A Modern Course in Aeroelasticity

Abstract

In recent years, machinery noise control has reached a state of importance.OSHA and other state and federal agencies concerned with noise control and reduction have promulgated requirements which machinery manufacturers and product fabricators must adhere.This symposium is timely since machinery noise, be it on land, in the air or beneath the sea, has been made a focal point, and more stringent requirements may be forthcoming in the near future.This symposium consisted of 54 papers, divided into nine main categories.The symposium commenced with two papers on activity and regulations of the Environmental Protection Agency (EPA) and OSHA.The next section considered papers on agricultural and equipment noise slanted towards engine produced noise and means of reducing it by a structural redesign.The next section dealt with machine element noise produced by circular saws, finite element of structure under impact loading, noise abatement of material handling equipment, vibration isolations and flow noise in axial fans.The latter becomes important because of its effect on human occupants who are supposed to be enjoying the ventilation of a closed room.The third section on "Forging and Impact Noise" contributes to hearing loss of individuals who are subjected to the phenomena.These papers consist of cold heading noise, punch press noise, and their reduction by shock isolation, plus a progress report on forging noise.The reviewer has experienced this type of noise when venturing into the shop areas.The section on "Diagnostic Noise Measurements" is important since without proper instrumentation and data acquisition, we can't investigate, identify, and evaluate these noise responses and suggest reasons for reducing same.The papers dwelled upon computerized noise modeling, machinery noise source analysis, sound power determination from a vibrating surface, microphone coupler use and viscoelastic properties which could be effectively employed in improving structural damping.Additional information is detailed on saw and scrap shaper noise.The fifth session on "Compliance and Noise Measurements" discuss EPA requirements for noise regulations of compressors and trucks.The latter is con-' General Electric Co., Schenectady, N.Y.