An efficient algorithm for the retarded time equation for noise from rotating sources

S. Loiodice, D. Drikakis, A. Kokkalis

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)
221 Downloads (Pure)


This study concerns modelling of noise emanating from rotating sources such as helicopter rotors. We present an accurate and efficient algorithm for the solution of the retarded time equation, which can be used both in subsonic and supersonic flow regimes. A novel approach for the search of the roots of the retarded time function was developed based on considerations of the kinematics of rotating sources and of the bifurcation analysis of the retarded time function. It is shown that the proposed algorithm is faster than the classical Newton and Brent methods, especially in the presence of sources rotating supersonically.

Original languageEnglish
Pages (from-to)336-348
Number of pages13
JournalJournal of Sound and Vibration
Early online date12 Oct 2017
Publication statusPublished - 6 Jan 2018


  • aircraft propellers
  • noise
  • rotorcraft

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