Measuring temperature of the ice surface during its formation by using infrared instrumentation

A non-destructive remote sensing technique was used to measure the surface temperature of a thin macroscopic water film flowing on a growing asymmetric ice accretion during its formation inside an icing research wind tunnel. Given the underlying thermodynamic conditions of this experimental series, the recorded surface temperature was always below the temperature of water fusion, Tm = 273.15 K, even when water shedding from growing ice accretions was observed visually. The surface temperature of ice accretions, Ts, ranged from −1 °C, for angular positions near the stagnation line, down to a certain minimum above the ambient temperature, Ta, for the greater angular positions, i.e. Tm > Ts > Ta.