This paper aims at presenting the organisation,the findings and the lessons learnt of a design casestudy workshop organized in the context of UB1-HIT joint master programme.After presenting the content and the evoluti...This paper aims at presenting the organisation,the findings and the lessons learnt of a design casestudy workshop organized in the context of UB1-HIT joint master programme.After presenting the content and the evolution of this workshop over the years,findings and lessons learnt are discussed and final conclusions and perspectives are being proposed at the end of the paper.展开更多
A general theory of microperforated-panel absorbers is proposed on the basis of equhaleot circuits. The characterizing parameters of the absorber are its relative acoustic resistance γ, the diameter d of the perforat...A general theory of microperforated-panel absorbers is proposed on the basis of equhaleot circuits. The characterizing parameters of the absorber are its relative acoustic resistance γ, the diameter d of the perforations and the resonance frequency fo. The later two form the perforate constaot k = , which, together with γ, decides the structure and characteristics of the microperforated-panel absorber. The maximum value of the absorption band width △f/f0 is (4/π)tan-1(1＋γ), as k approaches zero, and it does not change much as far as k is less than 1, the cavity depth is nearly a quarter wavelength of the resonance frequency For large values of k, the absorption band narrows down significalltly and the cavity depth required becomes a small fraction of the wavelength. The general properties of the microperforated absorber are discussed.展开更多
文摘This paper aims at presenting the organisation,the findings and the lessons learnt of a design casestudy workshop organized in the context of UB1-HIT joint master programme.After presenting the content and the evolution of this workshop over the years,findings and lessons learnt are discussed and final conclusions and perspectives are being proposed at the end of the paper.
文摘A general theory of microperforated-panel absorbers is proposed on the basis of equhaleot circuits. The characterizing parameters of the absorber are its relative acoustic resistance γ, the diameter d of the perforations and the resonance frequency fo. The later two form the perforate constaot k = , which, together with γ, decides the structure and characteristics of the microperforated-panel absorber. The maximum value of the absorption band width △f/f0 is (4/π)tan-1(1＋γ), as k approaches zero, and it does not change much as far as k is less than 1, the cavity depth is nearly a quarter wavelength of the resonance frequency For large values of k, the absorption band narrows down significalltly and the cavity depth required becomes a small fraction of the wavelength. The general properties of the microperforated absorber are discussed.
