Large-eddy simulations of the noise control of supersonic rectangular jets with bevelled nozzles

作者：Baodong Chen, Yitong Fan, Zifei Yin, Gaohua Li, Weipeng Li · 发表于：Journal of Fluid Mechanics · 年份：2025 · DOI：10.1017/jfm.2024.1180 · 被引用次数：14 · 研究领域：Aerodynamics and Acoustics in Jet Flows、Fluid Dynamics and Turbulent Flows、Acoustic Wave Phenomena Research

The bevelled nozzle is a promising noise control approach and has been tested to suppress the noise levels in supersonic circular jets, but not in rectangular jets so far. In this study, implicit large-eddy simulations are performed to analyse the noise control of supersonic rectangular jets with single- and double-bevelled nozzles. Three nozzle pressure ratios ( $NPR = 2.3$ , 3.0 and 5.0) are considered to form two over-expanded cold jets and one under-expanded cold jet, exhausted from a baseline convergent–divergent rectangular nozzle with an aspect ratio of 2.0. Results show that, with the increase of $NPR$ , the oscillation of the jet plume is switched from a symmetrical mode to a flapping mode (preferential in the minor-axis plane), then to a helical mode, together with a reduction of the screech frequency. The amplitude of the screech tone is the strongest in the flapping jet, and the turbulent mixing noise is the most prominent in the helically oscillating jet. The single-bevelled nozzle induces asymmetric shock-cell structures and deflects the jet plumes, and the double-bevelled nozzle primarily enables the enhancement of the shear-layer mixing and shortens the lengths of the jet potential cores. With the bevelled nozzles, the gross thrusts of the baseline nozzle are increased by $0.05 \sim 7.38$ %. Details on the characteristics of far-field noise in the jets with/without the bevel cuts and their noise control mechanisms are discussed using the Ffowcs Williams–Hawkin...