摘要
【目的】考察脉动气流掠过沸腾水面时,流动参数对水分蒸发效果的影响,探究脉动气流强化蒸发过程的机理。【方法】建立二维物理与数学模型,采用商用软件ANSYS FLUENT 14.5进行数值模拟,研究正弦脉动气流掠过沸腾水面时水分的蒸发情况,分析一定蒸发时间内脉动气流的振幅、频率、气流速度以及温度对水分蒸发的影响。【结果】相比于匀速气流,气流脉动时沸腾表面水分的相对蒸发量提高了约50%;脉动气流的相对振幅从0增加至1.0时,沸腾表面水分的相对蒸发量提高了约1.8倍;脉动气流的频率从0 Hz增加至110 Hz时,沸腾表面水分的相对蒸发量呈现出先增加后减小的变化;气流速度从4 m/s增加至10 m/s时,沸腾表面水分的相对蒸发量提高了约15.3倍;脉动气流的温度对沸腾表面水分蒸发的影响不明显;气流脉动时,水分蒸发速率呈周期性变化。【结论】脉动气流周期性地对水面水蒸气浓度边界层进行扰动,强化了水面的对流传质,从而促进了水分蒸发。
【Objective】To study the effects of different flow parameters on the water evaporation and investigate the mechanism of pulsating airflow's intensified evaporation when the pulsating airflow sweeping through the boiling water surface.【Method】A two-dimensional physical and mathematical model is established.Additionally,commercial software ANSYS FLUENT14.5is adopted for numerical simulation,to study the evaporation of water when the sinusoidal pulsating airflow was sweeping through the boiling water surface.The impacts of the amplitude,frequency,airflow velocity and temperature of the pulsating airflowat certain evaporation time on evaporation of water were investigated.【Result】Compared with uniform airflow,the relative evaporation of water on boiling surface increased by about50%when airflow is pulsating.When the relative amplitude of pulsating airflow increased from0to1.0,the relative evaporation of water on boiling surface increased by about1.8times.When the frequency of pulsating airflow increased from0Hz to110Hz,the relative evaporation of water on boiling surface increased first and then decreased.When airflow velocity increased from4m/s to10m/s,the relative evaporation of water on boiling surface increased by15.3times.The effect of the temperature of pulsating airflow on evaporation of water on boiling surface is not obvious.When the airflow is pulsating,the water evaporation rate fluctuates periodically.【Conclusion】Pulsating airflow perturbed the boundary layer of surface vapor concentration periodically and intensified the convective mass transfer of surface,thus facilitating water evaporation.
作者
娄晓博
凌长明
李儒松
陈明丰
LOU Xiao-bo;LING Chang-ming;LI Ru-song;CHEN Ming-feng(School of Mechanical and Power Engineering,Guangdong Ocean University, Zhanjiang 524088,China;Shenzhen Institute of Guangdong Ocean University, Shenzhen 518108, China)
出处
《广东海洋大学学报》
CAS
2018年第1期73-79,共7页
Journal of Guangdong Ocean University
基金
广东省科技计划项目(2016A010104021
2017A010104011
2017A050506054)
深圳市科技计划项目(JCYJ20170306162116012)
广东海洋大学动力工程及工程热物理重点学科建设项目(52130600801)
关键词
脉动气流
水分蒸发
相对蒸发量
数值模拟
沸腾表面
Pulsating Airflow
Water Evaporation
Relative Evaporation
Numerical Simulation
Boiling Surface
