Numerical Investigations of Trailing Edge Morphing at Low to Moderate Reynolds Number

Abstract

This study compares the effects of continuous trailing edge camber morphing and a hinged flap, on the aerodynamic performance of two symmetric airfoils: NACA0012 airfoil and the relatively thin NACA0003 airfoil, for a chord-based Reynolds number range of 104 to 106 , which represents the flight regime of micro aerial vehicles (MAVs). As a low-to-moderate Reynolds number regime has been considered in this study, the numerical simulations were performed using a Reynolds-averaged Navier-Stokes solver with a local correlation-based one-equation transition model. Results showed that use of camber morphing in lieu of hinged flap resulted in higher lift for both the NACA airfoils in almost all cases considered. Investigations of surface pressure coefficient revealed that delayed pressure recovery on both the suction and pressure surfaces near the trailing edge is primarily responsible for the production of higher lift for the airfoil with the continuous morphed trailing edge. Further, although use of continuous camber morphing of the trailing edge increases drag compared to the use of hinged flap, the aerodynamic efficiency is very similar for both the configurations. It was also observed that for a moderate angle of attack, the use of camber morphing in lieu of a hinged flap delayed trailing-edge flow separation in NACA0012 airfoil.