Influence of piston crown shape with different positions of spark plug and fuel injector, %EGR, and fuel system control on emissions from modified GDI engines compared with a base diesel engine

Abstract

In the present work, developed the combustion chamber profiles for spray, wall, and air guided mode GDI engines. Modified the piston top surface for each combustion chamber geometry of GDI engine from hemispherical bowl to trapezoidal bowl and pent roof shape which include a scoop type bowl on one side (towards injector position) to impart better squish, swirl, tumble and turbulence effects required to improve the mixture formation. Also, modified the cylinder head to each combustion chamber with different locations of spark plug and fuel injector. Optimized the fuel split injections with durations, ignition timing and percentage of exhaust gas recirculation towards emissions reduction, especially soot and oxides of nitrogen. Emission tests were conducted on base diesel engine and all three modified combustion chamber geometry GDI engine. It is clear from the results that oxides of nitrogen emission in wall guided mode was reduced up to 5% till 75% of the loads when compare with both spray-guided and air-guided combustion modes, and later it is increased. Overall, wall guided combustion chamber geometry GDI engine shows better results at 150 bar FIP, when compare with base Diesel engine; oxides of nitrogen emissions were reduced from 377 ppm to 77 ppm and soot emissions were reduced from 29.3 g/km to 4.5 g/km at high torque.

Combined Air-Wall Guided GDI Engine Performance and Emissions Control with E20 and Hydrogen Blended Fuel

“…The fuel consumption and HC, CO & Soot Particle emissions were reduced, but NOx emission was reduced up to 50% of torque and it increased thereafter. Also, the emission concentrations from a GDI engine with different CC geometry were compared with the same results of base-diesel engine (Shivakumar & Kumaresan 2022). The well performed wall-guided CC geometry GDI engine was compared with a base diesel engine, NOx and soot particle emission concentrations were reduced to a greater extent.…”