关键词: 汽油机, 直接起动, 运动学, 模拟

Abstract:

A three-dimensional model and a one-dimensional kinematics model for a direct injection gasoline engine were established and validated through engine experiments. The combustion characteristics in the first firing cylinder and the kinematics characteristics of the engine under the conditions of forward and reverse rotation were simulated when different fuel injection methods and spark ignition timings were employed at direct start. The results show that the peak cylinder pressure in the first firing cylinder after combustion in the cases of split injection is higher than that at single injection. But its magnitude is affected by spark ignition timing. Higher peak cylinder pressure increases the crank angles, which the engine can move in the reverse rotation direction. The engine speed in the forward rotation direction is the largest when the sequent cylinder is ignited at about 2° before the biggest reverse crank angles in both single injection and split injection, which is helpful to a successful direct start.

Key words: gasoline engine, direct start, kinematics, simulation