多次预喷射策略对柴油机燃烧噪声的影响

Influence of multiple pre-injection strategies on diesel engine combustion noise

为降低柴油机的燃烧噪声,建立台架试验平台,分析一次预喷和二次预喷策略下缸压、压力升高率和噪声的变化规律;利用GT-Power软件建立燃烧仿真模型,分析二次预喷策略下,不同预喷角和预喷油量对燃烧噪声的影响。试验结果表明:相比一次预喷策略,二次预喷策略的缸压和压力升高率峰值下降,压力升高率最大峰值约降低0.1 MPa/(°),燃烧噪声下降5.2 dB;仿真的缸压和压力升高率与试验结果相近,表明仿真模型精确;第一次预喷曲轴转角为-20°、预喷油量为1.4 mg,第二次预喷曲轴转角为-11°、预喷油量为1.2 mg的喷油策略对应的台架试验燃烧噪声明显低于原始试验噪声。

To reduce the combustion noise of a diesel engine,a bench test platform is established to analyze the changes in cylinder pressure,pressure rise rate,and noise under one and two pre-injection strategies.GT Power software is used to establish a combustion simulation model,analyzing the influence of different pre-injection angles and pre-injection quantities on combustion noise under two pre-injection strategies.The experimental results show that compared with the one pre-injection strategy,the peak cylinder pressure and pressure rise rate of the two pre-injection strategies decrease,the maximum peak pressure rise rate decreases by about 0.1 MPa/(°),and the combustion noise decreases by 5.2 dB.The simulated cylinder pressure and pressure rise rate are similar to the experimental results,and the simulation model is accurate.The combustion noise of the bench test corresponding to the fuel injection strategy with the first pre-injection crankshaft angle of-20°and the amount of 1.4 mg,and the second pre-injection crankshaft angle of-11°and the amount of 1.2 mg,is significantly lower than the original test noise.The optimized bench test combustion noise is significantly lower than the original test noise.