Abstract This numerical work examines the impact of an external magnetic field on the hydrothermal aspects of natural convection of a power-law non-Newtonian nanofluid inside a baffled U-shape enclosure. The enclosure is heated from the bottom and cooled from the baffles while the other walls are thermally insulated. Sinusoidal profile is chosen to describe the temperature distribution along the bottom wall. A comprehensive analysis is conducted to study the influence of pertinent parameters including Rayleigh number (Ra), Hartmann number (Ha), nanoparticle volume fraction (ϕ), aspect ratio of cold baffles (AR), inclination angle, and power-law index (n) on the flow and heat transfer characteristics in detail by using Galerkin finite element method. The obtained results show that the impact of n on the Nusselt number (Nu) is considerable for Ra=106 and inappreciable below this value. The influence of n and Ha on the heat transfer is significant when Ha is smaller than 30. For Ha

中文翻译：

---

磁场作用下U形腔内的非牛顿纳米流体自然对流

摘要 这项数值工作研究了外部磁场对带挡板的 U 形外壳内的幂律非牛顿纳米流体的自然对流的热液方面的影响。外壳从底部加热并从挡板冷却，而其他壁是隔热的。选择正弦曲线来描述沿底壁的温度分布。综合分析研究瑞利数(Ra)、哈特曼数(Ha)、纳米粒子体积分数(φ)、冷挡板纵横比(AR)、倾角、幂律指数等相关参数的影响( n) 使用 Galerkin 有限元方法详细了解流动和传热特性。获得的结果表明，当 Ra=106 时，n 对努塞尔数 (Nu) 的影响是相当大的，低于此值则不可估量。当 Ha 小于 30 时，n 和 Ha 对传热的影响显着。 对于 Ha