A Comparative Study on the Wake Sensing Mechanism of a Seal Whisker-Shaped Cylinder

This study conducts water channel experiments to measure and compare the lift forces experienced by the seal whisker-shaped sensor and the circular cylinder sensor in both no vortex generator and the wake of two types of circular cylinders. Particle Image Velocimetry (PIV) is employed to capture the velocity fields of the cylinder wake and the surrounding flow of the seal whisker-shaped cylinders. Spectral analysis of the lift signals reveals that both cylinder types exhibit a primary peak close to the vortex shedding frequency of the upstream circular cylinder. However, seal whisker-shaped cylinders demonstrate relatively weaker components in their lift signals that do not align with the primary frequency, indicating a stronger sensing capability of the upstream cylinder's wake. Modal analysis using Spectral Proper Orthogonal Decomposition (SPOD) on the PIV-measured velocity fields shows that the lift signals of both cylinder types are primarily induced by the vortices in the upstream cylinder's wake.