Vpliv načina vzbujanja zvočnega polja v impedančni cevi na rezultate meritev koeficienta absorpcije v časovni domeni

Prtenjak, Hana (author), Prezelj, Jurij (mentor)

Primerjani so koeficienti absorpcije različnih absorpcijskih materialov, ki smo jih vzbujali z različnimi signali ob različnih dolžinah snemanja. Uporabljena je bila metoda pulznega ločevanja, kjer je od meritev z vzorcem odšteta prvotna referenčna meritev in tako pridobljeni le podatki zvočnega signala odboja. Ugotovljena je neprimernost impulznega signala pri metodi in uporabnost sinusnega preleta pri izkoristku absorpcije. Prikazana je pomembnost dolžine časa snemanja in odstopanje posameznih meritev zaradi le te.

• Language: Slovenian
• Keywords: koeficient absorpcije, impedančna cev, metoda pulznega ločevanja, čas merjenja, absorpcijski materiali
• Work type: Final paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FS - Faculty of Mechanical Engineering
• Place of publishing: Ljubljana
• Publisher: [H. Prtenjak]
• Year: 2022
• Number of pages: XIV, 33 f.
• PID: 20.500.12556/RUL-139748
• UDC: 534.83:53.08(043.2)
• COBISS.SI-ID: 122379011
• Publication date in RUL: 07.09.2022

Secondary language

• Language: English
• Title: The influence of the mode of the sound field excitation in an impedance tube on the results of time domain absorption coefficient mesurements

Abstract

The absorption coefficients of different absorption materials excited with different signals at different recording lengths are compared. A pulse separation method was used, where the original reference measurement is subtracted from the sample measurement to obtain only the acoustic reflection signal data. The unsuitability of the pulsed signal method and the usefulness of the sine sweep in absorption efficiency are established. The importance of the length of the recording time is demonstrated and the deviation of the individual measurements due to it.

• Keywords: absorption coefficient, impedance tube, pulse separation method, time of measurement, sound absorbing materials