diesel engines. In case of replacement of diesel engines, the gas engines are expected to have matching power curve. Typically the performance of an engine is characterized by following three parameters- Max Power, Max Torque, Low end Torque. Through engine design and optimization of engine these parameters can be matched to diesel engine. Then fly-up speed of the engine remains under consideration, which means the second half of engine power curve that is between Max Power speed point and fly-up speed. The present article deals with shaping of the Power-torque curve of an engine beyond Max Power point. The technique used here for Power Curve shaping is controlled leaning operation.

Design of an efficient cooling system for new generation engines has become a critical task, which requires to be handled optimally at the design stage itself. This approach helps in minimizing the optimization trials, saving time and cost for finalization of patterns and castings. Study of water jacket core in the engine cylinder head and block is of complex nature. Shape, size and location of transfer holes play a vital role in judging the eddies formation and hot spots. It is required to eliminate the hot spots, thus improving cooling efficiency and durability of the component. Use of CFD technique is found to be an effective design tool while dealing with such kind of complex flow problems. In this paper, effective utilization of FIRE CFD code is described for water jacket design of a modular two-cylinder diesel engine being developed from scratch.

Dual fuel operating strategy offers great opportunity to reduce emissions like particulate matter and NOx from compression ignition engine and use of clearer fuels like natural gas. Dual-fuel engines have number of potential advantages like fuel flexibility, lower emissions, higher compression ratio, better efficiency and easy conversion of existing diesel engines without major hardware modifications. In view of energy depletion and environmental pollution, dual-fuel technology has caught attention of researchers. It is an ecological and efficient combustion technology. This paper summarizes a review of recent research on dual-fuel technology and future scope of research. Paper also throws light on present limitations and drawbacks of dual-fuel engines and proposed methods to overcome these drawbacks. A parametric study of different engine-operating variables affecting performance of diesel-CNG dual-fuel engines vis-à-vis base diesel operation is also summarized here.

The world is facing a twin crisis of environmental degradation and fossil fuel depletion. Alternative fuels are seems to be a promising solution for low exhaust emissions. Liquefied Petroleum Gas (LPG) is a prominent alternative fuel with well developed distributed infrastructure and increasing number of Gasoline engines are now being converted to run on LPG considering the fuel economy and low exhaust emissions. This paper describes the bi-fuel (LPG/Gasoline) concept on a single cylinder engine. Air cooled Direct Injection (DI) diesel engine converted to operate on gasoline engine with electronic ignition system and it is having feature to change the spark ignition timing w.r.t. speed. The compression ratio was also reduced suitable to SI operation. CFD analysis was performed to review and subsequently to increase the cooling capacity of the engine.

This paper discusses experimental outcome of port fuel injected engines operated on gasoline mode and LPG mode. Eight Passenger car PFI engines were tested by using computerized engine data acquisition and control system on gasoline mode and LPG mode. Objectives of this experimental study were 1) To establish generic performance trend for group of newly introduced gasoline/LPG passenger car bi-fuel engines in Indian market. This trend has been established. 2) To compare performance of one sample engine in gasoline and LPG mode. This performance has been compared from performance characteristics curves in both modes. 3) To establish methodology to compare and contrast the performance of various types of Gasoline/LPG passenger car engines. This methodology has been established for a group of engines. 4) To define new normalized figure of merit suitable for the performance comparison of passenger car engines. A parameter power per unit displacement has been defined.

This paper presents emission studies of four LPG vehicles of different specifications. Emissions were tested as per LPG-Bharat stage III driving cycle. Emission tests were carried out for urban cycle and extra urban cycle. Total time for urban and extra urban cycle was 1180 sec. Engine was run in LPG mode by using conversion system. Emissions were tested as per standard procedure and were compared. Emissions of engines were compared with each other. Corrected emissions were computed by deducting ambient reading from sample reading. Paper describes detail emission test procedure and results obtained. CO emissions were in the range of 38.9 to 111.3 ppm. HC emissions were in the range of 18.2 to 62.6 ppm. Nox emissions were 08 to 3.9 ppm and CO2 emissions were from 6719.2 to 8051 ppm. Paper throws light on emission results of LPG vehicles recently introduced in Indian automobile market.

The physical and chemical properties of biogas affect the choice of technology used for biogas scrubbing and combustion; therefore, knowledge of these properties is useful for optimizing biogas utilization. Since biogas contains primarily as bulk components methane and carbon dioxide. Other trace components (nitrogen, hydrogen sulfide, and trace organics) are present in relatively small quantity, the magnitude of which varies greatly and depends on the composition of the material digested. Although the small concentration of these traced gases have little effect on the physical properties of the gas, which influence the choice of technologies. In the present work, the analysis of the biogas composition related to its effects on the physical properties of the gas and which influence the choice of technologies used for spark ignition engines is presented.

The rising demand for cleaner vehicles considering the upcoming stringent emission norms like Euro-IV has promoted development of CNG vehicles. The need for expensive after treatment technologies has imposed constraints on Euro-IV Gasoline and Diesel engine development. On the contrary CNG engines have easily met Euro-III norms with Carburetion technology and Euro-IV and beyond norms with Injection technology. CNG has proved to be a clean and environmentally friendly fuel, significantly improving the ambient air quality of cities. The addition of Hydrogen to CNG has potential to even lower the CNG emissions and is considered to be the first step towards promotion of a Hydrogen economy. Worldwide experts have described Hydrogen as the cleanliest fuel for IC Engines [1, 2 and 3]. Hythane is the patented blend of 15% of Hydrogen in CNG by Energy content. HCNG is the blend of Hydrogen and CNG in varying proportions.

In recent years the Government of India has supported the use of Liquified Petrolium Gas (LPG) in public and private vehicles. One of the ways to reduce emission is use of alternative fuels. Among alternative fuels, LPG is one of the most promising mainly because of its low exhaust emissions. The papers about LPG used in three wheeler, cars for SI or CI converted to SI engines had been published extensively in the last two decades. The applications of LPG to bi-fuel or single fuel engines are tried widely at this time. But the extensive study of LPG for small SI single cylinder two stroke engine of three wheeler two stroke engine is not reported in depth. This paper describes development of bi-fuel (LPG/Gasoline) concept of a single air cooled 200 CC single cylinder two stroke engine for three wheeler application.

Compressed Natural Gas (CNG) engine has proved itself to be worthy replacement for diesel in heavy commercial and passenger transport application all over the world. In India, infrastructure development of CNG distribution and stringent emission regulations have increased the interest shown by Original Equipment Manufacturers (OEM) to concentrate to development of CNG vehicles in every segment. Indian cities are fighting pollution due to high vehicle density and since contribution of light commercial vehicles in intra city application is significant, application of dedicated CNG vehicle has been made mandatory. This paper discusses the development of dedicated CNG engine using injection technology meeting the upcoming BS-IV norms. The primary modifications made are in the cylinder head, piston, intake and exhaust systems. The engine being developed for commercial application, the best in class fuel economy is of prime focus.

A duel fuel diesel engine is a diesel engine fitted with a dual fuel conversion kit to enable use of clean burning alternative fuel like compressed natural gas. Dual fuel engines have number of potential advantages like fuel flexibility, lower emissions, higher compression ratio, better efficiency and easy conversion of existing diesel engines without major hardware modifications. In view of energy depletion and environmental pollution, dual fuel technology has caught attention of researchers as a viable technology keeping in mind the increased availability of fuels like Compresed Natural Gas (CNG). It is an ecological friendly technology due to lower PM and smoke emissions and retains the efficiency of diesel combustion. Traditionally dual fuel technology has been popular for large engines like marine, locomotive and stationery engines. However its use for automotive engines has been limited in the past due to constraints of limited supply of alternative fuels.

Compressed Natural Gas (CNG) is now looked upon as a leading renewable fuel for vehicles in INDIA due to mounting foreign exchange expenditure to import crude petroleum. Impending stringent emissions regulations for diesel engines, specifically exhaust particulate emissions have caused engine manufactures to once again examine the potential of alternative fuels. Much interest has centred on CNG due to its potential for low particulate and hydrocarbon based emissions and adulteration hostile nature. Significant amount of research and development work is being undertaken in INDIA to investigate various aspects of CNG utilization in different types of engines. This paper discusses the methodology for conversion of a diesel engine to dedicated CNG engine and to make the engine to meet EURO-V norms. The primary modifications are made on the piston, cylinder head, intake manifold, throttle body adaptation and exhaust system.

Environmental degradation is on the rise due to the increased motor vehicle population. One of the strategies adopted to curb deteriorating environmental quality is the use of alternative fuels like Ethanol, Compressed natural gas and Liquefied Petroleum Gas. Natural gas is the world's most plentiful combustible fuel, abundantly available in all the continents. This naturally occurring fuel requires little or no treatment prior to use as compared to liquid petroleum products. Natural gas is also the lowest costing fuel. The use of CNG as an automotive-fuel results in significant reduction in the level of vehicular pollutants CO, HC, NOx, SOx, Pb and PM [1, 2, 3 and 4]. Additionally, the use of CNG results in reduction in the emissions of greenhouse gases (CO2), owing to the lower Carbon-to-Hydrogen ratio of the methane (CH4), as compared to other hydrocarbon fuels [5, 6 and 7].

In this paper, the results obtained during the optimization of the dedicated CNG 6-Cylinder naturally aspirated engine are described with the optimization strategy. Most of the diesel engines after conversion to CNG engines are having high valve overlap leading to high HC emission along with less fuel economy and high swirl leads to reduced volumetric efficiency. These issues were examined in detail and experimentation was carried out to assess the effect of low swirl thereby resulting in high flow leading to increase in volumetric efficiency and reduced emissions. The engine variables optimized for CNG operation were the engine compression ratio, ignition timing, spark plug selection, catalytic converter loading, design of first stage regulator with improved heating circuit and second stage pressure regulators, mixer venturi size, power screw setting, and intake/ exhaust system geometry.

To meet the latest trends in internal combustion engines pertaining efficiency, emissions and durability, downsizing of the engine has become the key focus area. This paper describes about a robust, reliable and an integrated approach used in design and development of state of art high power density/ high speed engine developed from the concept, which can be adopted for passenger car and LCV application. A three-cylinder, 1.5 liter displacement diesel engine, fully balanced is being designed with an objective to produce 115kW @ 4200 rpm, delivering a specific power output over 75 kW/liter, which is at par with a contemporary class of specification in it. In the first stage, a derated version of 75 kW (50 kW/liter) with Euro-IV and Euro-V specifications is targeted aiming at smaller car and light motor vehicle segment and a prime-mover for hybrid application.

The ever-increasing energy demand is a prime concern of entire world. As gasoline prices soar and concern over harmful emissions mount, vehicles which run on alternate fuel sources like LPG and CNG are becoming increasingly important. In this experimental study single cylinder pickup van engine was tested as per IS 14599 by using LPG and CNG as fuel. Ordinary fuel for vehicle is gasoline. Full throttle performance was tested at different speeds on computerized engine test set up with data acquisition system and AVL eddy current dynamometer. Important performance characteristic curves have been investigated and compared in CNG mode and LPG mode. Curve fitting has been done and equations with regression coefficient have been derived. Statistical analysis for different engine parameters has been done in LPG and CNG mode by using matlab software. It was observed that maximum power and maximum torque in LPG mode was more than that in CNG mode.

In this experimental study four stroke, four cylinder, MPFI, SI engines were tested as per IS 14599. A group of six bifuel engines with different specifications was tested in gasoline mode and LPG mode. Engines were converted by using modification system to operate in LPG mode. Objective of this experimental study was to compare performance and emissions of PFI passenger car engines in gasoline mode and LPG mode and to establish generic performance trend for LPG/Gasoline bifuel engines by defining and computing normalized figure of merit, power per unit displacement. From experimental results, generic performance trend for passenger car engines was established. A unit parameter KW/lit was calculated for each engine for comparison in relation to rated torque, maximum exhaust gas temperature and speeds corresponding to maximum torque and maximum power.

Biogas is one of the most promising alternatives fuel for the future. Biogas, when used in automotive field, will help to bring down harmful emissions. However, some technical improvements are still needed, especially in the Indian automotive sector. In this research work 100% biogas operated two wheeler four stroke SI engine has been tested for exhaust gas emissions. The result shows the lower emissions than the existing petrol engine limits without exhaust gas after treatment. The current work clearly indicates the breakdown of compression ratio barrier and it is shown that the engine runs smoothly at compression ratio of 11:1 without any tendency of auto-ignition. Experiments were conducted by varying compression ratios from 9:1 to 11:1 and retaining the combustion chamber design. This study shows that using biogas in SI engines, it is particularly beneficial to reach interesting conversion efficiencies with low emissions.

This paper presents results and discussions of two hundred hours endurance test carried on single cylinder four-stroke cycle LPG cargo pickup van engine. Engine was run in cycle as suggested by manufacturer. Engine was run for one hour at speed corresponding to maximum torque and then it was run for one hour at speed corresponding to maximum power. This cycle was repeated for two hundred hours. Effects of endurance test on components of engine were studied. Engine was tested before endurance test at full throttle position and same engine was tested after endurance test at full throttle position. Performance of engine before and after endurance test has been compared and discussed. Objective of this experimental work was to study effect of endurance test on different components of engine and analyze and compare performance of engine before and after endurance test. Graphs of important engine parameters have been plotted and curve fitting has been done.