Applied Mechanics and Materials Vols. 813-814

Abstract: Rapid depletion of conventional fuels and growing requirements has led the researchers towards alternative sources like bio-fuels. Present work discusses the suitability of those bio-fuels in a naturally aspirated diesel engine by comparing the performance. Initially, the effect of bio-fuels on fuel consumption and thermal efficiencies are studied and compared with diesel. Thermal efficiency is improved and specific fuel consumption reduced, particularly with karanja oil when compared to diesel. Secondly, the energy balance of the engine is compared. Heat losses are found reducing in bio-fuels due to viscosity and heat rejected to coolant is found less with karanja oil when compared to diesel. Also, the engine emissions, particularly oxides of carbon, nitric oxides, and unburned hydrocarbons from bio-fuels and diesel are sensed using five-gas analyzer and compared. NO_x and CO₂ emissions are slightly more in bio-fuels when compared to diesel, while CO and HC emissions are less for bio-fuels.

Abstract: The present energy situation has stimulated active research interest in non-petroleum and non-polluting fuels, particularly for transportation, power generation, and agricultural sectors. This paper describes feasibility of utilization of Spark ignition (SI) engine in single fuel mode and to develop the optimum operating conditions in terms of fuel injection timing and fuel injection pressure. Many modifications were made for the developed direct fuel injection system to improve the performance of the 350 cc four stroke single cylinder petrol engine. The engine is tested to conduct performance, combustion emission characteristics with the aid of carburetor. As single cylinder small engines have low compression ratio (CR), and they run with slightly rich mixture, their power are low and emission values are high. In this study, methanol was used to increase performance and decrease emissions of a single-cylinder engine. Initially, the engine whose CR was 7.5/1 was tested with gasoline and methanol at full load and various speeds. This method is used for increasing the fuel efficiency of a vehicle by adding different percentage of methanol to the petrol and to decrease the pollutants produced during combustion process.

Abstract: The consequential use of biodiesel as a source of renewable energy sustained a rapid growth over the past few years due to its major advantages like biodegradability, higher lubricity, low toxicity and low CO₂ emissions. Generally, transesterification is used for the production of biodiesel by employing base catalysis. Here, this Biodiesel is prepared from Annona Squamosa (Custard apple) seed oil with methanol by using potassium hydroxide as a catalyst which is further tested in Compression Ignition (C.I) engines. In the present study, an attempt has been made to analyze the acoustical studies on various blend compositions of Biodiesel with conventional diesel in the ratios 0%, 20%, 40%, 60%, 80% and 100% by determining relative viscosity, ultrasonic velocity and density at 303K. From these experimental data, various molecular interaction parameters like adiabatic compressibility, viscous relaxation time, inter molecular free length, specific acoustical impedance are calculated and the results are discussed in the light of solute-solvent interaction.

Abstract: The aim of this research is to develop a mathematical model of a compression ignition engine using cylinder-by-cylinder model approach to predict the performances; indicated work, indicated torque, in-cylinder pressures and temperatures and heat release rates. The method used in the study is based on ideal diesel cycle and is modified by the numerical formulations which affect the performance of the engine. The model consists of a set of tuning parameters such as engine geometries, EGR fractions, boost pressures, injection timings, air/fuel ratio, etc. It is developed in Simulink environment to promote modularity. A single-zone combustion model is developed and implemented for the combustion process which accounts for ignition delay, heat release. Derivations from slider-crank mechanism are involved to compute the instantaneous volume, area and stroke at any given crank angle. The results of the simulation model have been validated with experimental results with a close match between them.

Abstract: In this study, the surface of a Piston Ring in the engine is coated with multilayered coating powder using plasma-spray technique, and its surface behavior is subsequently analyzed. The purpose of this study is to analyze the mechanical and thermal effects of surface coating for a Piston Ring during friction. Here specimens with and without coatings were prepared and then microstructure, hardness and corrosion tests were carried out. From the experimental results and Ansys results, it has been found that the coated specimen has improved the properties in improving the diesel engine performance. The results show less deformation and fewer scratches due to wear on the multilayer coated Piston Ring as compared to the uncoated one. The surfaces topography and the structure of the plasma spray coatings is observed on the scanning Electron microscope. The evaluation of the adhesion of coatings is made using the hardness test and also compared using the thermal barrier properties. Taking into account the results of measurements, one can state that the lowest wear and thermal resistance on piston rings by plasma spray coating.

Abstract: The project involves elimination of rejection of H-engines during testing by improved methods of automation in spill cut using pneumatics which control the injection timing and is subsequently used at a later state in the engine assembly to set the valve timing. Improper injection timing leads to excess smoke. The new method which we have opted reduces man power, time consumption and the fuel wastage an optimum level which increases the productivity of the engine.

Abstract: Biofuel plays a major role in IC engine nowadays. Used Ayurvedic Oil (UAO) is one among the alternative fuels utilized. The preliminary property studies were carried out and the UAO had undergone simple Transesterification process to be converted to Used Ayurvedic Oil Methyl Ester (UAOME). The Fourier Transform Infrared (FTIR) spectroscopy analysis confirmed the UAO to UAOME conversion. The Trobological investigation on UAOME is also conducted using Four Ball Wear Tester. The results showed that lower wear scar was observed in UAOME comparatively with diesel. From the results it is clear that the UAO can be a novel partial substitute for diesel fuel.

Abstract: Leaf Springs find its applications in most of the automobiles, In this paper a Finite element Analysis was done on a leaf spring model. The results were verified using the analytical values. Two different alternative materials were used to replace the steel. A comparative study was done on how the results change with the input parameters and also with the usage of alternative materials.

Abstract: High speed machining technology is an important trend of advanced manufacturing engineering because of its accuracy. Spindle used in high speed machinery are capable of operating at high speed. As the spindle rotates at high speed, heat is generated in the contact area between the bearings and spindle. This heat generation leads thermal deformation and results in inaccuracy during machining. To avoid the heat generation non-contact bearing like active magnetic bearing (AMB) has been used. The main limitation in active magnetic bearing is its large size. In view of this, an attempt has been made to design and analysis of active magnetic bearing to reduce size complexity. In this paper we have mainly focused on the leg geometry effect and size of the active magnetic bearing. ANSYS workbench tool is used to analyse the flux density in pole area and calculate the maximum load carrying capacity of the bearing.

Abstract: Tubular drive shafts are subjected to combined axial tension, torsional moment and bending moment. The structural integrity of the driveshaft is investigated by evaluating the change in strength, stiffness and the life of the driveshaft with the change in the crack length. A review of driveshaft failure analysis case histories identifies circumferential crack and arbitrarily oriented cracks to be critical. The singular stress field around a crack tip in a general shell structure is characterized by mixed mode membrane and bending stress intensity factors. Accurate determination of these stress intensity factors (less than 1%) are carried out by a subprogram named as 3MBSIF. The validation of Finite element model using ABAQUS and post processing subprogram 3MBSIF together is carried out using benchmarks, a set of standard test problems with known target solutions. Further SIFs are derived for cylindrical shell and the driveshaft under the action of bending moment. To quantify the change in the compliance of cylindrical shell and the driveshaft with change in crack lengths is studied by performing Modal Analysis. It was observed that the variation in frequency is higher for smaller crack angles.