Measurement of the Bubbly Flow Beneath Partial Attached Cavities Using Electrical Impedance Probes

Abstract

Surface electrical impedance probes are used to examine the bubbly flow beneath and in the closure region of partial attached cavities. A series of electrodes were mounted flush to the surface of a cavitating hydrofoil to detect the presence of liquid or vapor through changes in the impedance of the local fluid medium. Signals from the electrical probes were used to determine the near-surface gas-phase velocity and the shedding frequency of the gas phase. The impedance technique is shown to have the potential to measure advection velocities within a partial cavity, and the frequency content of the signal is used to determine the dynamics of the vapor shedding process. [S0098-2202(00)00501-0]