Lightweight Dual-Mode CNT-Aerogel Nanocomposite Stack for Anti- / De-Icing of Sub-20 kg UAVs

Abstract

Ice accretion on unmanned aerial vehicle (UAV) airframes and propulsion surfaces poses a critical operational hazard under low-altitude icing conditions. Even sub-millimetre leading-edge ice accumulation measurably degrades lift, increases drag, and can rapidly decrease aerodynamic stability and control authority [1]. Existing ice protection approaches developed for manned aviation (pneumatic boots, hot-air bleed systems, and conventional open-loop resistive heaters) are incompatible with the strict power budgets, limited thermal mass, and sub-25 kg weight envelopes characteristic of small UAV platforms [2]. A fundamental inefficiency shared by all conventional approaches is symmetric heat delivery: energy is distributed throughout the structure when only the upper ice-interface requires thermal input.

This work presents a six-layer nanocarbon electrothermal composite stack designed for UAV integration, built around the principle of directional heat confinement. The stack consists of, from outer surface inward:

a micro-textured fluoropolymer icephobic coating (100 μm),

a pyrolytic graphite sheet thermal spreading interlayer (20 μm),

a patterned carbon nanotube (CNT) Joule heating element (50 μm) [3],

a silica-fibre-reinforced aerogel insulation core (1250 μm) [4],

a polished aluminium infrared-reflective backing (30 μm),

and a PC-PET structural enclosure hosting an embedded PID sensor layer.

Each layer serves a distinct thermal or structural function co-designed to bias generated heat toward the ice interface rather than the substrate.

The stack's thermal performance is characterised through a three-tier analytical framework: a one-dimensional steady-state resistance network, a transient thermal model with distributed thermal mass, and a two-dimensional finite-volume simulation incorporating the pyrolytic graphite sheet (PGS) interlayer's anisotropic thermal conductivity tensor and an enthalpy-based treatment of latent heat. The directional confinement ratio, defined as the ratio of downward-to-upward thermal resistance, is Φ≈194 under clear-surface conditions at the −30∘C, 5 m/s design point, quantifying the designed thermal asymmetry between the ice-facing and substrate paths. The system operates in two modes. In anti-icing mode, a continuous heat flux of approximately 1.76 kW/m2 is estimated to maintain the surface against combined convective, radiative, substrate, and incoming-water thermal loads at the design point. In de-icing mode, a heater flux of 20–30 kW/m2 produces an estimated net thermal input of approximately 18.7–28.7 kW/m2 after external and substrate losses. The 2D transient ice model predicts complete melting of a 1 mm ice layer in approximately 18–28 seconds under the modeled conditions; actual ice shedding may occur earlier because complete layer melting is not required for release. An embedded PID controller using the PC-PET sensor layer is proposed for closed-loop temperature regulation and adaptive heater duty-cycle control, with the potential to reduce energy consumption relative to open-loop fixed-power operation.

The proposed architecture addresses a gap in the literature: To the authors’ knowledge, few prior systems integrate active Joule heating, directional aerogel thermal confinement, icephobic surface treatment, infrared reflection, and closed-loop embedded sensing within a single consolidated composite structure.

Acknowledgment:

The author gratefully acknowledges the open-source scientific community, including freely accessible academic literature, open-source computational tools (Python, NumPy, SciPy), and publicly available educational resources, without which this work would not have been possible.

ORCID:

Uğur Zaimoğlu: 0009-0004-4369-0125

References:

[1] R. Hann, A. Wenz, K. Gryte, and T. A. Johansen, "Impact of atmospheric icing on UAV aerodynamic performance," in Proc. 2017 Workshop on Research, Education and Development of Unmanned Aerial Systems (RED-UAS), Linköping, Sweden, Oct. 2017, pp. 66–71.

[2] N. C. Müller, B. Løw-Hansen, K. T. Borup, and R. Hann, "UAV icing: Development of an ice protection system for the propeller of a small UAV," Cold Regions Science and Technology, vol. 213, p. 103938, 2023.

[3] X. Yao, S. C. Hawkins, and B. G. Falzon, "A repairable carbon nanotube web-based electro-thermal heater and damage sensor for aerospace applications," The Aeronautical Journal, vol. 125, no. 1292, pp. 1833–1843, 2021.

[4] H. Li, W. Xu, L. Zhu, F. Xiao, Z. Yu, B. Hao, W. Huang, and K. Zhao, "Study on Thermal Insulation Performance of Silica Aerogel Thermal Insulation Blankets," Gels, vol. 10, no. 11, p. 707, 2024.

Publication Information

With future plans of Arxiv and major journals, the research's abstract is currently published in Nanotr'20 book of abstracts.

Available: https://nanotr.org/