Numerical investigation on aerodynamic load characteristics of an aircraft-mounted radome under rotor interference

Abstract

To ensure the structural reliability of the external radome mounted above the helicopter main rotor, high-fidelity Computational Fluid Dynamics (CFD) simulations were conducted to investigate the complex aerodynamic loads encountered during actual flight. Addressing the structural design requirements, this study employs the Reynolds-Averaged Navier-Stokes (RANS) equations combined with the momentum source method to simulate rotor interference. Crucially, the numerical algorithm was rigorously validated through grid independence studies, showing a deviation of less than 2.5% in key aerodynamic forces compared to refined meshes. The aerodynamic characteristics of five distinct configurations under typical flight conditions were systematically analysed. The research quantifies the impact of various geometric features—including smooth surfaces, intake/exhaust vents, additional bosses, and interferometers—on the aerodynamic forces and moments acting on the entire radome, its base, and the antenna housing. Simulation results reveal the surface pressure distribution characteristics and load evolution patterns under varying flight speeds and pitch angles. Quantitative analysis indicates that boss structures and sheet metal components in the base region are the primary contributors to significant drag increases (up to 107% compared to a smooth configuration), which systematically alter load magnitude and distribution. These findings provide critical data and theoretical support for local optimization and structural design of low-drag, high-reliability airborne equipment.