Aboud Emad D, Rashid Hayder K, Jassim Hussein M, Ahmed Saba Y, Waheed Khafaji Salwan Obaid, Hamzah Hameed K, Ali Farooq H
College of Engineering, Al-Musayab-Automobile Engineering Department, University of Babylon, Babylon, Hilla, Iraq.
College of Material Engineering, Ceramic Engineering Department, University of Babylon, Babylon, Hilla, Iraq.
Heliyon. 2020 Apr 24;6(4):e03773. doi: 10.1016/j.heliyon.2020.e03773. eCollection 2020 Apr.
The fluid flow and mixed convection heat transfer of a non-Newtonian (Cu-water) nanofluid-filled circular annulus enclosure in a magnetic field are investigated numerically for a two-dimensional, steady-state, incompressible, laminar flow using the Galerkin finite element method (GFEM). The Prandtl number (Pr = 6.2) and Grashof number (Gr = 100) are assumed to be constants, whereas the Richardson number varies within a range of 0 ≤ Ri ≤ 1, the Hartman number within a range of 0 ≤ Ha ≤60, the Power law index within a range of 0.2 ≤ n ≤ 1.4, and the volume fraction within a range of 0 ≤ φ ≤ 1. The enclosure consists of an outer rotating cylinder that is kept at a cold temperature (T) and an inner non-rotating cylinder kept at a hot temperature (T). The ratio of the inner circular diameter to the annulus space length is kept constant at 2. The results depict that the stream function increases with increasing power law index, even up to n = 1, which causes the fluid to behave as a Newtonian fluid. The magnetic field has a critical impact on the fluid flow pattern. The average Nusselt number increases with decreasing Richardson number, owing to the improved heat transfer by forced convection.
使用伽辽金有限元法（GFEM），对二维、稳态、不可压缩、层流的磁场中填充非牛顿（铜 - 水）纳米流体的环形封闭腔内的流体流动和混合对流换热进行了数值研究。假设普朗特数（Pr = 6.2）和格拉晓夫数（Gr = 100）为常数，而理查森数在0≤Ri≤1范围内变化，哈特曼数在0≤Ha≤60范围内变化，幂律指数在0.2≤n≤1.4范围内变化，体积分数在0≤φ≤1范围内变化。该封闭腔由一个保持低温（T）的外旋转圆柱体和一个保持高温（T）的内非旋转圆柱体组成。内圆直径与环形空间长度之比保持恒定为2。结果表明，流函数随着幂律指数的增加而增加，甚至直到n = 1，这使得流体表现为牛顿流体。磁场对流体流动模式有至关重要的影响。由于强制对流改善了传热，平均努塞尔数随着理查森数的减小而增加。
