Noise Radiation Predictions from Jet Instability Waves Using a Hybrid Nonlinear PSE-Acoustic Analogy Approach

Cheung, Lawrence; Bodony, Daniel J.; Lele, Sanjiva K.

doi:10.2514/6.2007-3638

Cited by 21 publications

(20 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The current mechanism only applies to subsonic jets. At high Mach numbers the sound radiation comes directly from the primary instability (Tam & Morris 1980; also shown clearly in the PSE of Cheung et al 2007). Salgado (2007) carried out linear PSE for a range of Mach numbers.…”

Section: Discussionmentioning

confidence: 99%

“…Thus there is no interaction between the base flow and the growing instabilities, which ought to be linked via Reynolds stresses. This effect can be brought into the PSE model, either using an energy equation as in Morris et al (1990) or by performing a fully nonlinear PSE as in Cheung et al (2007). It should be noted however that nonlinear PSE is not the same as the present nonlinear interaction approach.…”

Section: Discussionmentioning

confidence: 99%

“…The contents of the matrices can be found, for example, in Hein (2005). PSE has recently been applied to jet noise by Cheung et al (2007): linear PSE was found to be able to predict noise from supersonic jets, while nonlinear PSE, together with an acoustic analogy, was needed for subsonic jet noise. In the present work, by contrast, we use only linear PSE and compute the nonlinear interaction terms separately.…”

Section: (B ) Parabolized Stability Equationsmentioning

confidence: 99%

See 2 more Smart Citations

Nonlinear interaction model of subsonic jet noise

Sandham

Salgado

2008

Phil. Trans. R. Soc. A.

View full text Add to dashboard Cite

Noise generation in a subsonic round jet is studied by a simplified model, in which nonlinear interactions of spatially evolving instability modes lead to the radiation of sound. The spatial mode evolution is computed using linear parabolized stability equations. Nonlinear interactions are found on a mode-by-mode basis and the sound radiation characteristics are determined by solution of the Lilley-Goldstein equation. Since mode interactions are computed explicitly, it is possible to find their relative importance for sound radiation. The method is applied to a single stream jet for which experimental data are available. The model gives Strouhal numbers of 0.45 for the most amplified waves in the jet and 0.19 for the dominant sound radiation. While in near field axisymmetric and the first azimuthal modes are both important, far-field sound is predominantly axisymmetric. These results are in close correspondence with experiment, suggesting that the simplified model is capturing at least some of the important mechanisms of subsonic jet noise.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: (B ) Parabolized Stability Equationsmentioning

confidence: 99%

See 1 more Smart Citation

Nonlinear interaction model of subsonic jet noise

Sandham

Salgado

2008

Phil. Trans. R. Soc. A.

View full text Add to dashboard Cite

show abstract

“…The contents of the matrices can be found for example in Hein (2005). PSE has recently been applied to jet noise by Cheung et al (2007). Linear PSE was found to be able to predict noise from supersonic jets, while nonlinear PSE, together with an acoustic analogy was needed for subsonic jet noise.…”

Section: B Parabolized Stability Equationsmentioning

confidence: 99%

Jet noise from instability mode interactions

Sandham

Salgado

Agarwal

2008

14th AIAA/CEAS Aeroacoustics Conference (29th AIAA Aeroacoustics Conference)

View full text Add to dashboard Cite

A nonlinear interaction model is used to study sources of sound in jets. The model uses quadratic interactions of instability modes, which are obtained by solving the linear parabolized stability equations. Source terms involving nonlinear interactions are evaluated and a linear wave equation is solved with direct injection of the source terms. Thus the complete method solves only linear partial differential equations, coupled by nonlinear source terms. It allows the contribution of each modal interaction to be studied separately, giving a breakdown of the radiation pattern of each interaction. The method is demonstrated using a fixed base flow matched to the experiment of Stromberg et al. (J. Fluid Mech. 72(2), 1980). The squared streamwise velocity quadrupole is the largest source term for axisymmetric mode interactions, while for helical-helical mode interactions both the squared radial and squared azimuthal velocities are the main contributing sources, despite a strong cancelation effect between them. Results are also presented for an alternative implementation, in which the base flow is allowed to vary according to the Reynolds stresses of the developing instability modes. This model demonstrates sound production during mode growth and subsequent saturation.

show abstract

“…The parabolized stability equations (PSEs) provide an efficient way to compute unsteady perturbations about base flows, which organize into wavepackets for subsonic jets [145,146]. While this method has proved successful for subsonic jet noise [147], low-frequency noise from hot supersonic jets remains difficult to predict [148].…”

Section: (A) Trends In Hpc: Towards Exascale Computingmentioning

confidence: 99%

A second golden age of aeroacoustics?

Lele

Nichols

2014

Phil. Trans. R. Soc. A.

View full text Add to dashboard Cite

In 1992, Sir James Lighthill foresaw the dawn of a second golden age in aeroacoustics enabled by computer simulations (Hardin JC, Hussaini MY (eds) 1993 Computational aeroacoustics, New York, NY: Springer (doi:10.1007). This review traces the progress in large-scale computations to resolve the noise-source processes and the methods devised to predict the far-field radiated sound using this information. Keeping focus on aviation-related noise sources a brief account of the progress in simulations of jet noise, fan noise and airframe noise is given highlighting the key technical issues and challenges. The complex geometry of nozzle elements and airframe components as well as the high Reynolds number of target applications require careful assessment of the discretization algorithms on unstructured grids and modelling compromises. High-fidelity simulations with 200-500 million points are not uncommon today and are used to improve scientific understanding of the noise generation process in specific situations. We attempt to discern where the future might take us, especially if exascale computing becomes a reality in 10 years. A pressing question in this context concerns the role of modelling in the coming era. While the sheer scale of the data generated by large-scale simulations will require new methods for data analysis and data visualization, it is our view that suitable theoretical formulations and reduced models will be even more important in future.

show abstract

Noise Radiation Predictions from Jet Instability Waves Using a Hybrid Nonlinear PSE-Acoustic Analogy Approach

Cited by 21 publications

References 15 publications

Nonlinear interaction model of subsonic jet noise

Nonlinear interaction model of subsonic jet noise

Jet noise from instability mode interactions

A second golden age of aeroacoustics?

Contact Info

Product

Resources

About