A comparison of measurement techniques to determine the acoustic impedance at oblique sound incidence angle
نویسندگان
چکیده
In (3) φ is an arbitrary test function and ρ the density of the fluid. In consequence, to calculate the acoustic field and thus, to solve the acoustic wave equation, the impedance Za on the surface Γ has to be known. Hence, a measurement technique to determine the acoustic impedance is of great importance, because a realistic sound field can only be calculated, if the real acoustic impedance at oblique angle of sound incidence is known.
منابع مشابه
Experimental study and modelling of date palm fibre composite acoustic behaviour using differential evolution algorithm
Background and aims: In recent years, in most countries of the world, the provision of a calming environment without disturbing noise has become a need, which has subsequently led to significant growth in noise control techniques. It is now well documented that prolonged over-exposure to the excessive levels of environmental noise not only induces disabling hearing impairment but also contribut...
متن کاملطراحی و ساخت لوله امپدانس برای تعیین ضریب جذب صوتی برخی مصالح مورد استفاده در کنترل صدا
Introduction & Objective: Noise is one of the most important harmful agents in work environment. In spit of industrial improvements, exposure with over permissible limit of noise is counted as one of the health complication of workers. In Iran, do not exact information of the absorption coefficient of acoustic materials. Iranian manufacturer have not laboratory for measured of sound absorbanc...
متن کاملInvestigation of Acoustic Properties of Polymer Nanocomposites regarding Combined Sound Absorption and Insulation Characteristics
Introduction: Nowadays multiple techniques have been developed to noise control. One the most important way is the control based on sound absorption and insulation. The purpose of current study was to improve the acoustic properties of soft polyurethane foam regarding combined sound absorption and insulation characteristics. Materials and Methods: Polyacrylonitrile and polyvinylidine fluoride ...
متن کاملمقایسه روش های نسبت موج ایستا و تابع انتقال در تعیین ضریب جذب صوتی مصالح
Introduction: Sound absorption coefficient determination is one of the most important factors among material selection for indoor noise control. The objectives of this study were: 1) comparison sound absorption coefficient of different materials by standing wave ratio and transfer function methods, and 2) developing a regression model in adjusting provided results. Methods: In this study, 46 a...
متن کاملIridescent Perfect Absorption in Critically-Coupled Acoustic Metamaterials Using the Transfer Matrix Method
The absorption performance of a locally-reacting acoustic metamaterial under oblique incidence is studied. The metamaterial is composed of a slotted panel, each slit being loaded by an array of Helmholtz resonators. The system is analytically studied using the transfer matrix method, accounting for the viscothermal losses both in the resonator elements and in the slits, allowing the representat...
متن کامل