Synchronized Measurement of Cloud Cavitating Flow around a 3D Twisted Hydrofoil

Abstract

Cloud cavitation shedding from sheet cavitation usually can be seen on propellers, rudders and shaft brackets of fast running ships. The unsteady and instable behavior of these cavitation structures generally can produce severe impingement on the neighboring wall, which is one of the main reasons for vibration, noise and erosion induced by cavitation. Therefore, it is significant to know the relation between the cavitation structure and its reduced pressure signals, which can help to recognize the generation mechanism of cavitation impact. In this paper, cavitation behavior, pulse pressure and noise were synchronized measured to illustrate the dynamic characteristics of cavitation structures around a 3D twisted hydrofoil. The pressure fluctuation and noise were recorded under different cavitation numbers, including cases of flow without cavitation and with cavitation at the same incoming velocity. Then cavitation behavior and relevant pressure signals were compared both in time domain and in frequency domain to investigate the relation between the unsteady cavitation structures and the corresponding pressure response.