Boundary integral formulations in the time domain are discussed for use in calculating sound radiated from ducted rotating blade sources in uniform forward motion. The problem is posed in the scattering from which enables arbitrary sources to be specified. The theory is derived for ducts with acoustically absorbing liners, and it leads to a set of coupled singular integral equations governing the discontinuities in scattered pressure and normal velocity across the duct surface. When the duct is rigid, one of these is eliminated and the single remaining equations becomes an alternate to a boundary integral method for the rigid case that was described in a prior paper. A summary of a numerical implementation of the new rigid formulation is given, and results are compared to those obtained in the earlier work. The newer approach is more computationally efficient and requires only pressure data as input, but difficulties associated with eigensolutions arise in applying it. An approximate procedure that appears capable of circumventing has been devised.
Boundary integral formulations for ducted fun radiation calculations
Integrale Grenzformulationen für Berechnungen der Lärmausstrahlung bei Mantelstromtriebwerken
1995
9 Seiten, 7 Bilder, 8 Quellen
Conference paper
English
Boundary Integral Formulations for Ducted Fan Radiation Calculations
British Library Conference Proceedings | 1995
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