乙醇液滴撞击高温壁面蒸发过程的模拟预测研究

Simulation and Prediction of the Evaporation Process of Ethanol Droplets Impacting High Temperature Wall

采用CLSVOF方法,引入描述壁面润湿特性的动态接触角,建立了乙醇液滴撞击高温壁面的数值模型,对乙醇液滴撞击高温壁面后的沸腾蒸发过程展开了研究,并与实验数据进行了对比验证.研究表明:在相同液滴温度下,壁面温度越高,亲水性越强,乙醇液滴的撞击速度越快,液滴的沸腾时间越早,蒸发完成所用时间也越短.在此研究基础上,基于机器学习算法,建立了液滴蒸发预测模型,对乙醇液滴撞击高温壁面后蒸发剩余量随时间的变化进行了预测研究,并通过将不同机器学习算法的预测结果与模拟结果对比,选出最优预测模型.

The coupled level set and volume of fluid(CLSVOF)method was used to establish a numerical mod⁃el for ethanol droplets impacting high temperature wall through introduction of the dynamic contact angle to de⁃scribe the wetting characteristics of the wall surface.The boiling and evaporation process of ethanol droplets impacting high temperature wall was studied and compared with the experimental data.The results show that,at a fixed droplet temperature,the higher the wall temperature is,the stronger the hydrophilicity will be,and the faster the impacting velocity of ethanol droplet is,the earlier the droplet will boil and the shorter the evapo⁃ration time will be.Based on this,a prediction model for droplet evaporation was established with the machine learning algorithm,to study the change of the evaporation residual with time after the ethanol droplet collision with the high temperature wall.The optimal prediction model was selected through comparison of the predic⁃tion results of different machine learning algorithms with the simulation results.