Sound propagation through hot exhaust plumes with cooler cross-winds is present in many real world systems. One particular example is the sound propagation from exhaust stacks attached to open cycle gas turbine power stations. The research presented in this paper investigates the sound propagation from a reduced-scale exhaust stack, with a cross-flow from experiments conducted in a wind tunnel. Experimental measurements of the flow and temperature fields provide insight into the complex sound radiation characteristics. Results from the acoustic measurements show the change in the sound directivity arising from the inclusion of the hot exhaust plume, leading to non-axisymmetric sound directivity and a concentration of sound downwind of the exhaust stack outlet. In certain cross-flow conditions, the hot exhaust plume can increase the sound observed downwind by up to 11 dB when compared to the scenario of sound propagation from an exhaust stack in the absence of a heated jet or cross-flow. This paper describes the acoustic directivity at various radial distances from the exhaust stack, acoustic frequencies, jet temperatures, and cross-flow free-stream velocity. The results from this paper emphasise the importance of taking into consideration the hot exhaust plume with cooler cross-flow when estimating sound levels downwind of the stack.

中文翻译：

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在较冷的横流中通过升高的加热射流传播声音：一项实验研究

在许多现实世界的系统中，声音通过带有较冷侧风的热排气羽流传播。一个特殊的例子是从连接到开式循环燃气轮机发电站的排气烟囱的声音传播。本文介绍的研究通过风洞实验中的横流研究了缩小尺寸的排气烟囱的声音传播。流场和温度场的实验测量提供了对复杂声辐射特性的深入了解。声学测量结果表明，由于包含热排气羽流而导致声音方向性发生变化，导致非轴对称声音方向性和排气烟囱出口下风向的声音集中。在一定的错流条件下，与在没有加热射流或交叉流的情况下从排气烟囱传播声音的情况相比，热排气羽流可以将顺风观察到的声音增加多达 11 分贝。本文描述了距排气管的不同径向距离处的声学方向性、声学频率、射流温度和交叉流动自由流速度。本文的结果强调了在估计烟囱顺风声级时考虑具有较冷交叉流的热排气羽流的重要性。和横流自由流速度。本文的结果强调了在估计烟囱顺风声级时考虑具有较冷交叉流的热排气羽流的重要性。和横流自由流速度。本文的结果强调了在估计烟囱顺风声级时考虑具有较冷交叉流的热排气羽流的重要性。