Time-Dependent Effects of Glaze Ice on the Aerodynamic Characteristics of an Airfoil

الملخص EN

The main objective of this study is to estimate the dynamic loads acting over a glaze-iced airfoil.

This work studies the performance of unsteady Reynolds-averaged Navier-Stokes (URANS) simulations in predicting the oscillations over an iced airfoil.

The structure and size of time-averaged vortices are compared to measurements.

Furthermore, the accuracy of a two-equation eddy viscosity turbulence model, the shear stress transport (SST) model, is investigated in the case of the dynamic load analysis over a glaze-iced airfoil.

The computational fluid dynamic analysis was conducted to investigate the effect of critical ice accretions on a 0.610 m chord NACA 0011 airfoil.

Leading edge glaze ice accretion was simulated with flat plates (spoiler-ice) extending along the span of the blade.

Aerodynamic performance coefficients and pressure profiles were calculated and validated for the Reynolds number of 1.83 × 106.

Furthermore, turbulent separation bubbles were studied.

The numerical results confirm both time-dependent phenomena observed in previous similar measurements: (1) low-frequency mode, with a Strouhal number Sth≈0,013–0.02, and (2) higher frequency mode with a Strouhal number StL≈0,059–0.69.

The higher frequency motion has the same characteristics as the shedding mode and the lower frequency motion has the flapping mode characteristics.