Experimental studies on control strategies of gdi engine with different combustion chamber geometry for fuel economy and emissions control

Abstract

The present experimental study discusses the gasoline direct injection newline(GDI) engine combustion chamber geometry for spray-guided, wall-guided, newlineand air-guided combustion strategies were fabricated by using single cylinder newlinediesel engine. The piston crown shape is modified to trapezoidal bowl and newlinepent roof shape with a small bowl on one side of the pent roof surface to newlineimpart the tumble, swirl, squish and turbulence effects. The cylinder head in newlineeach of combustion chamber geometry was modified to fix the fuel injector newlineand spark plug at proper positions to obtain better mixing of fuel with air and newlinesuperior combustion of the mixture. The performance study and emission newlinetests are conducted on all the three modified gasoline direct injection engines newlineat fuel injection pressures (FIPs) of 100, 125, 150 and 175 bar with optimized newlineexhaust gas recirculation of 10%, 9%, and 9% respectively; three split newlineinjections at 320and#730;, 220and#730;, 90and#730; bTDC; 270and#730;, 110and#730;, 60and#730; bTDC; 290and#730;, 110and#730;, 70and#730; newlinebTDC respectively; and the ignition timings at 10and#730;, 9and#730;, 11and#730; bTDC respectively newlinefor Wall-guided, Spray-guided and Air-guided combustion chamber newlinegeometry. The performance and emission results showed better at 150 bar newlineFuel Injection Pressure for wall-guided combustion chamber geometry. The newlineperformance results showed that in-cylinder pressure for wall guided newlinecombustion chamber mode was increased by 2.71% and 8.82% respectively newlinewhen compared with spray guided and air guided combustion chamber newlinegeometry modes. At the same condition, the indicated thermal efficiency was newlineincreased by 3.45% and 6.1%, whereas the specific fuel consumption was newlinereduced by 10.3% and 13.3% respectively. Brake specific NOx (BS-NOx) newlineemissions from all the three combustion modes were reduced up to 5% till newline50% of loads and it increases for higher loads due to increase of an incylinder newlinepressure newline