Publications
This section features publications that include contributions from members of the SurfLabX team, highlighted with their names in bold.
Disclaimer: Please note that not all listed publications were developed as part of SurfLabX projects. Many reflect the past contributions of individual team members during their tenure with previous employers. This collection is intended to demonstrate the innovative capabilities and the commitment to scientific rigor of our team members. Our aim is to assure customers of the high level of expertise and meticulousness they can expect in their engagements with us. For detailed information on author affiliations and the projects, please access the official publication pages through the provided and hyperlinked DOI numbers.
Authors: Norbert KARPEN, Yasir A. MALIK, Elmar BONACCURSO, Ilia ROISMAN, Jeanette HUSSONG and Philippe VILLEDIEU
Year: 2023
Title: Experimental investigation of the accretion and shedding process on a heatable NACA0012 airfoil in ice crystal icing conditions
Type: Journal Publication
Publisher: Cold Regions Science and Technology
DOI: 10.1016/j.coldregions.2023.104030
Abstract: Ice crystal icing can lead to damage and flame-outs in the combustion chamber of an aircraft engine due to accretion and shedding of ice blocks. The present work aims at a better understanding of accretion and shedding phenomena by quantitatively analysing experimental investigations conducted at the icing wind tunnels of Airbus CRT and TU Braunschweig. Particular focus is laid on ice accretion and shedding resulting from ice crystal icing on heated substrates. Heatable NACA0012 airfoils were designed and tested in a broad range of parametric conditions. Generally, large ice accretions and large shed areas were observed on non-heated surfaces at positive wet bulb temperatures. On surfaces heated with a low heat flux the accreted area was larger, while with large heat fluxes mostly run-back of liquid water was observed. For the examined experimental conditions an ice accretion threshold existed beyond which there was continuous accretion or complete shedding. The experimental findings of this study not only consolidated previous studies in similar conditions, but also help identify new findings for heated surfaces at negative wet bulb temperatures and unheated surfaces with mixed-phase conditions at positive wet bulb temperatures. They form a large collection of new data on ice accretion and shedding and provide a comprehensive experimental database quantitatively analyzed for validating future physics based and numerical models.
Authors: Norbert KARPEN, Stefan DIEBALD, Fabien DEZITTER and Elmar BONACCURSO
Year: 2022
Title: Propeller-integrated airfoil heater system for small multirotor drones in icing environments: Anti-icing feasibility study
Type: Journal Publication
Publisher: Cold Regions Science and Technology
DOI: 10.1016/j.coldregions.2022.103616
Abstract: Atmospheric icing is one of the most common and hazardous environmental challenges for aircraft operations. So far, only large passenger aircraft, a few general aviation aircraft, and specialized rotorcraft are equipped with ice protection systems because of their additional energy consumption and weight. The emerging markets of small electric aircraft like Urban Air Mobility and Unmanned Aerial Vehicles for transportation, logistics, search and rescue, and other specialized operations will require efficient, lightweight and all-electric ice protection systems in order to allow operations in ice and snow conditions. In this work, an electrothermal ice protection system with an average heat power density of 1 W/m² was designed and developed for use on small multirotor drones. Commercially available propeller blades with diameters of 33 cm were retrofitted with lightweight multilayer heating foils independently powered by super-capacitors. The heated propellers were tested in close-to-real icing conditions in a small-scale icing wind tunnel. Thrust, rotational speed, and power consumption of a non-heated reference propeller and a heated propeller were compared. In glaze ice conditions at air temperatures > -5 °C the thrust of the non-heated propeller fluctuated between 60 % and 90 % with frequent cycles of ice accretion and shedding for the entire duration of the test. The heated propeller maintained a thrust of > 95% in the same icing conditions. In rime ice conditions at air temperatures < -8 °C the heating was not sufficient and the thrust of the non-heated and heated propellers similarly decreased over time. Heat flux calculations along the span of the propeller were made for different icing conditions and compared to the heat power density distribution of the tested ice protection system.
Authors: Norbert KARPEN, Elmar BONACCURSO, Ilia ROISMAN, Jeanette HUSSONG and Cameron TROPEA
Year: 2022
Title: Insights on Ice Particle Impacts Initializing the Ice Accretion Process during Ice Crystal Icing
Type: Conference Publication
Publisher: AIAA AVIATION 2022 Forum
Abstract: Ice crystal icing in jet engines influences the aerodynamic behavior of the stators heavily and may lead to damages to or even flame out of the engine. Efforts to study ice particle impacts, and ice layer accretion, erosion and shedding have recently increased to finally understand the true infliction and get simulations ready for deployment. The aim of this study is to discuss recent findings, outline the conditions in which ice layers start to form and how individual ice particle impacts contribute. Ice particle impact and early accretion experiments have been performed at the Airbus Central Research and Technology icing research facility and are qualitatively analyzed.
Authors: Jean-Mathieu SENONER, Pierre TRONTIN, Louis M. REITTER, Norbert KARPEN, Markus SCHREMB, Mario VARGAS and Philippe VILLEDIEU
Year: 2022
Title: Ice particle impact on solid walls: Size modeling of reemited fragments
Type: Journal Publication
Publisher: International Journal of Impact Engineering
DOI: 10.1016/j.ijimpeng.2022.104322
Abstract: The present work deals with ice particle fragmentation resulting from impact on a solid wall. First, a semi-empirical model to predict the size of the largest reemited fragment is presented. It is based on the energy-horizon theory of fragmentation developed by Grady (1988) in combination with a strain rate scaling based on the indentation radius formed upon impact. Model predictions are in good agreement with experimental data from six different sources. In addition, an empirical fit to the ice fragment volume distribution is sought. Different candidate fits, namely power law, Weibull and lognormal are proposed and evaluated both qualitatively and quantitatively. The fragment volume distributions appear to exhibit different trends for impact conditions representative of ice crystals and hailstones. For this reason, a less accurate yet more robust power law fit is proposed to model the available fragment volume distribution data.
Keywords: Ice crystal icing; Impact; Fragmentation; Energy-horizon theory; Maximum fragment diameter; Fragment volume distribution
Year: 2022 (Available until 3. Feb. 2025)
Title: Wie erzeugt ein Laser den Lotoseffekt? (How does a laser create the lotus effect?)
Type: Television Broadcast
Publisher: Servus TV / P.M. Wissen
Link: https://www.servustv.com/wissen/v/aa-273cg75ds2111/
Abstract: The surface structure of the lotus plant allows water and dirt to simply bead off. Technicians have replicated this effect for use in products such as car paints, facade paints, and eyeglass lenses. Recently, a scientist has succeeded in applying this lotus effect to various surfaces using laser technology. This innovation could make many aspects of our daily lives more efficient, including aviation.
Authors: Norbert KARPEN, Alexandre CUCO, Dominik KUENSTLER, Elmar BONACCURSO, Louis M. REITTER, Ilia V. ROISMAN and Cameron TROPEA
Year: 2021
Title: Characterizing Microscopic Ice Particle Impacts onto a Rigid Surface: Wind Tunnel Setup and Analysis
Type: Conference Publication
Publisher: AIAA AVIATION 2021 Forum
Abstract: Ice crystal impacts on aircraft components and their post-impact characteristics like fragment sizes and velocities are important factors influencing ice accretion on heated surfaces. Understanding the fundamental aspects of this process would allow to advance models and simulations of ice crystal icing phenomena on heated air probes or inside aircraft engines. In this study we present an experimental apparatus for icing wind tunnel tests that allows us to close some knowledge gaps about high-speed impacts of ice crystals in the range from tens of micrometers to 1.5 millimeters, which corresponds to the range encountered in natural ice crystal icing. A Python algorithm was developed to semi-automatically analyze large numbers of impact videos and thus improve the statistical significance of the results. The limitations of the setup and the consistency of the results will be discussed.
Authors: Clementine BELAUD, Vittorio VERCILLO, Max KOLB and Elmar BONACCURSO
Year: 2021
Title: Development of nanostructured icephobic aluminium oxide surfaces for aeronautic applications
Type: Journal Publication
Publisher: Surface and Coatings Technology
DOI: 10.1016/j.surfcoat.2020.126652
Abstract: In-flight icing due to the impingement of supercooled water droplets modifies the shape of the aerodynamic surfaces of aircraft, resulting in lower stall speeds and higher fuel consumption. Icephobic coatings help reducing the adhesion strength of ice to a surface and represent a promising technology to support mechanical/thermal ice protection systems. Superhydrophobic surfaces are water-repellent and embody a straightforward solution to tackle icing: nanostructured porous aluminium oxide layers are generated with anodization and superhydrophobicity can be reached by tuning the pores size. However, not much research has been done to verify if such surfaces are generally icephobic in representative icing conditions, or if they need to have additional properties to effectively reduce ice adhesion. In this work, we investigate the ice adhesion strength on cladded Aluminium Alloy 2024 (AA2024), an alloy commonly used for aerospace components, anodized with different process parameters in sulphuric and oxalic acid and hydrophobized by a commercial fluorinated product. Upon the optimization of the two anodization processes, the micro-/nanostructures generated on the surface were effective in reducing the ice adhesion strength. From icing wind tunnel tests, the surfaces anodized in oxalic acid showed superior icephobic (i.e., lower ice adhesion) properties compared to the ones anodized in sulphuric acid because of their larger air-to-solid surface ratio. The proposed anodization process is fast, easy to perform and to implement in existing production lines, low-cost, and operator- and environmentally-friendly.
Authors: Stephan MILLES, Vittorio VERCILLO, Sabri ALAMRI, Alfredo AGUILAR, Tim KUNZE, Elmar BONACCURSO and Andrés LASAGNI
Year: 2021
Title: Icephobic Performance of Multi-Scale Laser-Textured Aluminum Surfaces for Aeronautic Applications
Type: Journal Publication
Publisher: Nanomaterials
Abstract: Ice-building up on the leading edge of wings and other surfaces exposed to icing atmospheric conditions can negatively influence the aerodynamic performances of aircrafts. In the past, research activities focused on understanding icing phenomena and finding effective countermeasures. Efforts have been dedicated to creating coatings capable of reducing the adhesion strength of ice to a surface. Nevertheless, coatings still lack functional stability, and their application can be harmful to health and the environment. Pulsed laser surface treatments have been proven as a viable technology to induce icephobicity on metallic surfaces. However, a study aimed to find the most effective microstructures for reducing ice adhesion still needs to be carried out. This study investigates the variation of the ice adhesion strength of micro-textured aluminum surfaces treated using laser-based methods. The icephobic performance is tested in an icing wind tunnel, simulating realistic icing conditions. Finally, it is shown that optimum surface textures lead to a reduction of the ice adhesion strength from originally 57 kPa down to 6 kPa, corresponding to a relative reduction of ~90%. Consequently, these new insights will be of great importance in the development of functionalized surfaces, permitting an innovative approach to prevent the icing of aluminum components.
Authors: Matthias LINDNER, Andrei V. PIPA, Norbert KARPEN, Rüdiger HINK, Dominik BERNDT, Rüdiger FOEST, Elmar BONACCURSO, Robert WEICHWALD, Alois FRIEDBERGER, Ralf CASPARI, Ronny BRANDENBURG and Rupert SCHREINER
Year: 2021
Title: Icing Mitigation by MEMS-Fabricated Surface Dielectric Barrier Discharge
Type: Journal Publication
Publisher: Applied Sciences
Abstract: Avoiding ice accumulation on aerodynamic components is of enormous importance to flight safety. Novel approaches utilizing surface dielectric barrier discharges (SDBDs) are expected to be more efficient and effective than conventional solutions for preventing ice accretion on aerodynamic components. In this work, the realization of SDBDs based on thin-film substrates by means of micro-electro-mechanical-systems (MEMS) technology is presented. The anti-icing performance of the MEMS SDBDs is presented and compared to SDBDs manufactured by printed circuit board (PCB) technology. It was observed that the 35 µm thick electrodes of the PCB SDBDs favor surface icing with an initial accumulation of supercooled water droplets at the electrode impact edges. This effect was not observed for 0.3 µm thick MEMS-fabricated electrodes indicating a clear advantage for MEMS-technology SDBDs for anti-icing applications. Titanium was identified as the most suitable material for MEMS electrodes. In addition, an optimization of the MEMS-SDBDs with respect to the dielectric materials as well as SDBD design is discussed.
Author: Christian HERRLES
Year: 2020
Title: Erforschung und Erprobung der Einsatzfähigkeit von Füllmassen für die Erzeugung eines laminaren Fügeübergangs am Beispiel Flügelvorderkante/Flügelkasten (Investigation and testing of the usability of sealant materials to enable a laminar joint gap between the leading edge of a wing and the wing box)
Type: Doctoral Thesis
Publisher: Clausthal-Zellerfeld: Clausthal University of Technology.
Abstract: Future aircraft will be more fuel efficient thanks to an optimised laminar flow control on their outer skin. Concepts for connecting a laminar leading edge to a laminar wing box foresee a joint gap with a complex cross-section, which is filled with a suitable filler material and show an aerodynamically smooth surface in cruising altitude at -55 °C. Nowadays, joint gaps are exclusively filled manually. Due to rapidly increasing production rates of aircraft and very high requirements on the surface quality of laminar wing surfaces of future aircraft models, these manual processes must be automated. In order to enable a very smooth automated filler application process for joint gaps, the systematic correlation between the material properties of aerospace qualified fillers (polysulfide and polythioether based) and the application process are elaborated in the first part of this thesis. The material properties of these two component fillers (viscosity and curing caused shrinkage) were investigated with regard to the application temperature as well as the time between filler mixing and filler application. Subsequently, the in service properties of applied filler materials were tested with a focus on thermal and hygroscopic caused contraction and expansion respectively swelling and adhesion on different surfaces (aluminium, steel, titanium, primer and top coat) at room temperature and -55 °C. The second part of this thesis deals with the application of the appropriate amount of the highly viscous filler material along the joint. This application process is realised with nozzles whose orifice is adapted to the cross section of the joint gap. The nozzles are mounted to a press-out unit which is attached to a high-precision robot and are moved with a defined distance along the joint gap. A systematic investigation of the relevant parameters (joint gap geometry, time between filler mixing and filler application, pressing speed, nozzle speed, effect of gravity, distance between nozzle and joint gap) was carried out on straight gap samples with a semi-automated filler application process (manual programming of the trajectory). In order to fill joint gaps fully automatically, a self-referencing system has been developed, which is able to capture the three-dimensional trajectory respectively the crosssection of the joint gap with an optical measurement device. By using this data the robot and the press-out unit can be controlled. With this method, the robot is directly referenced to the assembly part (joint gap), independent of its position in space. The fully automated filler application process was tested on horizontally positioned and on tilted straight gap samples as well as on a two meter long joint gap between a CFRP landing flap part and four aluminium sheets.
Authors: Christian HERRLES, Elmar BONACCURSO and Christian WEIMER
Year: 2020
Title: Abschlussbericht für das Verbundprojekt LuFo V-2 OptiHyL “Optimierte Hybrid Laminarität am Seitenleitwerk – Optimides Hybrid Lamnarity on VTP”: Berichtszeitraum: 01.01.2016 bis 30.09.2019 (Final report for the joint project LuFo V-2 OptiHyL: Optimized Hybrid Laminarity on the Vertical Tail Plane: Reporting period: 01.01.2016 bis 30.09.2019)
Type: Report
Publisher: Airbus Defence & Space GmbH, Taufkirchen
Abstract: In the frame of the national funded LuFo V-2 project OptiHyL, Airbus Materials X has characterised in a laboratory scale the requirements and the handling of an HLFC-Technology (Hybrid Laminar Flow Control) in the application field of a VTP (Vertical Tail Plane) with respect to operational conditions like icing, contamination, rain and moisture. In the main work package 3 (HAP 3), which was coordinated by Airbus Materials X, the behaviour of filler materials in the joint gap between VTP-box and suction nose as well as the understanding of the clogging mechanisms of the micro-perforation caused by insects, water, ice and erosion was investigated.
In work package 3100 (AP-3100), new methods for filling complex shaped joint gaps with sealants and cover strips were developed and evaluated. On the one hand, the effect of a chemical and thermal sealant shrinkage and it’s interaction with the cover strip was investigated. On the other hand, the influence of higher temperatures (T > 60 °C) regarding sealant expansion and cover strip deformation was characterised. For simplifying the removal of cover strips on top of sealants, a heating foil based method was developed.
The analysis of moisture or water absorption by the micro-perforations as well as an icing wind tunnel campaign was carried out in work package 3200 (AP-3200). It was shown, that a surface modification (surface structuring by anodisation or by laser treatment and a subsequent surface functionalisation with a hydrophobic coating system) reduces the water permeability significantly. To enable the testing of micro-perforated samples in the iCORE (Icing and Contamination Research Facility) wind tunnel at Airbus Materials X, a new test setup with a NACA-like micro-perforated airfoil was designed and developed.
In work package 3300 (AP-3300), the contamination and cleaning of micro-perforations as well as the degradation of surface modified titanium grade 2 (material used for VTP suction nose) was investigated. For structuring the surface, galvanic processes were applied (TiO2 nanotubes and N4 process). The results of the tests show a clear correlation between the degree of contamination, pore clogging and pressure variation in the vacuum chamber. Furthermore, it could be demonstrated that applying suction through the micro-perforations from the inner side and simultaneously sprinkling water (deionised water at room temperature) from the outer side is suitable for removing insect residues from the micro-perforated surface. To test the degradation of the surface modified grad 2 titanium samples, sand and rain erosion tests were performed and evaluated with contact angle, roll off angle, roughness and optical microscope measurements.
Authors: M. LINDNER, D. BERNDT, K. TSCHURTSCHENTHALER, I. EHRLICH, B. JUNGBAUER, R. SCHREINER, A. V. PIPA, R. HINK, R. FOEST, R. BRANDENBURG, D. NEUWIRTH, N. KARPEN, E. BONACCURSO, R. WEICHWALD, A. MAX and R. CASPARI
Year: 2020
Title: Aircraft icing mitigation by DBD-based micro plasma actuators
Type: Conference Publication
Publisher: AIAA AVIATION 2020 Forum
Abstract: We present the application of plasma actuators as a technology for ice prevention at airfoils. The miniaturized dielectric barrier discharge (DBD) plasma actuators (PA) were fabricated by means of microelectromechanical systems (MEMS). We elucidate how to make the actuator samples scalable and applicable to any desired shape by the use of flexible inorganic zirconia substrates. For this purpose, we applied our developed embedding method to integrate the micro actuators in modern carbon/glass fiber reinforced polymer (CFRP/GFRP) materials. Next, the embedded actuator samples were mounted on a mechanical air profile-like fixture and placed in the icing wind tunnel iCORE. The samples were tested in rime ice conditions at temperatures of -15 to -20° C and air speeds up to 30 m/s. Unlike other groups we used a thin film zirconia substrate as dielectric for the plasma actuator. Due to the low substrate thickness of just 150 µm, an operating voltage of 2 kVRMS is already sufficient enough for a stable plasma formation. The experiments show that the operated actuator was able to prevent the ice formation and first indications of a De-icing function were also found. Hence, we show that it is feasible to realize an anti-icing system with zirconia-based plasma actuators operated at lower voltages compared to conventional ones.
Authors: Alexandre LAROCHE, Linda RITZEN, Javier MAYÉN GUILLÉN, Vittorio VERCILLO, Maria D’ACUNZI, Azadeh AGHILI, Jeanette HUSSONG, Doris VOLLMER and Elmar BONACCURSO
Year: 2020
Title: Durability of Superamphiphobic Polyester Fabrics in Simulated Aerodynamic Icing Conditions
Type: Journal Publication
Publisher: Coatings
Abstract: Fabrics treated to repel water, superhydrophobic, and water and oil, superamphiphobic, have numerous industrial and consumer-level benefits. However, the liquid repellency decreases in the course of time. This is largely due to chemical or physical changes of the coating due to prolonged exposure to relatively harsh environments. To develop more durable fabric treatments for specific applications, it is necessary to measure the extent to which the treated fabrics retain their low-wettability after being subjected to controlled aggressive environmental conditions. In this study, plain weave fabrics made from polyester filaments and coated with silicone nanofilaments in-solution were exposed to aerodynamic icing conditions. The coated fabrics showed superhydrophobic behavior, or superamphiphobic for those that were fluorinated. The wettability of the fabrics was progressively evaluated by contact angle and roll-off-angle measurements. The coated fabrics were able to maintain their low-wettability characteristics after exposure to water droplet clouds at airspeeds up to 120 m/s, despite damage to the silicone nanofilaments, visible through scanning electron microscopy.
Authors: Sabri ALAMRI, Vittorio VERCILLO, Alfredo AGUILAR, Frederic SCHELL, Marc WETTERWALD, Andrés MARC LASAGNI, Elmar BONACCURSO and Tim KUNZE
Year: 2020
Title: Self-Limited Ice Formation and Efficient De-Icing on Superhydrophobic Micro-Structured Airfoils through Direct Laser Interference Patterning
Type: Journal Publication
Publisher: Advanced Materials Interfaces
Abstract: Forward facing aerodynamic surfaces such as rotors and wings are susceptible to ice build‐up when exposed to atmospheric icing conditions. If not removed, accumulated ice on aircraft surfaces affects aerodynamics or rotation balance, which can ultimately lead to increased fuel consumption, reduced operational performance and to potentially hazardous situations. Laser surface structuring is proposed as an alternative technology to coatings for achieving icephobic properties and support anti‐icing and de‐icing processes on aerodynamic surfaces. However, to authors’ knowledge, no study available in the literature reports on the icing behavior of microtextured curved aerodynamic profiles and the effect of the laser surface treatment on the electrothermal heating used for ice protection systems. In this work, direct laser interference patterning is employed to fabricate hierarchical micro‐ and nanostructures directly on a non‐planar titanium airfoil. The anti‐icing performance of the laser‐treated airfoil is tested in an icing wind tunnel under simulated atmospheric conditions. The results demonstrate a self‐limiting ice growth, a decrease in the deicing electro‐thermal power up to 80%, and up 60% lower heating power necessary to keep the surface free of ice than on the reference airfoil.
Author: Vittorio VERCILLO
Year: 2020
Title: Durable Laser Patterned Metal Surfaces with Enhanced Icephobic Properties for Aerospace Applications
Type: Doctoral Thesis
Publisher: Technical University Dresden
DOI: 10.13140/RG.2.2.21398.47688
Abstract:
Ice accreting on external aircraft surfaces due to the impact of supercooled water droplets can negatively affect the aerodynamic performance and reduce the operational capability. Therefore, it must be prevented. Icephobic surfaces capable of reducing the adhesion strength of ice to a surface and to reduce or delay the ice accretion represent a promising technology to support thermal or mechanical ice protection systems. Icephobicity is similar to hydrophobicity in several aspects, and therefore superhydrophobic surfaces embody a straightforward solution to the icing problem. Short/ultra-short pulsed laser treatments have been proposed as a viable technology to generate superhydrophobic properties on metallic surfaces. However, it has not yet been verified if such surfaces are generally icephobic in representative icing conditions encountered by aircraft, or if they need to have additional properties to effectively tackle icing. In this work, the icephobic properties of laser-treated surfaces of alloys commonly used for aerospace components are investigated.
Aluminium Alloy AA2024 and Titanium alloy Ti6Al4V surfaces were textured with Direct Laser Writing (DLW), Direct Laser Interference Patterning (DLIP) and Laser-Induced Periodic Surface Structures (LIPSS), using pulse durations from the femtosecond to the nanosecond regime. It was found that tuning the spatial periodicity and the depth of the laser-generated structures, the ice adhesion strength under different icing conditions could be reduced. The most icephobic surface treatment was applied on a NACA0012 airfoil equipped with a novel Hybrid Ice Protection System (HIPS).The combination of a laser-treated icephobic/superhydrophobic surface with an electro-thermal ice protection system reduced the heating power required to keep the surface free of ice or to remove the ice formed on the surface with respect to the untreated reference surface. In the de-icing configuration, self-shedding of critical masses of accreted ice was observed, too, proving that such engineered surfaces can also provide passive ice protection. The durability of laser-treated surfaces was assessed over an extended time in operational environment in a flight test campaign: a laser-structured superhydrophobic/icephobic Ti6Al4V metal sheet was installed on the slat of an A350 test aircraft to assess its rain/sand erosion and its UV exposure resistance.
The icing of air intake protection grids of engines used on rotorcraft and turboprop engines was investigated as well. New experimental and analytical tools were developed to enable a quantitative study of grid icing under representative icing conditions in a lab-scale icing wind tunnel adopting a Design-of-Experiments approach. Analysis of the experimental data allowed developing and validating a general physical model for ice accretion on grid structures.
Authors: Vittorio VERCILLO, Norbert KARPEN, Alexandre LAROCHE, Javier Alejandro MAYÉN GUILLÉN, Simone TONNICCHIA, Raphael DE ANDRADE JORGE and Elmar BONACCURSO
Year: 2019
Title: Analysis and modelling of icing of air intake protection grids of aircraft engines
Type: Journal Publication
Publisher: Cold Regions Science and Technology
DOI: 10.1016/j.coldregions.2019.01.012
Abstract: Icing represents a major problem in the aviation industry. While icing of aerodynamic surfaces such as airfoils due to the impingement of supercooled liquid water droplets is widely studied, even if not yet fully understood, icing of supporting structures like protection grids of engine air intakes has been investigated to a lesser extent. An optimization of the design of the grids will help to reduce icing severity and delaying or avoiding loss of efficiency that could lead to hazardous situations.
The present study investigates the icing behaviour of stainless steel protection grids in use on rotorcraft and turboprop engines. New experimental and analytical tools were developed to enable a quantitative study of grid icing under representative icing conditions in a lab-scale icing wind tunnel. The variation of the most relevant parameters like liquid water content of the cloud, airspeed, ambient temperature and mesh size of the grid allowed the identification of their influence on the icing behaviour. Further analysis of the experimental data led to the development and validation of a general physical model for ice accretion on grid structures.
Year: 2018
Title: An alternative to chemically de-icing planes
Type: Television Broadcast and Online Article
Publisher: Euronews / Next
Abstract: The environmental impact of propylene glycol, commonly used in aircraft de-icing, has spurred research into alternative methods. A promising approach involves superhydrophobic coatings, inspired by the natural “lotus effect,” which prevent ice formation by making surfaces extraordinarily water-repellent. Researchers, including a team from the Technology Partners Foundation in Warsaw and Airbus Central R&T in Germany, are exploring various nanoparticle-based coatings. These coatings not only repel water but also resist atmospheric agents like sand, rain, and ultraviolet rays, critical for aircraft operation in diverse conditions. Current challenges include the durability and economic viability of these coatings, as frequent reapplications are not feasible. Continued research aims to refine these icephobic surfaces, potentially replacing traditional chemical and heat-based de-icing methods, thereby reducing environmental harm and improving fuel efficiency.