Design and validation methods for additively manufactured heat exchangers

金属添加剂制造(AM)被视为下一代热管理解决方案(例如热交换器)的关键使能技术。热交换器用于在两种流体之间传递热量，是航空航天、汽车和能源等部门许多工程系统中的重要部件。AM和热交换器之间的和谐是因为可以相对容易地制造复杂和错综复杂的内部几何形状(通道)，而不需要昂贵的制造阶段。因此，这些热交换器已经成为传统热交换器概念的高性能、紧凑和轻量化的替代品。然而，AM在开发成本和时间方面面临着巨大的挑战，特别是在可能需要迭代生产的情况下。一个典型的单机设备的成本可能在100万GB左右，而钛粉原料的成本约为400 GB/公斤。一台尺寸为200x200x200 mm的换热器需要大约10天的时间才能生产出来。因此，使用该技术迭代开发新的换热器概念在开发成本方面很容易超过GB 100k大关。本项目的目的是开发一种方法，使用户能够快速迭代地设计满足一组传热和压降要求的换热器核心，同时遵守空间限制。目前的愿景是将新的热传递模型与算法设计方法相结合。这将被用来自动化核心几何形状的设计，从而减少工程费用，并减少达成新提议所需的时间。还将设计和建造热交换器试验台，以验证建模工作，并通过将其用作硬件在环中，形成设计方法的组成部分。预计这项研究将在上述行业目前的减排趋势中发挥作用，这是因为减少了质量，从而节省了能源/燃料。此外，增强的性能还将有助于回收和利用这些系统中的废热。从更远的角度来看，这被认为有助于使未来的飞机推进和发电系统可行，例如氢燃料电池和广泛的电气化。

Metal additive manufacturing (AM) is viewed as a key enabling technology for the next generation of thermal management solutions (e.g. heat exchangers). Heat exchangers, used to transfer heat between two fluids, are essential components in many engineering systems in sectors such as aerospace, automotive and energy. The harmony between AM and heat exchangers arises through the relative ease with which complex and intricate internal geometries (channels) can be produced without the need for costly fabrication stages. As such, these heat exchangers have already established themselves as highly performant, compact and lightweight alternative to traditional heat exchanger concepts.However, AM presents significant challenges in terms of development costs and time, particularly where iterative production might be expected. A typical, single machine facility is likely to cost in the range of £1 million, and titanium powder feedstock costs approximately £400/kg. A heat exchanger with dimensions of 200 x 200 x 200mm would take approximately 10 days to produce. As such, to iteratively develop a new heat exchanger concept using this technology would easily exceed the £100k mark in terms of development cost.The aim of this project is to develop a methodology that enables the user to rapidly and iteratively design a heat exchanger core that meets a set of heat transfer and pressure drop requirements, whilst adhering to spatial constraints. The current vision is to combine novel heat transfer modelling with an algorithmic design approach. This will be used to automate the design of the core geometry and therefore reduce the engineering overhead and reduce the time required to reach a new proposition. A heat exchanger test bed will also be designed and built to validate the modelling work but also to form an integral part of the design methodology by using it as hardware-in-the-loop. It is expected that this research will play a role in the current trends of reduction in emissions in the aforementioned industries, owing to a reduced mass and therefore energy/fuel savings. In addition, enhanced performance will also help to recover and harness wasted heat within these systems. Looking further, it is thought that this could help make future aircraft propulsion and power generation systems viable, such as hydrogen fuel cells and widespread electrification.