The effect of the simulated ice accretion on the dynamic distortion of a diffusing S-duct inlet is numerically investigated. The LES turbulence model is used to simulate the unsteady flow separation and vortex shedding from the duct curvatures and ice accretion. The numerical methods for unsteady-flow solutions are validated with the wind-tunnel test data for dynamic inlet distortion. The results show that the protruding glaze ice horns create the strong vortex shedding structures that produce additional flow unsteadiness at the inlet engine face. In particular, the symmetrical glaze ice that uniformly covers the entire inlet lip increases the total pressure loss and fluctuation level more than the asymmetrical glaze ice with a less blockage to inlet flow. Furthermore, the symmetrical glaze iced inlet induces 17 times more severe instantaneous peak distortion than clean inlet at the free stream Mach number of 0.34.
International Journal of Aeronautical & Space Sciences – Springer Journals
Published: Jun 5, 2018