In this study, microchannel heat sinks with symmetric and parallel wavy microchannels are studied in a wide range of Reynolds numbers from 50 to 700 via a three-dimensional fluid-solid conjugate model. The results show that the symmetric configuration yields higher Nusselt numbers than the parallel one, and it is especially true at higher Reynolds numbers and larger amplitude-to-wavelength ratios. The heat transfer enhancement can be attributed to the fact that the symmetric configuration induces four Dean vortices in the cross sections perpendicular to the flow path, whereas there are only two Dean vortices in the parallel configuration, leading to stronger coolant mixing and hence the higher Nusselt numbers in the symmetric configuration. However, because of the presence of channel throats, the symmetric configuration also achieves a significantly high pressure penalty. As a result, the overall performance of the symmetric configuration is slightly lower than that of the parallel configuration. To enhance the performance of wavy microchannel heat sinks, modified symmetric and parallel wavy configurations are proposed, in which several transverse gaps are added into ribs to connect adjacent microchannels. The results demonstrate that such a secondary branch design significantly enhances Nusselt numbers for both the parallel wavy configurations owing to the enhanced fluid mixing between adjacent microchannels. Moreover, it is found that, as compared with its original wavy configurations, secondary branches slightly increase the pressure drop across the modified parallel configuration. Thus, the overall performances are markedly enhanced for the modified parallel configurations. As expected, secondary branches greatly reduce the pressure drop across the modified symmetric configuration. Beyond expectation, the suction effect of channel throats due to secondary branches can weaken the Dean vortices in the valley vs valley regions and worsen the heat transfer performance, especially for the heat sink with larger Re and amplitude-to-wavelength ratios. As a result, the modified symmetric wavy configurations are suggested to employ with a wider gap and small amplitude-to-wavelength ratio. Generally speaking, the modified parallel wavy configuration is more dominant than the symmetric one.

在这项研究中，通过三维流固共轭模型在雷诺数从 50 到 700 的广泛范围内研究了具有对称和平行波浪形微通道的微通道散热器。结果表明，对称配置比平行配置产生更高的努塞尔数，尤其是在更高的雷诺数和更大的幅度波长比时更是如此。传热增强可归因于对称配置在垂直于流动路径的横截面中引起四个迪安涡流，而平行配置中只有两个迪安涡流，导致更强的冷却剂混合，因此更高的努塞尔特对称配置中的数字。但是，由于通道喉道的存在，对称配置还实现了非常高的压力损失。因此，对称配置的整体性能略低于并行配置。为了提高波浪形微通道散热器的性能，提出了改进的对称和平行波浪形配置，其中将几个横向间隙添加到肋中以连接相邻的微通道。结果表明，由于相邻微通道之间增强的流体混合，这种二级分支设计显着提高了两种平行波浪构型的努塞尔数。此外，发现与其原始波浪形配置相比，次级分支略微增加了修改后的平行配置上的压降。因此，改进后的并联配置的整体性能显着增强。正如预期的那样，二级分支大大降低了经过修改的对称配置的压降。出乎意料的是，由于二次分支引起的通道喉道的吸入效应会削弱谷对谷区域的迪恩涡流并恶化传热性能，特别是对于具有较大Re和幅波比的散热器。因此，建议采用更宽的间隙和小幅度波长比的修改后的对称波浪配置。一般来说，修改后的平行波浪构型比对称的更占优势。出乎意料的是，由于二次分支引起的通道喉道的吸入效应会削弱谷对谷区域的迪恩涡流并恶化传热性能，特别是对于具有较大Re和幅波比的散热器。因此，建议采用更宽的间隙和小幅度波长比的修改后的对称波浪配置。一般来说，修改后的平行波浪构型比对称的更占优势。出乎意料的是，由于二次分支引起的通道喉道的吸入效应会削弱谷对谷区域的迪恩涡流并恶化传热性能，特别是对于具有较大Re和幅波比的散热器。因此，建议采用更宽的间隙和小幅度波长比的修改后的对称波浪配置。一般来说，修改后的平行波浪构型比对称的更占优势。建议采用更宽的间隙和小幅度波长比的修改后的对称波浪配置。一般来说，修改后的平行波浪构型比对称的更占优势。建议采用更宽的间隙和小幅度波长比的修改后的对称波浪配置。一般来说，修改后的平行波浪构型比对称的更占优势。