【摘要】 内燃机进气道及缸内气体的流动是一种十分复杂的三维湍流运动，对燃油的喷射、混和气体的形成、燃烧和排放有重要影响。利用数值模拟方法是了解气流运动、发展变化规律及气流与燃烧关系的主要手段之一。采用瞬态咬合法模拟气阀和活塞的运动，采用分块划分网格技术形成计算域的整体网格。微分方程的计算求解基于ＫＩＶＡ－３程序，加入以上子程序，计算针对四冲程柴油机的进气过程进行模拟计算。更多还原

【Abstract】 An existing multidimensional CFD code KIVA-3 for in-cylinder flow was modified to simulate port-and-cylinder gas flow in internal combustion engines. The effect of a moving valve with a stem was simulated using a new method called "snapper". Automatic numerical generation of body-fitted curvilinear coordinate system for field containing any number of arbitrary two or three- dimensional bodies is studied in the pre-processing code. A modified version of the κ - ε turbulence model which include volu-metric expansion effects was used in this code. Calculations were carried out for conditions from BTDC 200.0 degree to ATDC 20.0 degrees. The flow structure in the cylinder and the intake pork were studied.更多还原