Thermal modelling for Clean Sky Aircraft

随着航空业越来越面临减少对化石燃料依赖的压力，人们正在探索新的能源储存和转换途径。电池电力、氢电力（燃料电池）和氢燃烧都将面临新的热管理挑战。热管理系统是评估燃料电池架构的重量和可行性的关键。该项目将汇集航空工程的顶级要求和对压降和传热之间权衡的流体动力学理解。飞机上的热交换器是压力降受限的，前区的封装和集成是决定重量和阻力的关键。此外，关键的选型点是在炎热的天气起飞，需要有能力模拟瞬态响应和不同的巡航热管理策略，以实现最佳设计。研究将包括调查基本的传热和压降曲线，如横向流动中的平板和管道，并将其与全热交换器的工程等效物联系起来。将开发一种关于如何对热管理部件的重量进行建模的通用方法，以及一种用于估计单次飞行中的热循环和飞机寿命的工具。将特别注意尝试并包括可能对设计至关重要的高保真效应，如热膨胀和氢脆。总的目标是能够评估和质疑乐观的飞机概念的关键假设，并评估错误的热假设可能是关键的。

As the aviation industry is increasingly under pressure to reduce it's dependence on fossil fuels, new energy storage and conversion pathways are being explored. Battery-electric, hydrogen-electric (fuel cell) and hydrogen combustion all will have to deal with new thermal management challenges. The thermal management system is key in assessing weight and viability of fuel cell architectures. The project will bring together the engineering top-level requirements of aviation and a fluid dynamic understanding of the trade-offs between pressure drop and heat transfer. Heat exchangers in aircraft are pressure drop constrained, the packaging and integration of frontal area is key to determining weight and drag. Furthermore the critical sizing point is at take-off on a hot day, requiring capability to model transient response and different cruise thermal management strategies for optimal design. Research will include investigating fundamental heat transfer and pressure drop profiles such as the flat plate and tubes in cross flow, and relating these to the engineering equivalents of full heat exchangers. A general methodology on how to model weight of thermal management components will be developed, as well as a tool to estimate thermal cycles across a single flight and the lifetime of an aircraft. Particular care will be taken to attempt and include high fidelity effects that may be critical to designs such as thermal expansion and hydrogen embrittlement. The overall goal will be able to assess and question the key assumptions of optimistic aircraft concepts and evaluate where erroneous thermal assumptions could be critical.