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With the alarming increase in vehicular population, there is depletion of fossil fuel availability. Hence to overcome the difficulties, alternative fuels are tested and used in parts of the world. One of the difficulties with usage of alternate fuels is their high viscosity in comparison to fossil fuels. To overcome this, preheating of biofuel is a good option as it makes the fuel less viscous. In our research, we have used a helical coil heat exchanger to preheat the inlet fuel using the engine’s exhaust gas, making the system more sustainable since no external energy is used. In order to evaluate the effectiveness of preheating device a simulation study has been carried for the ethanol based biofuels. For simulation work, a set of boundary conditions has been arrived based on the experimental analysis. The results from the experiment such as velocity of air and fuel inlet were utilized as input for simulation work.

In-cylinder flow in diesel engines plays an important role in the combustion, thus affecting the emissions from the engine. Swirling flow inside the cylinder during intake and compression stroke is one of the important parameters that improve combustion. This paper deals with comparison between two different intake manifold geometries in a direct injection diesel engine in terms of their swirl generation mechanisms in the cylinder during suction stroke. The modified geometry involves a twisted tape inserted in the intake manifold for swirl generation. A three-dimensional numerical study of the flow behavior is performed using Computational Fluid Dynamics (CFD) and experimentally validated using a steady flow test bench. The effect of twist ratio on the swirl generation is simulated using CFD. The CFD study involves a transient case applied to a dynamic mesh which characterizes the downward movement of the piston during suction stroke.