Archives of Acoustics, 35, 1, pp. 35-48, 2010

Numerical method for modeling of acoustic waves propagation

Sławomir DYKAS
Silesian University of Technology, Institute of Power Engineering and Turbomachinery
Poland

Włodzimierz WRÓBLEWSKI
Silesian University of Technology, Institute of Power Engineering and Turbomachinery
Poland

Sebastian RULIK
Silesian University of Technology, Institute of Power Engineering and Turbomachinery
Poland

Tadeusz CHMIELNIAK
Silesian University of Technology, Institute of Power Engineering and Turbomachinery
Poland

In this paper, numerical results of modeling of acoustic waves propagation are presented. For calculation of the acoustic fluctuations, a solution of the full non-linear Euler equation is used. The Euler equations are solved with the use of a numerical scheme of third-order accuracy in space and time. The paper shows a validation process of the described method. This method is suitable also for an aerodynamic noise assessment on the basis of unsteady mean flow field data obtained from a CFD calculations. In such case this method is called a hybrid CFD/CAA method. The proposed method is numerically decoupled with CFD solution, therefore the information about the mean unsteady flow field can be obtained using an arbitrary CFD method (solver). The accuracy of the acoustic field assessment depends on the quality of the CFD solutions. This decomposition reduces considerably the computational cost in comparison with direct noise calculations.
The presented Euler acoustic postprocessor (EAP) has been used for modeling of the acoustic waves propagation in a cavity and in the flow field around a cylinder and an aerodynamic profile.
Keywords: acoustic wave; fluctuation; aerodynamic noise; Euler equations
Full Text: PDF
Copyright © Polish Academy of Sciences & Institute of Fundamental Technological Research (IPPT PAN).

References

Dykas S., Wróblewski W., Chmielniak T. (2006a), Numerical modeling of noise with the use of URANS and Euler methods, Chemical and Process Engineering J., 27, 626–694.

Dykas S., Wróblewski W. (2006b), A method for aerodynamic noise modeling in the transonic flows [in Polish: Metoda modelowania hałasu aerodynamicznego w przepływach okołodzwiekowych], Wyd. Politechniki Slaskiej, Gliwice.

Dykas S., Wróblewski W., Chmielniak T. (2008), Aerodynamic noise assessment using a CFD/CAA technique, Proc. of ASME, Berlin 2008, GT2008-50140.

Jacob M.C., Boudet J., Casalino D., Michard M. (2002), A rod-airfoil experiment as benchmark for broadband noise modeling, 3rd SWING Aeroacoustic Workshop, Stuttgart.

Prantle I. (2002), The aeroacoustics on the basis of acoustic analogies with LES and URANS [in German: Strömungsakustik auf der Basis akustischer Analogie mit LES und URANS], PhD Thesis, Universität Karlsruhe, 2002.

Sorgüven E. (2004), A Computational Aeroacoustic Method Using Large Eddy Simulation and Acoustic Analogy, PhD Thesis, Universität Karslruhe.

Tam C.K.W. (1995), Computational Aeroacoustics: Issues and Methods, AIAA Journal, 33, 10, 1788–1796.

Weyna S. (2005), An acoustic energy dissipation of the real sources [in Polish: Rozpływ energii akustycznych zródeł rzeczywistych], Wydawnictwa Naukowo-Techniczne.