Simulating Aircraft Icing

Icing on aircraft surfaces, appendages, and sensors, as well as the impact of icing on aircraft engines, are safety-critical aspects of aircraft design that impact the whole supply chain. Achieving regulatory certification is a complex and time-consuming process involving simulation models, icing tunnels and flight testing. Recent regulatory changes and industry focus around high altitude ice crystals and supercooled large droplets (SLD) have further challenged the design process and the time to market for new aircraft and technology.

Watch this montage of computational ice accretion on a full-size DLR-F6 wing/body/nacelle/pylon geometry

Aircraft can experience in-flight icing as they pass through clouds containing supercooled liquid droplets and ice crystals. These droplets range from just a few microns to supercooled large droplets (SLD) that are over 100 times larger. Both droplets and ice crystals impact exposed surfaces and freeze on impact, or run back as a liquid film and freeze. SLDs may be so heavy that they can strike well behind the protected areas of an aircraft. The accumulated ice can subsequently break off and impact other surfaces downstream of the initial accretion site.

Ice buildup airfoils

Icing can cause severe problems. On aerodynamic surfaces, icing can cause loss of lift, momentary imbalance and disruption of control surface operation. Aircraft engines can experience: air intake obstruction (surge, stall), break off and ingestion (flameout, ballistic damage), dew rime/glaze icing and ice crystal formation. Overall, the aircraft can suffer aerodynamic performance degradation and added weight, cost and maintenance of ice-protection systems.

ANSYS provides a unique combination of advanced computational fluid dynamics and icing simulation expertise in a common working environment. The solution is 3D, so it captures real-world behavior, provides the most efficient simulation workflow available and has an extensive database of industry validation. In addition, the simulation outputs are designed to comply with the FAA’s Appendices C, D and O.

ANSYS icing simulation enables companies and engineers to develop products faster, test designs earlier in the development cycle, reduce the number of physical prototypes and produce a better solution than would be possible using traditional design methods.

Fenscap ice surface

Spatially dependent ice roughness on the wing and nacelle

Anti-icing adaptation

Integrated ice protection system design

Simulating aircraft icing