Numerical Prediction and Experimental Verification of Ice Accretion on Turboprop Nacelles

To address the airworthiness compliance verification requirements for icing on large transport aircraft, this study investigates the icing characteristics of turboprop engine nacelles through numerical simulations and icing wind-tunnel tests. The Reynolds-averaged Navier–Stokes method was employed for external flowfield calculations, Eulerian approach for droplet trajectory analysis, and Messinger model for ice accretion prediction. Focusing on a turboprop engine nacelle of a large amphibious aircraft, systematic analyses were conducted on grid resolution, computational steps, critical icing conditions, and ice shapes. The influence of parameters such as droplet diameter and temperature on ice accumulation was quantified, revealing a critical median volumetric diameter of [Formula: see text] and critical temperature of [Formula: see text]. A novel hybrid scaling criterion was developed for three-dimensional nacelle models, preserving the inlet leading-edge geometry and pressure distribution while minimizing model length, followed by experimental validation in a 3-m-scale icing wind tunnel. Results demonstrated good agreement between numerical predictions and experimental ice shapes, confirming the effectiveness of the multistep icing calculation method and grid reconstruction technique for complex three-dimensional configurations. The blockage effect from tunnel walls was found to increase critical ice accumulation by approximately 12% through flowfield and droplet distribution alterations. These analytical methodologies and parametric relationships provide valuable references for similar turboprop engine nacelle icing analyses.