Ice accretion is significantly detrimental to a range of different industries worldwide. Current methods for reducing ice adhesion include the use of lubricants, hydrophobic coatings, or soft elastomers, all of which exhibit limited durability. As an alternative, here sparsely confined metallic sheets are suspended and the surface buckling instability is tailored, resulting in ice adhesion strengths on par with these prior strategies but without the use of any coatings. These Buckling Elastomer‐like Anti‐icing Metallic Surfaces, or BEAMS, exhibit ultra‐low ice adhesion (<1 kPa) and the mechanical resilience of metals. Results from an icing wind tunnel confirmed the efficacy of BEAMS toward impact ice accreted in realistic conditions via the high‐speed impingement of ≈20 µm droplets at −20 °C. The BEAMS sheet confinement, boundary conditions, and physical dimensions of both the ice and the metallic plates can be altered to minimize ice adhesion via the mechanics of plate buckling. Additionally, BEAMS that detach ice without directly contacting it are designed, the scalability of BEAMS is demonstrated, and their durability is verified using rain erosion, sandblasting, thermal extremes, and repeated icing/de‐icing, both in an icing wind tunnel and on a benchtop system.

The Federal Aviation Administration has worked with Transport Canada and others to develop allowance times for aircraft operating in ice-pellet precipitation based upon wind-tunnel experiments with a thin high-performance wing. These allowance times are applicable to many different airplanes. Therefore, the aim of this work is to characterize the aerodynamic behavior of the wing section in order to better understand the adverse aerodynamic effects of anti-icing fluids and ice-pellet contamination. Aerodynamic performance tests, boundary-layer surveys, and flow visualization were conducted at a Reynolds number of approximately 6.0 × 10 6 and a Mach number of 0.12. Roughness and leading-edge flow disturbances were employed to simulate the aerodynamic impact of the anti-icing fluids and contamination. In the linear portion of the lift curve, the primary aerodynamic effect is the thickening of the downstream boundary layer due to the accumulation of fluid and contamination. This causes a reduction in lift coefficient and an increase in pitching moment (nose up) due to an effective decambering of the wing. The stalling characteristics of the wing with fluid and contamination appear to be driven at least partially by the effects of a secondary wave of fluid that forms near the leading edge as the wing is rotated in the simulated takeoff profile. These results have provided a much more complete understanding of the adverse aerodynamic effects of anti-icing fluids and ice-pellet contamination on this wing.

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A scaled landing gear has recently been tested in the NRC 0.9 m 3/4-open jet wind tunnel. It provided experimental data that were used to investigate the capability and methodology of a CFD flow solver to predict adequately the noise generated on the landing gear surfaces and in its wake. Near-field and far-field noise predictions using CFD were carried out. FFTs of the landing gear surfaces for a given frequency were also carried out. Comparison of the results demonstrates that CFD can predict adequately the noise around complex geometries such as landing gears. Nomenclature C p = pressure coefficient dB = decibels f = frequency FFT = fast Fourier transform Hz = hertz k = turbulent kinetic energy SPL = sound pressure level u ' = local perturbation velocity X,Y,Z = axis coordinates in wind tunnel y + = law-of-the-wall coordinate ∆ = cell dimension ε = turbulent dissipation rate