Tham khảo tài liệu 'noise and vibration control episode 6', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | TM 5-805-4 AFJMAN 32-1090 CHAPTER 6 AIRBORNE SOUND CONTROL 6-1. Introduction. a. This chapter draws together much of the factual content of the earlier chapters and presents a systematic approach for evaluating noise data and arriving at design decisions for controlling the noise of electrical and mechanical equipment transmitted between room within a building and to other nearby structures. The chapter concludes with discussions of the various noise control treatments that are practical and available for solution of equipment noise problems. Almost all sound analysis problems can be divided into considerations of the 1 Source 2 Path and 3 Receiver. Noise and vibration for specific problems may be reduced by using the following system approach 1 Reduce noise and vibration at the source by using quieter equipment or noise-reducing modifications. 2 Prevent noise transmission by using barriers and prevent vibration transmission by using vibration isolators. 3 Relocate the receiver. b. Sources of mechanical equipment sound are provided in appendix C. Considerations for Paths are given in chapters 3 4 and 5. Criteria for acceptable sound is given in chapter 2. Chapter 7 provides a similar discussion for sound transmitted via air distribution systems in buildings. Considerations for vibration control are given in chapter 8. 6-2. Indoor Sound Analysis. a. The approach suggested here is essentially a flow diagram of sound from source to receiver following certain prescribed steps. 1 The SPL or PWL values are obtained for each noise source from appendix C or other available source date . 2 The acoustic conditions inside the MER source room and in the receiving rooms are calculated. 3 The SPL values of all equipment sources are extrapolated to the interior MER walls and surfaces of interest chap 3 . 4 Noise criteria are selected for all the receiving rooms of interest chap 2 . 5 Wall and floor designs are selected to permit acceptable amounts of equipment noise into the .
