Modelling for Collective Effect of Muffler Geometric Modifications and Blended Microalgae Fuel Use on Exhaust Performance of a Four-Stroke Diesel Engine: A Computational Fluid Dynamics Approach

摘要

Engine performance significantly depends on the effective exhaust of the combustion gases from the muffler. With stricter BSVI norms more efficient measures have to be adopted to reduce the levels of emissions from the exhaust to the atmosphere. Muffler along with reducing the engine noise is intended to control the back pressure as well. Back pressure change has a significant effect on muffler temperature distribution which affects the NO_x emission from the exhaust. Many research communications have been made to reduce the exhaust emissions like HC, CO and CO_2 from the exhaust by using different generation biofuels as an alternative fuel, yet they have confronted challenges in controlling the NO_x content from the exhaust. This work presents the combined effect of Muffler geometry modifications and blended microalgal fuel on exhaust performance with an aim to reduce NO_x emission form a four-stroke engine. In this exertion, the computational fluid dynamics model is developed to analyze the effect of muffler geometry modification on vital exhaust parameters of an engine. The engine is powered with a blend of chlorella microalgae and diesel. The engine used for testing is a four-stroke diesel, water-cooled, SOHC engine. The muffler geometry such as Chambered Elliptic (CE), and Turbo Elliptic (TE) are designed for study. The reference for designing the mufflers in CREO was published literature and company product blueprints. The combined effect of muffler geometry modification and blended microalgal fuel use on back pressure, chamber temperature, pressure and velocity distribution are deliberated. The result shows that the chambered elliptic muffler using B5 (5% Algal fuel) developed significantly less exhaust temperature, whereas the gas density is more in case of turbo elliptic muffler using B20 (20% Algal fuel). Finally, the velocity is slightly higher in the case of Turbo Elliptic (TE) muffler using B20 blend. Significant decrease in back pressure was noted for B20 blended fuel in case of TE over CE. The exhaust temperature was notably reduced in all B5 blends for all muffler’s geometries created. The work also aims to explore the effect on NO_x emissions by analyzing the use of the combined effect of microalgae fuel and muffler geometry modifications on exhaust parameters by controlling the back pressure in the muffler. Almost no research is reported in this [1] field of work for microalgal fuels which is the objective of this work.