Numerical analysis of ice accretion and aerodynamic degradation on the NACA 0009 thin airfoil at low Mach numbers

Icing on airfoils is one of the major challenges affecting the aerodynamic performance of aerial vehicles, especially under cold weather conditions. Most previous research has focused on simulating icing on conventional geometries such as aircraft wings, wind turbine blades and thick airfoils, primarily under high-speed conditions. However, the impact of icing on thin airfoils at low speeds and Mach numbers between 0.1 and 0.3 has not been widely studied, even though it plays an important role for low-altitude and light aircraft. In this work, the NACA 0009 thin airfoil is chosen, and its aerodynamic performance under icing conditions is examined through numerical simulation. After validating the numerical model against experimental data, the effects of increasing angle of attack ([Formula: see text] to [Formula: see text]) and Mach number (0.1 to 0.3) on ice shape and thickness, flow field characteristics and aerodynamic coefficients (lift and drag) are evaluated. The results show that at a fixed angle of attack, increasing the Mach number under low-speed conditions significantly expands the iced region. Also, increasing the angle of attack changes the icing pattern and makes it asymmetrical. Additionally, in Mach numbers 0.3 and angles of attack [Formula: see text]–[Formula: see text], flow separation and a sharp drop in aerodynamic performance occur due to ice growth on the leading edge, effectively reducing the stall angle.