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A thermodynamic cycle simulation model is described for a dual fuel open combustion chamber compression ignition engine. The model has been formulated for the compression, combustion, expansion, exhaust and intake processes. The combustion model is simulated by estimating the heat release rates due to the injected dissel fuel and the secondary fuel (biogas) supplied through the intake manifold. The injected fuel's heat release rate is computed from the preparation and burning rates, uhile that of the biogas is determined from the entrainmBnt of air and biogas mixture into the fuel spray. A finite difference scheme is employed to solve the gas exchange process for both the exhaust and intake systems. The overall comparison shous that the model satisfactorily predicted the experimental data.

A thermodynamic simulation model for the 4-stroke cycle of a single cylinder spark ignition engine operating on neat methanol is described in this paper. The development of the model for all the processes is illustrated. It computes the gas pressure, gas temperature and the rate of formation of nitric oxide and carbon monoxide at each crank angle using basic energy equation and reaction kinetic mechanism. A gas exchange model has been formulated by finite difference scheme to evaluate the mass flow rate through valves and the properties in the intake and exhaust systems. The validation of the above model has been carried out by comparing the predicted and experimental data at different operating conditions encompassing changes in fuel-air equivalence ratio, speed, load, spark timing and compression ratio. The special characteristics of methanol such as rapid burning rate, high power output and reduced nitric oxide emissions have been truthfully predicted by the model.

In this paper the experimental investigations relating to the performance and emission characteristics of a single cylinder spark ignition engine operating on a newly designed gasoline fuel injection system are described. This gasoline fuel injection system was operated under port and manifold injection configuration by controlling the duration of injection with an analogue based control system, which uses the information corresponding to engine speed and throttle positions. A comparison between the manually controlled fuel injection system with that of the analogue controlled version had indicated that the overall performance of the analogue base fuel injection system is better than that of the manually controlled system fuel injection.

Experimental investigations relating to the comparative assessment of the performance and emission characteristics of port and manifold gasoline injection systems of a single cylinder four stroke spark ignition engine are described. These investigations have been carried out under carburettor, port injection and manifold injection modes The experiments pertaining to the injection mode were conducted for both the single and double hole injectors by optimising the injection pressure, injection timing and its duration. Optimisation of injection timing and duration was done in terms of engine crank angle by means of a newly designed crank angle selection unit in conjunction with a developed optical crank shaft encoder capable of generating pulses at one degree crank angle intervals.

Experimental investigations relating to the performance and emission characteristics under idling conditions of a three cylinder passenger car spark ignition engine operating on a conventional carburettor and a developed single point gasoline fuel injection system are described in this paper. The idling performance at different engine speeds was studied by carrying out comprehensive engine testing on a test bed in two phases. In the first phase, experiments were conducted on an engine fitted with a conventional carburettor whilst they were extended to the engine provided with a developed electronic single point fuel injection (SPI) system, whose fuel spray was directed against the direction of air flow. The injection timing of the SPI system was varied from 82 deg. before inlet valve opening (or 98 deg. before top dead center) to 42 deg. after inlet valve opening (or 26 deg. after top dead center).

Ethanol is an alternative renewable fuel produced from various agricultural products. Ethanol-diesel emulsion technique is used for the utilization of ethanol in diesel engines wherein ethanol is used without any modification. The performance, combustion and emission characteristics of a direct injection (DI) diesel engine for off-highway application were evaluated using ethanol-diesel microemulsions. The addition of ethanol to diesel fuel simultaneously decreases calorific value, kinematic viscosity and stability of fuel. Ethyl acetate was used as an additive/ingredient to keep the blends in homogeneous and stable state. Blends (D80/E13/EA07; D70/E17/EA13; D60/E23/EA17) were selected for engine experiments based on stability behavior and fuel properties. The results showed no significant power reduction in the engine operation with ethanol-diesel microemulsions.

This paper describes the experimental investigations on a single cylinder, two stroke spark ignition engine in the carburettor and in-cylinder injection (GDI) modes. The experiments were conducted on the engine in the carburettor mode up to 80% throttle opening and for different combinations of speed and load. The engine was modified and fitted with an in-cylinder injector in the head. Fuel was supplied through injector with the help of a high pressure DC pump. Experiments for varying speed and load were conducted under in-cylinder injection mode up to 80% throttle opening. It was observed that there is a significant reduction in BSFC, unburnt HC and CO emissions. Also, the power output of the engine has shown an improvement.

In a dual fuel engine a primary fuel that is generally a gas is mixed with air, compressed and ignited by a small pilot- spray of diesel as in a diesel engine. Dual fuel engines generally suffer from the problem of lower brake power and lower peak engine cylinder pressure due to lower volumetric efficiency, although an improvement in brake specific energy consumption is observed compared to pure diesel mode. Results indicate that with an increase in percentage of CNG substitution the brake power decreases. The exhaust gas temperature and peak cylinder pressure also decrease. The rate of pressure rise is higher at lower engine speeds (1100, 1400 rev/min), although at 1700 and 2000 rev/min it is lower. The delay period throughout the engine speed shows an increasing trend. The coefficient of variation is also higher throughout the engine speeds and shows an increasing trend. The brake specific energy consumption is lower at 1100, 1400 and 1700 rev/min and at 2000 rev/min it is higher.

The methyl ester of karanja oil, known as biodiesel, is receiving increasing attention as an alternative fuel for diesel engine. This paper presents the results of investigations carried out in studying the fuel properties of karanja oil methyl ester (KOME) and its blend with diesel from 20% to 80% by volume and in running a DI diesel engine with these fuels. Engine tests have been carried out with the aim of obtaining performance characteristics such as Brake specific fuel consumption(BSFC), brake thermal efficiency, brake power, exhaust gas temperature, emission such as CO, UBHC, NOx, smoke opacity and combustion parameters to evaluate and compute the behavior of the diesel engine running on KOME and its blends with diesel fuel. The addition of KOME to diesel fuel has significantly reduced CO, UBHC and smoke emissions but it increases the NOx emission slightly.

Experimental investigations relating to the use of producer gas in a spark ignition engine are reported in the proposed paper. The experimental setup consists of a single cylinder diesel engine converted to operate on a spark ignition engine mode coupled to a swinging field electrical dynamometer. A downdraft closed top charcoal gasifier has been used to generate the producer gas. After cooling and cleaning, it is fed to a venturi type gas carburetor, which ensures proper mixing of gas and air before it enters the engine. Testing of the converted engine was carried out under gasoline mode at a specified compression ratio. However subsequent tests on producer gas operation were performed at different compression ratios. The significant outcome of the present investigations include the satisfactory conversion of diesel engine to a spark ignition mode for neat producer gas operation and satisfactory operation of gas carburetor designed and developed for the purpose.

Performance, combustion and emissions investigations relating to the use of gasoline injection in a spark ignition engine are described in this paper. The engine used for experimental purpose is a motorcycle engine of 13.4 kW (18 HP). Experimental engine test setup is designed to operate in carburetion as well as in injection mode [1]. Electronic controlled throttle body injection system is designed to operate test engine in injection mode. This paper also present the procedure used for gasoline fuel injection optimization and discussed the results obtain for minimum fuel consumption, for maximum power and for minimum brake specific fuel consumption, for optimization of the start of injection (i.e. injection delay), injection duration and injection pressure, for the entire operating range, of the research engine used for investigation.

The increasing use of natural gas as a vehicle fuel has generated considerable research activity to characterize the performance of engines utilizing this fuel. A light duty prechamber diesel engine was run under naturally aspirated and turbocharged CNG- Diesel dual fuel mode at four engine speeds 1100, 1400, 1700 and 2000 rpm. The maximum percentage of CNG substitution continues up to the engine knock limited power. The experimental results indicate a fall in brake power under naturally aspirated CNG-Diesel dual fuel mode compared to neat diesel operation. It was due to decrease in volumetric efficiency and slower combustion. Although turbocharged dual fuel operation shows an increase in brake power as well as an improvement in brake specific energy consumption as it provides a better air/fuel mixing and improves the homogeneous natural gas/air charge.

A method of measuring exhaust velocity with respect to crank angle in a 4-stroke spark ignition engine is described as is a new method of automatically selecting a crank angle in an engine under running conditions. The method of obtaining the exhaust velocity, using the selected crank angle, is also dealt with. The exhaust velocity measured for both motoring and firing conditions is included. The results provided for the firing conditions include different exhaust configurations. The cycle-to-cycle fluctuation is also provided for the above configurations.

Performance, combustion and emission characteristics relating to the use of 20% methanol and 80% gasoline in a spark ignition engine are described in this paper. The engine used for experimental purpose is a motorcycle engine of 13.4 kW (18 hp). A new online multi liquid fuel mixing system has been developed for perfect mixing and hence found to be better for investigating effects of Methanol - Gasoline blend (M20) which enhances engine performance and reduces exhaust emissions. Performance tests conducted under Throttle Body Injection (TBI) showed considerable performance improvement in power output and in thermal efficiency, as well as substantial reduction in BSFC, HC, and CO emissions than that of a conventional carbureted engine. The results of this work can contribute to improve the air pollution in the urban area.

In this paper the experimental investigations relating to the performance and emission characteristics of a single cylinder spark ignition engine operating on a newly designed gasoline fuel injection system is described. This gasoline fuel injection system was operated under port injection configuration by controlling the duration of injection with PC based control system, which uses the information corresponding to engine speed and throttle positions. A comparison between the manually controlled version had indicated that the overall performance of the PC based fuel injection system is better than that of the manually controlled system fuel injection system.

A mathematical model for the gas exchange process and to estimate the pressure, temperature, velocity and mass flow rate at selected points in the exhaust and intake systems of a 4 stroke, single cylinder spark ignition engine is described. In order to evaluate the model, the computed data of gas pressure in intake system was compared with the experimental data while for the exhaust, the comparison include gas pressure and velocity. A satisfactory correlation was observed between the computed and test data.

This paper deals with the development and evaluation of a mathematical model for a 4-stroke, single-cylinder, spark ignition engine. This paper has two parts. The first part describes the development of the mathematical model and the computer program. The assumptions that were made in the model are also described. The instruments that were developed for the evaluation of the model are included in the second part, which also contains the evaluation of the results obtained from the model. The simulation results are found to agree well with the experimental data.

A Comprehensive computer simulation model was developed for a single cylinder spark ignition engine to simulate the Compression, Combustion, Expansion, Exhaust and Intake processes including the heat losses through the cylinder walls. The gas exchange processes were simulated with the help of a finite difference scheme and a separate boundary condition was developed for the throttle action on a conventional carburetor. The model after validating with the experimental data was used to arrive at the optimum duration and lift of the intake valve corresponding to different throttle positions of the equivalent conventional engine. These optimum values were used in the design of a 3 dimensional cam. Based on this design a new variable valve timing engine (VVT) has been designed and developed. Comparison between the computed and experimental data for the VVT engine was observed to be satisfactory.

The effect of variation in injection pressure and Injection timing on the performance and exhaust emission characteristics of a direct injection, naturally aspirated Diesel engine operating on Diesel and Diesel-Biodiesel Blends were studied. A three-way factorial design consisting of four levels of injection pressure (150,210, 265,320 bar), four levels of injection timing (19° btdc, 21.5° btdc, 26° btdc, and 30.5° btdc) and five different fuel types (D100, B10, B20, B40, and B60) were employed in this test. The experimental analysis shows that when operating with Linseed Oil Methyl Ester-Diesel blends, we could increase the injection pressure by about 25% over the normal value of 20MPa. The engine performance and exhaust emission characteristics of the engine operating on the ester fuels at advanced injection timing were better than when operating at increased injection pressure.