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Computational Fluid Dynamics (CFD) of transpiration cooling and noise reduction in jet engines

喷气发动机蒸腾冷却和降噪的计算流体动力学 (CFD)

基本信息

批准号：
1941360
负责人：
金额：
--
依托单位：
Queen's University Belfast
依托单位国家：
英国
项目类别：
Studentship
财政年份：
2017
资助国家：
英国
起止时间：
2017 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=studentship-1941360
关键词：
Computational Fluid Dynamics CFD transpiration

项目摘要

In recent years, the reduction of noise emissions in airports has gained more importance due to the increase in air traffic. Airbus global market forecast predicts a 4.4% global annual air traffic growth over the next 20 years. Studies also concluded that aircraft noise has a negative impact on people's quality of life and health. In the UK alone over 1 million of people are living in areas where aircraft noise is above levels recommended for health. The Advisory Council for Aviation Research and innovation in Europe (ACARE) has set goals to reduce the perceived noise emission by 65% until 2050 with respect to the year 2000. In the past, jet engine noise was predominantly due to jet noise and fan noise. Jet noise has been reduced by increasing the bypass of turbofan engines while fan noise has been reduced through effective acoustic liners and complex designs of fan blade geometry. These efforts on the reduction of jet and fan noise have left combustion noise as an important remaining contributor. The total noise radiated by a gas turbine combustion chamber system consists of "direct" and "indirect" noise. Fluctuation in heat release rate from the turbulent flame causes an unsteady volumetric expansion and contraction, leading to a pressure wave which constitutes the "direct" acoustic noise. The "indirect" noise is generated due to the acceleration of entropy waves through the combustor, and in particular turbine blade rows. Recent studies showed that the level of indirect entropy noise could be on the same order of magnitude or larger than the direct acoustic noise. This requires more investigation of underusing the generation and dissipation of entropy noise as they convect through the turbine blade rows. In this PhD project a high fidelity CFD analisys will be performed using an open source software (i.e. OpenFoam) to investigate the detailed flow physics involved in the convection of entropy waves as they convect through the nozzle guide vane and turbine rotor blade rows. This will enable us to understand passive and active techniques to reduce the contribution of indirect entropy noise to the generation of the total noise in a gas turbine. This will have a great impact in designing new gas turbines but ultimately on peoples life affected by noise emission.

近年来，由于空中交通的增加，减少机场的噪音排放变得更加重要。空中客车全球市场预测预测未来20年全球空中交通量将以每年4.4%的速度增长。研究还得出结论，飞机噪音对人们的生活质量和健康有负面影响。仅在英国，就有超过100万人生活在飞机噪音超过健康建议水平的地区。欧洲航空研究和创新咨询理事会（ACARE）已经设定了到2050年相对于2000年将感知噪声排放减少65%的目标。在过去，喷气发动机噪声主要是由于喷气噪声和风扇噪声。通过增加涡轮风扇发动机的旁通来降低喷气噪声，而通过有效的声学衬套和风扇叶片几何形状的复杂设计来降低风扇噪声。这些减少喷气和风扇噪声的努力使燃烧噪声成为一个重要的剩余贡献者。燃气涡轮机燃烧室系统的总辐射噪声由“直接”噪声和“间接”噪声组成。湍流火焰的放热率波动引起不稳定的体积膨胀和收缩，导致压力波，构成“直接”的声学噪声。“间接”噪声是由于通过燃烧器，特别是涡轮机叶片排的熵波的加速而产生的。最近的研究表明，间接熵噪声的水平可以在相同的数量级或大于直接声学噪声。这就需要更多地研究熵噪声通过涡轮机叶栅对流时产生和耗散的不足。在本博士项目中，将使用开源软件（即OpenFoam）进行高保真CFD分析，以研究熵波对流通过喷嘴导叶和涡轮机转子叶片排时所涉及的详细流动物理。这将使我们了解被动和主动技术，以减少间接熵噪声的气体涡轮机的总噪声的产生的贡献。这将对设计新的燃气轮机产生很大影响，但最终会影响到人们的生活。