A Measurement Method for Vibration Characterization in Gas Foil Bearing Rotor Systems Based on PVDF Sensor

Abstract In gas foil bearing (GFB) rotor systems, accurate vibration characterization is essential for optimizing the performance and the stability of high-speed rotating machinery. This study presents a novel measurement method for rotor vibration analysis based on polyvinylidene fluoride (PVDF) sensor arrays to quantify the gas film pressure distribution within GFB rotor systems. By interpolating and fitting the measured gas film pressure data, the distribution function was derived. This function was then integrated to calculate the gas film forces, which were incorporated into the kinetic equations of the system to characterize rotor vibrations. The accuracy of the pressure measurement technique was validated through comprehensive comparisons between theoretical pressure predictions and experimental measurements across multiple operating speeds. The theoretical results were validated through experimental data obtained from free speed reduction tests, where the calculated vibration amplitudes closely matched the measured ones. This method demonstrates the potential of PVDF sensor arrays for both accurately measuring gas film pressure and deriving vibration characteristics, providing a deeper understanding of the dynamics of GFB rotor systems and offering critical insights for improving the performance of high-speed machinery.