Meritve koeficienta absorpcije zvoka materialov v impedančni cevi z metodo odštevanja impulznih odzivov

Mostar, Klemen (author), Prezelj, Jurij (mentor)

Metodo Adrienne (SIST EN 1793-1), ki se uporablja za merjenje zvočne absorpcije protihrupnih ograj, hočemo implementirati v impedančno cev in s tem izračunati absorpcijski koeficient poljubnega vzorca v bistveno hitrejšem času kot z metodo razmerja amplitud stoječega valovanja (SIST ISO 10534-1:1999), ki se uporablja za merjenje zvočne absorpcije poljubnih materialov v impedančni cevi. V impedančni cevi smo izračunali absorpcijski koeficient petim različnim vzorcem po metodi razmerja amplitud stoječega valovanja in po implementirani metodi Adrienne, pri kateri smo primerjali impulzni odziv vpadnega in odbitega zvoka v časovni domeni. S primerjavo impulznih odzivov smo izračunali zelo podobne rezultate kot z metodo razmerja amplitud stoječega valovanja, in sicer šestkrat hitreje in v desetkrat boljši frekvenčni ločljivosti.

• Language: Slovenian
• Keywords: zvočno absorpcijski koeficient, impedančna cev, metoda Adrienne, metoda razmerja amplitud stoječega valovanja, zvočno absorpcijski materiali, metoda odštevanja impulznih odzivov
• Work type: Bachelor thesis/paper
• Organization: FS - Faculty of Mechanical Engineering
• Year: 2017
• PID: 20.500.12556/RUL-95458
• Publication date in RUL: 20.09.2017

Secondary language

• Language: English
• Title: Measurements of sound absorption coefficient in impedance tube with impulse responses subtraction method

Abstract

The Adrienne method (EN 1793-1), used to measure the sound absorption of noise barriers, is to be implemented in an impedance tube to calculate the absorption coefficient of any sample much quicker than with the method using standing wave ratio (ISO 10534- 1: 1998), which is used to measure the sound absorption of any materials in the impedance tube. In the impedance tube, we calculated the absorption coefficient of five different samples with the standing wave ratio method and with the implemented Adrienne method, in which we compare the impulse response of the incident and reflected sound in the time domain. By comparing impulse responses, very similar results were calculated six times faster and with a ten times better frequency resolution as with the standing wave ratio method.

• Keywords: sound absorption coefficient, impedance tube, method using standing wave ratio, adrienne method, sound absorbing materials, impulse responses subtraction method