Prediction of ducted diaphragm noise using a stochastic approach with adapted temporal filters

Karban U., Schram C., Sovardi C., Polifke W.

INTERNATIONAL JOURNAL OF AEROACOUSTICS, vol.18, no.1, pp.49-72, 2019 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 18 Issue: 1
  • Publication Date: 2019
  • Doi Number: 10.1177/1475472x18812811
  • Journal Name: INTERNATIONAL JOURNAL OF AEROACOUSTICS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.49-72
  • Keywords: Stochastic noise generation and radiation method, aeroacoustic analogies, duct acoustics, tailored Green's function, large eddy simulation, BOUNDARY-CONDITIONS, TURBULENT VELOCITY, SIMULATION, FLOW, WAVE
  • Middle East Technical University Affiliated: No

Abstract

The noise production by ducted single- and double-diaphragm configurations is simulated using a stochastic noise generation and radiation numerical method. The importance of modeling correctly the anisotropy and temporal de-correlation is discussed, based on numerical results obtained by large eddy simulation. A new temporal filter is proposed, designed to provide the targeted spectral decay of energy in an Eulerian reference frame. An anisotropy correction is implemented using a non-linear model. The acoustic propagation problem is solved using Lighthill's aeroacoustic analogy with a tailored Green's function obtained analytically. Comparison with scale-resolved data indicates that accurate far-field noise predictions are obtained for both single and double diaphragm configurations, with computational costs significantly reduced with respect to the scale-resolved approach. A grouping scheme for the noise sources based on the octree structure is introduced to minimize the memory requirements and further reduce the computational cost.