Abstract This study examines the momentum and heat transfer aspects of the laminar forced-convection induced by a pulsatile flow of power-law fluids past a heated circular cylinder by numerically solving the time-dependent momentum and energy equations over the ranges of dimensionless parameters as the cylinder Reynolds number based on the mean velocity (0.1 ≤ Re ≤ 40), Prandtl number (0.7 ≤ Pr ≤ 100), power-law index (0.3 ≤ n ≤ 1.4), frequency (0 ≤ ω* ≤ π) and amplitude (0 ≤ A ≤ 0.8). The detailed kinematics of the flow and temperature fields is visualized in terms of instantaneous streamlines and isotherm contours, especially adjacent to the cylinder. Further detailed insights are developed by examining the distribution of the pressure coefficient and local Nusselt number along the surface of the heated cylinder at different instants of time during the course of a periodic cycle. Finally, the overall gross characteristics are reported in terms of the time average drag coefficient and Nusselt number. It is possible to achieve varying levels of enhancement in the overall mixing of fluid and heat transfer under appropriate conditions of the amplitude of velocity, Reynolds number and power-law index. This is explained via the dynamics of the separated flow regions in terms of their growth and collapse during the course of a pulsation cycle. The fluid shear-thinning behavior promotes heat transfer in line with that seen in non-pulsating flows and shear-thickening behavior impedes it with reference to the corresponding value in Newtonian fluids otherwise under identical conditions.

中文翻译：

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幂律流体在加热圆柱体上的脉动流动：流动和传热特性

摘要 本研究通过对无量纲参数范围内的瞬态动量和能量方程进行数值求解，研究由幂律流体脉动流过加热圆柱体引起的层流强制对流的动量和传热方面的问题。基于平均速度 (0.1 ≤ Re ≤ 40)、普朗特数 (0.7 ≤ Pr ≤ 100)、幂律指数 (0.3 ≤ n ≤ 1.4)、频率 (0 ≤ ω* ≤ π) 和振幅 ( 0 ≤ A ≤ 0.8)。流场和温度场的详细运动学通过瞬时流线和等温线轮廓可视化，尤其是在圆柱体附近。通过检查压力系数和局部努塞尔数在周期性循环过程中的不同时刻沿加热圆柱表面的分布，可以得到更详细的见解。最后，根据时间平均阻力系数和 Nusselt 数报告总体总体特征。在速度幅度、雷诺数和幂律指数的适当条件下，可以在流体和传热的整体混合中实现不同程度的增强。这是通过分离的流动区域在脉动循环过程中的增长和崩溃方面的动态来解释的。