加热表面水珠运动特性研究

Study of Water Drop Motion Characteristics on Heating Surface

为研究加热表面的水珠运动特性,提出了加热表面水珠的几何参数、受力及其运动过程的计算方法。试验获得了水珠的表面阻滞力、黏性阻力和气动力计算关系式中的相关系数,给出了不同风速条件下水珠运动的临界直径,进行了加热表面水珠运动试验并对其过程进行了数值计算。试验结果表明:水珠的无量纲表面阻滞力保持恒定,运动时受到的黏性阻力与其运动速度和宽度有关,在外流场作用下所受的气动力可采用修正圆球阻力公式进行计算。将试验获得的相关系数加入水珠运动模型中,对加热表面水珠运动过程进行数值计算,计算结果与试验结果吻合,说明本文所述方法能够准确地模拟加热表面水珠大小和位置随时间的变化。

To study the water drop motion characteristics on heating surface,a method is proposed to calculate the geometric parameters,force and motion process of water drop on the heating surface.Experiments are conducted to calibrate the correlation coefficients used in the calculation of surface retention force,the viscous drag and the aerodynamic force.The critical diameter of drop movement is given for different wind speeds.Water drop movement on heating surface is investigated by experimental and computational approaches.The results show that the dimensionless surface retention force keeps constant and the viscous drag is related to the drop velocity and width.The aerodynamic force under the action of outside airflow can be calculated by the correction of sphere drag formula.By applying correlation coefficient obtained in the experiment to the numerical model,water drop movement on heating surface can be predicted.The computation results fit well with the test results.It is concluded that the present method can simulate the time history of water drop size and location on the heating surface accurately.