Dynamic and static wettability of advanced materials used in aeronautical applications

Abstract

The search for icephobic external surface materials in aircraft icing applications has been ongoing since the early days of aviation. Given the recognized superlative properties of carbon nanotubes (CNTs) across many different disciplines, the implementation of CNTs in polymer matrix composites has sparked a great interest in their mechanical/electrical properties and wetting character, in addition to their suitability for aircraft icing applications. Within this framework, a new developed methodology capable of determining the nature of wettability, consequent to CNT implementation is desired. Thus, this article presents a novel methodology -henceforth referred to as the dynamic and static wettability scheme for advanced materials -which examines the wettability of materials reinforced with CNTs, for potential utilization within the aerospace industry. The described methodology herein can be employed in order to numerically examine empirically acquired results with an extended possibility to include alternative materials outside the scope of the considered ones. Results are shown for a decision matrix that discriminates between hydrophobic and hydrophilic surfaces based on their static and dynamic wettability properties. Moreover, idealized wetting character representations of the different considered aerospace materials are presented. Keywords: aerospace materials, aircraft icing, carbon nanotube wettability, corona splashing measurement tool, dynamic and static wettability scheme for advanced materials, fl uid structures, hydrophilicity, hydrophobicity, liquid water concentration. INTRODUCTIONThe usage of polymeric matrix composites has become more frequent in a number of different industries including electronics, the automotive and the aerospace industry [1]. The aerospace sector in particular has embraced the usage of polymeric matrix composites in civil and military aircraft, often with weight consideration in mind. Due to the superior mechanical and physical properties that have been observed in carbon nanotubes (CNTs), a natural consideration is whether CNTs can be utilized as reinforcing agents to further enhance the mechanical and physical properties of polymeric matrix composites. For this reason, researchers have conducted various research efforts in order to examine the infl uence of CNTs on the mechanical properties of the aforementioned materials [2,24]. A factor of great importance in aerospace applications due to high speed fl ight of, for instance, Earth entry vehicles and aircraft, is erosion [3]. In particular, Gohardani et al. [4], examined the erosion resilience, mechanical properties and acoustic impedance of a selection of polymer matrix composites reinforced with CNTs at 0.5% wt. for potential use in aeronautics. In this study, some disparities were observed between the different properties of the materials, but nominally similar erosion resilience values for the considered materials were encountered despite the presence of CNTs. The reasoning behind this observation was attribu...

The Exploration of Icephobic Materials and Their Future Prospects in Aircraft Icing Applications

“…In particular one recent study conducted by Gohardani et al [5], has considered rain erosion characteristics of a set of polymer matrix composites reinforced with carbon nanotubes, as external surface materials on aircraft, depicted in figure 2. As an extension to this study, Gohardani examined the ice adhesion characteristics of these materials in aircraft icing applications [2] and further explored their wettability properties [6,7]. enables a chemically functionalized solution which has an affinity to the infiltrated liquid and arrests its movement.…”