Two-scale conjugate heat transfer solution for micro-structured surface
Two-scale conjugate heat transfer solution for micro-structured surface
复制标题
微结构表面两尺度共轭传热解决方案
DOI：
10.1002/fld.5190
复制
发表时间：
2023
影响因子：
1.8
通讯作者：
He L
中科院分区：
文献类型：
--
作者：
He L
模拟微结构表面上的湍流的主要挑战来自两个截然不同的空间长度尺度。对于流固耦合共轭传热（CHT），也存在时间尺度差异。目前的工作解决了基于双尺度框架的尺度差异。对于空间尺度差异，采用双重网格化来通过从局部细网格生成并传播到全局粗网格域的源项将全局粗网格域与微结构周围的局部细网格块耦合。源项驱动的粗网格解的收敛性和鲁棒性通过平衡的涡粘阻尼来增强。在这项工作中，以前只为流体域开发的双尺度方法被扩展到固体域，以便现在可以准确有效地解决微元件周围的热传导问题。流固时间尺度的差异是由频域方法处理。时间平均（零次谐波）以与稳态CHT相同的方式有效地获得。值得注意的是，壁温不稳定性可以简单地从流体温度谐波通过壁流固温度谐波传递函数以最小的计算成本获得。开发的CHT能力验证了一个实验性的内部冷却通道与多个表面肋元件。针对一个包含100个微结构的试验构形，分别对纯流体域、纯固体域和流固耦合CHT解进行了分析，验证了本文框架和实现方法的有效性.一些结果也用来说明该方法的主要基本工作。
The primary challenges for simulating a turbulent flow over a micro‐structured surface arise from the two hugely disparate spatial length scales. For fluid–solid coupled conjugate heat transfer (CHT), there is also a time‐scale disparity. The present work addresses the scale disparities based on a two‐scale framework. For the spatial scale disparity, a dual meshing is employed to couple a global coarse‐mesh domain with local fine‐mesh blocks around micro‐structures through source terms generated from the local fine‐mesh and propagated to the global coarse‐mesh domain. The convergence and robustness of the source terms driven coarse‐mesh solution is enhanced by a balanced eddy‐viscosity damping. In this work, the two‐scale method previously developed only for a fluid‐domain is extended to a solid domain so that thermal conduction around micro‐elements can now be resolved accurately and efficiently. The fluid–solid timescale disparity is dealt with by a frequency domain approach. The time‐averaged (zeroth harmonic) is effectively obtained in the same way as steady CHT. And remarkably, wall temperature unsteadiness can be simply obtained from the fluid temperature harmonics through a wall fluid–solid temperature harmonic transfer‐function at minimal computational cost. The developed CHT capability is validated for an experimental internal cooling channel with multiple surface rib‐elements. For a test configuration with 100 micro‐structures, the fluid domain‐only, the solid domain‐only and the fluid–solid coupled CHT solutions are analyzed respectively to examine and demonstrate the validity of the present framework and implementation methods. Some of the results also serve to illustrate the primary underlying working of the methodology.