Enhancement of heat and mass transfer by herringbone microstructures in a simple shear flow
Enhancement of heat and mass transfer by herringbone microstructures in a simple shear flow
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DOI：
10.1063/5.0094725
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发表时间：
2022-03
影响因子：
4.6
通讯作者：
Yanxing Wang;Hui Wan;T. Wei;J. Abraham
中科院分区：
文献类型：
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作者：
Yanxing Wang;Hui Wan;T. Wei;J. Abraham
使用格子玻尔兹曼方法对覆盖有交错人字形结构的表面上的简单剪切流的传热和传质特性进行了数值研究。识别出两种流动运动。第一个是人字形结构上方的螺旋流振荡，将热量和质量从顶面平流到人字形结构。第二种是脊之间的凹槽中的流动再循环，将热量和质量从结构尖端周围的区域平流到其侧壁和底表面。这两种基本的流动运动耦合在一起形成复杂的传输机制。结果表明，当平流传热传质在较大的雷诺数和施密特数下发生时，总传热速率对施密特数的依赖关系服从幂律，其指数与湍流传热的Dittus-Boelter方程相同。随着雷诺数的增加，总传输速率对雷诺数的依赖性也接近幂律，且指数接近Dittus-Boelter方程中的指数。
The heat and mass transfer characteristics of a simple shear flow over a surface covered with staggered herringbone structures are numerically investigated using the lattice Boltzmann method. Two flow motions are identified. The first is a spiral flow oscillation above the herringbone structures that advects heat and mass from the top plane to herringbone structures. The second is a flow recirculation in the grooves between the ridges that advects heat and mass from the area around the tips of the structures to their side walls and the bottom surfaces. These two basic flow motions couple together to form a complex transport mechanism. The results show that when advective heat and mass transfer takes effect at relatively large Reynolds and Schmidt numbers, the dependence of the total transfer rate on Schmidt number follows a power law, with the exponent being the same as that in the Dittus-Boelter equation for turbulent heat transfer. As Reynolds number increases, the dependence of the total transfer rate on Reynolds number also approaches a power law, and the exponent is close to that in the Dittus-Boelter equation.