Experimental Results for Ice Crystal Icing on Hemispherical and Double Wedge Geometries at Varying Mach Numbers and Wet Bulb Temperatures

Eulerian and Lagrangian Ice-Crystal Trajectory Simulations in a Generic Turbofan Compressor

“…The presence of liquid water in the air, in the particle, or as a thin film on the wall, will strongly influence the sticking ability of the particles [40,41]. Experimental observations suggest [42,43] that the particle sticking efficiency mainly depends on the ratio of liquid water content (LWC) and total water content (TWC). The sticking efficiency ε is defined as the ratio of particle mass that sticks to the surface and the total impinging particle mass.…”

A comprehensive accretion model for glaciated icing conditions

“…The shaved ice method has been dropped since it appeared impractical for such a large facility (Griffin et al, 2014). Mixed phase conditions have been tested experimentally at RATFac from NRC with an hemispheric test model (Currie and Fuleki, 2016). For the coldest conditions, with a wet bulb temperature from −8 • C to −5.5 • C, the right end of the plateau (see below) has not been exhibited since accretion remains possible with supercooled liquid droplets only.…”

Eulerian method for ice crystal icing in turbofan engines

“…The first three of these facilities are capable of simulating ice crystals under various altitude conditions. These upgrades have resulted into a number of experimental studies on glaciated and mixed-phase accretion for various geometries: an aerofoil shape by Struk et al [127], a NACA-0012 aerofoil by Al-Khalil et al [2] and Struk et al [126], a double-wedge aerofoil by Currie et al [23,22] and Struk et al [124,126], a streamlined body with an axi-symmetric hemispherical nose, with a cylindrical nose and with a conical nose by Currie et al [22,24,25], a bleed slot in a compressor stage by Knezevici et al [71,72] and an aerofoil in a compressor transition S-duct by Mason et al [96].…”

“…Fully frozen particles impacting a cold surface will simply bounce and leave no or only a very thin layer of frost on the surface. Currie et al [22,25] have investigated the ice accretion on four different geometries: a wedge aerofoil with a chord of 221 mm and either a nose in the form of a hemisphere, cone or curved cylinder with 4.1 Particle impingement a (maximum) diameter of 44.5 mm attached to a streamlined afterbody. The icing surfaces of the geometries are made of a titanium alloy.…”

“…K d depends on the substrate temperature T s because the lower the substrate temperature the faster the droplets will freeze resulting in a smaller amount of remaining liquid to which the crystals can stick. The model in Equation (4.4) is based on the experimental observation from Currie et al [22,25], described in section 4.1.2, that the particle sticking efficiency strongly depends on the ratio of LWC i c and IWC. Furthermore, two separate efficiencies for mixed phase (ice crystals and droplets) and melting phase (partially melted ice crystals) conditions are defined because it was observed that for the same ratio LWC/TWC the sticking efficiency was higher for melted particles than for mixed conditions.…”