IMPACT: Experimental and Numerical Ice Shapes on Swept-Wing Models with Straight and Undulated Leading Edges

This paper presents part of the results of the experimental swept wing icing campaign undertaken as part of the CleanSky 2 IMPACT project (GA no. 885052), along with the numerical simulation results obtained with Ansys FENSAP-ICE and Fluent Icing. One of the goals of this experimental campaign was to provide high quality ice shape validation data for 3D icing simulation codes on undulated leading edges, which are of interest due to their potential tolerance to aerodynamic performance degradation due to ice. Using the NACA 3421
airfoil profile as baseline, an undulated leading-edge geometry was designed and tested in addition to the original straight leading edge, to study the differences in ice shape formations on both geometries. The experiments were carried out at the Rail Tec Arsenal (RTA) facility in Vienna (Austria). The wing model had a sweep of 20º and a chord length of 1.5m. The icing conditions included air speeds from 60 to 70m/s, static temperatures from -20° to -1.4° C,
LWCs from 0.21 to 0.64 g/m3, and MVDs from 20 to 101.4 microns. Icing times were set to 15 minutes, with two runs extended to 45 minutes. The experimental data collected include 3D ice scans and 2D ice tracings extracted from these scans, ice thickness distributions, ice density measurements, and aerodynamic forces. The numerical simulations are done using the multi-shot method in FENSAP-ICE, which updates the CFD mesh regularly to account for the two-way coupling of surface deformation and air flow. Simulation model settings studied include mesh resolution, icing time between mesh updates, and ice density options.