Ice Penetration Research Articles

Miniature impulse radar sensor for snow and ice penetration sensing and weak layer detection

Miniature impulse radar sensor for snow and ice penetration sensing and weak layer detection

Machine learning-assisted chemical design of highly efficient deicers

The use of deicers in urban areas, on runways and aircrafts has raised concerns about their environmental impact. Understanding the ice-melting mechanism is crucial for developing environmentally friendly deicers, yet it remains challenging. This study employs machine learning to investigate the ice penetration capacity (IPC) of 21 salts and 16 organic solvents as deicers. Relationships between their IPC and various physical properties were analysed using extreme gradient boosting (XGBoost) and Shapley additive explanation (SHAP). Three key ice-melting mechanisms were identified: (1) freezing-point depression, (2) interactions between deicers and H2O molecules and (3) infiltration of ions into ice crystals. SHAP analysis revealed different ice-melting factors and mechanisms for salts and organic solvents, suggesting a potential advantage in combining the two. A mixture of propylene glycol (PG) and sodium formate demonstrated superior environmental impact and IPC. The PG and sodium formate mixture exhibited higher IPC when compared to six commercially available deicers, offering promise for sustainable deicing applications. This study provides valuable insights into the ice-melting process and proposes an effective, environmentally friendly deicer that combines the strengths of organic solvents and salts, paving the way for more sustainable practices in deicing.

Assessing the impacts of ice penetration on monitoring water levels of high-latitude and -altitude lakes from CryoSat-2 altimetry

The CryoSat-2 satellite provides high-precision and long-term monitoring of global lake levels, offering advantages for water resource management, ecological protection, and disaster warning. However, the lake ice penetration by radar electromagnetic waves of CryoSat-2 altimetry tends to result in underestimation of water levels for lakes in high latitudes and altitudes. By contrast, the laser altimetry of ICESat-2 enables us to obtain the height measurements from lake ice surface and the ice penetration impacts on lake levels can be nearly ignored in the ICESat-2 elevation product. After converting the CryoSat-2 and ICESat-2 altimetry data to the same datum and height reference system, the water level difference of (near-) synchronous observations between the two satellites could be mainly attributed to the influences by the lake ice penetration from CryoSat-2 data. In this study, totally 257 lakes in high-latitude (north of 50°N) and high-altitude (the Tibetan Plateau, TP) regions that are covered by both CryoSat-2 and ICESat-2 satellite tracks are examined to explore the characteristics of ice penetration impacts on water level measurements. The altimetry data during unfreezing seasons (June to October) are used to correct the systematic height biases of these two satellite measurements, thus their water level differences during freezing seasons (November to May of the following year) are deemed as the influences of ice penetration on lake level measurements by CryoSat-2 radar altimetry. The results show that the maximum underestimation depth of water level for each lake varies within the range of 0.01–3.47 m, with an average of 0.90 m. Particularly in North America with a dense distribution of lakes, the underestimation of lake levels by CryoSat-2 gradually ascends with increasing latitude. CryoSat-2 underestimates lake levels in Europe and the TP less than in North America. Among different months, the lake ice leads to the maximum underestimation on the water level by CryoSat-2 altimetry in March. The spatial and temporal characteristics of lake ice impacts on the water level measurements by CryoSat-2 altimetry would be an essential reference for quantifying and reducing the uncertainties of satellite radar altimetry for monitoring inland water dynamics.

Research of thermoelectric null-thermostat

Objective. The purpose of the study is to develop and study the design of a thermoelectric null-thermostat, characterized by low power consumption, in which high accuracy of temperature stabilization of the reference junctions of differential thermocouples is achieved by placing them directly near the water-ice interface.Method. The study was carried out on an experimental model of a thermoelectric null-thermostat. To study heat transfer processes, visual observation of the movement of the ice-water interface in the null-thermostat chamber was carried out. Temperature values were recorded at the lower and upper bases of the chamber, as well as at the hot and cold junctions of the thermoelectric module (TEM) using thermocouples.Result. The dependences of the change in temperature of the upper and lower base of the working chamber, as well as the phase boundary over time, the duration of time for complete ice penetration on the TEM supply current, and the temperature difference, respectively, between the surface of the cold junction of the TEM and the lower base of the working chamber were obtained , the surface of the hot junction of the thermal module and the upper base of the working chamber.Conclusion. It has been established that the speed of movement of the phase boundary strongly depends on the value of the supply current of the thermoelectric battery, which corresponds to the heat flow at the upper and lower base of the working chamber. As follows from the data presented, the change in temperature of the upper base is more noticeable than the lower one. At a current of 2, 4 and 6 A, the speed of movement of the phase boundary is 0.007 m/h, 0.01 m/h and 0.013 m/h, respectively. In this case, the duration of complete melting of ice, corresponding to the duration of operation of the null thermostat, when the TEM supply current changes from 2 to 7 A, is reduced from 1,91⋅104 s to 1,38⋅104.

Experimental Study on IRV Ramming Artificial Model Ice

When the icebreaker sails in the polar region, it adopts continuous and ramming icebreaking operations. When the ice condition exceeds the design working condition, it uses the ramming icebreaking method to advance. The nonlinear icebreaking process and complex ice conditions make it difficult to accurately predict the ice-strengthened ships’ ramming performance. This paper develops a scale-ratio brittle model of ice to simulate thick, level ice and predicts the ice penetration distance and bow load of an icebreaking research vessel (IRV) model at different speeds. The test results show that the penetration distance of the scoop-shaped bow IRV increases with the ramming speed and the average and extreme values of the contact load increase with the increase in the speed. The experimental results are a valid complement to the ice tank tests and do not cover all aspects of ship design. The main purpose is to develop a test program and performance prediction scheme for studying penetration distance and ice load during ram icebreaking.

Evaluation of the effectiveness of air heating of the icebreaker anti-icing device at the compressor inlet

Anti-icing devices that provide increased ice penetration are widely used on modern icebreakers. The devices based on the pneumatic pressurization of the icebreaker hull with air pumped by a special compressor are most common. When operating at low temperatures, there is a danger of compressor failure due to icing of the compressor intake tract. To protect the receiving path, it is necessary to increase the temperature of the air entering the compressor to safe values. Possible heating methods are recirculation of compressed air in the compressor and its heating in a special heat exchanger. A diagram of an anti-icing system that allows you to implement both methods of air heating is presented in the paper; the principle of its operation is described. An urgent problem of selecting the most preferred method of air heating is considered in the paper. As an evaluation criterion, it is proposed to use the energy costs necessary to ensure air heating, cooling parameters of modern internal combustion engines with a high level of boost and advanced engines. To solve this problem, an algorithm that takes into account the features of the operation of the anti-icing device compressor, the requirements for the temperature of the receiving air, the properties of heat carriers is proposed. The calculation method is based on the classical equations of thermodynamics and heat transfer. The results of the calculations performed allow us to compare the energy costs for ensuring an increase in air temperature to the required values when using various methods of heat supply. The conclusions drawn on the basis of the calculations carried out allow us to conclude that the most rational way to warm up the intake air of the compressor of the anti-icing device is the joint use of recirculation and a heat exchanger. A promising direction for improving anti-icing devices is the optimization of the temperature modes of the compressor operation, rationalization of the supplied heat distribution, automation of the control for the temperature regime of the pneumatic boost.

Development of a dynamic ice penetration model for runway de-icing products through performance experimental characterization

During winter, the clear runway concept is crucial to airports for maintaining passenger and employee safety. Research can optimize de-icing product application rates, thereby reducing costs and environmental impact. Currently, three aerospace standards exist for evaluating the performance of runway de-icing products. These comparative tests—ice melting, ice undercutting, and ice penetration tests—are carried out jointly in a systematic way and indicate whether a runway de-icing product is effective in actively reducing the presence of ice. Here we present a numerical model for the ice penetration method, for fluid runway de-icing product, with the goal of deepening the knowledge in this field. We apply a series of laboratory-based tests to measure the performance of runway de-icing products, and develop a new model to analyze the behavior of each product. The principal observation is that the product is more effective at 1 min and effectiveness decreases following an inverse logarithmic curve trend to 30 min. Through modeling, we observe that the dominant mode of heat transfer is natural laminar convection, and the model predicts a uniform melt length for the entire tube section. Thus, simplified ice penetration modeling using AS6211 can acceptably predict the rate of ice penetration as a function of time (mm/min), with the modeling confirmed by our experimental results. The future application of our simplified model to other existing de-icing fluid characterization test methods could identify the effects of diluted or undiluted solid runway de-icing products on ice penetration rates and ultimately on spreading rates.

Histone H3 and H4 Modifications Point to Transcriptional Suppression as a Component of Winter Freeze Tolerance in the Gall Fly Eurosta solidaginis.

The goldenrod gall fly (Eurosta solidaginis) is a well-studied model of insect freeze tolerance. In situations of prolonged winter subzero temperatures, larvae of E. solidaginis accept ice penetration throughout extracellular spaces while protecting the intracellular environment by producing extreme amounts of glycerol and sorbitol as cryoprotectants. Hypometabolism (diapause) is implemented, and energy use is reprioritized to essential pathways. Gene transcription is one energy-expensive process likely suppressed over the winter, in part, due to epigenetic controls. The present study profiled the prevalence of 24 histone H3/H4 modifications of E. solidaginis larvae after 3-week acclimations to decreasing environmental temperatures (5 °C, -5 °C and -15 °C). Using immunoblotting, the data show freeze-mediated reductions (p < 0.05) in seven permissive histone modifications (H3K27me1, H4K20me1, H3K9ac, H3K14ac, H3K27ac, H4K8ac, H3R26me2a). Along with the maintenance of various repressive marks, the data are indicative of a suppressed transcriptional state at subzero temperatures. Elevated nuclear levels of histone H4, but not histone H3, were also observed in response to both cold and freeze acclimation. Together, the present study provides evidence for epigenetic-mediated transcriptional suppression in support of the winter diapause state and freeze tolerance of E. solidaginis.

Peak loads during dynamic ice-structure interaction caused by rapid ice strengthening at near-zero relative velocity

A series of ice penetration tests with a rigid structure, with controlled oscillation, and with a single-degree-of-freedom structure were performed to investigate the peak load-velocity dependence for ethanol-doped model ice during a test campaign at the Aalto Ice and Wave Tank. For the rigid structure and controlled-oscillation tests, the ice drift speed ranged between 1 and 150 mm s−1. In the controlled-oscillation tests, amplitudes of oscillation between 0.40 and 15.90 mm and frequencies of oscillation between 0.143 and 4 Hz were prescribed such that the relative velocity between ice and structure never became negative. A constant ice drift deceleration experiment with a single-degree-of-freedom structure was performed to investigate the development of frequency lock-in and intermittent crushing in the model ice and compare the results with the rigid structure and controlled-oscillation tests. It was found that the peak load-velocity dependence identified in the rigid structure tests was not always uniquely defined as identified in the controlled-oscillation tests because the loading history affected the peak load at ice failure. A rapid strengthening of the ice developed at low relative velocity and carried over to high relative velocity until the ice failure dissipated the strengthening effect. The strengthening effect, observed in the rigid structure and controlled-oscillation tests, was also observed during frequency lock-in and intermittent crushing in the single-degree-of-freedom structure test. The observations in the present study indicate that the so-called velocity and compliance effects in ice-structure interaction originate from the same strengthening effect. It then follows that peak loads on compliant structures cannot exceed peak loads on rigid structures in the same ice conditions, with the only difference being that the peak loads on compliant structures occur at apparently higher far-field ice drift speeds due to the change in relative velocity.

Understanding two key processes associated with alpine lake ice phenology using a coupled atmosphere-lake model

Study regionLake Nam-Co, a typical deep alpine lake in the central of Tibetan Plateau. Study focusThis study investigates the role of surface turbulent fluxes in simulating lake freeze-up and the role of solar radiation transfer (when lake ice exists) in simulating the lake ice break-up. New hydrological insightsIn the coupled model, the realistic representation of surface turbulent heat fluxes is crucial to simulate the lake freeze-up. This is because turbulent heat fluxes, especially the latent heat, directly controlling the lake water temperature through energy exchange between water and atmosphere. Additionally, the partitioning of solar radiation transfers when lake ice exist is crucial in simulating lake ice break-up. The proportion absorbed by the ice surface will be released associated with upward longwave radiation and turbulent heat fluxes, and only a fraction is used for surface ice-water phase change. The proportion absorbed by the subsurface layer ice is directly used for ice-water phase changes. The proportion absorbed by the water, through ice penetration, is temporarily stored and used for ice melting through heat exchange between the ice and water. The offline FLake model is much less sensitive to the above two processes, implying the importance and necessity in improving the model physics in coupled model.

Experimental study and numerical modeling of the thermo-hydro-mechanical processes in soil freezing with different frost penetration directions

This research work presents an experimental and numerical study of the coupled thermo-hydro-mechanical (THM) processes that occur during soil freezing. With focusing on the artificial ground freezing (AGF) technology, a new testing device is built, which considers a variety of AGF-related boundary conditions and different freezing directions. In the conducted experiments, a distinction is made between two thermal states: (1) The thermal transient state, which is associated with ice penetration, small deformations, and insignificant water suction. (2) The thermal (quasi-) steady state, which has a much longer duration and is associated with significant ice lens formation due to water suction. In the numerical modeling, a special focus is laid on the processes that occur during the thermal transient state. Besides, a demonstration of the micro-cryo-suction mechanism and its realization in the continuum model through a phenomenological retention-curve-like formulation is presented. This allows modeling the ice lens formation and the stiffness degradation observed in the experiments. Assuming a fully saturated soil as a biphasic porous material, a phase-change THM approach is applied in the numerical modeling. The governing equations are based on the continuum mechanical theory of porous media (TPM) extended by the phase-field modeling (PFM) approach. The model proceeds from a small-strain assumption, whereas the pore fluid can be found in liquid water or solid ice state with a unified kinematics treatment of both states. Comparisons with the experimental data demonstrate the ability and usefulness of the considered model in describing the freezing of saturated soils.

Friction on Ice: How Temperature, Pressure, and Speed Control the Slipperiness of Ice

We present sphere-on-ice friction experiments as a function of temperature, contact pressure, and speed. At temperatures well below the melting point, friction is strongly temperature dependent and follows an Arrhenius behavior, which we interpret as resulting from the thermally activated diffusive motion of surface ice molecules. We find that this motion is hindered when the contact pressure is increased; in this case, the friction increases exponentially, and the slipperiness of the ice disappears. Close to the melting point, the ice surface is plastically deformed due to the pressure exerted by the slider, a process depending on the slider geometry and penetration hardness of the ice. The ice penetration hardness is shown to increase approximately linearly with decreasing temperature and sublinearly with indentation speed. We show that the latter results in a nonmonotonic dependence of the ploughing force on sliding speed. Our results thus clarify the complex dependence of ice friction on temperature, contact pressure, and speed.

The single freezing episode of early-age cementitious composites: Threshold properties of cement matrix ensuring the frost resistance

The freezing is recognized as one of the most dangerous phenomena jeopardizing the durability of cement-based materials. In this work, the cementitious material exposed to a single freezing event after 1, 2, 3, 7, 14, 21, and 28 days of hydration was investigated. The change of mechanical parameters, e.g. compressive strength and Young’s modulus, due to individual water crystallization was determined. Water freezing in cement paste proceeds at depressed temperature, which can be calculated using Gibbs-Thomson equation. The change of the in-pore ice content profile in temperature domain along with hydration was calculated using differential scanning calorimetry and was related with the degradation of mechanical properties. The two dominant mechanisms inducing water freezing can be recognized in cement paste: gradual ice penetration and ice nucleation. The change of microstructure along with hydration was monitored using mercury porosimetry. These observations allowed to determine the threshold properties which provide the resistance of cementitious materials to the single freezing at early age. The research was supplemented with isothermal calorimetry and XRD data of the applied binder.

Effect of Temperature and Prewetting for Ice Penetration with Sodium Formate

Granular sodium formate (NaCOOH) is a popular deicer used at airports. It is mainly used to weaken compacted snow/ice and thereby facilitate mechanical ice removal. Earlier research has developed a set of methods quantifying deicer performance, but linking these test results to operational guidelines is difficult. The main objective of this study is to increase the knowledge of how temperature and prewetting affect the ice penetration performance of granular sodium formate. A new method to evaluate the development of ice penetration process is presented here. Ice penetration tests were performed with single grains on large, optically clear ice cubes, and digital image analysis is used to quantify the initial waiting time, penetration rate and –depth, and melted volume. Eighteen tests including dry and prewetted sodium formate grains were performed at three different temperatures (–2°C, −5°C, and −10°C). Prewetting reduced the initial waiting time (the time it takes before the particles started to penetrate) by a few minutes at −10°C, but at higher temperatures, this reduction was insignificant. The particles penetrated the ice at a constant rate. At −10°C, the particles penetrated at 10–15 mm/hour, while at −2°C this speed is about five times higher. Prewetting does not seem to have a clear beneficial effect on the penetration rate. Suggestions are given on how to capture the results from this study into operational guidelines for deicing operations at airports, using sodium formate as deicer.

Ice Penetration by a Bluff-Body Melting Probe

Abstract We analyze the operation of melting probes as a Stefan problem for the liquid/solid interface surrounding the probe. We assume that the liquid layer is thin and, therefore, amenable to analysis by the lubrication theory. The resulting Stefan problem is solvable in the closed form. The solution determines the dependence of the penetration speed on the temperature differential between the probe and the surrounding ice, the size, shape and weight of the probe, the viscosity of liquid water and the thermal properties of solid ice.

The TRIPLE/nanoAUV initiative a technology development initiative to support astrobiological exploration of ocean worlds

From a scientific point of view, the exploration of oceans on other planets and moons in our solar system is extremely enticing, however, from a technical point of view, it is an almost insurmountable challenge. It is this particular combination of space and ocean-going equipment that makes developing a coherent system such a demanding task. The TRIPLE/nanoAUV Initiative, where the acronym TRIPLE stands for “Technologies for Rapid Ice Penetration and subglacial Lake Exploration”, is intended to specifically address the design and realization of an autonomous underwater vehicle, the nanoAUV, for future space missions that can be operated in conjunction with melting probes for reaching subglacial lakes or ocean waters. Any conceivable technical concept has to first undergo extensive testing in appropriate Earth-analogue environments which at least come close to the actual conditions that are expected on the envisaged space mission in order to provide an indication of the technical feasibility. For the time being Antarctica appears to be the most favorable region for the anticipated test missions including reaching subglacial lakes like the one in the Dome C region although other regions like Devon Ice Cap in Canada will be considered as well. It is not just the basic physical conditions such as a thick ice cover above liquid water/seawater but also the sparsity of microbial life forms that makes it a good Earth-analogue environment [1] as it poses similar challenges to the deployed systems as found on space missions. Just recently, it was discerned that the basic requirements of a planetary mission, melting through the ice and deploying robotic systems into the water body below, are perfectly matching the interest of terrestrial scientific missions. The recent larger breaks off of the Antarctic ice shelf have exposed pristine ocean regions that due to their difficult accessibility necessitate the use of robotic exploration tools. This momentum shall be used to get one step closer to a future planetary mission by evaluating related scientific and technical concepts in Earth-analogue environments.

Peridynamic solution for submarine surfacing through ice

ABSTRACT This paper establishes a numerical model for simulating submarine surfacing through the ice. The numerical model is simplified to be the interaction between a submarine and an ice sheet. The ice sheet is discretized into a number of ice material particles, and the motion and the failure of them are calculated by the peridynamic method. A contact detection method is used to determine the interpenetration between ice material particles and the submarine. To verify the feasibility of peridynamics in modelling ice failure, the two cases of three-point bending of columnar ice and vertical penetration of ice sheet for a cylinder are simulated. Convergence studies are taken with respect to the particle spacing size for submarine surfacing through ice. The surfacing process of the submarine has been simulated, and the calculation results are discussed. The calculated ice failure feature is similar to the full-scale observation.

Frost Survival Mechanism of Vegetative Buds in Temperate Trees: Deep Supercooling and Extraorgan Freezing vs. Ice Tolerance.

In temperate climates, overwintering buds of trees are often less cold hardy than adjoining stem tissues or evergreen leaves. However, data are scarce regarding the freezing resistance (FR) of buds and the underlying functional frost survival mechanism that in case of supercooling can restrict the geographic distribution. Twigs of 37 temperate woody species were sampled in midwinter 2016 in the Austrian Inn valley. After assessment of FR, infrared-video-thermography and cryo-microscopy were used to study the freezing pattern in and around overwintering vegetative buds. Only in four species, after controlled ice nucleation in the stem (−1.6 ± 0.9°C) ice was observed to immediately invade the bud. These buds tolerated extracellular ice and were the most freezing resistant (−61.8°C mean LT50). In all other species (33), the buds remained supercooled and free of ice, despite a frozen stem. A structural ice barrier prevents ice penetration. Extraorgan ice masses grew in the stem and scales but in 50% of the species between premature supercooled leaves. Two types of supercooled buds were observed: in temporary supercooling buds (14 species) ice spontaneously nucleated at −20.5 ± 4,6°C. This freezing process appeared to be intracellular as it matched the bud killing temperature (−22.8°C mean LT50). This response rendered temporarily supercooled buds as least cold hardy. In 19 species, the buds remained persistently supercooled down to below the killing temperature without indication for the cause of damage. Although having a moderate midwinter FR of −31.6°C (LT50), some species within this group attained a FR similar to ice tolerant buds. The present study represents the first comprehensive overview of frost survival mechanisms of vegetative buds of temperate trees. Except for four species that were ice tolerant, the majority of buds survive in a supercooled state, remaining free of ice. In 50% of species, extraorgan ice masses harmlessly grew between premature supercooled leaves. Despite exposure to the same environmental demand, midwinter FR of buds varied intra-specifically between −17.0 and −90.0°C. Particularly, species, whose buds are killed after temporary supercooling, have a lower maximum FR, which limits their geographic distribution.

Deep supercooling enabled by surface impregnation with lipophilic substances explains the survival of overwintering buds at extreme freezing.

The frost survival mechanism of vegetative buds of angiosperms was suggested to be extracellular freezing causing dehydration, elevated osmotic potential to prevent freezing. However, extreme dehydration would be needed to avoid freezing at the temperatures down to −45°C encountered by many trees. Buds of Alnus alnobetula, in common with other frost hardy angiosperms, excrete a lipophilic substance, whose functional role remains unclear. Freezing of buds was studied by infrared thermography, psychrometry, and cryomicroscopy. Buds of A. alnobetula did not survive by extracellular ice tolerance but by deep supercooling, down to −45°C. An internal ice barrier prevented ice penetration from the frozen stem into the bud. Cryomicroscopy revealed a new freezing mechanism. Until now, supercooled buds lost water towards ice masses that form in the subtending stem and/or bud scales. In A. alnobetula, ice forms harmlessly inside the bud between the supercooled leaves. This would immediately trigger intracellular freezing and kill the supercooled bud in other species. In A. alnobetula, lipophilic substances (triterpenoids and flavonoid aglycones) impregnate the surface of bud leaves. These prevent extrinsic ice nucleation so allowing supercooling. This suggests a means to protect forestry and agricultural crops from extrinsic ice nucleation allowing transient supercooling during night frosts.

Experimental Investigation on the Ice Formation and Growth in Ex Vivo Bovine Liver

The paper presents a set of experiments to characterize the ice front propagation in ex vivo bovine liver samples. Based on previous successful experiments using water and agar-gel as tested materials, the methodology infers the ice evolution in the sample from temperature measures obtained at the cooling device only, with a technique known as mirror image. No analytical or numerical solutions are proposed for the phase change propagation inside the tested material, such as for instance the Stefan approach as a classical free boundary problem for a parabolic partial differential equation. Thermal events inside the tested material, such as the heat flux released during the phase transition, have been deduced by the measured temperatures and the numerical solution of the thermal field inside the cooling device, conceived to mimic some thermal features of an actual cryogenic probe. The application domain for these experiments is in the cryoablative therapy, and the aim is to help providing an increased knowledge on the thermal effects to better deduce the effectiveness of the treatment and reduce recurrences, while at the same time avoid damages in the proximal anatomical structures. Results show that it is possible to detect the triggering of ice formation at the interface between the liver samples and the cooling device and predict the ice front propagation according to a law linear on the heat subtracted per unit of area. In a few tens of seconds, the maximum ice penetration distance is about 2 mm inside the liver tissue, with a penetration rate that goes from 0.2 mm/s to 0.02 mm/s. Moreover, adopting a special sample configured as an agar-gel coating superimposed to an ex vivo liver layer, the arrival time of the ice penetrating the liver and the temperature at the interface between these materials were detected, in order to estimate the part of the heat flux useful to the ice formation with respect to that spent for cooling the surrounding medium. Based on this preliminary result, to improve the cryoablation effectiveness it could be useful to increase the heat flux per unit of surface at the beginning, instead of the ablation duration.