为了有效地模拟实际工业应用中的液雾蒸发和燃烧,采用有限差分方法对无限热传导液滴蒸发模型进行了研究,并与相关的实验数据进行了对比和验证,发现采用定常的背景热质条件对网格的大小不敏感,但在实际计算过程中采用的当地瞬时热质条件所依赖的网格大小,对液滴蒸发具有重要影响.研究表明只有当网格的尺寸达到液滴直径的10倍左右时,采用当地瞬时的热质条件才可以得到满意的结果.此外,还发现关联数的校正格式及液滴在网格内的初始位置对液滴蒸发的影响不大.
To effectively simulate spray evaporation and combustion in realistic industrial applications, a finite difference method was used to study droplet evaporation with infinite thermal conductivity assumption, and the results were compared to relevant experimental data for validation. It is found that the model is insensitive to grid size when constant underlying temperature and mass conditions are used. However, the local instantaneous temperature and mass conditions are dependent on grid size in actual realistic calculations, which imposes significant effects on droplet evaporation prediction. Only when the local grid size is around 10 times of the droplet diameter, satisfactory results can be obtained using the local instantaneous temperature and mass conditions. In addition, corrective schemes for incidence number and initial droplet position in a grid cell have negligible effects on droplet evaporation simulation.