Unsteady cavitation on hydrofoil surfaces induces complex pressure pulsations whose spatiotemporal evolution and source mechanisms remain insufficiently understood. In this study, unsteady cavitating flow around a Clark-Y hydrofoil is numerically investigated under different cavitation numbers, and the pressure pulsation tracking network framework based on field-point mapping is proposed. By jointly analyzing gas volume fraction, streamlines, and multiple vortex identification criteria, the typical cavitation evolution cycle of attachment, development, shedding, breakup, and regeneration is identified. The Liutex Ω method is shown to exhibit superior physical consistency in capturing dominant vortex structures correlated with cavitation dynamics. At the field scale, high-density monitoring points distributed on the hydrofoil surface are used to extract dominant and multi-order frequency components, peak-to-peak amplitudes, and phase characteristics of pressure pulsations and gas volume fraction, enabling identification of source regions and disturbance propagation paths. At the point scale, magnitude-squared coherence matrices are employed to quantify coupling strength and propagation characteristics among locations. Furthermore, the Fourier regularized Gram matrix and phase spectrum distributions are introduced to achieve phase-insensitive, high-dimensional characterization of multi-frequency coupling behavior. The results indicate that strong cavitation is associated with more stable dominant frequencies, enhanced nonlinear coupling within characteristic frequency bands, and concentrated phase responses near source regions sensitive to cavitation number. With increasing cavitation number, frequency coupling strength, coherence level, and spatial correlation weaken. The proposed field-point mapping framework provides an interpretable and scalable approach for analyzing the spatiotemporal evolution and source localization of cavitation-induced pressure pulsations.
Tang et al. (Mon,) studied this question.