A semi-analytical model for the influence of temperature on sound propagation in sintered metal fiber materials

A semi-analytical model is developed to predict the influence of temperature on the sound absorbing performance of sintered metal fiber materials (SMFMs) by extending the Johnson-Champoux-Allard-Lafarge (JCAL) model. In this model, threemicro-structure factors of the SMFMs - the Kozeny number and the thermal and viscous shape factors - are calculated by applying the multi-scale asymptoticmethod (MAM), and the temperature effect is taken into account by considering the variations of the thermo-physical parameters of saturated air with temperature. Key transport parameters (e.g., viscous and thermal permeability, tortuosity, viscous and thermal characteristic lengths) are then directly determined by fiber diameter and porosity of the material. High-efficiency of the semi-analytical model is demonstrated for estimating the influence of topological parameters upon sound absorption under different temperatures. The transport parameters obtained by the proposed model agree well with those calculated using fully numerical simulations. Also, the model predictions are in accordance with existing experimental measurements at different temperatures. The model reveals not only the underlying mechanisms of temperature effect on sound propagation in porous metals, but also provides a theoretical guideline for the sound absorption application of SMFMs in high temperature environments. (C) 2017 Elsevier Ltd. All rights reserved.