Efficient mode-matching based on closed form integrals of Pridmore-Brown modes

M. Oppeneer, S.W. Rienstra, P. Sijtsma

Research output: Chapter in Book/Report/Conference proceedingConference contributionAcademicpeer-review


A new mode matching method is developed for acoustic modes in axially sectioned lined ducts with parallel, but otherwise arbitrary mean flow. The method is evaluated in detail for radially symmetric mean flow, with so-called Pridmore-Brown modes, satisfying the radial Pridmore-Brown equation. Classically, the matching of the modal representations at the interfaces between the sections is based on continuity of pressure and velocity in combination with projection to a suitable but unrelated set of test functions by means of a standard integral inner-product. The alternative we propose here uses essentially the same Pridmore-Brown modes but instead of the standard inner-product we apply a particular bilinear form that can be evaluated in closed form. Apart from numerical efficiency, this approach features also a higher accuracy because it avoides the inherently inaccurate numerical quadrature of oscillating functions. The results are compared with results obtained by an implementation of the classical approach, and the agreement is excellent, with higher accuracy and with greater computational efficiency.
Original languageEnglish
Title of host publication19th AIAA/CEAS Aeroacoustics Conference (Berlin, Germany, May 27-29, 2013)
PublisherAmerican Institute of Aeronautics and Astronautics Inc. (AIAA)
Number of pages21
ISBN (Print)978-162410213-4
Publication statusPublished - 2013
Event19th AIAA/CEAS Aeroacoustics Conference - Berlin, Germany
Duration: 27 May 201329 May 2013


Conference19th AIAA/CEAS Aeroacoustics Conference


Dive into the research topics of 'Efficient mode-matching based on closed form integrals of Pridmore-Brown modes'. Together they form a unique fingerprint.

Cite this