Ice Mitigation Research Articles

Innovative ice mitigation: Exploring the potential of choline-based deep eutectic solvents and ionic liquids synergies

The development of anti-icing coatings for extremely low temperatures is still emerging. Deep eutectic solvents (DESs), as subset of ionic liquid (IL) analogues, have recently gained increasing attention for their unique and versatile applications. Given no investigation regarding anti-icing capabilities of DESs, our study focused on the exciting potential of choline-based DESs. The intriguing potential of hydrogen bonding through the synergistic combination of DESs and ILs offers significant promise for innovative solutions to ice-related challenges that remain largely unexplored. We conducted a comprehensive study on the anti-freezing properties of DESs by synthesizing choline-based ILs featuring both hydrophilic and hydrophobic anions. We aimed to explore how the diverse hydrogen-bond donors in DESs combined with the synthesized ILs to enhance the system’s ability to prevent ice formation. Substituting ethylene glycol (EG) with glycerol (GL) resulted in achieving an ice formation temperature of − 36 °C and an exceptionally low ice adhesion strength of 10 kPa, due to a thicker quasi-liquid layer on the coating surface, confirmed by solid-state NMR spectroscopy. The altered frost formation patterns of the DES-containing coatings demonstrated an enhance resistance against frost formation. This comprehensive study underscored the promising synergy between DESs and ILs for highly effective ice mitigation.

Characterization of Plasma-Induced Flow Thermal Effects for Wind Turbine Icing Mitigation

Dielectric barrier discharge plasma actuators have recently become desirable devices for simultaneous flow control and ice mitigation applications, with particular interest in wind turbines operating in cold climates. Considering the potential of plasma actuators for these specific applications, it is necessary to deeply understand the thermal effects generated by the plasma-induced flow to proceed with further optimizations. However, due to the local high electric field and high electromagnetic interference generated, there is a lack of experimental studies on the topic. The current work implements an in-house experimental technique based on the background-oriented schlieren principle for plasma-induced flow thermal characterization. Since this technique is based on optical measurements, it is not affected by the electromagnetic interference issues caused by the plasma discharge. A detailed experimental analysis is performed on a conventional Kapton actuator exploiting the relation between the actuator surface temperature and the induced thermal flow. The influence of the input voltage and the transient plasma-induced flow thermal behavior is analyzed. The results demonstrate that plasma actuators are fast response time devices that can heat the adjacent medium in less than a second after starting the operation.

Ice growth detection and the de-icing using dual functional capacitive sensor

Ice detectors are vital for ice mitigation systems, ensuring accurate ice growth measurements across multiple icing-de-icing cycles. Residue ice on the sensor can lead to erroneous readings in subsequent cycles, so its removal is critical to obtain accurate readings. This article presents a novel capacitive ice detector with self-deicing functionality employing nichrome electrodes for both sensing and de-icing. The sensor underwent testing in a cooling chamber for validation. The results confirm the developed ice detector’s ability to quantify ice within 1 to 4 mm with up to 7.5 % error, while the de-icing unit consumes 35 W to remove a 2 mm ice layer in 60 s. Capacitive sensor de-icing can significantly enhance the performance of ice mitigation systems. This research significantly advances ice detection technology by providing a reliable method for accurate ice measurement and removal, offering a valuable foundation for future improvements in the field of ice mitigation systems.

Bioinspired Polymers: Bridging Nature’s Ingenuity with Synthetic Innovation

This review delves into the cutting-edge field of bioinspired polymer composites, tackling the complex task of emulating nature’s efficiency in synthetic materials. The research is dedicated to creating materials that not only mirror the strength and resilience found in natural structures, such as spider silk and bone, but also prioritize environmental sustainability. The study explores several critical aspects, including the design of lightweight composites, the development of reversible adhesion methods that draw inspiration from nature, and the creation of high-performance sensing and actuation devices. Moreover, it addresses the push toward more eco-friendly material practices, such as ice mitigation techniques and sustainable surface engineering. The exploration of effective energy storage solutions and the progress in biomaterials for biomedical use points to a multidisciplinary approach to surpass the existing barriers in material science. This paper highlights the promise held by bioinspired polymer composites to fulfill the sophisticated needs of contemporary applications, highlighting the urgent call for innovative and sustainable advancements.

Phase change surfaces with porous metallic structures for long-term anti/de-icing application

HypothesisIce mitigation has received increasing attention due to the severe safety and economic threats of icing hazards to modern industries. Slippery icephobic surface is a potential ice mitigation approach due to its ultra-low ice adhesion strength, great humidity resistance, and effective delay of ice nucleation. However, this approach currently has limited practical applications because of serious liquid depletion in the icing/de-icing process. ExperimentsA new strategy of phase change materials (PCM)-impregnation porous metallic structures (PIPMSs) was proposed to develop phase changeable icephobic surfaces in this study, and aimed to solve the rapid depletion via the phase changeable interfacial interactions. FindingsEvaluation of surface icephobicity and interfacial analysis proved that the phase changeable surfaces (PIPMSs) worked as an effective and durable icephobic platform by significantly delaying ice nucleation, providing long-term humid tolerance, low ice adhesion strength of as-prepared samples (less than 5 kPa), and signally improved maintaining capacity of impregnated PCMs (less than 10 % depletion) after 50 icing/de-icing cycles. To explore the interfacial responses, phase change models consisting of the unfrozen quasi-liquid layer and solid lubricant layer at the ice/PIPMSs interfaces were established, and the involved icephobic mechanisms of PIPMSs were studied based on the analysis of interfacial interactions.

Long-lasting ceramic composites for surface dielectric barrier discharge plasma actuators

The developed research presents a novel experimental study of the cost-effective MgO-Al2O3, MgO-CaZrO3 perovskite, and thermally stable YSZ ceramic composites for DBD plasma actuators in aerospace applications. This study focuses on the implementation of ceramic DBD plasma actuators for aerodynamic flow control and ice creation mitigation. For this purpose, electrical power consumption analysis, induced flow velocities assessment, and mechanical and thermal characterization were performed. MgO-Al2O3 presented higher induced velocities than its zirconia-based counterparts of up to 3.3 m/s, and lower heat dissipation, achieving a ceiling temperature of 46 ºC, being thereby the best-suited candidate for active flow control mechanisms. In contrast, YSZ had very high-power consumption translated into a maximum surface temperature of 155.4 ºC, establishing itself for ice mitigation. This extensive research evinces that the strategic combination of the developed ceramics' thermomechanical, thermoelectric, and electromechanical properties allows them to be a promising breakthrough material for DBD plasma actuators.

Railway operations in icing conditions: a review of issues and mitigation methods

This article focuses on studying the current literature about railway operations in icing conditions, identifying icing effects on railway infrastructure, rolling stock, and operations, and summarizing the existing solutions for addressing these issues. Even though various studies have been conducted in the past on the impact of winter, climate change, and low temperatures on railway operations, not much work has been done on optimizing railway operations under icing conditions. This study demonstrates that further research is needed to better understand ice accretion and its effects on different parts of railways. It appears that railway infrastructure faces serious problems during icing conditions, and additional research in this field is required to precisely identify the problems and suggest solutions. Therefore, it is important to enhance the knowledge in this area and suitable optimal and cost-effective ice mitigation methods to minimize icing effects on railway operations and safety.

Electrothermal/photothermal superhydrophobic coatings based on micro/nano graphite flakes for efficient anti-icing and de-icing

Currently, a series of anti/de-icing coatings that combine active and passive methods can take advantage of various energy sources to significantly improve anti/de-icing efficiency. However, the preparation of multifunctional coatings often relies on complex preparation techniques, expensive raw materials and additional control systems, which limit the practical application of such ice mitigation strategies. This study combined active and passive ice mitigation methods to construct an electrothermal/photothermal superhydrophobic coating. According to the laminar distribution of graphite molecules, micro/nano-scale flaky graphite particles are produced by a convenient mechanical wiping method, which provide the coating with superhydrophobicity, electrothermal and photothermal properties at the same time through a strong binding effect with PDMS. The dynamic, static anti/de-icing performances and the reliability of the electrical/photothermal properties of the coating are experimentally verified. This multifunctional ice mitigation strategy avoids complex control systems and cumbersome preparation processes, providing a new and viable path to effective anti/de-icing.

Ice Accretion on Rotary-Wing Unmanned Aerial Vehicles—A Review Study

Ice accretion on rotary-wing unmanned aerial vehicles (RWUAVs) needs to be studied separately from the fixed-wing UAVs because of the additional flow complexities induced by the propeller rotation. The aerodynamics of rotatory wings are extremely challenging compared to the fixed-wing configuration. Atmospheric icing can be considered a hazard that can plague the operation of UAVs, especially in the Arctic region, as it can impose severe aerodynamic penalties on the performance of propellers. Rotary-wing structures are more prone to ice accretion and ice shedding because of the centrifugal force due to rotational motion, whereby the shedding of the ice can lead to mass imbalance and vibration. The nature of ice accretion on rotatory wings and associated performance degradation need to be understood in detail to aid in the optimum design of rotary-wing UAVs, as well as to develop adequate ice mitigation techniques. Limited research studies are available about icing on rotary wings, and no mature ice mitigation technique exists. Currently, there is an increasing interest in research on these topics. This paper provides a comprehensive review of studies related to icing on RWUAVs, and potential knowledge gaps are also identified.

Recent Developments on Dielectric Barrier Discharge (DBD) Plasma Actuators for Icing Mitigation

Ice accretion is a common issue on aircraft flying in cold climate conditions. The ice accumulation on aircraft surfaces disturbs the adjacent airflow field, increases the drag, and significantly reduces the aircraft’s aerodynamic performance. It also increases the weight of the aircraft and causes the failure of critical components in some situations, leading to premature aerodynamic stall and loss of control and lift. With this in mind, several authors have begun to study the thermal effects of plasma actuators for icing control and mitigation, considering both aeronautical and wind energy applications. Although this is a recent topic, several studies have already been performed, and it is clear this topic has attracted the attention of several research groups. Considering the importance and potential of using dielectric barrier discharge (DBD) plasma actuators for ice mitigation, we aim to present in this paper the first review on this topic, summarizing all the information reported in the literature about three major subtopics: thermal effects induced by DBD plasma actuators, plasma actuators’ ability in deicing and ice formation prevention, and ice detection capability of DBD plasma actuators. An overview of the characteristics of these devices is performed and conclusions are drawn regarding recent developments in the application of plasma actuators for icing mitigation purposes.

Microporous metallic scaffolds supported liquid infused icephobic construction

Hypothesis: Ice accretion on component surfaces often causes severe impacts or accidents. Liquid-infused surfaces (LIS) have drawn much attention as icephobic materials for ice mitigation in recent years due to their outstanding icephobicity. However, the durability of LIS constructions remains a big challenge, including mechanical vulnerability and rapid depletion of lubricants. The practical applications of LIS materials are significantly restrained, and the full potential of LIS for ice prevention has yet to be demonstrated.Experiments: A universal approach was proposed to introduce microporous metallic scaffolds in the LIS construction to increase the applicability and durability, and to prompt the potential of LIS for ice mitigation. Microporous Ni scaffolds were chosen to integrate with polydimethylsiloxane modified by silicone oil addition.Findings: The new LIS construction demonstrated significantly improved durability in icing/de-icing cyclic test, and it also offered a solution for the rapid oil depletion by restraining the deformation of the matrix material. Low ice adhesion strength could be maintained via a micro-crack initiation mechanism. The results indicated that the multi-phase LIS construction consisting of microporous Ni scaffolds effectively addressed the shackles of the icephobicity deterioration of LIS materials, confirming a new design strategy for the R&D of icephobic surfaces.

Improvement in electrical characteristics by surface modification of multi-wall carbon nanotube based buckypaper for de-icing application

Icing hazards often cause severe mobility concerns, safety risks, and even accidents in modern industries. Various ice mitigation strategies have been employed. Electro-thermal heating approach is a popular measure for ice protection, in which heat is generated electrically by internal components and then transferred to the outer surface for anti-icing and de-icing operation. Given the increasing usage of composites in aircraft structures, self-heating fibre reinforced polymer composite has been studied as an ice protection solution for the new generation aircraft. The present work focuses on improving electrical characteristics of carbon nanotube (CNT) based buckypaper (via surface functionalization) and the heating performance with an ice-phobic resin. The results indicated that surface functionalization of multi-wall carbon nanotubes (MWCNTs) was effective in obtaining MWCNT buckypaper (CNP) with improved electrical conductivity. The de-icing test confirmed the electro-thermal heating performance of the CNP based composite in a climate chamber at −20°C. The utilisation of surface modified MWCNTs in self-heating composites could be a promising strategy for maintaining lightweight and efficiency for electro-thermal systems to mitigate icing hazards.

Dynamic Mitigation Mechanisms of Rime Icing with Propagating Surface Acoustic Waves.

Ice accretion on economically valuable and strategically important surfaces poses significant challenges. Current anti-/de-icing techniques often have critical issues regarding their efficiency, convenience, long-term stability, or sustainability. As an emerging ice mitigation strategy, the thin-film surface acoustic wave (SAW) has great potentials due to its high energy efficiency and effective integration on structural surfaces. However, anti-/de-icing processes activated by SAWs involve complex interfacial evolution and phase changes, and it is crucial to understand the nature of dynamic solid–liquid–vapor phase changes and ice nucleation, growth, and melting events under SAW agitation. In this study, we systematically investigated the accretion and removal of porous rime ice from structural surfaces activated by SAWs. We found that icing and de-icing processes are strongly linked with the dynamical interfacial phase and structure changes of rime ice under SAW activation and the acousto-thermally induced localized heating that facilitate the melting of ice crystals. Subsequently, interactions of SAWs with the formed thin water layer at the ice/structure interface result in significant streaming effects that lead to further damage and melting of ice, liquid pumping, jetting, or nebulization.

An integrated ice tracking and mitigation system on the stagnation line of a cylindrical surface based on thermal imaging and electro-thermal elements

This work aims to research and develop an integrated ice tracking and mitigation technique based on thermal imaging and heat elements along a stagnation line of a cylindrical surface. It tracks and measures ice accumulation during an ice event and ice decrement during de-icing using sequential thermal images and image processing algorithms. It also employs an infrared camera to monitor the processes of ice buildup, de-icing, and relaxation by measuring the average temperature of the target surface. Thermal imaging measurements are validated using an optical camera. The measurements suggest that the average uncertainty of the ice thickness determined from thermal and optical images during ice buildup is about 0.16 mm, and about 0.1 mm during ice mitigation. The suggested method provides proper evaluation for a wide range of cold environment applications.

Hydrophobically/oleophilically guarded powder metallurgical structures and liquid impregnation for ice mitigation

Icing hazards often pose operational and safety challenges. Various surface and coating approaches have been attempted for ice mitigation purposes, but the durability remains an outstanding issue. Inspired by traditional powder metallurgy and slippery icephobic surfaces, a new strategy for slippery liquid-impregnated porous metallic structure (LIPMS) with gradient porosity was proposed in this study for ice mitigation, by directly impregnating selected liquids into sintered porous copper components with hydrophobic/oleophilic guarding consideration. The results indicated that robust LIPMS with desired porosity were obtained, significantly delaying the icing of surface water droplets, providing good frost resistance in a high humid environment, and demonstrating ultra-low ice adhesion strength (less than 1 kPa). It was confirmed that the hydrophobic/oleophilic guarding design significantly improved icephobic durability, attributing to its role in repelling external water and maintaining internal slippery liquid. To offer a comprehensive understanding of icephobic mechanisms and the potentials of LIPMSs, a concept of ice initiation position was also proposed and theoretically discussed. The pivotal factor of icephobic LIPMS is to maintain the icing initiation position at the unfrozen liquid–liquid interface or inside the homogeneous liquid, thus inhibiting icing and facilitating the ice removal.

Ice Accretion on Fixed-Wing Unmanned Aerial Vehicle—A Review Study

Ice accretion on commercial aircraft operating at high Reynolds numbers has been extensively studied in the literature, but a direct transformation of these results to an Unmanned Aerial Vehicle (UAV) operating at low Reynolds numbers is not straightforward. Changes in Reynolds number have a significant impact on the ice accretion physics. Previously, only a few researchers worked in this area, but it is now gaining more attention due to the increasing applications of UAVs in the modern world. As a result, an attempt is made to review existing scientific knowledge and identify the knowledge gaps in this field of research. Ice accretion can deteriorate the aerodynamic performance, structural integrity, and aircraft stability, necessitating optimal ice mitigation techniques. This paper provides a comprehensive review of ice accretion on fixed-wing UAVs. It includes various methodologies for studying and comprehending the physics of ice accretion on UAVs. The impact of various environmental and geometric factors on ice accretion physics is reviewed, and knowledge gaps are identified. The pros and cons of various ice detection and mitigation techniques developed for UAVs are also discussed.

Anti-icing fluids interaction with surfaces: Ice protection and wettability change

Some aircraft anti-icing fluids can dangerously weaken on hydrophobic surfaces. However, information about such fluids and surfaces was not full. Therefore, we considered the interaction of commercially available Newtonian and pseudo-plastic anti-icing fluids with super-hydrophilic and hydrophobic aluminum surfaces. In freezing rain simulations, no noticeable surface effect was observed on fluid endurance times at 10% ice coverage of the surfaces. The difference with previous works can be caused by fluid surface tensions, the contact angle hysteresis of test plates, and fluid viscosity (the last is irrelevant for Newtonian fluids). In further comparative studies, the roughness must also be considered because on rough hydrophobic surfaces the Newtonian fluid took longer to freeze once ice coverage surpassed 20% compared to smooth super-hydrophilic surfaces. Furthermore, the fluid physical adsorption in the surface texture leads to the drifting of receding contact angles of water on hydrophobic surfaces, thereby worsening their water-repelling. Thus, smooth hydrophobic surfaces are probably the preferred solution for ice mitigation systems contacting aircraft anti-icing fluids.

Analysis of derating and anti-icing strategies for wind turbines in cold climates

Wind turbines located in cold climates suffer from reduced power generation due to ice accretion. This paper presents a novel method for comparing and evaluating two emerging ice mitigation strategies: tip-speed ratio derating and electrothermal anti-icing. The method used takes into account accumulated ice mass, net energy losses both during and after an icing event, and financial breakeven points; it is demonstrated for the assessment of the NREL 5 MW reference wind turbine during different icing events. Our results show how derating can be preferred over electrothermal anti-icing and how this changes for different wind speeds, icing conditions, ambient temperatures, and system costs. For a 1-hour extreme icing event, it is expected that derating will reduce accumulated ice mass and daily power loss by up to 23% and 37%, respectively. Anti-icing was identified to be the preferred strategy when there were 42 in-cloud icing event occurrences per year, ambient temperatures were above −5 °C, and the system cost was no higher than 2% of the turbine’s capital cost. This research demonstrates to wind turbine operators how different strategies can be selected to improve performance during icing conditions.

Solution-Processed All-Ceramic Plasmonic Metamaterials for Efficient Solar-Thermal Conversion over 100-727°C.

Low-cost and large-area solar-thermal absorbers with superior spectral selectivity and excellent thermal stability are vital for efficient and large-scale solar-thermal conversion applications, such as space heating, desalination, ice mitigation, photothermal catalysis, and concentrating solar power. Few state-of-the-art selective absorbers are qualified for both low- (<200°C) and high-temperature (>600°C) applications due to insufficient spectral selectivity or thermal stability over a wide temperature range. Here, a high-performance plasmonic metamaterial selective absorber is developed by facile solution-based processes via assembling an ultrathin (≈120nm) titanium nitride (TiN) nanoparticle film on a TiN mirror. Enabled by the synergetic in-plane plasmon and out-of-plane Fabry-Pérot resonances, the all-ceramic plasmonic metamaterial simultaneously achieves high, full-spectrum solar absorption (95%), low mid-IR emission (3% at 100°C), and excellent stability over a temperature range of 100-727°C, even outperforming most vacuum-deposited absorbers at their specific operating temperatures. The competitive performance of the solution-processed absorber is accompanied by a significant cost reduction compared with vacuum-deposited absorbers. All these merits render it a cost-effective, universal solution to offering high efficiency (89-93%) for both low- and high-temperature solar-thermal applications.

Ultrasonic de-icing of wind turbine blades: Performance comparison of perspective transducers

Icing brings a significant harm for renewable energy installations and in aviation. Wind turbine blades, high voltage transmission lines, photovoltaic panels, airplane wing and helicopter blades often suffer from icing, which causes considerable losses of energy due to performance deterioration. Energy efficiency is a pivotal issue for wind turbines. Active ice mitigation system for wind turbines has not yet been commercialized due to the difficulty in overcoming the higher costs associated with a decrease in turbine power output. Ultrasonic de-icing as a new and potential energy-efficient de-icing technique has raised the increasing interest with its energy-saving effect, low running costs, good applicability and environmental conservation. Basic parameters of semi-hard lead zirconate titanate (PZT-4), lead magnesium niobate-lead titanate (PMN-PT) and lithium niobate (LiNbO3) materials are compared in this paper in terms of ultrasonic de-icing feasibility and efficiency. The theoretical models with applied ultrasonic guided wave propagation theory are established and the following simulations are carried out. The experiments with aluminum and composite plates are conducted to demonstrate the feasibility of ultrasonic de-icing and correspondence with simulations. Comparing with the lead zirconate titanate transducer, lithium niobate actuator shows the advantages both in performance and in environmental concern.