喷油压力对柴油撞壁喷雾及燃烧特性的影响

Aiming to further improve the combustion performance of a lateral swirl combustion chamber with a throat size of 100 mm for direct injection diesel engines, this study investigates the effects of fuel injection pressure (80~ 120 MPa) on the impinging spray and combustion process in a constant volume combustion system. Experimental results indicate that as the injection pressure increases, the interaction between the impinging spray and the lateral swirl walls becomes prominent. Higher injection pressure improves the wall-flow-guided effect and the penetration capacity of the interferential wall jet, both of which promote improved fuel spray diffusion. When the injection pressure is reduced from 120 to 80 MPa, the wall-flow-guided effect is weakened, leading to the accumulation of residual fuel near the split arcs. This phenomenon results in localized areas of high temperature and high KL factor distribution. Moreover, a high-temperature flame remains in the interferential zone for the 80 MPa fuel injection pressure at 3. 7 ms during the burn-out process. For the lateral swirl combustion system, increasing the fuel injection pressure contributes to exerting wall-flow-guided and interferential interaction effects, improving the combustion rate and accelerating soot oxidation.