Numerical aerodynamic simulations of a NACA airfoil using CFD with block-iterative coupling and turbulence modelling

TLDR

Numerical aerodynamic simulations of a stationary, pitching NACA airfoil at high Reynolds numbers are presented. The study employs a block‑iterative coupling CFD method with a two‑equation RANS turbulence model for fluid‑structure interaction, and extends simulations to assess aeroelastic effects at non‑zero angles of attack, higher vibration amplitudes, and large Reynolds numbers. The simulations accurately predict force coefficients and flutter derivatives, and demonstrate that the CFD method can effectively assess aerodynamic and aeroelastic performance under conditions beyond laboratory reach, suggesting its applicability to realistic 3D aircraft predictions. Keywords: numerical simulations, fluid‑structure interaction, block‑iterative coupling, flutter derivative identification, forced vibration amplitude; funding from the Foundation for the Author of National Excellent Doctoral Dissertation of PR China and the Natural Science Foundation of PR China.

Abstract

Abstract Numerical aerodynamic simulations are presented for a National Advisory Committee for Aeronautics (NACA) airfoil that is stationary and pitching at high Reynolds numbers. A new improved CFD method based on block-iterative coupling is used with a computational scheme for fluid-structure interaction, in which a form of two-equation RANS turbulence model is adopted. Firstly, basic simulations were performed using the proposed CFD method and turbulence model, which provides good prediction of the airfoil force coefficients and flutter derivatives compared with the well-known experimental measurement and analytical formulation. Then, extended airfoil flow simulations were carried out to examine the potentially significant effects on aeroelasticity from several influencing factors, including non-zero equilibrium angles of attack, increased forced vibration amplitudes and large Reynolds number. Both the basic and extended simulations reveal that using the proposed CFD method can provide effective assessment of aerodynamic and aeroelastic performance of airfoils even for operating conditions beyond those a laboratory test can approach, indicating the possibility of extending the methodology proposed for realistic aerodynamic and aeroelastic prediction of 3D full-scale aircraft structures. Keywords: numerical simulationsfluid-structure interactionblock-iterative couplingflutter derivative identificationforced vibration amplitude Acknowledgements The work was financially supported by a Foundation for the Author of National Excellent Doctoral Dissertation of PR China (Funding Code 2002030) and the Natural Science Foundation of PR China (Funding Codes: 10972048, 90815023 and 50608012). The authors are also grateful for support from the Cardiff Advanced Chinese Engineering Centre.