Enhancing Heat Transfer in Porous Metals through Optimisation of Flow Resistance

由于体积功率密度的不断增加以及部署热管理所处的恶劣环境，热管理已成为电子领域的一个关键问题。由于传统的被动冷却技术不足以满足高散热率的要求，通常需要主动冷却。通过强制流体冷却，多孔金属在散热方面已经被证明是高效和经济的。阻碍其更广泛应用的一个主要问题是，由于其对流体流动的巨大阻力，工作流体通过冷却装置所需的泵送功率很高。本项目旨在解决由空间保持器法制造的具有独特的多孔结构和独特的传热行为的多孔金属在热应用中的科学和技术问题。研究的目的是了解流动阻力、换热和孔结构之间的机理关系，并开发技术来创建定制的多孔金属结构，以显著增强换热性能，同时将流动阻力降至最低。将进行制造、性能表征、建模和工艺开发相结合的工作，以确定支撑多孔金属中热流体行为的基本结构属性，量化它们对换热系数和流体流动阻力的影响，并设计和创建异质多孔结构，以实现整体主动冷却性能的阶梯变化。全球热管理产品市场规模超过100亿美元，年增长率为6.8%。英国在这一市场占有相当大的份额，在开发电子产品主动冷却设备的新材料和新技术方面处于领先地位。该项目将为设计和制造一种前景看好的多孔金属提供科学理解和技术开发，目前工业正在开发用于热管理应用的多孔金属。这项研究将确保英国在这一利基领域保持领先地位。这项研究还将有助于用于环境和能源应用的非热孔产品的研究和开发，如吸音器、多孔电极和催化剂载体，其中流动阻力具有确定的影响。

Thermal management has become a critical issue in electronics because of increasing volumetric power densities and the harsh environments in which they are deployed. Active cooling is often required for high rates of heat dissipation because conventional passive cooling techniques are inadequate. Porous metal has been demonstrated to be highly efficient and cost effective in heat dissipation by forced fluid cooling. A main problem impeding its wider application is the high pumping power required to move the working fluid through the cooling device due to its large resistance to fluid flow.This project sets out to address the scientific and technical issues in thermal applications of porous metals manufactured by the space holder methods, which have distinctive porous structure and unique heat transfer behaviour. The aims of the research are to understand the mechanistic relationships between flow resistance, heat transfer and pore structure and to develop technologies to create tailored porous metal structures for significantly enhanced heat transfer performance with minimised flow resistance. A combination of manufacturing, properties characterisation, modelling and process development will be carried out to identify the fundamental structural properties underpinning the thermal fluid behaviour in porous metals, to quantify their effects on heat transfer coefficient and fluid flow resistance, and to design and create heterogeneous porous structures for a step change in overall active cooling performance. The global market for thermal management products is more than $10 billion with an annual growth rate of 6.8%. UK has a significant share in this market and is one of the leaders in developing new materials and technologies for active cooling devices for electronics. This project will provide scientific understanding and technical development underpinning the design and manufacture of a promising class of porous metals that are currently being developed by industry for thermal management applications. This research will ensure that UK maintains the leading position in this niche field. This research will also benefit the research and development of non-thermal porous products for environmental and energy applications, e.g., sound absorbers, porous electrodes and catalyst supports, where flow resistance has a deterministic effect.