Author/Editor		Holeček, Nikola; Širok, Brane; Hočevar, Marko; Podgornik, Rudolf; Grudnik, Rok
Title		Reducing the noise emitted from a domestic clothes-drying machine
Type		članek
Source		Noise Control Eng
Vol. and No.		Letnik 54, št. 3
Publication year		2006
Volume		str. 5-13
Language		eng
Abstract		In recent years the development of large household appliances has increasingly focused on the reduction of noise. In this paper we report on attempts to reduce the sound-power level of an existing clothes dryer by investigating the aerodynamic noise sources. The critical points were determined on the basis of spatial sound-intensity measurements and sound-pressure-level spectra measurements. The changes to produce the modifieddryer, version I, involved corrections to the secondary-flow fan s inlet region. For version II we considered a different design of the heat exchanger. For this we set up a measurement station in order to analyze the aerodynamic properties of heat exchangers. The velocity and the acoustic properties of the heat exchangers were measured to help in the selection of the heat exchanger in accordance with the aeroacoustics theory that connects turbulent fluctuations and noise generation. After performing all the modifications, the A weighted total sound-power level was reduced from 76.0 to 66.5 dB for left rotation and from 73.8 to 64.7 dB for right rotation.