Surface Roughness Effects on Unsteady Transition Property over a Pitching Airfoil

Relaminarization of jet impingement on a flat plate using separation-induced transition correction turbulence modeling preliminarily applied in archeological applications

“…The reformulation of the sustaining turbulence technique was fundamentally purposed by Krumbein et al [ 16 ] and applied in the NASA common research model for natural laminar flow configuration. Then, Li et al [ 17 ] studied the transition flow on an airfoil as influenced by surface roughness. They concluded that the frequency, transition, and transition location were affected by the roughness.…”

A CFD Analysis of Oscillating Airfoil with Leading Edge Roughness: Comparing Correlations for Equivalent Sand Grain Roughness

“…In an effort to understand roughness-fluid interaction for pitching airfoils, various studies have been performed. Recently, Nandi et al [6] and Yi et al [7] applied the surface roughness effects in a dynamic pitching airfoil, S809 and NACA0012, respectively, where Nandi et al used Langtry-menter's 𝛾 − 𝑅𝑒𝜃 equation model [8] to simulate the laminar-turbulent transition, and Yi et al added the roughness amplification parameter (𝐴𝑟) transport equation to 𝛾 − 𝑅𝑒𝜃 model. They have shown that the transition location moves upstream with LER influence.…”

“…Therefore, it is necessary to verify the prediction of dynamic stall characteristics when applying the ESGR created for the static case to the dynamic case. Studies have shown that arbitrary LER affects dynamic stall characteristics when used in a pitching airfoil simulation [6,7]. But still, verification and validation for realistic roughness have yet to be presented.…”