HISTORICAL DEVELOPMENTS IN THE CONTROL OF NOISE GENERATED BY SMALL AIR-MOVING DEVICES

The development of scaling laws for describing the noise generated by air-moving devices began with Madison in the 1940s. This paper reviews the development of the technology for the understanding and control o f noise from small air-moving devices. Following a section on general rules for air-moving device performance and noise emission, progress i s reviewed in the reduction of air-moving device noise up to 1982. The work initiated by the Technical Group on Computers and Business Equip ment of the Institute of Noise Control Engineering of the U.S.A. is re viewed, and progress is described in several areas of interest during the period 1982-1994. Emphasis is placed on measurement techniques, id entification of noise sources and noise reduction, speed control, envi ronmental effects, and scaling laws for air-moving device noise. The p aper also includes suggestions for future research. (C) 1994 Institute of Noise Control Engineering.