A Compact Icing Research Tunnel for Ice Adhesion Characterization

Abstract

A compact icing facility is developed to allow the measurement of ice adhesion tensile stress and fracture energy of aerospace impact ice, in coordination with thermal measurements, to ensure a well-characterized thermal environment. The facility was 1.5 m wide, 1.5 m long, and 2.1 m tall, and the tunnel is equipped with a single MOD-1 spray nozzle to produce a cloud of supercooled droplets at the targeted mean volumetric diameter for a liquid water content range from 2 to . The compact icing research tunnel (CIRT) was used to generate ice accretion on an aluminum test specimen, which was then measured to determine the ice tensile adhesion strength for two conditions: impact ice and static ice. The static ice was made by freezing motionless deionized water on the aluminum test specimen, whereas impact ice was obtained as a result of water droplets freezing after impacting the specimen at the velocity of about , with air and surface temperature both at . It was found that the substrate temperature increased significantly through the accretion process, to about 5°C for static ice and 7°C for impact ice (where the latter includes a significant increase in humidity).