Quasi-Steady Modeling of Ice Accretion on a Helicopter Fuselage in Forward Flight

Abstract

Computational modeling of ice accretion on a rotorcraft is an alternative and/or a complement for flight test in icing certification and ice protection system design. Although computational fluid dynamics solutions of helicopter flow have advanced in the last few years, icing simulations are rare and, to the best of the authors’ knowledge, none has modeled helicopter icing completely. In this work, a three-dimensional simulation of long-term in-flight ice accretion, accounting for rotor-fuselage quasi-steady interaction, is performed. For flow solution, the three-dimensional compressible turbulent Navier–Stokes equations are solved, with the rotor modeled as an actuator disk that imparts radial and azimuthal distributions of pressure rise and swirl to the flow field. The authors’ code FENSAP-ICE is used to solve the three-dimensional flow, impingement, and ice accretion. The flow solutions for a test case, at two forward speeds, are obtained and validated against published experimental results and then used to illustrate icing on the helicopter’s fuselage. Also, in this work, the effects of different parameters (such as forward speed, ambient temperature, droplet diameter, and liquid water content) on droplet impact, ice accretion, and the aerodynamic degradation of helicopter fuselage, were studied.