Al_2O_3-H_2O纳米流体冻结过程的数值模拟和试验研究  

Numerical Simulation and Research on the Freezing Process of Al_2O_3-H_2O Nanofluid

作　　者：郭蘅 邸倩倩[1] 刘斌[1] 周智勇[1] 苏芸[1] 

机构地区：[1]天津市制冷技术重点实验室、天津商业大学,天津300134

出　　处：《流体机械》2015年第6期50-55,共6页Fluid Machinery

基　　金：十二五国家科技支撑计划重点项目(2011BAD24B01);天津市科技支撑项目(14ZCZDNC00016)

摘　　要：纳米流体作为强化换热介质,是目前的研究热点,但关于其相变过程的研究较少。利用当量比热法,在COMSOL有限元模拟软件中对质量分数为5%,不同粒径(10、20、50、100、500nm)的Al2O3-H2O纳米流体和去离子水的冻结过程进行数值模拟,并将模拟结果和试验结果进行了对比。二者具有较好一致性,表明烧杯中心和壁面附近的温度变化趋势有较大区别,中心处的温度变化更能反映样品的冻结过程;当质量分数为5%时,Al2O3-H2O纳米流体的相变时间与去离子水相比较短,且纳米流体的相变时间随Al2O3粒径的增大而增加。Nanofluid which can enhance heat transfer is one of the main research hotspots now. But the research on its phase transformation is very few. We simulated the freezing processes of Al2O3-H2O nanofluid with different particle sizes of 10,20,50, 100 and 500nm（ mass fractions of 5% ）and deionized water using the equivalent specific heat through the finite element simulation software COMSOL. The results of the simulation and experiment were compared with each other. And the two resuhs have good consistency under the same mass fraction of 5%. They all show that there is a great difference between the temperature trends at the centre and boundaries of the beaker,and the former reflects the freezing processes of these samples better. The time of phase change of Al2O3-H2O nanofluid is shorter than that of the deionized water,and it increases with the diameter of the Al2O3 nanop- articles.

关 键 词：Al2O3-H2O纳米流体 相变 当量比热 

分 类 号：TQ460.6[化学工程—制药化工]