Icing Collection Efficiency Prediction Using an Eulerian-Eulerian Approach

A collection efficiency model using an Eulerian-Eulerian approach is implemented within CFD++, the commercial CFD code from Metacomp Technologies, in which a finite volume scheme is employed to discretize the droplet and gas flows. The continuous phase and droplet governing equations are solved in a coupled fashion with the appropriate momentum and energy transfer between the phases. CFD simulations have been performed assuming various droplet diameters and distributions in order to validate icing collection efficiencies on engines, airfoils and glaze ice shapes. Applications to icing clouds with median volumetric diameters greater than 50 microns which fall outside the Appendix C envelope have also been considered. Supercooled large droplet (SLD) impingements require an extended numerical model to account for droplet rebound and splash mechanisms near solid boundaries. Simulations with SLD modeling have shown that these mechanisms considerably influence impingement predictions.