Deicing Research Articles

Piezoelectric deicing system for aeronautics: Extensional mode actuator and power supply

AbstractRecent research shows a growing interest in low‐power avionic deicing systems, in particular, those based on piezoelectric actuators for their energy efficiency. The system generates micrometric vibrations in the structure to delaminate and break the ice with a low power requirement. However, designing the power supply and its control for driving piezoelectric actuators is challenging due to their distinctive capacitive behavior at most frequencies, especially in deicing applications requiring high operational frequency. This contribution addresses the two cross‐dependent parts of the deicing system, that is the piezoelectric actuator designed for breaking any kind of ice on a large area and its power supply made of a 1 kW/200 V/2 MHz auxiliary resonant commutated pole inverter (ARCPI). The choice of this converter is based on the specific constraints of the application, such as varying the operating frequency with the actuator working conditions, the long cables and necessary insulation between the actuator and its supply, the soft‐switching operation and reactive energy balancing for a good efficiency. Based on these criteria, the converter was developed and realized in the laboratory. Deicing tests confirmed effective operation with a power input density of 122 mW/cm2, using nine piezoelectric patches per dm2.

Study on Shutter Heating Performance of Gas Turbine Intake System

Abstract Aiming at the anti-icing and de-icing requirements of gas turbine intake system, study the heating performance of a typical shutter vane, and compares and analyzes the influence of different ambient temperature and different electrothermal pipe heat generation rate on vane temperature distribution and heat transfer characteristics. The results show that the air convection at different positions on the blade surface of the louver leads to the difference in the temperature distribution of the upper and lower surfaces of the blade, as well as the leading edge and trailing edge of the blade, and the leading edge of the blade, as the area with the lowest overall temperature distribution of the blade, should be focused on in the design of anti-icing and de-icing systems. Increasing the heat production rate of the electric heating tube, there is more heat flow near the midline of the blade, which makes the temperature rise at this position the highest, and it is necessary to pay attention to the energy waste and blade damage caused by local overheating of the blade. Therefore, when the ambient temperature increases from 245.15 K to 318.15 K, the leaf temperature increases from 248.73 K to 322.74 K, and the temperature rise also increases from 3.58 K to 4.59 K. The electrothermal technology can be used to the anti-icing and de-icing of the intake system shutters on the basis of choosing the heat generation rate of the electrothermal tube reasonably.

Facile and Scalable Fabrication of High Water Absorption Composite Electrothermal Porous Ceramics for Electrothermal De-icing

Facile and Scalable Fabrication of High Water Absorption Composite Electrothermal Porous Ceramics for Electrothermal De-icing

Geothermal bridge deck de-icing using a novel external hydronic heating system with insulated pipe loops

A geothermal-based external hydronic heating system (EHHS) has been developed as an effective solution to address the de-icing needs of in-service bridges with minimum negative impacts on the structure, traffic, and environment. This paper discusses the implementation and operational response of a new design of the EHHS in which rather than the whole bottom surface of the bridge deck, only the hydronic heating loops are covered with insulation material and provides the accessibility for visual inspection of the bridge deck. The first full-scale external hydronic heating system with an insulated loop (EHHS-IL) was installed on a mock-up bridge deck in north Texas and tested in a record snowstorm with a low ambient temperature of −19.5 ˚C. The system operated in three different stages, and the inlet fluid temperature was adjusted according to the weather forecast. Overall, during a 10-day operation, three ice and snow events and 209 hours of freezing ambient temperature were observed. The heating system was able to maintain the heated bridge deck surface temperature above freezing except for 1.3 hours when the −19.5 ˚C low ambient temperature coincided with snowfall. The average surface heat flux during the test varied from 34.8 – 84 W/m2, and the average heating efficiency was estimated at 17.7 %. The seasonal performance factor (SPF) of the system remains consistently greater than 1 during the heating period. Also, 422 kWh of electrical energy was consumed during 10 days of operation by the entire geothermal de-icing system. This new geothermal bridge deicing system offers a practical solution to icy bridges by retrofitting.

TiN/acetylene black composite coatings: Enhanced durability and superhydrophobicity for all-day anti-Icing applications

Current advancements in anti-icing coatings emphasize the integration of photothermal, electrothermal, and superhydrophobic features to significantly enhance de-icing efficiency. However, these multifaceted coatings often involve intricate preparation methods and costly materials, making them susceptible to damage and reduced durability. This research aims to overcome these challenges by combining active and passive anti-icing principles to achieve full-time efficient anti-icing. A novel strategy is devised to modify the wettability of epoxy resins by grafting a fluorinated oligomer using a curing agent bridging technique. By utilizing micron-sized Titanium Nitride (TiN) and nanosized Acetylene Black fillers within a fluorine-modified epoxy resin, applied through a simple spray technique, the resulting coating exhibits excellent photothermal, electrothermal, and superhydrophobic properties. Evaluations confirm the coating’s robust mechanical durability for extended operational use and its stabilized effectiveness in photothermal and electrothermal de-icing. Notably, this approach maintains electrical conductivity by eliminating the filler hydrophobic modification, also enhancing the mechanical performance of nanocarbon-based multifunctional anti-icing coatings. Moreover, it simplifies the manufacturing process, reduces cost of coating materials, and enables broad application across various substrate surfaces.

Bio‐Inspired Hybrid Laser Direct Writing of Interfacial Adhesion for Universal Functional Coatings

AbstractEnhancing interfacial adhesion between functional coatings and target surfaces facilitates long‐term stable service by mitigating interferences of mechanical mismatches. Design of mechanical interlocks affords an effective strategy to strengthen the interfacial bonding with durability and compatibility, but the in‐depth investigations are still lacked. Herein, a gecko‐inspired hierarchical strategy realized by hybrid laser direct writing is proposed, which incorporates an armored frame scale for surface protection and a riveted anchor scale for interlocks. Such dual‐scale configurations endow the functional coatings with the stronger adhesion to the targets than the pristine and mono‐scale cases, resulting in 2 orders of magnitude enhancement resistant to tape peeling tests. Utilizing this scheme, a laser‐induced integrated deicing system is in situ manufactured on thermoplastics, primarily comprising superhydrophobic structures, carbon‐based sensors as well as adhesive copper (Cu) interconnects and heaters, where Cu‐based devices exhibit superior resistance to water impacts and stress fatigue. Interfacing with signal processing modules, such an all‐in‐one system demonstrates real‐time temperature monitoring and high efficiency in deicing (4.24 folds faster than the control group). The facile route for intensified adhesion holds promise in the interfaces within advanced equipment and under harsh scenarios.

Low ice adhesion on soft surfaces: Elasticity or lubrication effects?

HypothesisSoft materials are promising candidates for designing passive de-icing systems. It is unclear whether low adhesion on soft surfaces is due to elasticity or lubrication, and how these properties affect the ice detachment mechanism. This study presents a systematic analysis of ice adhesion on soft materials with different lubricant content to better understand the underpinning interaction. ExperimentsThe wetting and mechanical properties of soft polydimethylsiloxane with different lubricant content were thoroughly characterized by contact angle, AFM indentation, and rheology measurements. The collected information was used to understand the relationship with the ice adhesion results, obtained by using different ice block sizes. FindingsThree different de-icing mechanisms were identified: (i) single detachment occurs when small ice blocks are considered, and the ice completely detaches in a single event. In the case of larger ice blocks, the reattachment of the ice block is promoted by either: (ii) stick–slip or, (iii) interfacial slippage, depending on the lubricant content.It was confirmed that the ice adhesion strength not only depends on material properties but also on experimental conditions, such as the ice dimensions. Moreover, differently than on hard surfaces, where wetting primarily determines the icephobic performance, also elasticity and lubrication should be considered on soft surfaces.

Withdrawn: Low ice adhesion on soft surfaces: Elasticity or lubrication effects?

HypothesisSoft materials are promising candidates for designing passive de-icing systems. It is unclear whether low adhesion on soft surfaces is due to elasticity or lubrication, and how these properties affect the ice detachment mechanism. This study presents a systematic analysis of ice adhesion on soft materials with different lubricant content to better understand the underpinning interaction. ExperimentsThe wetting and mechanical properties of soft polydimethylsiloxane with different lubricant content were thoroughly characterized by contact angle, indentation, and rheology measurements. The collected information was used to understand the relationship with the ice adhesion results, obtained by using different ice block sizes. FindingsThree different de-icing mechanisms were identified: (i) single detachment occurs when small ice blocks are considered, and the ice completely detaches in a single event. In the case of larger ice blocks, the reattachment of the ice block is promoted by either: (ii) stick–slip or, (iii) interfacial slippage, depending on the lubricant content.It was confirmed that the ice adhesion strength is not a material property, since it depends on the ice block size. As such, differently than on hard surfaces, where wetting primarily determines the icephobic performance, also elasticity and lubrication need to be considered on soft surfaces.

Improving resonant ice protection systems with substrate optimization

Electro-mechanical de-icing systems are low-energy ice protection solutions based on ice fracture mechanisms. This article focuses on resonant electro-mechanical de-icing systems that actuate modes of flexion, which require low energy compared to extension modes. However, fracture propagation limits are encountered when using such flexural modes, preventing the ice from being completely detached from the substrate. This study demonstrates the feasibility of extending the ice detachment area by optimizing the thickness of the substrate. First, the interest and the limits of flexural resonant modes are discussed. Then the de-icing of a simple metallic beam in free conditions using a flexural mode is improved owing to the parametric optimization of the substrate thickness. The optimization is verified by tests on aluminum prototypes. The optimization results are then extended to a clamped composite plate and then to a NACA profile, showing interest in the approach to fully de-ice structures with modes of flexion, even in the case of complex geometries. With this last example, the study also demonstrates the feasibility of electro-mechanical ice protection systems for carbon fiber reinforced Polymer composite structures.

Dual-drive energy conversion plasmonic Ag@MXene thermal management textiles inspired by bearing structure

Multifunctional wearable textiles can simulate human perception and convert it into visual data, which has advanced application prospects. As an important branch, thermal management wearable textiles have been widely concerned in the aspects of thermal insulation, flame retardant, photothermal anti-icing, electrothermal deicing and even water evaporation. Here, inspired by the bearing structure, we simply soaked the PET textile in Ag@MXene hybrid solution several times to form a Ag@MXene conductive network with Ag NPs as the connection point on the textile fiber, and finally carry out hydrophobic modification. Based on plasma effect, the synergistic action of Ag NPs and MXene enhances the photothermal response of the material. In addition, the addition of Ag NPs effectively reduces the stacking between MXene layers and forms a Ag@MXene conductive network with Ag NPs as the connection point on the textile fibers. The stable temperature range of PDMS/Ag@MXene PET textile is 70–80 °C under one solar illumination intensity, and the stable temperature of PDMS/Ag@MXene PET textile can reach 117 °C at a constant voltage of 3 V. Based on the excellent thermal effect, this textile achieves photothermal anti-icing, electric thermal de-icing, keeping warm and removing sweat. The textile has a water evaporation efficiency of about 0.58 g h−1, which can achieve excellent anti-sweat function. Finally, the textile also achieved rapid flame retardant within 7 s. PDMS/Ag@MXene PET textile processes excellent photothermal and electrothermal conversion ability, acid/water stability and flame retardant ability, and has promising application prospects in thermal management textiles such as deicing and anti-icing, fire prevention, warmth and water evaporation.

Multi-layer composite thermal management coating strategy for efficient electrothermal ice removal

Effective anti/de-icing technologies are essential to the safety of equipment in freezing conditions. Currently, electrothermal deicing technology is widely adopted in engineering areas, but how to enhance the electrothermal deicing efficiency is currently focused by engineering technicians. Herein, we introduce a multi-layer composite thermal management coating strategy for effective and energy-saving electrothermal anti/de-icing. In the composite coating system, trilayer structures, containing a superhydrophobic surface layer, electrothermal middle layer, and heat insulation bottom layer, are involved that called superhydrophobic electrothermal insulation coating system (SEIC). The heat generated by the electrothermal layer is impeded by the bottom insulation layer to avoid the heat conduction loss, and rapidly conveys to the upper surface to melt ice, thereby greatly enhancing deicing efficiency. More importantly, the surface layer demonstrates superhydrophobic and anti-photothermal performances, which effectively keep the surface out of contaminant and solar overheating in summer. The synergism of superhydrophobicity and electric heating guarantees exceptional anti-icing properties of the composite coating system by reducing water-coating contact time, prolonging freezing time, reducing ice adhesion, and melting ice by electric heating. The efficient SEIC offers an eco-conscious, energy-saving path for anti-icing in the engineering field, which holds significant application in prospects.

Selection of second step micro-morphology for anti-icing surfaces based on icing time

Superhydrophobicity are associated with surface two-step micro/nanostructure together morphology. However, it is uncertain for Superhydrophobic surface (SHS) whether having anti-icing ability if without detailed knowledge of the surface morphology. For this reason, we proposed a three-dimensional (3-D) icing model to analyze anti-icing properties and determine the second step morphology suitable for the anti-icing. Followed by it, representative samples (hydrophobic or hydrophilic, metal or nonmetal, organic or inorganic) were selected for freezing measurement to confirm theoretical results. Ranked order is a sine wave/cone frustum/prism/cylinder/cuboid/paraboloid, and a semi-sine-wave model by the anti-icing time from high to low. The anti-icing property still depends on the surface micro-scale and micro-morphology to a great extent as hydrophobicity does. Effect of morphology on anti–icing will be significantly reduced even neglected, if the solid–liquid contact fraction being small enough. Meanwhile we also found that both the time for drop in temperature and the icing time are directly related to the solid fraction, whether the freezing singularity appears depends on freezing velocity or hydrophilicity. The predictions of the model largely agree with the experimental observations, also opening up possibilities for rational design of anti-icing SHS by selecting suitable morphology in micro scales.

Low-energy avionic piezoelectric deicing system

Piezoelectric actuators are widely used in several applications and are becoming increasingly attractive in aircraft and industrial contexts, mainly when efficiency and economical energy conversion are required. One of these applications is the avionic piezoelectric deicing system. Piezoelectric actuators are considered as a potential solution for developing a low-energy ice protection system for aircraft. This type of system applies vibration to the structure by activating its own resonant frequencies to generate sufficient stress to break the ice and cause it to delaminate from the substrate. The deicing mechanism depends strongly on the chosen excitation mode, whether it is flexural (bending) mode, extension (stretching) mode, or a combination in between, hence affecting the efficiency and effectiveness of the deicing process. In this contribution, a proof of concept of a deicing system utilizing lightweight piezoelectric actuators with minimal power requirement is proposed. Deicing was demonstrated with a power input density of 0.074 W cm−2 and a surface ratio of 0.07 piezoelectric actuators per cm2. First, a numerical method for positioning piezoelectric actuators and choosing the proper resonance mode was validated to assist in the system’s design. Then, the numerical method was used to implement piezoelectric deicing on a more representative structure of an aircraft wing or nacelle. Finally, a converter topology adapted for deicing application was proposed.

Adhesive strength of ice on solid surfaces under dynamic heating condition

A clear and comprehensive understanding of the dynamic changes in ice adhesion during the operation of thermal de-icing systems on an airplane can help in realizing safer operation of these systems. In this study, we aim to elucidate the ice adhesion decay pattern on different materials under thermal de-icing conditions. Molds are used to form ice on the surfaces of aluminum alloy, stainless steel, titanium alloy, and polytetrafluoroethylene (PTFE), and then their initial and dynamic ice adhesive strengths are measured. The effects of surface roughness and heating rate are also explored. The results show that the residual adhesive strength is almost linearly proportional to the instant temperature before it rises to −0.5 °C for the three types of metallic surfaces. However, for PTFE surfaces, instead of a reduction in the adhesive strength caused by heat, adhesive failure occurs due to the high stress induced by thermal deformation of the substrate. Under dynamic heating conditions, the impact of substrate’s roughness on the adhesive strength is significantly weakened, and the heating rate has a minor effect on the relationship between adhesive strength and instant temperature.

Ultra-efficient and thermally-controlled atmospheric structure deicing strategy based on the Peltier effect

Snow and ice coverage pose significant threats to the safe and stable operation of energy equipment. To address the challenges of high power consumption and thermal damage to materials resulting from prolonged use of thermal ice melting technology, this study developed and tested a low-power, thermally controlled de-icing system. The system employs thermoelectric material as the heating element to minimize power consumption and prevent thermal damage to the substrate material. Compared to traditional thermal elements, it offers advantages such as single-sided heat production, a high thermal performance coefficient, and a rapid temperature rise rate. Investigating the effects of temperature difference and current on the heat production coefficient of the system and conducts comparative experiments on the thermal response of different heating elements in low-temperature environments. Furthermore, to further reduce power consumption and minimize unnecessary sensible heat within the ice layer, the thermal control system is designed to maintain the interface temperature between 3 and 5 ℃. This approach selectively melts the interface ice layer to form a water film, facilitating ice layer removal through gravity and centrifugal force. The de-icing energy density achieved with this method is only 10.31 J/cm2, resulting in a 32.167 % reduction in power consumption compared to continuous heating. For the flat plate heating structure, the study explores the physical mechanism of interface temperature control by establishing the relationship between temperature and current through a thermal circuit model. The calculated results closely align with experimental findings, with the maximum error not exceeding 15 %.

Asymmetrically superwetting Janus membrane constructed by laser-induced graphene (LIG) for on-demand oil–water separation and electrothermal anti-/de-icing

Superwetting functional surfaces based on laser-induced graphene (LIG) have a wide range of applications in many fields. However, single wettability LIG films are difficult to respond to complex and changing environmental conditions. Despite the large number of experiments were carried out to demonstrate the formation of LIG, there is a lack of studies on the process and formation mechanisms of LIG. In this study, the conversion of PEI to graphene was systematically investigated by both experimental and molecular dynamics simulations. A new method for obtaining Janus membranes with both superhydrophobicity and superhydrophilicity by ethanol and plasma treatment of LIG is proposed. The asymmetrically superwetting Janus membrane are shown to realize the on-demand controllable separation of light oil–water and heavy oil–water. In addition, the superhydrophobic LIG is used as a coating material with excellent electrothermal properties, which provide the performance of anti-icing and electrothermal de-icing. The asymmetrically superwetting Janus membranes prepared by the proposed simple and environmentally friendly method are shown to have a variety of prospective applications.

Numerical Analysis of the Wing Leading Edge Electro-Impulse De-Icing Process Based on Cohesive Zone Model

Aircraft icing has historically been a critical cause of airplane crashes. The electro-impulse de-icing system has a wide range of applications in aircraft de-icing due to its lightweight design, low energy consumption, high efficiency, and other advantages. However, there has been little study into accurate wing electric-impulse de-icing simulation methods and the parameters impacting de-icing efficacy. Based on the damage mechanics principle and considering the influence mechanisms of interface debonding and ice fracture on ice shedding, this paper establishes a more accurate numerical model of wing electric-impulse de-icing using the Cohesive Zone Model (CZM). It simulates the process of electric-impulse de-icing at the leading edge of the NACA 0012 wing. The numerical results are compared to the experimental results, revealing that the constructed wing electro-impulse de-icing numerical model is superior. Lastly, the effects of varying ice–skin interface shear adhesion strengths, doubler loading positions, and impulse sequences on de-icing effectiveness were studied. The de-icing rate is a quantitative description of the electro-impulse’s de-icing action, defined in the numerical model as the ratio of cohesive element deletions to the total elements at the ice–skin interface. The findings reveal that varying shear adhesion strengths at the ice–skin interface significantly impact the de-icing effect. The de-icing rate steadily falls with increasing shear adhesion strength, from 66% to 56%. When two, four, and seven impulses were applied to doubler two, the de-icing rates were 59%, 71%, and 71%, respectively, significantly increasing the de-icing efficiency compared to when impulses were applied to doubler one. Doubler one and two impulse responses are overlaid differently depending on the impulse sequences, resulting in varying de-icing rates. When the impulse sequence is 20 ms, the superposition results are optimal, and the de-icing rate reaches 100%. These studies can guide the development and implementation of a wing electric-impulse de-icing system.

Electromechanical ice protection system: de-icing capability prediction considering impedance matching effect

Abstract Due to the safety threats caused by icing, the de-icing system is essential in the aviation industry. As an effective method, the electromechanical de-icing system (EDS) is a new ice-protection system based on mechanical vibration principles. For the majority of the current research on system de-icing capability estimation, the effect of impedance-matching is not considered. Impedance matching plays a very important role in improving the performance of the electromechanical system, so we must also consider the impact of impedance matching when designing the EDS. In the present study, a de-icing capability prediction method considering the impact of an impedance-matching device is established based on experimental and numerical methods. The results indicate that the impedance-matching effect has no impact on the mechanical vibration of the structure for the same load power. Meanwhile, impedance-matching devices can significantly improve the power factor and increase the interface shear stress/strain for de-icing. Eight different vibrational modes were tested, and the experimental results showed that the actual interface shear strain after impedance matching is inversely proportional to the de-icing time. The verification experiments were conducted and the accuracy of the proposed prediction method was verified.

Piezoelectric resonant ice protection systems - Part2/2 : benefits at aircraft level

Piezoelectric resonant de-icing systems are attracting great interest. This paper aims to assess the implementation of these systems at the aircraft level. The article begins with the model to compute the power requirement of a piezoelectric resonant de-icing system sized from the prototype detailed in Part 1/2 of this article. Then the mass, drag, and fuel consumption of this system and the subcomponents needed for its implementation are assessed. The features of a piezoelectric resonant de-icing system are finally computed for aircraft similar to Airbus A320 aircraft and aircraft of different categories (Boeing 787, ATR 72 and TBM 900) and compared with the existing thermal and mechanical ice protection systems. A sensitivity analysis of the main key sizing parameters of the piezoelectric de-icing system is also performed to identify the main axes of improvement for this technology. The study shows the potential of such ice protection systems. In particular, for the realistic input parameters chosen in this work, the electro-mechanical solution can provide a 54% reduction in terms of mass and a 92% reduction in terms of power consumption for an A320 aircraft architecture, leading to a 74% decrease in the associated fuel consumption compared to the actual air bleed system.

Temporal and Spatial Thermal Performance of A Ground Heat Exchanger in Response to Bridge Solar Recharging and Deicing Operations: A Pilot Full-Scale Study

A full-scale mock-up geothermal bridge was built in Texas, USA, to evaluate the field performance of a novel external geothermal bridge de-icing system. The geothermal bridge system comprises a single U-loop ground heat exchanger (GHE) 131 m deep, a geothermal heat pump, four circulation pumps, and hydronic heating loops attached to the bridge deck. A comprehensive monitoring system was implemented to monitor the spatial ground temperature response. The geothermal bridge system was operated and monitored for solar collector and bridge de-icing operations totaling 99 days between August 2019 and April 2020. An average heat injection of 5.7 W/m was observed during the solar collector operation. Based on the defined control volume, approximately 48.9–380.8 kWh of energy, corresponding to 3.7-28.5% of the total injected energy, was available at the end of the solar-collector operation. Moreover, test results showed that 31.7-39.4% of stored thermal energy was preserved for utilization in the first winter de-icing test. The radius of the influence zone of the GHE operation was found to be 3.45 m. The outcome of the field experimental studies and further data collection performed over a year of operations showed that the heat injection into the soil by bridge solar collector was 54% more effective than heat extraction from the ground during the several de-icing tests performed from 2019 to 2020.