基于飞秒激光改性表面核化点密度研究

Study on Nucleation Site Density of Surfaces Modified by Femtosecond Laser

以不锈钢材料为实验件,采用飞秒激光技术加工有序微纳结构来制备改性表面,并以去离子水为工质开展池沸腾核化点密度实验研究,获取了不同热工参数条件下3种不同实验表面(常规表面、改性表面1、改性表面2)的核化点密度实验数据,定量分析了核化点密度随壁面过热度的变化规律,并以李权模型为基础拟合得到改进核化点密度模型。研究发现,3种实验表面的核化点密度均随壁面过热度的升高而增大,且相同热工参数下改性表面的核化点密度显著大于常规表面;改进模型优化了核化点密度的预测值,且预测值与实验数据吻合较好。

Using stainless steel as the experimental piece,femtosecond laser technology is used to fabricate ordered micro-nano structures to prepare modified surfaces.The pool boiling nucleation site density experiment is carried out with deionized water as the working medium,and the nucleation site density experimental data of three different experimental surfaces(conventional surface,modified surface 1,and modified surface 2)under different thermal parameters are obtained.The variation law of nucleation site density with wall superheat degree is quantitatively analyzed,and an improved nucleation site density model is obtained by fitting on the basis of the Liquan model.It is found that the nucleation site density of the three experimental surfaces increases with the increase of wall superheat degree,and the nucleation site density of the modified surface is significantly higher than that of the conventional surface under the same thermal parameters.The improved model optimizes the predicted value of nucleation site density,and the predicted value is in good agreement with the experimental data.