Noise Generation in Hot Nozzle Flow
Noise Generation in Hot Nozzle Flow
复制标题
热喷嘴流中产生的噪音
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
F. Bake
中科院分区：
文献类型：
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作者：
K. Knobloch;T. Werner;F. Bake
在燃气涡轮机的燃烧室中的燃烧过程期间，由不稳定的热释放产生的噪声是众所周知的。然而，被称为间接燃烧噪声的效应仅在最近才受到相当大的关注。当熵或涡量波动将受到强速度梯度的影响时，如在高压涡轮机的喷嘴导向叶片中，将产生间接燃烧噪声。这一现象的第一个实验证据是几年前在一个专门的小规模实验室实验中获得的。德国航空航天中心（DLR）最近在热声试验台（HAT）进行的实验旨在通过研究冷空气点注入热平均流时通过喷嘴的声音传播和声音产生来进一步了解这种现象。喷管马赫数从亚音速到音速是变化的。基于传播时间分析的第一结果揭示了喷嘴位置处的噪声产生。对喷嘴马赫数、冷流温度以及冷空气喷射方式（径向/轴向吹扫）等参数进行了研究。Copyright © 2015 by ASME
Noise originating from the unsteady heat-release during the combustion process in the combustor of a gas turbine is well known. However, an effect known as indirect combustion noise has received considerable interest only recently. Indirect combustion noise will be generated, when entropy or vorticity fluctuations will be subject to a strong velocity gradient like in nozzle guide vane of the high pressure turbine. First experimental proof of this phenomenon could be obtained some years ago in a dedicated small-scale laboratory experiment. Recent experiments performed in the Hot Acoustic Test rig (HAT) by the German Aerospace Center (DLR) aim at further understanding of this phenomenon by investigating the sound propagation through a nozzle and sound generation when cold air spots are injected into a hot mean flow. The nozzle Mach number was varied from subsonic to sonic conditions. First results based on propagation time analysis reveal noise generation at the location of the nozzle. Parameter studies of nozzle Mach number, temperature of the cold streaks, and the way the cold air is injected (radial/axial blowing) have been performed.Copyright © 2015 by ASME