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Tham khảo tài liệu 'aero-acoustic test programs_7', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Simpo PDF Merge and Split Unregistered Version - http www.simpopdf.com One investigation 18 also dealt with the direct comparison of the sound pressure level at the scaled far-field microphone positions obtained for the bare model jet and those obtained at the same positions for the model exhaust system respectively. For Figure 31 the results of a model-scale investigation show how the axial distance of the jet exhaust from the augmenter entrance .X-N influences the sound power that enters the augmenter. The larger the axial distance the smaller is the sound power that enters the augmenter at mid and high frequencies. At low frequencies where the noise source is within the augmenter the axial distance has little influence on the sound jet power that enters the augmenter. In Figure 32 the results of a model-scale investigation show how the particular position of a 12-in. 304.56 mm long 15 ft 4.57 m at fullscale lined augmenter segment with a 60-in. 1523 mm 75 ft 23 m at full-scale hard-walled augmenter influences the power-based insertion loss. References 3 17 and 18 studies for a variety of model-scale and specific acoustical treatments. contain results of scale-model acoustical engines exhaust system configurations 63 Simpo PDF Merge and Split Unregistered Version - http www.simpopdf.com 1. Ati r.uaced Jet Jois a 2. Flitt-Generated tee 3. Flanking throcgh the Augjnenter Tubs Wall i. Transmission through the Building Walls ù Roof 5. Transmission through the Intake Muffler 5. Transmission through the Front Door Figure 23 Principal Paths of Heise Radiated from a Hush-Hoưae 64 Simpo PDF Merge and Split Unregistered Version - http .
