Applied Mechanics and Materials Vols. 592-594

Abstract: Effect of mass flow rate of inlet gas on holdup mass in a high efficiency cyclone has been performed. Cyclone as heat transfer equipment may be used for drying, solidification, water removal, solvent recovery, sublimation, chemical reaction and oxidation. In all such cases, performance of cyclone depends on the surface area of the solid particles inside the cyclone. The holdup varies with the variation in operating parameters. This proposed work will present an effect of mass flow rate of inlet gas on cyclone heat exchanger and calculation of holdup mass by varying the mass flow rate of inlet gas, solid feed rate and diameter of the particle.

Abstract: LPG is a mixture of gas, mainly propane and butane. It is commonly used as a fuel for cooking and as a transportation fuel. It is normally created as a by-product of petroleum refining and from the production of Natural Gas. An experiment is conducted to obtain the operating characteristics of the four stroke three cylinder inline water cooled spark ignition engine operated with LPG and methanol. The engine is started with LPG and methanol with various ratios at constant volume rate in the vaporizer. Solenoid valve was used to allow either LPG or petrol in the carburetor. The LPG supplied through the vaporizer and the quantity is metered by hanging type weighing scale. The additives are added with LPG before supplied to the vaporizer. The performance characteristics of engine were analyzed using petrol with increase in load. Further the engine run with LPG and adjusts the flow based on the mixing of additives. The best ratio of additives can be selected based on the experimental results obtained in the engine.The findings of the present research work suggest that optimum % of methanol as additive to increase the overall performance and to reduce the emission levels.

Abstract: In this investigation, a thorough thermodynamic analysis of the water/lithium bromide absorption refrigeration cycle in the absence of solution heat exchanger is performed. The influence of operating temperature on the thermal loads of components, COP_c (Carnot Coefficient of Performance), COP_E (Enthalpy based Coefficient of Performance) and efficiency ratio (η) is studied. It is concluded that the COP_c and COP_E values decreases with increasing condenser and absorber temperature but increase with increasing generator and evaporator temperatures .

Abstract: This study focuses on effect of piston shape on in-cylinder flows in a conventional loop scavenged two-stroke engine using CFD. Three piston-shapes viz., flat, flat with center-bowl and flat with center-dome are analyzed along with standard piston. The CFD solution has been obtained by using commercial code STAR-CD. First the CFD results are compared with those of experimental values obtained from particle image velocimetry (PIV). For comparison among various piston shapes, various parameters viz., velocity vector plots, tumble ratio (TR), turbulent kinetic energy (TKE) at various crank angles are used. Scavenging and trapping efficiencies are also calculated for each piston configuration. From the results, it is found that flat with center-bowl piston is the best in terms of in-cylinder flow characteristics. It gives higher TR and TKE with very little effect on efficiencies.

Abstract: Considering the fuel demands, lots of researches have been done in the field of alternate fuels. After attaining the saturation level in this research area, still we are in need to find some alternate ways for fuel demand. Previous researchers concluded that approximate addition of 0-20% of vegetable oil with conventional diesel fuel leads to closer performance of diesel oil and controlled carbon emission; additionally they proved that there is no engine modifications needed for this optimized blend characteristic usage. Likewise, Chemical additives also can be added directly with diesel fuel and fuel blends of vegetable oils in which various researches concluded that 0-10% addition of chemical additives providing closer performance to diesel fuel. If we specifically pointing about solvent ether say Di-ethyl ether, resulting preferable performance to use as alternate fuel up to 0-5% and accepted results have been provided on some vegetable oils such as POME, Neem oil. In case of Jatropha oil, Proper results and Experiments are not found to be used as better alternative solution with Di-ethyl ether blend. This article brings us to enhanced experiment details and results obtained on Di-ethyl ether with Jatropha oil blend in which optimized Bio-diesel blend (J20= 80% diesel and 20% Jatropha oil) is taken as base fuel throughout the experiment. Keeping J20 oil as base fuel, experiments are conducted with various proportions of Di-ethyl ether (0-12%). Additionally it provides, engine performance characteristics and emission parameters when compared to conventional diesels, Jatropha blend (J20), Di-ethyl ether blend.

Abstract: Diesel engines generate undesirable emissions during the combustion process.Various control methods have been developed to reduce nitrogen oxides (NOx) andparticulate matter (PM) emissions from diesel engines so that the strict emission regulationscan be fulfilled. Oxides of nitrogen (NOx) and particulate matter (PM) are the mainpollutants from diesel engines and it has been proven that the method of introducing waterwith fuel to be a powerful and economical technique for reducing these pollutants. Water-Diesel emulsion is a new type of fuel which can be used in place of diesel fuel for thepurpose to get the reduction in emissions of diesel engines.Many studies have been done on emulsion fuels and have concluded that this technique hasthe potential to significantly reduce the formation of NOx and PM and improve combustionefficiency. The emulsified fuel contains water and diesel fuel with some suitable surfactantsto stabilize the system. An important aspect pertaining to water-diesel emulsion as a fuel fordiesel engines is that it can be used without any modification in the existing engine. Thispaper presents an overview of recent progress in research of using water-diesel emulsion forthe purpose of improving emission characteristics of a single cylinder direct injection dieselengine.

Abstract: The current worldwide trend of rapid economic development and increasing energy requirement in the transportation sector are one of many segments that is responsible for a growing share of fossil fuel usage. Supply and demand for fuel is accelerating prices and eventually will affect availability. The selected contemporary paper will address on how a prototype Stirling engine capable of reining in waste heat spilling out of the typical engine exhaust and its intensity level to oppose against the tyranny of inefficiency. Stirling engine systems are fuel flexible with respect to source of thermal energy and unprocessed waste heat that resulting in entropy rise can be harvested to power Ancillaries and increase overall efficiency. The preliminary prototype design and methodology follows process, heat to mechanical energy and latter to electrical energy. Experimental verification of analytical data was carried out and presented here. The shortcomings of these methods are highlighted and an alternative approach to solving particulars suggested.

Abstract: The rapidly growing trend for higher capacity steam turbines with large steam flows demand the use of long lengths and large size pipes. Thermal expansions of up-to 50mm and pipe diameters up-to 2600mm are required to be dealt with calling for the use of Expansion Joints to control the stresses in both the pipes as well as the end equipment. The bellows in the Expansion Joints used for the steam turbine application are stretched to their limiting values of the stresses in order to make them as flexible as possible with the aim of limiting the pipe and end equipment operational stresses. Three fundamental types of loading are presented to provide insight into the way bellows convolutions are stressed during operation. The optimization of the bellows profile geometry is discussed briefly. A comparison of the resulsts obtainied by proven computational methods as well as by using international EJMA standard is made to highlight the safety built in the well established methods used.

Abstract: Prototype fast breeder reactor’s (PFBR) secondary pumps have sealing between the rotating shaft and the stationary parts to prevent cover gas leakage into ambient air. This is achieved by means of triple mechanical seals with oil as buffer fluid. The oil for cooling the mechanical seals and bearing is supplied from an external source and is re-circulated after cooling and cleaning. During testing of secondary pumps several issues related to mechanical seal arrangement, material, oil temperature and oil leakage into process side were confronted. This paper discusses the successful resolution of such issues.

Abstract: The present study investigates the effect of air-side oxygen concentration enrichment on the performance and emission of a single cylinder diesel engine using a bio-fuel blend as fuel. In this study, a natural phenolic compound, namely, cardanol is selected as the bio-fuel, which is obtained from the shell of cashew nut after purification. A blend of B10M10 (10% cardanol +10% methanol + 80% diesel by volume) is prepared and tested in the engine at various loading conditions. The experiments are carried out at atmospheric oxygen condition and an increment of 3, 5, and 7% of atmospheric oxygen concentration by weight. There is a drastic reduction in HC, CO, and smoke except for NOx emission. The level of NOx emission increases as the oxygen concentration in the intake air is increased. The performance characteristic will increase as the oxygen concentration increases, and higher brake thermal efficiency is obtained for B10M10 at 7% oxygen concentration. B10M10 with 7% oxygen enrichment gives better results, similar to diesel, except for NOx emission.