Heat Transfer for Hydrogen-based Propulsion

氢基推进的传热

• 批准号: 2902853
• 金额: --
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2024
• 资助国家: 英国
• 起止时间: 2024 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2902853
• 关键词: Heat; Transfer; Hydrogen; based; Propulsion

Heat Transfer for Hydrogen-based PropulsionAim: Develop novel light-weight heat-transfer solutions suitable for liquid hydrogen in aircraft engine applications.Objectives: - Combine steady and transient experiments with CFD to explore the flow and heat transfer processes used to heat and pressurise cryogenic hydrogen.- Measure the extent of heat transfer inhibition caused by density changes and study the effects of transients on flow and heat transfer.- Explore the scope for non-volatile, proxy fluids to represent cryogenic hydrogen to ease experiments in the Oxford Thermofluids Institute's laboratory.- Develop innovative instrumentation to study cryogenic and supercritical liquid hydrogen boundary layer transition in the microchannels used in the heat exchangers.Brief description: This project will explore key enabling technologies for the use of hydrogen in aircraft propulsion as one potential avenue in achieving carbon reduction. Liquid hydrogen requires compression and heating before being introduced into the combustion chamber. The proposed research in two-phase flow heat exchangers would enable conditioning of hydrogen in the fuel system prior to burning in combustor and is therefore critical to the success of hydrogen burning combustion. The influence of tube entry effects, surface roughness, curvature and turbulators on steady and transient heat transfer characteristics will be studied and appropriate models developed to aid heat exchanger design and support numerical modelling validation. Novelty of Research Methodology: We will explore the extent of any heat transfer inhibition caused by density changes as the liquid hydrogen is heated. The extreme absolute temperatures and temperature ratios (surface to fluid) introduce key challenges in instrumentation requirements for high accuracy measurements. To address the development of cryogenic measurement methods for thermal management, we will use liquid nitrogen at the outset. This approach will serve as a risk mitigation before performing liquid hydrogen experiments. Experiments with varying hydraulic diameter, from much less than to much great than capillary length scale will be conducted. We will quantify the impact of flow dynamics when vapour bubbles diameters are comparable to the tube diameter. Such conditions can result in low and high heat transfer coefficients and control the pressure drop and flow distributions within multiphase flows. We will design and build uniform heat flux boundary condition test sections for cryogenic experiments and implement electrical resistive heating in thin-walled stainless steel tubes to provide well-defined boundary conditions. These data will form the core test vehicle for experimental studies of liquid hydrogen flow on both shell and tube side of heat exchanger designs.The project will lead to the production of a holistic model of a turbofan followed by parametric studies which will vary heat exchanger size, thermodynamic cycle and weight to achieve efficiency metrics for overall system level performance.This project falls within the EPSRC 'Building a green future'/ 'Energy and decarbonisation theme'. Companies or Collaborators involved: The Oxford Thermofluids Institute and Rolls-Royce.

氢基推进器的传热目的：开发适用于飞机发动机应用中液氢的新型轻质传热解决方案目的：-将稳态和瞬态实验与CFD相结合，探索用于加热和加压低温氢的流动和传热过程。-测量密度变化引起的传热抑制程度，并研究瞬态对流动和传热的影响。探索非挥发性替代流体代表低温氢的范围，以简化牛津热流体研究所实验室的实验。发展创新的仪器，以研究低温和超临界液态氢边界层在用于热交换器的微通道transition.Brief Description：这个项目将探索关键的使能技术，在飞机推进使用氢作为一个潜在的途径，在实现碳减排。液态氢在被引入燃烧室之前需要压缩和加热。在两相流热交换器中提出的研究将使得能够在燃烧器中燃烧之前调节燃料系统中的氢，因此对于氢燃烧燃烧的成功至关重要。将研究管入口效应、表面粗糙度、曲率和散热器对稳态和瞬态传热特性的影响，并开发适当的模型，以帮助热交换器设计和支持数值建模验证。研究方法的新奇：我们将探讨当液氢被加热时，密度变化引起的任何传热抑制的程度。极端的绝对温度和温度比（表面与流体）对高精度测量的仪器要求提出了关键挑战。为了解决用于热管理的低温测量方法的发展，我们将在一开始就使用液氮。这种方法将在进行液氢实验之前作为一种风险缓解措施。将进行不同水力直径的实验，从远小于毛细管长度尺度到远大于毛细管长度尺度。当蒸汽气泡直径与管道直径相当时，我们将量化流动动力学的影响。这种条件可能导致低和高的传热系数并控制多相流内的压降和流量分布。我们将设计和建造用于低温实验的均匀热流边界条件测试段，并在薄壁不锈钢管中实施电阻加热，以提供明确的边界条件。这些数据将成为热交换器壳程和管程液氢流动实验研究的核心测试工具。该项目将导致涡轮风扇整体模型的生产，然后进行参数研究，改变热交换器的尺寸，热力学循环和重量，以实现整个系统级性能的效率指标。该项目福尔斯属于EPSRC“建设绿色未来”/“能源和脱碳”主题。参与的公司或合作者：牛津热流体研究所和劳斯莱斯。