Tab.1

Engine specifications

Fig.1

Calculation grid at top dead center of the original engine

Tab.2

Initial and boundary conditions of simulations

Tab.3

Model used in simulation calculations

Fig.2

Verification of grid independence

Fig.3

Comparison of test and simulation of in-cylinder pressure and heat release rate of original engine

Fig.4

Comparison of test and simulation of NOx and soot in main combustion chamber of original engine

Tab.4

Structural parameters of prechamber

Tab.5

Effect of angle and diameter of passage in prechamber on indicated thermal efficiency and emissions

Fig.5

Three-view diagram of 3D model of prechamber combustion system and a partial view of prechamber

Fig.6

Calculation grid at top dead center of single passage prechamber combustion system

Fig.7

Indicated thermal efficiency and soot versus NOx emissions of prechamber system under different operating conditions

Fig.8

Influence of passage angle of prechamber on peak average temperature,exhaust temperature, and peak cylinder pressure in cylinder

Fig.9

Combustion phase and combustion duration at different prechamber passage angles

Fig.10

Mass fractions at varying equivalence ratios for original engine and prechamber combustion system

Fig.11

Influence of different prechamber passage angles on turbulent kinetic energy history in main combustion chamber

Fig.12

Distribution of energy of original engine and prechamber system

Fig.13

NOx and soot emission history at different through-hole angles of prechamber

Fig.14

Effect of diameter of passage in prechamber on the pressure in cylinder

Fig.15

Combustion phase and combustion duration at different prechamber passage diameters

Fig.16

Effect of diameter of passage in prechamber on the turbulent kinetic energy course in main combustion chamber

Fig.17

Distribution of energy of original engine and prechamber system

Fig.18

NOx and soot emission history at different prechamber passage diameters