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Experimental and CFD study of the selected acoustic helicoidal resonator as a final element of an air installation

Łapka Wojciech, Jakubowski Piotr

Vibrations in Physical Systems

2023

Vol. 34, nr 1

art. no. 2023112

The work presents an analysis of the selected helicoidal resonator as the end element of the air installation. Laboratory tests of the acoustic pressure level were performed at the outlet of the air installation in a room for different flow speeds. The measurement methodology in accordance to standards PN-EN ISO 3741 and PN-EN ISO 5135, which describes the acoustic test facilities, instrumentation and procedures to be used for precision grade determination of sound power levels in octave or one-third-octave bands of a noise source in reverberation test rooms. The numerical CFD tests show the shape of the air stream in the function of the distance from the installation outlet for different flow speeds. Due to the helicoidal shape of the analyzed acoustic helicoidal resonator, the air stream also turns, which can be used to effectively mix air in the room.

Acoustic attenuation performance of Helmholtz resonator and spiral duct

Łapka W., Cempel C.

Vibrations in Physical Systems

2008

Vol. 23

247--252

This work examines a comparison of acoustic attenuation performance of well known Helmholtz resonator and spiral element inserted into circular duct, which creates spiral duct. The paper consists results of numerical computations by the use of Finite Element Method. Here the spiral is a kind of resonant element, which can be applied in circular ducts, mainly for low speed velocity ducts e.g. ventilation, air-conditioning and heat systems. Results are presented as a transmission loss. The sound attenuation performances of Helmholtz resonator and spiral duct depend on their geometrical relationships. The most important observation is that the sound attenuation in both solutions are based on similar phisical phenomenon – resonance.