| Abstract | At the request of Electrolux (Canada) Ltd., the Engine Laboratory agreed to carry out an experimental programme to measure the noise characteristics produced by their three vacuum cleaner models. The main objectives of this experimental programme were to measure the noise nuisance caused to an operator of these devices and to examine in detail the aerodynamic and acoustic performance of their main source of noise - the blower units used inside these machines. The experimental programme was carried out in two phases. Under Phase I, noise measurements of each complete vacuum cleaner unit were made and the results were reported in Reference 1. Noise measurements of the motor-blower units and the acoustic and the aerodynamic performance of the blower units comprised Phase II tests.
Though under Phase I noise measurements were carried out on three cleaner models, at the request of the manufacturer Phase II tests were conducted only on the motor-blower units of the two recent models, viz. the Gold and Upright cleaner units. In order to determine the effect of the vacuum cleaner casing and other accessories inside the casing on motorblower noise generation, the sound power levels radiated by the motorblower unit of the Upright cleaner were measured in each one-third-octave band under anechoic conditions. With the aim of relating the generated noise to the aerodynamic performance, aerodynamic and acoustic measurements were carried out inside the duct attached to the inlet side of the blower units. The effect of changes in inlet geometry and diffuser vane numbers were studied to suggest means for noise reductions without drastic modifications in the design of the blower units.
This report describes the experimental details and the results of the Phase II tests. |
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