Model to simulate the acoustical absorption of laminated fiberglass insulation

Abstract

While fiberglass insulation is known to be a very good acoustical absorber in the audible frequency range, it is not often used for this purpose in rooms because of its appearance and its delicate structural rigidity. Additionally, in some situations, notably medical facilities, the material is inappropriate because of its potential to trap and retain bacteria and dirt. In this work, we report on a study of laminate-coated fiberglass. Although the addition of a laminate coating degrades the acoustical absorption, previous experimental work demonstrated that the composite structure retains a high absorption coefficient. A model of the wall with the installed fiberglass/laminate composite was developed and a wavenumber integration approach was applied to this model to assess the impact of the laminate on the performance of the system. The estimated reflection and transmission losses are computed as functions of auditory frequency and incidence angles with and without the laminate layer to compare the distributions of acoustical energy. This work is performed under a Hafstad fellowship sabbatical appointment.