以某高升功率柴油机燃烧系统为研究对象,首先采用AVL-Fire软件对燃烧过程进行了三维数值仿真,分别采用WAVE模型、Dukowicz模型以及旋涡破碎(EBU)模型描述雾化、蒸发以及燃烧过程.采用k-ε双方程湍流模型描述湍流流动,数值结果与实验值对比验证了所采用计算模型的合理性,然后对原型机燃烧过程中的三维流动、传热以及燃油分布状况展开分析,得到了原型机燃烧系统的不足之处,在此基础上,根据高升功率柴油机对燃烧过程的要求,对燃烧室结构进行改进设计,并进行相应的三维数值仿真.改型前后的燃烧系统数值结果对比表明,燃烧室形状对燃烧系统的性能影响很大,改型后的燃烧系统在燃烧组织方面得到显著改进,放热率与有效功率得到明显提高.%The combustion system in a high specific power diesel was studied. Firstly,3D numerical simulation of the combustion process in the chamber was carried out by AVL-Fire. The WAVE model,the Dukowicz model and the Eddy Break Up model were utilized to predict the fuel atomization,evaporation and combustion processes,respectively,and the k-s two-equation turbulence model was employed to predict the turbulent flow. The predicted average pressure and effective power agree well with the measured ones,verifying the employed numerical models. Secondly the detailed analysis of the numerical three-dimensional flow field,thermal field and oil distribution during the combustion process were carried out,and the disadvantages of the original combustion system were found out. . The structure of combustion system was modified on the basis of the above-mentioned analysis. Then The modified combustion system was also numerically simulated by using the same numerical models as the original chamber. Finally the numerical results of the original and the modified combustion system show that the performance of the combustion system is significantly affected by the shape of the combustion chamber,and that the combustion organization of the modified combustion system is significantly improved compared with that of the original one,resulting in great increase in the effective power and heat release rate of the combustion system.
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