First Ice
Bubbles Encased in Ice
Ice Damages With Liquid Veins
Water expands when it freezes, a fact that's often blamed for ice-cracked roads. But expansion isn't what gives ice its destructive power. In fact, liquids that contract when freezing also break up materials like pavement and concrete. (Image credits: pothole - I. Taylor, experiment - D. Gerber et al.; research credit: D. Gerber et al.; via APS Physics) Read the full article
Erie Ice
Lake Erie, the shallowest of the Great Lakes, sees large swings in ice cover over the winter. In late January 2022, the lake was nearly completely frozen over, with 94 percent of its area covered in ice. By February 3rd, ice cover had dropped to 62 percent before rising again to 90 percent by the 5th. (Image credit: J. Stevens/USGS; via NASA Earth Observatory) Read the full article
Liquid water is easily electrically charged, due to its polar nature. That's why rubbing a comb is enough to deflect a stream of water. Ice is harder to charge, but it can happen, especially when there are temperature gradients across the ice. (Image credit: frost - Miriams-Fotos, figure - R. Mukherjee et al.; research credit: R. Mukherjee et al.; via ChemBites; submitted by Kam-Yung Soh)
Rings of Ice
Ice build-up is a major hazard on airplane wings and control surfaces, but ice can accrete on internal engine components, too. When this happens, the turbofan jet engine can lose power. Such incidents have been observed in high-altitude flight even when pilots observed little to no inclement weather. Researchers think this ice accretion may occur when the plane flies through a cloud of tiny ice crystals. These ice crystals get ingested into the engine, where they hit the warmer internal surfaces and melt. Over the course of the flight, the engine components cool off due to this influx of ice and water. Eventually, ice begins to form and grow inside the engine, ultimately resulting in power loss. Researchers have recreated such ice cloud conditions in a facility at NASA Glenn Research Center and tested a full-scale jet engine for ice accretion. They aim to gather the data necessary to improve commercial engine capabilities under ice ingestion. (Video credit: NASA Glenn Research Center)
Source: nasa.gov
Icing on airplane wings remains little understood and a major hazard. These photos show examples of ice formation along the leading edge of a swept wing. If an aircraft flies through a cloud of supercooled water droplets, the droplets will freeze shortly after impact with the aircraft's wings. As ice continues to build up in strange shapes, the aerodynamic profile of the wing changes, which can lead to disastrous effects as the stall and control characteristics of the wing shift. (Photo credit: NASA Glenn Research Center)