On the Use of Linear Acoustic Multiports to Predict Whistling in Confined Flows

• The use of linear acoustic multiport models to analyse the existence of flow driven instabilities, that is - self-sustained oscillators or whistles - is addressed. By combining the scattering and reflection matrices for a system and searching for eigenfrequencies (zeros) in the critical half-plane, the existence of exponentially growing instabilities can be determined. In practice, the available frequency domain data are only known along the real axis; then the search for zeros may be done via the so-called Nyquist stability criterion generalized to an N-degree of freedom system. The method has been validated by two test cases, a T-junction and a Herschel-Quincke tube. In both cases, the occurrence and the frequencies of the self-sustained oscillations were correctly predicted.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Maskinteknik -- Strömningsmekanik och akustik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Mechanical Engineering -- Fluid Mechanics and Acoustics (hsv//eng)

Nyckelord

Fluid mechanics

Strömningsmekanik

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)