Impingement Analysis on Nacelle Inlet, Multibody Airfoil, and Swept Tail Cases under SLD Conditions

This paper presents impingement analysis on a nacelle inlet, multibody airfoil, and swept tail under Supercooled Large Droplet (SLD) conditions in icing tunnels. Impingement and collection efficiency calculations are crucial for ice shape and protection analyses. The aerospace icing community selected three cases for simulation, focusing on SLD conditions, which require specific mathematical models for accurate representation. The present authors used a Reynolds-averaged Navier-Stokes computational fluid dynamics (CFD) tool to evaluate pressure coefficients and collection efficiency, comparing them with experimental data. CFD simulations incorporated fully turbulent flow using various turbulence models and Eulerian droplet transport, considering experimental droplet distribution. The results showed acceptable deviations despite SLD simulation challenges and experimental data problems. A secondary conclusion suggests simplifying a 27-bin distribution to a 10-bin distribution to take into account the cumulative mass curve. An accumulated mass index is proposed to compare different simulations. Importantly, the CFD accurately captures the impingement limits, enhancing its value for engineering purposes. This study demonstrates the suitability of the CFD method by showcasing its application to address aircraft certification challenges, emphasizing the importance of integrating engineering perspectives within CFD simulation results.