High-speed jet noise

Bailly, Christophe; Fujii, Kozo

doi:10.1299/mer.15-00496

Cited by 40 publications

(21 citation statements)

References 79 publications

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“…The noise from imperfectly expanded supersonic jet is admitted to be generated by three main mechanisms: 2,3 the convection of large turbulent structures in the shear layer, the mixing of fine turbulent scales in the shear layer and the interaction of turbulent structures with shocks. The first one is associated with the Mach wave radiation and the third one with the broadband shock-associated noise.…”

Section: A Jet Noise Sourcesmentioning

confidence: 99%

“…59 This noise source has a broadband spectrum, except when a feedback loop with the early instability waves development occurs, inducing a tonal noise known as screech. 3 The broadband shock-associated noise (BBSAN) is dominant essentially upstream. A model has been proposed by Tam and Tanna 59 to predict the BBSAN peak frequency according to…”

Section: Broadband Shock-associated Noisementioning

confidence: 99%

“…1 Since the founding work of Lighthill, supersonic jet noise has been carefully investigated, as extensively reviewed by Tam 2 or Bailly and Fujii. 3 Experimental studies have first been conducted to identify noise sources as reported by Tam et al 4 for instance. Based on measured data, three main components have been highlighted: the turbulent mixing noise, the broadband shock-associated noise and the Mach wave radiation.…”

Section: Introductionmentioning

confidence: 99%

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Accurate simulation of the noise generated by a hot supersonic jet including turbulence tripping and nonlinear acoustic propagation

et al. 2019

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A procedure to accurately simulate a free hot supersonic jet and its associated noise, which uses simultaneously a turbulence tripping method and a two-way coupling between a flow solver and a nonlinear acoustic solver, is proposed in this study. A Mach 3.1 overexpanded hot jet is computed via a large-eddy simulation by solving the filtered Navier-Stokes equations with a finite volume method on unstructured grids. The resulting noise is propagated in the far field by solving the full Euler equations with a high-order discontinuous Galerkin method on unstructured grids. The full convergent-divergent nozzle is explicitly included in the computational domain thanks to the unstructured flow solver. Both a refined grid and a geometrical boundary layer tripping in the convergent are used to get highly disturbed turbulent conditions at the nozzle lips. The flow field appears to agree with the expected turbulence behavior and the available experimental data. The jet development shows significant improvement compared to similar past simulations. The far field acoustic levels are finely recovered at most of observation angles. An analysis of the acoustic near and far fields is then performed. The studied conditions lead to strong shock-associated noise and Mach wave emission. The spatio-frequency and azimuthal content of the acoustic field is described in order to identify the main noise properties. A particular noise component, different from screech tones and radiating upstream like Mach waves, is highlighted. Nonlinear propagation effects are finally quantified through specific metrics. They are found significant in both the near and the far fields which justifies the use of a nonlinear acoustic solver.

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Section: A Jet Noise Sourcesmentioning

confidence: 99%

Section: Broadband Shock-associated Noisementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Accurate simulation of the noise generated by a hot supersonic jet including turbulence tripping and nonlinear acoustic propagation

et al. 2019

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“…Noise produced by imperfectly expanded supersonic jets differs from subsonic jet noise by the emergence of shock noise. Major knowledge about supersonic jet noise is available in comprehensive reviews, for example in Tam (1995), Raman (1999) or Bailly & Fuji (2016). The present paper focuses on the screech, a strong tonal contribution of shock noise.…”

Section: Introductionmentioning

confidence: 99%

Experimental characterisation of the screech feedback loop in underexpanded round jets

2017

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Near-field acoustic measurements and time-resolved schlieren visualisations are performed on 10 round jets with the aim of analysing the different parts of the feedback loop related to the screech phenomenon in a systematic fashion. The ideally expanded Mach number of the studied jets ranges from $M_{j}=1.07$ to $M_{j}=1.50$. The single source of screech acoustic waves is found at the fourth shock tip for A1 and A2 modes, and at either the third or the fourth shock tip for the B mode, depending on the Mach number. The phase of the screech cycle is measured throughout schlieren visualisations in the shear layer from the nozzle to the source. Estimates of the convective velocities are deduced for each case, and a trend for the convective velocity to grow with the axial distance is pointed out. These results are used together with source localisation deduced from a two-microphone survey to determine the number of screech periods contained in a screech loop. For the A1 and B modes, four periods are contained in a loop for cases in which the radiating shock is the fourth, and three periods when the radiating shock tip is the third, whereas the loop of the A2 mode contains five periods.

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“…High speed jet noise is a major issue in aeronautics and astronautics which has been extensively investigated as reviewed by Seiner [1], Tam [2] or Bailly and Fujii [3] for instance. Imperfectly expanded hot supersonic jets generated by rocket motors at lift-off induce severe acoustic loads on the launcher and its payload [4] as illustrated in figure 1.…”

Section: Introductionmentioning

confidence: 99%

Assessment of a Two-Way Coupling Methodology Between a Flow and a High-Order Nonlinear Acoustic Unstructured Solvers

Langenais

Vincent

Peyret

et al. 2018

Flow Turbulence Combust

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A two-way coupling on unstructured meshes between a flow and a high-order acoustic solvers for jet noise prediction is considered. The flow simulation aims at generating acoustic sources in the near field while the acoustic simulation solves the full Euler equations, thanks to a discontinuous Galerkin method, in order to take into account nonlinear acoustic propagation effects. This methodology is firstly validated on academic cases involving nonlinear sound propagation, shock waves and convection of aerodynamic perturbations. The results are compared to analytical solutions and direct computations. A good behaviour of the coupling is found regarding the targeted space applications. An application on a launch pad model is then simulated to demonstrate the robustness and reliability of the present approach.

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High-speed jet noise

Cited by 40 publications

References 79 publications

Accurate simulation of the noise generated by a hot supersonic jet including turbulence tripping and nonlinear acoustic propagation

Accurate simulation of the noise generated by a hot supersonic jet including turbulence tripping and nonlinear acoustic propagation

Experimental characterisation of the screech feedback loop in underexpanded round jets

Assessment of a Two-Way Coupling Methodology Between a Flow and a High-Order Nonlinear Acoustic Unstructured Solvers

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