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Numerical Studies for the Interaction of Solid and Liquid Debris with Aircraft Modules
Published in Ahmed F. El-Sayed, Foreign Object Debris and Damage in Aviation, 2022
In-flight icing could occur when an aircraft flies in a temperature range between −40 °C and 0 °C. In these conditions, supercooled large droplets can form from small droplets which freeze upon contacting with a propeller. The shape of the formed ice depends on the LWC, the droplet diameter, the airspeed, and ambient temperature. For low temperatures (−40 to −10 °C), low airspeed, and low LWC, the ice immediately freezes and forms “Rime ice.” At higher temperatures (−18 to 0 °C), higher airspeed, and high LWC, the forming of “Glaze ice” has a double horn. These glaze ices are more dangerous than rime ice, and both alter the shape of the airfoil changing the aerodynamic characteristics, adding weight, and possibly bringing the airfoil out of balance [162].
Multiphase Flows with Droplets and Particles
Published in Greg F. Naterer, Advanced Heat Transfer, 2018
External flow with impinging droplets on a freezing surface occurs in various scientific and engineering systems. For example, icing of aircraft, ships, wind turbines, overhead power lines, and other structures involves external flow with impinging droplets on an ice surface. The ice growth begins as rime ice where impinging droplets freeze fully upon impact on the surface. Then a transition to glaze ice may occur when incoming droplets partially freeze and create a runoff flow of unfrozen water. The release of latent heat by the ice during freezing leads to a local temperature increase and formation of the unfrozen water layer.
A comparative study of property-constant and property-variable icing models
Published in International Journal of Green Energy, 2023
Xuan Zhang, Xin Liu, Jingchun Min, Mengjie Song, Keke Shao, Bing Huang
Most theoretical icing models start from the classical Messinger’s model (Messinger 1953) developed by balancing latent heat release and heat transfer at the gas–liquid interface and followed by several researchers (Macklin and Payne 1967; Myers 2001). In those models, the ice layer is regarded as glaze ice having the same physical properties as bulk ice, and the heat conduction in the water film is usually ignored. The glaze ice typically forms under a slow freezing rate at a cold temperature with the runback water film accompanied (Figure 1a). At a very cold temperature, the incoming water droplets freeze rapidly, and rime ice forms with air trapped within the pore spaces between ice crystals (Figure 1b) (Janjua et al. 2018). Therefore, rime ice is a special kind of porous medium, as presented in the experimental icing images on different surfaces (Myers 2001; Myers and Hammond 1999; Zhang, Wu, and Min 2017). Myers and Chris (1998) and Du et al. (2010) included the rime ice layer and runback water in their models but still assumed that the rime ice has constant physical properties. Kong and Liu (2014) developed an aircraft supercooled icing model by considering the properties of dendritic ice growth in supercooled water. Janjua et al. (2018) defined a solid volume fraction of ice in the rime layer and proposed an icing model based on four stages: rime, primary mixed, secondary mixed, and glaze ice.