Static and Dynamic Pressure Measurement in Flight Test Application With Optical Fabry–Pérot Sensors

Abstract

Conventional electrical pressure sensors show degradation of their performance in harsh environments because of their low overload protection, drawn back membrane, susceptibility to electromagnetic influences, and corrosion. Fiber-optic measurements overcome those challenges and promise to be a robust sensing solution for vigorous flight testing. We developed a passive fiber-optic Fabry-Pérot pressure sensor with a minimum thickness of 1.6 mm, natural frequency above 250 kHz, linear transfer characteristic, burst pressure resistance above >30 times full-scale, and without conductive corrosive materials. It can measure aerostatics, aerodynamics, and aeroacoustics down to 70-dB SPL. In combination with an industrialized edge filter measurement device, the fiber-optical sensor's simplified instrumentation is demonstrated on a microlight aircraft, performing dynamic maneuvers. The measurement data of near-stall flight situations demonstrate the monitoring capabilities of detached airflow in harsh environments.