Abstract

This study reports on a mathematical model for predicting the fluid and heat flow characteristics of a Z-shaped corrugated foam heat sink. Experiments were carried out to validate local as well as overall pressure drop predictions. The mathematical model was further validated against corrugated carbon foam experimental measurements from the literature. A general flow parameter emerges from the formulation that is descriptive of flow uniformity. Based on a scaling analysis, it was found that a relatively low permeability foam, compared to the square of the conduit hydraulic diameter, is more effective than high permeability foam because of its ability to achieve uniform flow distribution. An illustrative study is carried that estimates the optimum number of porous fins that can be packaged within a given volume under fixed pressure drop constraint. Further, this study elaborates on the importance of achieving uniform flow distribution across the porous fins. The ideal condition of uniform flow was found to be useful in increasing the rate of heat transfer when compared with the actual condition of non-uniform flow for the range of parameters explored in this work. Finally, the impact of the flow non-uniformity parameter on the overall Nusselt number is illustrated.

摘要

本研究报告了用于预测 Z 形波纹泡沫散热器的流体和热流特性的数学模型。进行了实验以验证局部和整体压降预测。根据文献中的波纹碳泡沫实验测量结果进一步验证了数学模型。描述流动均匀性的公式中出现了一般流动参数。根据比例分析，发现与管道水力直径的平方相比，相对低渗透性泡沫比高渗透性泡沫更有效，因为它能够实现均匀的流量分布。进行了一项说明性研究，该研究估计了在固定压降约束下可以封装在给定体积内的多孔翅片的最佳数量。此外，这项研究详细说明了在多孔翅片上实现均匀流动分布的重要性。与本研究中探索的参数范围内的非均匀流动的实际条件相比，均匀流动的理想条件有助于提高传热速率。最后，说明了流动非均匀性参数对整体 Nusselt 数的影响。