Meloni Stefano, Di Marco Alessandro, Mancinelli Matteo, Camussi Roberto
Department of engineering, University of RomaTre, Rome, Italy.
Département Fluides, Thermique et Combustion, Institut Pprime - CNRS-Université de Poitiers-ENSMA, Chasseneuil-du-Poitou, Poitiers, France.
Sci Rep. 2020 Jun 4;10(1):9140. doi: 10.1038/s41598-020-66037-2.
The wall pressure fluctuations induced by a subsonic circular jet on a rigid flat plate have been investigated considering two jets with different exit section diameters at the same Mach number. The analysis is aimed at completing the series of papers presented by the authors on the interaction between a subsonic jet and infinite tangential flat plate where the exit Mach number was the only parameter of the jet flow that was varied. In order to analyse other effects out of the Mach number, two configurations with different nozzle exhaust diameters were explored with the objective of isolating the Reynolds number effect keeping fixed the exit Mach number. The nozzle exhaust diameters are 12 mm and 25.4 mm and the instrumented flat plate, installed parallel to the jet flow, is moved at different radial distances from the jet axis. The pressure footprint on the plate has been measured in the stream-wise direction by means of a pair of flush-mounted pressure transducers, providing point-wise pressure signals. Wall pressure fluctuations have been characterised in terms of spectral and statistical quantities. The effect of Reynolds is evidenced and possible scaling relationships that account for the Reynolds dependence are proposed. Implications for modeling the spectral coherence have been considered by the application of the Corcos' model and the effect of the jet Reynolds number on the model coefficients is analyzed.
研究了亚音速圆形射流在刚性平板上引起的壁面压力波动，考虑了在相同马赫数下具有不同出口截面直径的两种射流。该分析旨在完善作者此前发表的一系列关于亚音速射流与无限大切向平板相互作用的论文，在这些论文中，出口马赫数是射流流动中唯一变化的参数。为了分析马赫数之外的其他影响，研究了两种具有不同喷嘴出口直径的配置，目的是在保持出口马赫数不变的情况下分离雷诺数效应。喷嘴出口直径分别为12毫米和25.4毫米，与射流流动平行安装的仪器平板在距射流轴线不同的径向距离处移动。通过一对嵌入式压力传感器在流向方向上测量平板上的压力分布，提供逐点压力信号。壁面压力波动已根据频谱和统计量进行了表征。证明了雷诺数的影响，并提出了考虑雷诺数依赖性的可能比例关系。通过应用科尔科斯模型考虑了对频谱相干性建模的影响，并分析了射流雷诺数对模型系数的影响。
