Fibre Optical Ice Sensing: Sensor Model and Icing Experiments for Different Ice Types

Atmospheric ice growth can be a potential hazard for structures like high-voltage lines, wind turbines or antennas in alpine regions. Fibre optical ice sensing is a possible approach to detect and monitor ice accretion. The sensing principle is based on the optical coupling between individual glass fibre bundles due to the accreted ice. Recent publications show the feasibility of ice monitoring with this approach by means of experimental studies. In this paper the properties and capabilities of fibre optical sensing for ice detection and thickness measurement are investigated by means of sensor modelling and sensor simulation, as well as dedicated measurements using a prototype. A new sensor model is developed, which includes all relevant interactions between the sensor and the ice accretion process. Simulations for different ice types are performed where the random nature of the ice accretion process is considered. By means of the measurements, the simulation results are verified and the sensor can be assessed for different types of ice regarding its capabilities to detect early ice formation and to measure the ice thickness.