Computational study of airfoil stall flutter Limit Cycle Oscillations

TL;DR

This study uses advanced numerical simulations to analyze stall flutter limit cycle oscillations of a NACA0012 airfoil, accurately predicting dynamic behaviors across different flow regimes and validating against experimental data.

Contribution

It provides the first comprehensive numerical prediction of large amplitude oscillations across the full experimental velocity range, filling a significant research gap.

Findings

Simulations qualitatively match experimental stall mechanics.

Predictions overestimate critical velocity, underestimate oscillation amplitudes.

Rigorous computational criteria are necessary for accurate aeroelastic modeling.

Abstract

This paper presents a comprehensive numerical investigation of a NACA0012 undergoing Stall Flutter Limit Cycle Oscillations (LCO) across distinct fluid dynamics regimes. It accurately models Small Amplitude Oscillations (SAO) in the transitional Reynolds regime and Large Amplitude Oscillations (LAO) in the moderate regime, observed in different experimental campaigns. The SAO analysis serves as a verification of the computational framework against established numerical benchmarks. Crucially, the LAO simulations represent the first documented prediction across the full experimental velocity range correlated against available measured data, addressing a significant literature gap. The predictions fidelity relies on rigorous computational criteria defined through a detailed sensitivity analysis. This demonstrated numerical requirements significantly more demanding than those typically employed for computing static polars or simulating dynamic pitching motion of rigid airfoils, underscoring the severity of the aeroelastic problem. Quantitatively the simulation systematically over-predicts the critical onset velocity and under-predicts the LCO amplitudes.However, the results show strong qualitative agreement with experimental observations, successfully reproducing key dynamic stall mechanics and bifurcation phenomena.