The Impact of Icing on the Airfoil on the Lift-Drag Characteristics and Maneuverability Characteristics

Abstract

Icing has now become an important factor endangering flight safety. This paper takes the icing data of the NACA 23012 airfoil as an example, establishes an icing influence model for real-time simulation based on icing time and aircraft angle of attack, and analyzes the influence of different icing geometry on aircraft characteristics. The two-dimensional interpolation method is used to improve the model of the aircraft’s stall area, which is mainly divided into the correction of the lift-drag coefficient linear area and the stall area and the correction of the aircraft stability derivative and the control derivative. The aerodynamic equation of the airplane after icing is established, and the modal analysis of the airplane under different icing conditions is completed through the linearization of the flight equation. The closed-loop simulation system of the altitude holding mode and roll attitude holding mode is used to calculate and analyze the flight quality changes of the aircraft after the wing surface is frozen. The analysis results show that, under icing conditions, in the range of small angles of attack, icing has no obvious influence on the aircraft mode. As the degree of icing increases, the throttle skewness and the negative deflection angle of the airplane’s level flight requirements continue to increase. The case of icing flight in altitude hold and roll hold modes shows that flying in the autopilot mode under severe icing conditions is very dangerous and is prone to cause the aircraft to stall.

Research on the Determination Method of Aircraft Flight Safety Boundaries Based on Adaptive Control

“…Obviously, this is due to the fact that the original envelope value did not change with the actual icing conditions and therefore did not prevent the aircraft from exceeding its safe flight range. For this reason, it is necessary to introduce the concept of adaptive flight boundaries for icing aircraft, to dynamically determine the boundaries in real-time, and to protect the boundaries based on reliable control means [3][4][5][6].…”