Passive Flow Control of a NACA 0018 Airfoil using Triangular Porous Texturing Elements

Passive flow control techniques offer a promising means of enhancing aerodynamic performance without the need for external energy input. This study explores the aerodynamic effects of Triangular Porous Textured (TPT) elements applied to a NACA 0018 airfoil. To evaluate the efficacy of this passive flow control method, a comparative analysis was conducted between a baseline airfoil and one modified with TPT elements. The TPT configuration consists of 1 mm equilateral triangular prisms, spaced 5 mm apart within each row and 4 mm between rows. Aerodynamic forces were measured using a force balance mounted at midspan on the trailing edge of each airfoil. In addition, planar Particle Image Velocimetry (PIV) data was acquired at the three-quarter span position for pre-stall, stall, and post-stall angles of attack across multiple freestream velocities. The primary objective of this investigation is to enhance lift characteristics and delay flow separation through boundary layer modification. Performance metrics include lift and drag coefficients, pitching moment behavior, and near-wall turbulence characteristics. The effectiveness of the TPT elements is evaluated through a combination of force measurements, PIV flow field analysis, and computational fluid dynamics (CFD) simulations.