Document Type : Original Article

Authors

1 Mech. Engg. Dept. Faculty of Engg. Ferdowsi University of Mashhad

2 Full Professor, Department of Mechanics, Department of Mechanical Engineering, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad, Iran

Abstract

The research investigates the growth of ice on the wing of a UAV, both with and without a winglet, and its effects on aerodynamic coefficients at low Reynolds numbers using a numerical method. The wing configuration is rectangular, employing the NACA0020 airfoil cross-section. Simulations were performed using a numerical method based on the finite volume method, a pressure-based algorithm, and second-order upwind scheme for convective flux calculation. Turbulent flow is modeled using the Spalart-Allmaras turbulence model. For ice modeling, the FENSAP-ICE commercial software, a modular ice simulation system, was utilized. The iterative ice accumulation simulation process includes successive calculations of airflow, water droplet paths, collection efficiency, and heat transfer balance to determine the shape of the accumulated ice. Calculations were conducted at Reynolds numbers of at an angle of attack of 10 degrees. Results indicate that the ice profile formed on the leading edge of the airfoil generates a swirling flow in this region due to depressions above and below the ice mass. This swirling flow increases the back pressure coefficient and decreases the drag coefficient compared to the wing without ice. Adding a winglet alters the airflow and reduces air resistance by controlling the induced vortices from the wingtip, thereby increasing lift and reducing drag. Consequently, the airflow speed increases, reducing ice accumulation and enhancing the aerodynamic efficiency of the wing.

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