Experimental investigation of aerodynamic performance of airfoils fitted with morphing trailing edges

Abstract

General rightsThis document is made available in accordance with publisher policies. Please cite only the published version using the reference above. Full terms of use are available: http://www.bristol.ac.uk/pure/about/ebr-terms The aerodynamic performance and wake development of a NACA 0012 airfoil fitted with morphing trailing edges were studied using experimental and computational techniques. The NACA 0012 airfoil was tested with morphing trailing edges having various camber profiles with the same trailing edge tip deflection. The aerodynamic force measurements for the airfoil were carried out for a wide range of chord-based Reynolds number and angles of attack with trailing edge deflection angle of β = 5• and 10• . The experiments were validated with steady-state RANS simulation using SpalartAllmaras turbulence model. Experimental results show that the camber profiles of the morphing trailing edges significantly affect the airfoil's aerodynamic performance and effectiveness in improving the lift coefficient further by tailoring the morphing profiles. Hot-wire measurements showed that the downstream wake development can also be influenced as a result of changing the morphing trailing edge camber profile. It was found that highly cambered trailing edge profiles provide higher lift coefficients and increased maximum lift coefficient compared to moderately cambered profiles while the lift-to-drag ratio slightly decreases. Velocity contour plots show that the separation near the trailing edge is further delayed at high angles of attack for airfoils with highly chambered morphing trailing edge. This study shows that the effective design space of the morphing trailing edges can be expanded taking into account the optimal aerodynamic performance requirements. The study also suggests that in order to achieve optimum aerodynamic performance, independent surface morphing of the suction and pressure surface camber will be required to delay the onset of flow separation.

Aerodynamic Performance and Wake Development of Airfoils with Serrated Trailing-Edges

“…In order to reduce this dominant trailing-edge noise, several passive methods such as serrated trailing-edges [6][7][8], porous surface treatments [9][10][11], brushes [12,13] and morphing trailing-edges [14][15][16] have been under investigation over the past two decades. In particular, serrated trailing-edges have received considerable interest due to their simple yet efficient noise reduction capabilities amongst all the other passive trailing-edge treatments.…”

Effects of Streamwise Surface Treatments on Trailing Edge Noise Reduction

“…To reduce the turbulent boundary layer trailing edge noise, various passive airfoil noise control methods have been developed, such as trailing edge serrations [5,[8][9][10][11][12][13][14][15][16][17][18][19][20][21], trailing edge brushes [22][23][24], porous trailing edge [25][26][27][28][29][30], airfoil shape optimization [31,32], trailing edge morphing [33,34] and more recently upstream surface treatment [35][36][37]. It was shown both analytically [8][9][10][11][12] and experimentally [5,[13][14][15][16][17][18][19][20][21] that trailing edge noise levels can be reduced by modifying the trailing edge geometry with serrations so that the flow disturbances are scattered into sound with reduced efficiency.…”

Experimental Investigation of Flow Around Three-Element High-Lift Airfoil with Morphing Fillers

“…One of the prominent sources of airframe noises are the high-lift devices namely the slats and flaps. In order to reduce these prominent noise sources several passive and active flow control methods have been investigated in the past it includes morphing structures [1,2], porous materials [3,4], surface treatments [5] and serrations [6][7][8].…”