Mitigating the Impact of Icing through Active and Passive Technologies
AAC is active in the field of icing countermeasures in the form of passive coatings and active heating systems and electromechanical acuators, since 2008.
Although in-flight icing is considered to be a well-managed problem in commercial aviation, it remains a risk factor in the realm of smaller aircraft, drones and electric aircraft. Additionally, icing frequently has an impact to the customer experience, when delays due to holding pattern or ground de-icing measures occur.
AAC has been an active developer of anti-icing and de-icing coatings since its foundation in 2010. Two developmental lines are pursued: Passive and active coatings for de-icing and anti-icing. Combined these two methods can form a hybrid anti-icing system.
Active coatings are conductive paints used as electrothermal heating elements. The benefit of conductive paints is their flexibility regarding the underlying surface geometry, which means, that 3D surfaces can be coated and seamless transitions at the rim of the coating can be achieved. This is especially important to limit the impact on the aerodynamic properties of the aircraft.
Passive anti-icing coatings developed by AAC, can be used as stand-alone or as top-coat on the conductive paint. In this way, a hybrid, synergetic anti-icing system is realized. The passive top-coat reduces the energy demand of the electrothermal heater underneath.
AACs passive anti-icing coatings are based on very durable base systems that are formulated to exhibit a low ice adhesion. AAC has the in house capability to measure ice adhesion shear force and coating durability, which accelerates the development cycle.
AAC anti-icing coatings can also be applied in other fields, such as wind energy.
List of Anti-Icing Research Projects
AAC has been involved in R&D of anti-ice coatings since 2008 and has successfully participated in more than 8 national and European projects, involving wind park operators (WEB) and aircraft manufacturers (Diamond Aircraft, Airbus):
- 2008: Anti-Ice: “Anti-icing/De-icing Systems to improve Aircraft Performance and Safety. Combination of icephobic coatings with piezoelectric de-icing for aircraft.”
- 2011: IceGrid: “icing and de-icing of restraining grids in the air-conditioning system of passenger aircraft and mobile pre-conditioned air units (PCA-units) is investigated.”
- 2012: Rotorblattenteisung: “Increased productivity through management of ice build-up on rotor blades. Combination of icephobic coatings with electrothermal heating layers for wind energy applications”.
- 2013: IceDrip: “Aircraft anti-icing and de-icing through assemblies of conducting varnish and functional coatings. Combination of icephobic coatings with electrothermal heating layers for aircraft leading edge anti-icing and de-icing”.
- 2017: LubRes “Novel anti-ice surfaces based on lubricant reservoirs in polymer coatings. Development of novel eco-friendly erosion resistant icephobic coatings for aircraft“. In this project SLIPS surfaces were prepared and characterised.
- 2020: JOICE: “Joint Austrian In-flight Icing Research Venture 2020+”. In JOICE AAC is working on a combined anti-icing and de-icing system, utilizing AAC coatings, electrothermal heating and mechanical de-icing. In wind tunnel test, the increase in efficiency of the thermal and mechanical methods by the application of the coatings will be determined (onging). A laboratory test plant to measure the ice adhesion shear force was. Link to project website.
- 2020: IMPACT: “AIrcraft advanced rear end and eMpennage oPtimisAtion enhanced by anti-iCe coaTings and devices“. In work package 2 of IMPACT AAC conducts a TRL3 assessment of anti-icing coatings for aerospace applications. The expertise of AAC in coating characterisation is applied and deepened. This includes accelerated weathering, environmental simulations and surface characterisation. Link to project website.
- 2022: LABELO: “Laser Structured Anti-Icing Coatings for Aerospace Applications.” Novel femtosecond laser structured surfaces are further chemically treated to exhibit a long lasting and strong anti-icing effect.
AAC has a strong network of partners, which grants access to:
- Icing wind tunnel experiments
- Determination of accreted ice shapes
- Simulation of ice accretion
- Aviation specific rain and sand erosion tests
- Industrial production and up-scaling for anti-icing paints