Abstract: This paper is mainly intended to establish the predicting model for detecting sound absorbing properties of activated carbon fiber. By testing viscose-based activated carbon fiber with different specification through an impedance tube, the sound absorbing properties of activated carbon fiber are examined in the 250-1600Hz middle and low frequencies acoustic range. Based on models of characteristic impedance and propagation constant proposed by Delany and Bazley, the predicting model of characteristic impedance and propagation constant with acoustic characteristic parameters is established by employing the least square method. Moreover, the model of sound absorbing coefficient is therefore formed and tested, of which the result is compared with the testing result, showing that the result based on predicting model is basically coincide with the testing result. The reliability of the established model concerning sound absorbing materials is explored, which provides the theoretical base for develop and design sound absorbing materials of activated carbon fiber.

Key words: activated carbon fiber, sound absorbing coefficient, airfolw resistivity, inherent impedance, propagation constant