Better Bubblers: Jet Impingement Within a Dead-End Channel

更好的起泡器：死端通道内的射流冲击

• 批准号: EP/V02695X/1
• 负责人: James Jewkes
• 金额: $ 31.61万
• 依托单位: University of Leicester
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FV02695X%2F1
• 关键词: Better; Bubblers; Jet; Impingement; Within

In the high pressure aluminium die casting (HPADC) and injection moulding (IM) industries, a unique flow field is used to cool slender mould protrusions: a jet impingement confined within a dead-end channel, known in industry as a 'bubbler'. These devices are used ubiquitously, however their implementation within a mould has been constrained by the limitations of 2D machining; recent advances in Additive Manufacturing (AM) now offer timely and novel opportunities to improve their design. Our challenge is that the heat- and flow-regime associated with a bubbler has received limited attention in the literature, so an improved understanding is required to access the optimum cooling performance that the AM of these devices can enable. The goal of this project is therefore to establish the heat and flow phenomenology associated with bubblers, and to develop novel methods that will enable their design to be optimised for AM, to be achieved though the following objectives:1) Development of a highly-resolved computational fluid dynamics (CFD) dataset that reveals the bubbler heat- and flow-configuration in detail. Isothermal and conjugate heat transfer (CHT) wall-resolved large eddy simulations (LES) of the basic co-annular flow-field will be performed, and validated against the experimental dataset.2) Elucidation of the flow physics via the collection and analysis of experimental results. Particle image velocimetry (PIV) data will be obtained using a novel cold-flow optical experimental rig, and used to parameterise the basic flow-field and to validate the isothermal simulations. Heat transfer data will be obtained using Coventry's existing aluminium casting experiment, for validation of the CHT simulations.3) Development of novel shape optimisation methods for HPADC inserts. The adjoint method finds the gradient of the governing Navier-Stokes equations, enabling tailored shape deformation in pursuit of a particular objective function, which will need to be developed to enable the maximisation of heat removal and heat-flux uniformity across the protrusion. An optimised geometry will then be laser sintered by our partners at CastAlum Ltd., to be tested experimentally and demonstrated in an industrial setting.This will lead to:- A thorough description of the coupling of fluid dynamics and heat-transfer behaviour arising from inherent and induced boundary and free shear-layer turbulence in annularly confined jet-impingement, achieved through the application of LES and PIV, with a novel focus upon heat transfer through both the impingement surface and the annular confining wall, leading to;- Significantly improved bubbler operating parameters providing efficient heat removal rates, and correlations for their prediction for a full suite of configurations;- An optimisation strategy for HPADC that maximises heat removal and heat flux uniformity, that will accelerate the adoption of AM methods within the industry.In parallel, the project will advance modelling techniques, and set new benchmarks in the numerical simulation of jet-impingement that will have use far-beyond the nominal application. The work will be of direct benefit to UK HPADC and IM industries, laying rigorous theoretical foundations that, allied with the flexibility in design provided by AM, will better control the heat removal from the most problematic areas of their moulds, resulting in reduced cycle times thereby increasing product volume, extending the life of the expensive tools, and maintaining product quality over extended (150k+) cycles. It will therefore provide industry with a pronounced commercial advantage and reduction in the overall production plant life cycle costs. A bubbler's flow field arises in other engineered systems, from high pressure jet cutting, to electronics cooling, and even to artificial lung ventilation.

在高压铝压铸（HPADC）和注塑（IM）行业中，使用独特的流场来冷却细长的模具突起：限制在死端通道内的射流冲击，在工业中称为“气泡”。这些设备被广泛使用，但它们在模具中的实现受到2D加工的限制;增材制造（AM）的最新进展现在为改进其设计提供了及时和新颖的机会。我们面临的挑战是，与起泡器相关的热量和流动状况在文献中受到的关注有限，因此需要更好的理解才能获得这些设备的AM可以实现的最佳冷却性能。因此，该项目的目标是建立与起泡器相关的热和流动现象学，并开发新的方法，使其设计能够针对AM进行优化，通过以下目标实现：1）开发高分辨率的计算流体动力学（CFD）数据集，详细揭示起泡器热和流动配置。对基本的共环流场进行等温和共轭传热（CHT）壁面分辨大涡模拟（LES），并与实验结果进行对比验证。2）通过收集和分析实验结果阐明流动物理。粒子图像测速（PIV）数据将获得使用一种新的冷流光学实验台，并用于参数化的基本流场和验证等温模拟。热传递数据将使用考文垂现有的铝铸造实验，CHT模拟验证。3）开发新的形状优化方法的HPADC插入。伴随方法找到了控制Navier-Stokes方程的梯度，使得能够实现定制的形状变形以追求特定的目标函数，这将需要被开发以使得能够最大化整个突起的热移除和热通量均匀性。然后，我们的合作伙伴CastAlum Ltd.将对优化的几何形状进行激光烧结，这将导致：-通过LES和PIV的应用，对环形限制射流冲击中固有的和诱导的边界和自由剪切层湍流引起的流体动力学和传热行为的耦合进行全面描述，并对通过冲击表面和环形限制壁的传热进行新的关注，导致;- 显著改进的起泡器操作参数，提供有效的排热速率，以及它们对一整套构型的预测的相关性;- HPADC的优化策略，最大限度地提高散热和热通量均匀性，这将加速AM方法在行业内的采用。同时，该项目将推进建模技术，并在射流冲击的数值模拟中建立了新的基准，其用途将远远超出标称应用。这项工作将直接受益于英国HPADC和IM行业，奠定严格的理论基础，与AM提供的设计灵活性相结合，将更好地控制模具中最有问题的区域的散热，从而减少循环时间，从而增加产品体积，延长昂贵工具的寿命，并在延长（150 k+）周期内保持产品质量。因此，它将为工业提供显著的商业优势，并降低整个生产设备的生命周期成本。起泡器的流场出现在其他工程系统中，从高压射流切割，到电子冷却，甚至到人工肺通气。

项目成果

Adjoint Method for the Optimisation of Conformal Cooling Channels of 3-D Printed High-Pressure Tools for Aluminium Casting

用于优化铝铸件 3D 打印高压工具随形冷却通道的伴随方法

• DOI: 10.4271/2022-01-0246
• 发表时间: 2022
• 期刊: SAE International Journal of Advances and Current Practices in Mobility
• 作者: Zeng T

Energy and Sustainable Futures: Proceedings of the 3rd ICESF, 2022

能源与可持续未来：2022 年第三届 ICESF 会议记录

• DOI: 10.1007/978-3-031-30960-1_31
• 发表时间: 2023
• 作者: Zeng T