Abstract
Abstract
The paper is devoted to noise reduction in engineering networks. It is indicated that the slotted silencer is promising for systems with large cross-section air ducts and flues. The technological and operational possibilities of including in the silencer the additional slotted section are noted. The additional two-slot section containing Helmholtz resonators is presented. Based on the calculations it was found that broadband noise reduction is provided by tuning the slotted resonators in a geometric progression with a denominator of 20.8. For a section with three resonators in each slot duct the following is shown: the resonator with the highest tuning frequency does not significantly effect the noise reduction of the other two resonators; the resonator with the highest tuning frequency can be placed between resonators with lower tuning frequencies. Compact placement of slotted resonators is proposed. The length of the device is shorted by 1.5 times while reducing the efficiency by 30%. The obtained data show that the silencer section composed from Helmholtz slotted resonators allows fulfilling silencer with additional noise reduction in the frequency range of 31.5-125 Hz and acceptable length.