STUDY ON EFFECT OF FUEL INJECTION STRATEGY ON COMBUSTION NOISE AND EXHAUST EMISSION OF DIESEL ENGINE

The traditional mechanical fuel supply system has already been no way to satisfy the requirement of more stringent fuel consumption and emission legislation. For the past few years, it has been the hot topic to improve combustion and emission performance of diesel engine through optimizing the fuel injection strategy. All kinds of spray, combustion, and emission models were studied and then a new 3-D spray model coupled with the cavitating flow inside the nozzle was put forward to well consider the primary atomization induced by cavitating flow and turbulence in nozzle holes. The model, combined with combustion and emission models were used for simulating the single-injection combustion of 1015 diesel engine and validated through comparing the results from simulation with those from experiment. With the above verified models, different injection strategies were further investigated to reveal the effect of pilot injection timing, quantity, and main injection timing on combustion noise and exhaust emission of diesel engine.