温度对流场中液滴运动轨迹偏转作用的研究

Temperature Deflection Effect on Drop Trajectory in the Flowing Field

推导了扩散相液滴运动轨迹模型和温度场中平均流修正模型,并优化了计算方法.直接数值模拟结果表明:平均温度和温度分布方式不同都会引起温度剖面和平均流剖面发生相应的变化,但它们的表现形式各不相同.因为温度场的变化会改变液滴所受到的不平衡剪应力,所以温度不同液滴的运动轨迹也不同,这种变化的动力来源于温度剖面和平均流剖面发挥的作用,它显著地影响液滴的聚结效率,因此,适当地调节流场温度可以改善流场的聚结条件.在层流流场中液滴的运动方式受温度分布的影响具有一定的随机性,但随机变化因素中包含确定性因素.液滴的聚结效率在一定程度上依赖于流场的平均温度,但温度分布方式也是影响聚结效率的不可忽视的因素,温度是理论反演计算和简化工程计算的必要条件.

A trajectory model of dispersed phase drops and A modified model of basic flow in the temperature field between two inclined parallel plates were derived with the optimized calculation. The analytical results of direct numerical simulation indicate that the difference of both the mean temperature and temperature distribution may lead to changes of mean flow profiles and temperature profiles,but their functions are very different. The trajectories of a drop may vary with the changes of unbalanced shearing force acting on a drop induced by temperature field. The dynamic sources of changeable processes stem from the action of mean flow profiles and temperature profiles,which have a great effect on the coalescence efficien-cies. Hence,the coalescence conditions of the flowing field may be improved by the proper adjustment of temperature in the flowing field. Although the flowing field is in the laminar flow state,temperature distribution leads to the fact that in the change of drop motion,there are not only stochastic factors but also determinate factors. The difference in the degree of coa-lescence efficiency depends on the mean temperature to a certain extent,but the temperature distributions are indispensable to coalescence efficiency. The factors of temperature field are indispensable to sovling the theoretical simplification of the inverse operation and engineering calculation.