Spectral Analysis of Pressure, Noise and Vibration Velocity Measurement in Cavitation

Abstract

The article deals with experimental investigation of water cavitation in the convergent-divergent nozzle of rectangular cross-section. In practice, a quick and simple determination of cavitation is essential, especially if it is basic cavitation or cavitation generated additionally by the air being sucked. Air influences the formation, development and size of the cavity area in hydraulic elements. Removal or reduction of the cavity area is possible by structural changes of the element. In case of the cavitation with the suction air, it is necessary to find the source of the air and seal it. The pressure gradient, the flow, the oxygen content in the tank, and hence the air dissolved in the water, the air flow rate, the noise intensity and the vibration velocity on the nozzle wall were measured on laboratory equipment. From the selected measurements the frequency spectrum of the variation of the water flow of the cavity with cavitation without air saturation and with air saturation was compared and evaluated.

Reduction of the suction pressure of a liquid ring vacuum pump with a supersonic gas ejector

“…As the first step the digitization of the signals from the installed sensors was made [4]. Since the signal in the digital form has an electrical value, it was necessary to convert them to the values of the actual measured parameters.…”

Research on Noise-Induced Characteristics of Unsteady Cavitation of a Jet Pump

“…Jablonská et al. 36 measured the noise intensity and vibration velocity of a spatialized Venturi tube with and without air saturation, respectively. The results indicated that the added air can suppress the noise intensity.…”

“…In the previous literature, Mancuso 35 conducted an experimental and numerical investigation on the performance of a swirling jet reactor with different geometric configurations and measured and analyzed the cavitation noise of different geometric shapes at different inlet pressures. Jablonskáet al 36 measured the noise intensity and vibration velocity of a spatialized Venturi tube with and without air saturation, respectively. The results indicated that the added air can suppress the noise intensity.…”

Measurement of Aerodynamic and Acoustic Quantities Describing Flow around a Body Placed in a Wind Tunnel

“…For future research, these extensive reference sources can be used for numerical modeling and experimental measurements of acoustic wave generation in the wind tunnel on actual car components. Methods of measuring and processing noise and vibrations and also numerical methods are also described in articles [16], [17], [18], [19].…”