Aerodynamic Performance Enhancement Through Triangular Porous Texturing on Infinite Flat Plates: A Computational Fluid Dynamics Approach

This computational study examines how an embedded Triangular Porous Texturing (TPT) patch modifies near-wall turbulence and wall shear in a turbulent flat-plate boundary layer, with the goal of providing guidance for ongoing higher-fidelity simulations and experiments. The configuration consists of a canonical smooth flat plate and a modified plate with an array of 1 mm equilateral triangular elements arranged in 16 rows within a reduced spanwise domain, with 5 mm spacing between elements in a row and 4 mm between consecutive rows, beginning approximately 36 mm downstream of the leading edge. Two embedded TPT variants are considered: a cutout solid TPT patch, in which the texture behaves as a purely geometric roughness, and a bleed-through TPT patch that incorporates an internal bleed network. Simulations are performed in ANSYS Fluent using steady RANS with the k-w SST turbulence model at freestream velocities U_inf = 10 and 20 m s−1, with an inlet turbulence intensity of 3% and turbulent length scale of 14.2 mm. Results show that the cutout solid TPT patch acts primarily as a roughness-like geometry: it generates separation and reattachment over each element, amplifies near-wall turbulent kinetic energy and Reynolds shear stress, and produces strongly modulated streaks of elevated skin-friction coefficient and streamwise wall shear over the patch. The bleed-through configuration preserves the geometric imprint of the texture but weakens separation and stagnation, reducing peak inner-layer turbulence levels and moderating the extremes of wall shear while allowing the boundary layer to recover to near-canonical profiles within one patch length downstream. At these Reynolds numbers, both TPT configurations behave as localized modifiers of the inner layer rather than global drag-reduction devices, but the bleed-through design demonstrates how carefully configured transpiration and pressure relief can mitigate roughness penalties and redistribute near-wall shear in a controlled manner.