CAA broadband noise prediction for aeroacoustic design

Ewert, Roland; Dierke, Jürgen; Neifeld, Andrej; Appel, Christina; Siefert, Malte; Kornow, Oliver

doi:10.1016/j.proeng.2010.09.027

Cited by 22 publications

(51 citation statements)

References 21 publications

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“…12 The FRPM discretization realizes white-noise up to a wave-number cut-off defined by the spatial resolution of the auxiliary mesh. Compared to the initial RPM discretization, the FRPM approach mainly has the advantage that more easily recirculation areas in the mean-flow fields can be taken into account.…”

Section: Frpm Discretizationmentioning

confidence: 99%

“…But so far these predictions were based only on 2D computations. This paper will show that the successor of the RPM method, the Fast Random Particle Method (FRPM), 1 developed by Ewert and Siefert,11,12 produces results as good as RPM and also covers 3D problems. The extension of 2D calculations to 3D assumes a frequency dependent coherence length scale in spanwise direction, which was inferred from the surface pressure characteristics at a trailing edge.…”

Section: Introductionmentioning

confidence: 99%

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A generic computational study of broadband high-lift noise generation for simplified slat and flap problems

Dierke

Appel

Siebert

et al. 2012

18th AIAA/CEAS Aeroacoustics Conference (33rd AIAA Aeroacoustics Conference)

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In previous work a RANS based simulation technique for the simulation of broadband slat noise was established. The computational approach is based on acoustic perturbation equations forced by stochastic sound sources to simulate sound generation and radiation in space and time. Good agreement was found between predicted and measured slat noise spectra and for trailing edge noise generated at a NACA 0012 airfoil. In this work the simulation approach is applied to generic high-lift noise problems defined in the framework of the European project VALIANT. The problems considered are sound generation at the slat and the flap of simplified high-lift geometries. Results of the time-averaged mean flow and turbulence statistics from RANS are evaluated and compared to measurements. A comparison of the statistics of the stochastic fluctuations with flow data is provided. Acoustic sound generated by the stochastic source model is evaluated and compared to measurements. As a general outcome of the study, the agreement between the RANS flow fields to measurements is quite good. The reconstruction of the turbulence statistic by FRPM is in general accurate, but in some reagions it differes from the target statistic. The agreement of the acoustic far field predictions to the measured data is satisfying. The overall procedure is with a computational effort of around two days quite short.

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Section: Frpm Discretizationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A generic computational study of broadband high-lift noise generation for simplified slat and flap problems

Dierke

Appel

Siebert

et al. 2012

18th AIAA/CEAS Aeroacoustics Conference (33rd AIAA Aeroacoustics Conference)

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“…A Discontinuous Galerkin (DG) method based on Lagrange polynomials [33] provided a robust, accurate, and efficient discretization of the APE on that grid. The APE's turbulent source term was computed via the fast random particle mesh (FRPM) method [34] based on a Reynolds-Averaged Navier Stokes (RANS) solution. Fig.…”

Section: Airframe Noise Prediction Using Discontinuous Galerkin Methomentioning

confidence: 99%

“…26(a)). In the second step, unsteady turbulent fluctuations are taken into account by using the random-particlemesh method (RPM) developed in the DLR [34]. The efficiency of the RPM method allowed to simulate a large portion of the fuselage (several square metres) which would not have been possible with unsteady, scale resolving CFD simulations.…”

Section: Refraction and Scattering In High Mach Number Boundary Layersmentioning

confidence: 99%

Aeroacoustics research in Europe: The CEAS-ASC report on 2010 highlights

Nagy

2011

Journal of Sound and Vibration

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“…Although this TE noise theory was introduced nearly 40 years ago and other methods have been developed in the meantime, such as stochastic methods coupled with acoustic analogies [c.f. 7,8] which are purely computational, or methods based on rapid distortion theory [see, e.g., 29], that are applied mainly to aerofoil interaction problems and not to aerofoil self-noise, the subject of the current paper, Amiet's classical theory is still one of the best performing semi-analytical noise prediction methods and remains the underlying element in current noise prediction tools for the design of airfoils [see, e.g., 44,25]. Even only very recently, Amiet's classical theory was extended to include effect of rotation for wind turbine applications [39].…”

Section: Introductionmentioning

confidence: 99%

Compressible-Flow DNS with Application to Airfoil Noise

Sandberg

2015

Flow Turbulence Combust

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Airfoil self-noise is the noise produced by the interaction between an airfoil with its own boundary layers and wake. Self-noise is of concern as it is an important contributor to the overall noise in many applications, e.g. wind turbines, cooling fan blades, or air frames, to name a few. The continued growth of available computing power has made direct numerical simulations (DNS) of compressible flows with application to airfoil noise possible. Challenges associated with such simulations and numerical details of a DNS code that is able to exploit modern high-performance computing systems are presented. Results obtained from DNS of flow over NACA-0012 airfoils at moderate Reynolds number are used to evaluate the accuracy of approximations commonly made in deriving trailing edge noise theories. The data are also used to identify additional noise sources present in airfoil configurations. Finally, DNS are employed to study the noise reducing effect of trailing-edge noise serrations, indicating that the noise reduction is mainly due to a changed scattering mechanisms and not a change in the incidence turbulence field.

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CAA broadband noise prediction for aeroacoustic design

Cited by 22 publications

References 21 publications

A generic computational study of broadband high-lift noise generation for simplified slat and flap problems

A generic computational study of broadband high-lift noise generation for simplified slat and flap problems

Aeroacoustics research in Europe: The CEAS-ASC report on 2010 highlights

Compressible-Flow DNS with Application to Airfoil Noise

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