舰用柴油机预混合等压燃烧的数值模拟及试验研究

运用CFD软件Star-cd对一台舰用高速大功率柴油机实现预混合近似等压燃烧进行了缸内喷雾及燃烧过程的模拟计算,主要考察了不同压缩比的燃烧室型线,以及喷油器喷孔参数对柴油机性能、缸内温度场、速度场和NO排放的分布的影响.经过多方案的计算分析,确定了高速大功率柴油机实现预混合近似等压燃烧的压缩比和喷孔参数,并能在提高柴油机性能的同时降低排放.通过对最优方案的台架试验,在直喷式柴油机上实现了预混合等压燃烧要求的放热率.

Experimental and numerical study of premixed equal-pressure combustion in a vessel diesel engine

The spray and combustion process in cylinder of premixed equal-pressure combustion in high power diesel engine is simulated by CFD software Star-cd,with focus on the effects of the combustion chambers at different compression ratio and parameters of injector holes to the performance of diesel engine, temperature field in cylinder,velocity field and NO distributing. The compression ratio and parameters of injector holes which can realize the premixed equal-pressure combustion in diesel engine can be determined in terms of the calculation results, and the emission can also be eliminated while the performance can be improved. According to the experiments based on the optimized project, the desired heat release rate of premixed equal-pressure combustion in DI diesel engine can be realized.