Analysis and prediction of supersonic heated jet noise in axisymmetric air jets

轴对称空气射流超音速加热射流噪声分析与预测

• 批准号: 2275424
• 金额: --
• 依托单位: University of Strathclyde
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2275424
• 关键词: Analysis; prediction; supersonic; heated; jet

Heated jet flows introduce a number of interesting and peculiar features of jet noise spectrum that have not been fully understood or indeed, self-consistently explained. One of these features is the apparent quietening of supersonic jets at high jet temperature ratio. This aspect of jet noise remains an important area of research not least because understanding any kind of mechanism of jet noise reduction will ultimately aid noise abatement strategies. In addition however the fact that the quietening owes its existence to a purely fluid mechanical means is more reason to understand and develop rational mathematical models to explain it. On the other hand, for low subsonic acoustic Mach number jets, an increase in temperature produces an increase in sound. The main purpose of this Ph.D. project is to utilize the in-house codes at Mississippi State University to map out the turbulence structure across the range of acoustic Mach number and jet temperature ratio. After which we shall use this information within an acoustic analogy model for the far field noise spectrum.The Ph.D. student will be part of collaborative team of researchers and academics from Mississippi State University and the NASA Glenn Research Center. During the second year of study, the student will be based at Mississippi. The work will involve Computational Fluid Dynamics (CFD) of jet flows using Large Eddy Simulations as well as aero-acoustic modelling using various Applied Mathematical techniques.

加热喷流引入了一些有趣的和奇特的喷流噪声频谱尚未完全理解的特点，甚至，自洽解释。这些特征之一是在高喷流温度比下超声速喷流的明显消音。这方面的喷气噪音仍然是一个重要的研究领域，尤其是因为了解任何一种机制的喷气噪音减少将最终有助于噪音消减策略。然而，除此之外，由于纯粹的流体力学手段而导致的消音现象的存在，更有理由去理解和发展合理的数学模型来解释它。另一方面，对于低亚音速声学马赫数的喷流，温度的增加会引起声音的增加。这个博士学位的主要目的项目是利用密西西比州立大学的内部代码绘制出在声学马赫数和射流温度比范围内的湍流结构。之后，我们将在远场噪声频谱的声学模拟模型中使用此信息。学生将成为来自密西西比州立大学和美国宇航局格伦研究中心的研究人员和学者合作团队的一员。在学习的第二年，学生将在密西西比。这项工作将涉及使用大涡模拟的射流计算流体动力学（CFD）以及使用各种应用数学技术的航空声学建模。