A comprehensive numerical model for mixed-phase and glaciated icing conditions

Eulerian method for ice crystal icing in turbofan engines

“…Another assumption that has been made by Trontin et al [132] is that for the case of mixedphase conditions part of the accumulated water remains trapped between the ice crystals or in the ice layer. This is confirmed by experiments that have been conducted by Currie et al [23].…”

“…In the work of Trontin et al [132] also the characteristics of the secondary particles, in terms of diameter, sphericity and velocity have been described. If L ≤ L c2 , a portion ε of the particle sticks to the wall and a portion (1 − ε) of the particle is re-emitted into the flow as a bounced particle.…”

“…Ideally, when trying to represent all the details, the final model should cover the general behaviour of particle impact with an acceptable level of accuracy and modest computation time. In MooseMBIce an impact model has been implemented similar to the one proposed by Trontin et al [132,139]. In the impact model three different impact regimes are defined: sticking, bouncing and shattering.…”

“…Furthermore, this model might underestimate the ice accretion further downstream from the leading edge due to the normal restitution coefficient ξ n increasing with increasing distance from the leading edge. Trontin et al [132] have proposed a new sticking efficiency model which depends on the melting ratio η i c of the ice crystals, the mass fraction of impinging droplets Y d and the mass fraction of impinging ice crystals Y i c :…”

“…During the melting process the non-spherical ice crystal will become more spherical and eventually end up as a spherical water droplet. Since the evolution of sphericity has not yet been investigated experimentally, a simple model, similar to the one used in Trontin et al [132,139], has been applied to adapt the heat and mass exchange coefficients for spherical particles to non-spherical particles. During the melting process the sphericity is linearly interpolated between Φ 0 and 1 in the following way: 27) where α i and α w are the volume fraction for ice and liquid water, respectively.…”