Acoustic energy flow in lined ducts containing uniform or “plug” flow

✍ Scribed by B.J. Tester

• Publisher: Elsevier Science
• Year: 1973
• Tongue: English
• Weight: 531 KB
• Volume: 28
• Category: Article
• ISSN: 0022-460X
• DOI: 10.1016/s0022-460x(73)80103-8

✦ Synopsis

In connection with the method (used in simple insertion loss models) of relating, approximately, the perturbed duct field to the acoustic field radiated from the duct termination, expressions have been formulated for the energy flows associated with individual modes, according to certain definitions. It has been shown that the axial energy flow in a uniform flow duct can only be strictly equated with the radiated energy if the radiation is from an "inlet flow" termination, if the axial energy flow is calculated according to the energy flux defined by Cantrell and Hart and if the duct walls are non-absorptive. If the duct walls are absorptive the duct and radiated energy flows are approximately identical if the duct energy flow is primarily due to the existence of well "cut-on" modes.