Zhou Tao, Chen Bingchao, Liu Huanling
School of Electromechanical Engineering, Xidian University, Xi'an 710071, China.
Micromachines (Basel). 2021 May 21;12(6):594. doi: 10.3390/mi12060594.
In recent years, in order to obtain a radiator with strong heat exchange capacity, researchers have proposed a lot of heat exchangers to improve heat exchange capacity significantly. However, the cooling abilities of heat exchangers designed by traditional design methods is limited even if the geometric parameters are optimized at the same time. However, using topology optimization to design heat exchangers can overcome this design limitation. Furthermore, researchers have used topology optimization theory to designed one-to-one and many-to-many inlet and outlet heat exchangers because it can effectively increase the heat dissipation rate. In particular, it can further decrease the hot-spot temperature for many-to-many inlet and outlet heat exchangers. Therefore, this article proposes novel heat exchangers with three inlets and one outlet designed by topology optimization to decrease the fluid temperature at the outlet. Subsequently, the effect of the channel depth on the heat exchanger design is also studied. The results show that the type of exchanger varies with the channel depth, and there exists a critical depth value for obtaining the minimum substrate temperature difference. Then, the flow and heat transfer performance of the heat exchangers are numerically investigated. The numerical results show that the heat exchanger derived by topology optimization with the minimum temperature difference as the goal (Model-2) is the best design for flow and heat transfer performance compared to other heat sink designs, including the heat exchanger derived by topology optimization having the average temperature as the goal (Model-1) and conventional straight channels (Model-3). The temperature difference of Model-1 can be reduced by 37.5%, and that of Model-2 can be decreased by 62.5% compared to Model-3. Compared with Model-3, the thermal resistance of Model-1 can be reduced by 21.86%, while that of Model-2 can be decreased by 47.99%. At room temperature, we carried out the forced convention experimental test for Model-2 to measure its physical parameters (temperature, pressure drop) to verify the numerical results. The error of the average wall temperature between experimental results and simulation results is within 2.6 K, while that of the fluid temperature between the experimental and simulation results is within 1.4 K, and the maximum deviation of the measured and simulated was less than 5%. This indicated that the numerical results agreed well with the experimental results.
近年来，为了获得具有强大热交换能力的散热器，研究人员提出了许多热交换器以显著提高热交换能力。然而，即使同时对几何参数进行优化，采用传统设计方法设计的热交换器的冷却能力仍然有限。然而，使用拓扑优化来设计热交换器可以克服这种设计限制。此外，研究人员已经运用拓扑优化理论设计了一对一和多对多进出口热交换器，因为它可以有效提高散热率。特别是，对于多对多进出口热交换器，它可以进一步降低热点温度。因此，本文提出了通过拓扑优化设计的具有三个进口和一个出口的新型热交换器，以降低出口处的流体温度。随后，还研究了通道深度对热交换器设计的影响。结果表明，热交换器的类型随通道深度而变化，并且存在一个临界深度值以获得最小的基板温差。然后，对热交换器的流动和传热性能进行了数值研究。数值结果表明，与其他散热器设计相比，以最小温差为目标通过拓扑优化得到的热交换器（模型2）在流动和传热性能方面是最佳设计，包括以平均温度为目标通过拓扑优化得到的热交换器（模型1）和传统的直通道（模型3）。与模型3相比，模型1的温差可降低37.5%，模型2的温差可降低62.5%。与模型3相比，模型1的热阻可降低21.86%，而模型2的热阻可降低47.99%。在室温下，我们对模型2进行了强制对流实验测试，以测量其物理参数（温度、压降）来验证数值结果。实验结果与模拟结果之间的平均壁温误差在2.6K以内，而流体温度的实验结果与模拟结果之间的误差在1.4K以内，测量值与模拟值的最大偏差小于5%。这表明数值结果与实验结果吻合良好。
