Optimization of Dimpled Surface of NACA0012 Airfoil to Enhance the Aerodynamic Performance

Abstract

This study investigates the impact of dimple surfaces on the aerodynamic performance of NACA0012 airfoil. Numerical analyses were conducted to compare the aerodynamic performance of baseline, dimples, and optimized airfoil. Two-dimensional simulations of the airfoil were undertaken to investigate superior dimple configuration between inward and outward dimples, optimum dimple diameter, and optimum dimple position relative to the chord length. The simulation was conducted using Ansys fluent, employing the steady SST k-ω turbulence model with a fluid velocity of 18 m/s (chord-based Reynolds number of 6.7 * 10⁴). The result of the study shows that inward dimples located at different positions on the upper surface of the airfoil at 8-degree angle of attack have superior aerodynamic performance in terms of lift-to-drag (LtD) ratio. Numerical simulations were conducted for nine distinct Minitab optimization design cases for dimpled NACA0012 airfoil to identify and validate optimum dimple diameter and dimple position relative to the chord length of the airfoil. Concerning the NACA0012 chord, the optimum dimple diameter is 2 mm, and the optimum dimple position is 47.26% for the airfoil's leading edge. Dimple surface optimization also brings about delayed boundary layer separation, reduction in drag coefficient, and, consequently, increases the LtD ratio.