SOUND WAVE RADIATOR FOR SILENCING OF ACTIVE NOISE CONTROL SYSTEM

摘要

PURPOSE:To form a sound field which averts the generation of standing waves in a duct and has the same frequency as the frequency of a signal for silencing in the duct by providing the wall surface part of the duct to be installed with a speaker for silencing with plural partition walls extending radially in the duct from the speaker for silencing to divide the inside of the duct to passages having irregular-shaped sections. CONSTITUTION:The wall surface at the bottom of the duct 1 is provided with the speaker 3 for silencing so as to radiate sound waves for silencing within the duct 1. The wall surface part of the duct l installed with the speaker 3 for silencing is provided with the plural partition walls 21 extending radially in the duct from the speaker 3 for silencing by using thin sheet materials, by which the inside of the duct 1 is divided to the passages having the irregular- shaped sections. The sound waves for silencing radiated from the speaker 3 for silencing into the duct 1 generate reflection within the irregular sections, thereby preventing generation of the standing waves in the duct 1 according to such constitution.