全空穴模型中柴油非冷凝气质量分数的选取

针对广泛用于柴油喷孔内双相流计算的全空穴模型,提出了一个柴油非冷凝气质量分数与喷射压力和背压压差之间的幂函数关系式,幂函数的指数大小由与空穴刚刚产生和空穴已发展到柴油喷孔出口这两种状态相对应的非冷凝气质量分数确定。使用这个幂函数关系式计算了不同喷射压力下柴油的非冷凝气质量分数,然后使用全空穴模型和mixture多相流模型,计算了不同喷射压力下的柴油喷孔内双相流,并与试验数据进行了比较,结果表明,计算的柴油喷孔流量和喷孔内空穴场与试验结果基本吻合。

Mass Faction Selection of Diesel Non-condensable Gas in Full Cavitation Model

For the full cavitation model used widely in calculating the two phase flow in diesel nozzle ,a power function be‐tween the mass fraction of non‐condensable gas and the pressure difference between inlet and outlet in diesel nozzle was put for‐ward .The exponent of function was determined by the corresponding mass fraction of non‐condensable gas with the initial cavi‐tation and the cavitation extended to diesel nozzle .The mass fraction of non‐condensable gas and the two phase flow of diesel nozzle under different injection pressures were calculated according to the power function and the full cavitation model and mix‐ture model ,and the results were compared with the experimental data .The results shows that the calculated flow rate and cavi‐tation field in diesel nozzle coincide with the experimental results .