Document Type

Article

Source of Publication

Acta Acustica united with Acustica

Publication Date

1-1-2019

Abstract

© S. Hirzel Verlag · EAA Over many years, scientists and engineers have developed a broad variety of mathematical formulations to investigate the propagation and interactions with flow of flow-induced noise in early-stage of product design and development. Beside established theories such as the linearized Euler equations (LEE), the linearized Navier–Stokes equations (LNSE) and the acoustic perturbation equations (APE) which are described in an Eulerian framework, Galbrun utilized a mixed Lagrange–Eulerian framework to reduce the number of unknowns by representing perturbations by means of particle displacement only. Despite the advantages of fewer degrees of freedom and the reduced effort to solve the system equations, a computational approach using standard continuous finite element methods (FEM) suffers from instabilities called spurious modes that pollute the solution. In this work, the authors employ a discontinuous Galerkin approach to overcome the difficulties related to spurious modes while solving Galbrun’s equation in a mixed and pure displacement based formulation. The results achieved with the proposed approach are compared with results from previous attempts to solve Galbrun’s equation. The numerical determination of acoustic modes and the identification of vortical modes is discussed. Furthermore, case studies for a lined-duct and an annulus supporting a rotating shear-flow are investigated.

ISSN

1861-9959

Publisher

S. Hirzel Verlag GmbH

Volume

105

Issue

6

First Page

1149

Last Page

1163

Disciplines

Electrical and Computer Engineering

Keywords

Computation theory; Degrees of freedom (mechanics); Galerkin methods; Linearization; Navier Stokes equations; Product design; Shear flow; Acoustic perturbation equations; Discontinuous galerkin; Discontinuous Galerkin finite-element method; Displacement-based formulations; Linearized Euler equations; Mathematical formulation; Product design and development; Scientists and engineers; Finite element method

Scopus ID

85077953005

Creative Commons License

Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.

Indexed in Scopus

yes

Open Access

yes

Open Access Type

Hybrid: This publication is openly available in a subscription-based journal/series

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