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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.

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.

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.

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.

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.

The objective of this paper is the prediction of efficiency and NOx emission of a Spark Ignition engine based on engine design and operational parameters using artificial neural networks (ANN). This paper deals with quasi-dimensional, two-zone thermodynamic simulation of four-stroke SI engine fueled with biogas. The developed computer model has been used for the prediction of the combustion and emission characteristics of biogas in SI engines. Predicted results indicate that the presence of carbon dioxide can reduce oxides of nitrogen (NOx) emissions, but since lower cylinder pressures result, engine power and thermal efficiency are reduced. This is mainly due to the lower heating value of biogas. Using the results from this program, the effects of operational and design parameters of the engine were investigated. For real time computations in electronic control unit (ECU) an artificial neural network (ANN) model has been suggested as an alternative to the engine simulation model.

The purpose of this work was to obtain a detailed comparison of engine performance and exhaust emissions from compressed natural gas and gasoline fueled Spark Ignition (SI) engines. This research deals with a quasi-dimensional, two-zone, thermodynamic simulation of four-stroke SI engine fueled with a wide range of liquid and gaseous fuels. The results show that the power output of the engine was reduced when fueled by natural gas due to its low volumetric efficiency, but both fuels exhibited nearly equal thermal efficiency. Significant lowering of flame propagation rates with the lower hydrocarbons (methane, ethane, propane) of natural gas fueled spark ignition engine is observed with the corresponding increases in the average length of the combustion duration and ignition delay times. The validity of the model has been carried out with reliable data obtained under same engine setup and yields satisfactory agreement with the corresponding predicted values.