磁场作用下不同润湿性表面结霜实验研究

研究了在冷面温度T_w=-10℃和-30℃，环境相对湿度RH=60%和80%，3种润湿性表面在不同磁场强度下的结霜规律。通过可视化观测和图像二值化处理计算，分析了磁场强度和表面接触角对霜晶形态、水珠粒径、结晶时间、液滴和霜晶覆盖率、霜层厚度和密度的影响。结果表明：磁场作用下，疏水性表面水珠粒径减小40%左右，结晶时间延长500 s以上，凝结水珠分布更加稀疏；结霜厚度和密度随着磁场强度和接触角的增大而减小；随着冷面温度的降低和相对湿度的增大，表面特性和外加磁场对结霜过程的影响降低。

Experimental study of frosting on different wettability surfaces under magnetic field

The frosting laws of three kinds of wettable surfaces under different magnetic field strengths were studied under cold surface temperature T_w=-10℃ and -30℃, environmental relative humidity RH=60% and 80%. Through visual observation method,image binarization is processed and calculated,the effect of frost morphology,water droplets diameter,water droplets crystallization time,water droplets coverage,frost crystal coverage,frost layer thickness and frost density under the different magnetic field intensity and surface contact angle are well explained. The results showed that adding magnetic field in combination with hydrophobic surface,the diameter of water droplets decreases by about 40%, and the crystallization time is prolonged by more than 500 s,the distribution of condensate droplets is more sparse. Frost thickness and frost density decrease as the increase of magnetic field strength and surface contact angle,providing possibility of restrain the frosting effectively. As the temperature of the cold surface decreases and the relative humidity increases, the influence of the surface properties and the external magnetic field on the frosting process decreases.