Coherent leakage of sound from a mixed layer surface duct - Revisited
MetadataShow full item record
The coherent leakage of a signal from a mixed-layer surface duct with no rough surface scattering is a subject which received considerable attention decades ago. As is well known, coherent leakage of sound from a surface duct reduces progressively as frequency rises from below a nominal trapping frequency to higher values. Considered as modal leakage, or attenuation, the rate of coherent leakage with range for a surface ducted scenario is related to the imaginary part of the horizontal wave number, and may be determined through the use of a modal model of transmission. Such a calculation is performed through an iterative technique, and so when speed is desirable in the calculation, use of a direct analytic expression for leakage would be preferred. To that end, a brief study was made of the suitability of some of the expressions derived originally by Furry and described by Pederson and Gordon (JASA, 47, 304-326, 1970), as the basis for such a determination for the first acoustical mode, in particular. This work includes comparison of leakage rates obtained from expressions based on early work by Furry against results from both the ORCA modal model, and from simulations based on the wave number integration model SCOOTER, for a mixed-layer surface ducted scenario with frequencies relevant to the onset of duct trapping. The work also includes a brief review of some of the early literature relating to leakage of sound from the surface duct.
Showing items related by title, author, creator and subject.
Rajamohan, Ganesan (2012)Mixed convection heat transfer in horizontal and vertical ducts with flow through the duct plays an important role in the design and operation of several industrial equipment involving heat transfer and fluid flow phenomena. ...
Experimental study on mixed convection heat transfer for thermally developing flow in horizontal ducts with radiation effectsGanesan, Rajamohan; Narayanaswamy, Ramesh; Gorin, Alexander; Perumal, Kumar (2011)This research focuses on the interaction of surface radiation with laminar mixed convection heat transfer for thermally developing airflow in horizontal ducts. The duct cross section is made of two differentially heated ...
Ganesan, R.; Narayanaswamy, Ramesh; Perumal, K. (2015)In this research, experiments are performed to study the laminar flow mixed-convection heat transfer with radiation effects for a hydrodynamically fully developed and thermally developing airflow in a horizontal duct. The ...