Aerodynamic Characteristics of 4% Cambered-Plate and NACA0012 Airfoil at the Reynolds Numbers Region for Micro Air Vehicles

Abstract

In the Reynolds number region lower than approximately 1.0 × 10⁵, which corresponds to the Reynolds number region of a Micro Air Vehicle, thinner and sharper leading edge airfoil performs better than thicker and blunter one. This research focuses on the difference in flowfields which are clarified by means of streamline calculation and surface pressure distribution measurement. Numerical studies were performed to the blunt type NACA0012 airfoil and both numerical and experimental studies were performed to the thinner type 4% cambered-plate airfoil. The performance of the NACA0012 airfoil is deteriorated with decreasing Reynolds number, whereas that of the 4% circular arc cambered-plate airfoil is not affected. The deterioration of the NACA0012 airfoil performance is mainly due to the laminar boundary layer separation near the trailing edge; such phenomena are not essential to the performance in the cambered-plate airfoil results. This paper also demonstrates that the flow separation at the trailing edge can be estimated from the temporal amplification factor of the oscillatory mode which is calculated by the global linear stability analysis.