磁性纳米流体Fe_3O_4-H_2O对流换热特性研究  

STUDY ON CONVECTIVE HEAT TRANSFER CHARACTERISTICS Fe_3O_4-H_2O MAGNETIC NANOFLUID

作　　者：吴治将[1,2] 殷少有[1,2] 

机构地区：[1]顺德职业技术学院机电工程学院,佛山528333 [2]广东高校热泵工程技术开发中心,佛山528333

出　　处：《太阳能学报》2015年第2期517-521,共5页Acta Energiae Solaris Sinica

基　　金：国家自然科学基金(51246006)

摘　　要：建立磁性纳米流体Fe3O4-H2O对流换热特性实验系统，研究有无外磁场、磁场强度、磁场方向，纳米粒子质量分数、轴向比等因素对磁性纳米流体对流换热系数的影响。实验结果表明：对流换热系数随磁场强度的增加而增大；当磁场方向与流体运动方向一致时，外磁场强化了对流换热过程;外磁场对低流速流体的对流换热过程影响比对高流速更为显著；外磁场作用于流体入口段时对流换热系数得到明显提高；质量分数范围Ot=0．6％-0．8％的Fe3O4-H2O纳米流体可有效强化其对流换热性能。The experimental system of convective heat transfer characteristics of Fe3O4-H2O nanofluid was set up. The influences of external magnetic field, magnetic field intensity, magnetic field direction, mass fraction of nanoparticles and axial ratio on convective heat transfer characteristics of magnetic nanofluid were discussed. The experimental results show that the convective heat transfer coefficient increases with increase of magnetic field intensity. When the motion direction of magnetic nanofluids and the magnetic field direction are same, the convective heat transfer process will be enhanced obviously. The effect of external magnetic field on the convective heat transfer coefficient of low velocity fluid is more significant than high velocity fluid. The convective heat transfer coefficient can be raised obviously if the external magnetic field operates in entrance section of fluids. Fe3O4-H2O nanofluids with the mass fraction of 0.6%-0.8% can effectively enhance convective heat transfer characteristics of Fe3O4-H2O nanofluids.

关 键 词：纳米粒子 磁场 对流 传热 

分 类 号：TK124[动力工程及工程热物理—工程热物理]