Sea and sound radiation from ventilating system terminations

Statistical energy analysis (SEA) application for computing of sound radiation from terminations (terminal orifice) of ventilating systems is presented. Reverberating sound field arises in air ducts as in any other enclosed space. Energy density of the reverberating sound field in terminate duct is calculated using SEA. It is demonstrated how to define power balance equations for duct system with arbitrary number of straight ducts, bends, branchings and terminations. Total sound power radiated from termination is calculated as sum of radiation of traveling waves from sources and radiation from reverberating sound field in terminal duct. As an example radiation from termination of typical ventilation system is calculated. It is shown that radiation from reverberating field in terminate duct may occur higher than radiation which comes with traveling waves from sources.