Abstract Two-dimensional laminar fluid flow and heat transfer characteristics have been investigated numerically for a oscillating fin mounted on the top wall of backward facing step with constant bottom wall temperature. OpenFOAM is used to solve the governing equation of mass, momentum and energy conservation with the appropriate boundary conditions. Air is used as a working fluid with constant thermo-physical property ( Pr = 0.71). It is found that the oscillating fin is the most effective method with highest average Nusselt number and lowest pressure drop, to enhance the mixing and heat transfer when it is compared to the different types of stationary fin arrangement. Further, the effect of frequency (which is directly proportional to the amplitude of velocity) and oscillation have been investigated and found that the average Nusselt number increases with the increase in velocity amplitude. It is also observed that the change in average Nusselt number is negligible with the increase in the amplitude of oscillation for a constant velocity amplitude. A correlation is also presented to express the effectiveness of the fin ( η f ) in terms of ratio ( K v ) of velocity amplitude ( V o ) to the flow velocity ( U f ) and is observed to follow the power law with constant exponent as η f = c K v 0.3 .

中文翻译：

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后向台阶分离流中翅片振荡对强化传热的影响

摘要 对安装在后向台阶顶壁上且底壁温度恒定的振动翅片二维层流流体流动和传热特性进行了数值研究。OpenFOAM 用于求解具有适当边界条件的质量、动量和能量守恒的控制方程。空气用作具有恒定热物理性质（Pr = 0.71）的工作流体。结果表明，与不同类型的固定翅片布置相比，振荡翅片是具有最高平均努塞尔数和最低压降的最有效的方法，可以增强混合和传热。更多，已经研究了频率（与速度幅度成正比）和振荡的影响，发现平均努塞尔数随着速度幅度的增加而增加。还观察到，对于恒定速度振幅，随着振荡振幅的增加，平均努塞尔数的变化可以忽略不计。还提出了一个相关性来表示翅片 ( η f ) 的有效性，即速度幅度 ( V o ) 与流速 ( U f ) 之比 ( K v ) 的关系，并观察到其遵循指数不变的幂律。因为 η f = c K v 0.3 。