In this study was clarified the mechanism of noise generation, which is responsible for the discrete frequency component and on which cavitation has an important effect. Experiments have shown that there is a characteristic discrete frequency, which is in close correlation with the cavitation process, and is a result of structural vibrations caused by implosion of bubbles and bombardment of the inner surfaces of the pump.
COBISS.SI-ID: 10947099
Noise, generated by a centrifugal blower, can be divided into airborne and structure borne noise. Their contribution to the total emitted noise is hard to determine, but it is crucial for the design of noise control measures. An analysis of the most important noise origin was performed by measurements of the transfer function between noise and vibration, under different types of excitation. The analyses have shown that the dominant noise source of a centrifugal blower can be attributed to the aerodynamically generated noise which exceeds the vibration-induced noise for more than 10 dB.
COBISS.SI-ID: 11736347
In this paper sound generated during a gas metal arc welding (GMAW) process is used for assessing and monitoring of the welding process and for prediction of welding process stability and quality. A new algorithm based on the measured welding current was established for the calculation of emitted sound during the welding process. The algorithm was verified for different welding condition, different welding materials and different specimen. The comparisons have shown that the calculated values are in good agreement with the measured values of sound signal.
COBISS.SI-ID: 11800347
This paper describes an analytical procedure that was used in conjunction with measurements of noise near the individual sources and in a neighboring residential area to rank order the contribution of the various sources to the total sound level. The sources are assumed to be incoherent and not too close together. Among about 200 noise source 16 were shown to be the main contributors to the total emitted noise. Application of the analytical model reduced the sound level in the neighboring community by up to 15 dB.
COBISS.SI-ID: 516144409
A sound in a cooling liquid generated by the quenching process contains sufficient information about the process. Traditionally, the quenching process can be controlled by selecting different process parameters, like the characteristics of the cooling liquid, the velocity of the cooling liquid flow, its temperature, the temperature of the work-piece etc. The possibility of controlling the quenching process by using acoustic cavitation is considered in this article. It bases on using of ultrasound for disintegration of the vapor bubbles and increasing of heat transfer to the work-piece.
COBISS.SI-ID: 11657755