Aeroacoustics of T-junctions : An experimental investigation

• An experimental method for determining the aeroacoustic properties of side branch orifices allowing for any combination of grazing and bias flow is presented. The geometry studied, a T-junction, is treated as an active acoustic three-port. The passive properties, describing the reflection and transmission of an incident acoustic wave, are described by a system matrix while the active properties are described by a source vector. Expressions for the acoustic impedance under various mean flow and acoustic incidence configurations are developed. In addition, methods for identifying regions where the system can generate sound, by studying only the passive properties, are discussed. A self-sustained oscillation is triggered at one of the identified regions by coupling a resonant system to the three-port.

Subject headings

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

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

Keyword

GRAZING MEAN FLOW

ACOUSTIC-IMPEDANCE

PERFORATED PLATES

CIRCULAR ORIFICE

BOUNDARY-LAYER

FLUID MACHINES

PIPE

SYSTEMS

DUCT

POTENTIALITY

Acoustics

Akustik

Publication and Content Type

ref (subject category)

art (subject category)