Significant share of vacuum cleaner suction units market belongs to the wet suction unit for household and professional aspiration. Heavy operation conditions, high performance and long operation life; low mass and smaller dimensions, and low level of noise are only few of criteria for a new suction unit development. This paper present systematic approach to identification of noise sources on existing suction unit. On the bases of CFD analyses a new idea for geometrical and dimensional optimization are proposed. The presented solutions are foundation for a new improved bypass motor.
F.06 Development of a new product
COBISS.SI-ID: 11574811Proceedings of the EAA-EUROREGIO 2010, 1st European Congress on Sound and Vibration integrating First Forum of Young Researchers in Acoustics was edited by members of the program group. Proceedings was published on a CD ROM and abstracts of the papers were published in a special issue of the Journal Acta Acoustical united with Acustica. Program of the congress with all necessary information’s is still accessible on the congress website: http://www.fs.uni-lj.si/sda/euroregio.htm.
C.01 Editorial board of a foreign/international collection of papers/book
COBISS.SI-ID: 4008811This work deals with the method for cavitation detection in centrifugal pumps, based on noise and vibration measurement in an audible range, from 20 Hz to 20 kHz. The research showed that this detection method is reliable and efficient. Cavitation phenomenon in the pump causes great increase of noise and vibration level in wide frequency range. At some particular discrete frequencies even higher levels can be achieved. Results showed that this method can be successfully used for detection and monitoring of development cavitation in centrifugal pumps.
D.09 Tutoring for postgraduate students
COBISS.SI-ID: 11791899Cavitation in a centrifugal pump may cause a deterioration in performance curves, pitting and material erosion, structure vibration and noise. The aim of this wok was to prevent the onset of the cavitation process in the pump by increasing of the pressure in the pump nozzle where cavitation is usually first appears. The pressure was increased by supplying fresh water in the pump nozzle from the suction reservoir through a small pipe parallel arranged to the main suction pipe. On this way, the operating point was moved towards the higher flow rate, whith higher NPSH critical values.
F.02 Acquisition of new scientific knowledge
COBISS.SI-ID: 11320091Preschool teachers and their assistants are daily exposed to high levels of noise. It is known that concentrations of cortisol are in direct correlation with stress. Level of cortisol in saliva were analysed for estimate noise exposure at work. Cortisol secretion is increasing due to level of stress. The aim of this study was to analyse if the concentrations of cortisol are changing due to noise levels in kindergarten. Measured results have shown that there is no direct correlation between noise levels and cortisol values, but detailed analyses are still in progress.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 4008555