Abstract
This paper considers the minimization of the total acoustic power radiated from a large duct opening. The sound field in the large duct opening is not always represented by a harmonic modal function. Therefore, the authors consider that the complex pressure amplitude at any position in duct opening can be regarded as random function, and propose a method employing an active noise control in order to minimize the total acoustic power by designing the duct opening, leading to change the complex pressure amplitude in the duct opening. The power reducing performance was verified by applying the method to the transducer noise radiating from the large duct opening.
