| With the development of science and technology,the noise pollution becomes more and more serious as the large industrial machines and vehicles bring to human being.Noise is one of most crucial problem to affect individual's daily life and health.To control and solve the noise problem,people always use the porous acoustic material.It is important and meaningful to investigate the absorption performance and features of such the material.The most commonly-used porous acoustic material is melamine foam.It has several disadvantages,for example,the absorption coefficient is not good enough,it is easy to absorb moisture and decay and it is flammable.Computer simulation is an important method for science and engineering research.The melamine foam and the improved composite material are investigated in COMSOL Multiphysics based on Biot Theory and JohnsonChampoux-Allard Model.After optimizing several parameters of the melamine foam,the improved sound pressure field and level,the enhanced sound absorption coefficient are found in the composite material.It offers a fundamental proof on the design of the improved inner structure of composite material.Then,the graphene oxide and functionalized carbon nanotubes melamine foam composite material were synthesized and investigated on its inner structure,flow resistance and sound absorption performance.As investigated in the interval between 250 Hz and 1600 Hz,it enhanced the acoustic absorption coefficient from 0.7 to 0.9 at the peak and 100% in the low frequency interval.It can be concluded into the larger flow resistance,bigger tortuosity against sound wave propagation,internal reflection,interfacial damping and better heat conductivity of the incorporated carbon material.Furthermore,the inclusion of GO and CNT provides other properties including moisture insulation and fire retardancy.This kind of innovative sound absorbing material is easy to synthesize and suitable for industrial applications. |
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