【摘要】 基于分子动力学理论,建立了气泡冷凝换热模型,对水蒸气气泡在过冷水中的生长和分离过程进行了数值研究,分析过冷度、进口速度和壁面接触角对气泡生长和分离的影响,并与无相变过程进行了对比。研究表明,随着过冷度的提高,气泡在分离时的体积减小,且当过冷度高于一定值以后气泡不能分离;随着蒸汽进口速度的增加,气泡的生长和分离时间减小,且能够分离的临界温度增大;当壁面的静态接触角小于一定值时,气泡的生长和分离时间不变;随着静态接触角的继续增大,气泡的分离时间增加。更多还原

【Abstract】 A bubble condensation heat transfer model is built based on molecular dynamics, the growth and separation process of water vapor bubbles in cold water is numerically analyzed. The effects of subcooling degree, inlet velocity, and surface contact angle on the growth and separation of water vapor bubbles is analyzed and compared it with those of without condensation. The result shows that: The volume of bubbles during separation decreases as condensate depression increases and bubbles stop separating if condensate depression is above a threshold; With vapor inlet velocity increased, the time needed to grow and separate for decreases and the critical temperature to separate increases; The time to grow and separate remains the same when surface static contact angle is below a threshold; The time to separate increases as surface static contact angle increases.更多还原