A High Spatial Resolution Optical Fiber Fluctuating Pressure Sensing Array

A high spatial resolution fluctuating pressure sensor array based on a fiber-optic Fabry-Perot (FP) cavity is proposed to address the limited wavenumber measurement capability in underwater turbulent boundary layers (TBLs). The sensor array comprises 40 fiber-optic FP pressure sensing units with a diameter of 0.8 mm and a spacing of 1 mm. It demonstrates an average sensitivity of 7.8 pm/Pa and a wavenumber measurement range of 3140 rad/m. The turbulent wall surface of a square tube was subjected to experimental measurements under a flow velocity of 2 m/s, facilitating successful capture of the frequency-wavenumber spectrum for fluctuating pressure. The obtained results were found to be consistent with simulation analysis.