Based on the better fuel/air mixture formation and combustion of the lateral-swirl combustion system(LSCS)， the differences in the combustion and emission results between the LSCS and the ω combustion system were analyzed under different working conditions using a single-cylinder test system. Then a simulation calculation was used to compare the mixture equivalence ratio and velocity of the working medium in the two combustion chambers

elucidating the working mechanism of the two chambers. The test results show that compared with the ω combustion system

the brake specific fuel consumption of the LSCS decreases by 3.83%

and the soot emission decreases by 82.21% under the same operating conditions. And LSCS has higher heat release rate

in-cylinder pressure and temperature. The simulation results show that the fuel jet is separated evenly in both sides of the convex edge after the spray impingement in the LSCS

avoiding the accumulation of the fuel near the chamber wall. Then the LSCS can make full use of the circumferential air in the combustion chamber

improve the combustion

and decrease the soot emission at the same time.