Cold Regions Science and Technology最新文献_第6页

Response characteristic parameters of six-bundle conductor lines in ultra-heavy ice zones following ice-shedding

IF 3.8 2区工程技术 Q1 ENGINEERING, CIVIL

Cold Regions Science and Technology

Pub Date : 2024-12-08 DOI: 10.1016/j.coldregions.2024.104396

Yu Teng, Bo Yan, Xinrui Zhou, Hao Yang, Yingbo Gao, Kaiwen Wu, Huachao Deng

For a transmission line passing through ultra-heavy ice zones, the ice on the conductor line may be thicker than 50 mm, and in this case small initial tension in the conductor lines leads to obvious nonlinear vibration following ice-shedding. In this paper, dynamic responses of six-bundle conductor lines in ultra-heavy ice zones are numerically simulated by means of the nonlinear geometric finite element (FE) method, which is verified by reduced-scale modeling test. The jump height, axial unbalanced force and transverse swing of conductor lines following ice-shedding are defined to reflect the characteristics of the dynamic responses. Parameter study on the dynamic responses of isolated-span and multi-span lines with different structural, icing, ice-shedding, and wind parameters following ice-shedding is carried out and a dataset is then created. Using the dataset and the extra-trees machine learning algorithm, prediction models for the dynamic response parameters are created and the software is developed. Estimation formulas for the maximum jump height and transverse swing of multi-span lines in ultra-heavy ice zones are proposed. The obtained results provide a foundation for the design of the electric insulation clearance and structure strength of the six-bundle conductor lines in ultra-heavy ice zones.

{"title":"Response characteristic parameters of six-bundle conductor lines in ultra-heavy ice zones following ice-shedding","authors":"Yu Teng, Bo Yan, Xinrui Zhou, Hao Yang, Yingbo Gao, Kaiwen Wu, Huachao Deng","doi":"10.1016/j.coldregions.2024.104396","DOIUrl":"10.1016/j.coldregions.2024.104396","url":null,"abstract":"<div><div>For a transmission line passing through ultra-heavy ice zones, the ice on the conductor line may be thicker than 50 mm, and in this case small initial tension in the conductor lines leads to obvious nonlinear vibration following ice-shedding. In this paper, dynamic responses of six-bundle conductor lines in ultra-heavy ice zones are numerically simulated by means of the nonlinear geometric finite element (FE) method, which is verified by reduced-scale modeling test. The jump height, axial unbalanced force and transverse swing of conductor lines following ice-shedding are defined to reflect the characteristics of the dynamic responses. Parameter study on the dynamic responses of isolated-span and multi-span lines with different structural, icing, ice-shedding, and wind parameters following ice-shedding is carried out and a dataset is then created. Using the dataset and the extra-trees machine learning algorithm, prediction models for the dynamic response parameters are created and the software is developed. Estimation formulas for the maximum jump height and transverse swing of multi-span lines in ultra-heavy ice zones are proposed. The obtained results provide a foundation for the design of the electric insulation clearance and structure strength of the six-bundle conductor lines in ultra-heavy ice zones.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"231 ","pages":"Article 104396"},"PeriodicalIF":3.8,"publicationDate":"2024-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143154425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

In-situ characterization of wave velocity in ice cover with seismic observation on guided wave

IF 3.8 2区工程技术 Q1 ENGINEERING, CIVIL

Cold Regions Science and Technology

Pub Date : 2024-12-05 DOI: 10.1016/j.coldregions.2024.104392

Jiahui Gao , Yuxiang Zhang , Dingyi Ma , Zhinan Xie , Anliang Wang , Haonan Zhang

In-situ characterization of the acoustic velocity of sea ice is crucial for the successful application of related technologies. However, the elastic waveguide properties of ice sheets convert the acoustic energy into elastic waves of different modes. The overlap in both time and frequency domains poses significant challenges to the accuracy and feasibility of wave velocity estimation. A method for in-situ characterization of wave velocity in ice is proposed. Guided waves are generated through a unidirectional impact on the upper surface of the ice, and the resulting wavefield is collected within a close range using multi-wave, multi-component observations. By applying filters designed based on the polarization features, the wave packets of the S0 mode and SH waves are isolated. The arrival times of these waves are then used to estimate their respective propagation velocities. The propagation velocity of the S0 mode at low frequencies is approximated with that of the longitudinal wave in plate. The resulting propagation velocities of the longitudinal and shear waves are found to be consistent with previously reported results. A quantitative analysis of the uncertainty in velocity estimation is also included to identify the main causes and discuss potential solutions.

{"title":"In-situ characterization of wave velocity in ice cover with seismic observation on guided wave","authors":"Jiahui Gao , Yuxiang Zhang , Dingyi Ma , Zhinan Xie , Anliang Wang , Haonan Zhang","doi":"10.1016/j.coldregions.2024.104392","DOIUrl":"10.1016/j.coldregions.2024.104392","url":null,"abstract":"<div><div>In-situ characterization of the acoustic velocity of sea ice is crucial for the successful application of related technologies. However, the elastic waveguide properties of ice sheets convert the acoustic energy into elastic waves of different modes. The overlap in both time and frequency domains poses significant challenges to the accuracy and feasibility of wave velocity estimation. A method for in-situ characterization of wave velocity in ice is proposed. Guided waves are generated through a unidirectional impact on the upper surface of the ice, and the resulting wavefield is collected within a close range using multi-wave, multi-component observations. By applying filters designed based on the polarization features, the wave packets of the S0 mode and SH waves are isolated. The arrival times of these waves are then used to estimate their respective propagation velocities. The propagation velocity of the S0 mode at low frequencies is approximated with that of the longitudinal wave in plate. The resulting propagation velocities of the longitudinal and shear waves are found to be consistent with previously reported results. A quantitative analysis of the uncertainty in velocity estimation is also included to identify the main causes and discuss potential solutions.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"231 ","pages":"Article 104392"},"PeriodicalIF":3.8,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143154424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Study on icing characteristics of bundled conductor of transmission line based on shadowing effect analysis

IF 3.8 2区工程技术 Q1 ENGINEERING, CIVIL

Cold Regions Science and Technology

Pub Date : 2024-12-04 DOI: 10.1016/j.coldregions.2024.104393

Yafei Huang , Yangning Chen , Xin Yang , Zhongyi Yang , Zhan Ouyang , Xingliang Jiang , Muhammad S. Virk

Icing on transmission lines significantly threatens the safety and stability of power system. Particularly for bundled conductors, the shadowing effect of the upwind conductor on the downwind one affects airflow and droplet distribution, leading to unique icing characteristics. This paper employs numerical simulations and icing tests to investigate the icing shadowing effect of bundled conductors. Firstly, the distributions of airflow and droplets around the bundled conductor are solved by the Eulerian-Eulerian two-phase flow model. Then, by solving mass and thermodynamic balance equations, the icing mass and shape accreted on the bundled conductors under various icing conditions are obtained. Further, two novel parameters, the shadowing coefficient and the offset angle, are introduced to quantify the shadowing effect's impact on ice mass and shape. The findings indicate that the ice mass ratio on the downwind conductor to the upwind conductor is influenced by wind speed, wind angle, bundle spacing, conductor diameter, and droplet parameters. In most cases, the ratio is less than 1; however, under certain wind angles, this ratio exceeds 1. The shadowing effect also impacts the ice shape on the downwind conductor, inducing an additional offset in the ice shape. The magnitude of this offset angle is also correlated with environmental parameters. Finally, the accuracy of our numerical simulations is validated by the outcomes of natural icing tests.

{"title":"Study on icing characteristics of bundled conductor of transmission line based on shadowing effect analysis","authors":"Yafei Huang , Yangning Chen , Xin Yang , Zhongyi Yang , Zhan Ouyang , Xingliang Jiang , Muhammad S. Virk","doi":"10.1016/j.coldregions.2024.104393","DOIUrl":"10.1016/j.coldregions.2024.104393","url":null,"abstract":"<div><div>Icing on transmission lines significantly threatens the safety and stability of power system. Particularly for bundled conductors, the shadowing effect of the upwind conductor on the downwind one affects airflow and droplet distribution, leading to unique icing characteristics. This paper employs numerical simulations and icing tests to investigate the icing shadowing effect of bundled conductors. Firstly, the distributions of airflow and droplets around the bundled conductor are solved by the Eulerian-Eulerian two-phase flow model. Then, by solving mass and thermodynamic balance equations, the icing mass and shape accreted on the bundled conductors under various icing conditions are obtained. Further, two novel parameters, the shadowing coefficient and the offset angle, are introduced to quantify the shadowing effect's impact on ice mass and shape. The findings indicate that the ice mass ratio on the downwind conductor to the upwind conductor is influenced by wind speed, wind angle, bundle spacing, conductor diameter, and droplet parameters. In most cases, the ratio is less than 1; however, under certain wind angles, this ratio exceeds 1. The shadowing effect also impacts the ice shape on the downwind conductor, inducing an additional offset in the ice shape. The magnitude of this offset angle is also correlated with environmental parameters. Finally, the accuracy of our numerical simulations is validated by the outcomes of natural icing tests.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"231 ","pages":"Article 104393"},"PeriodicalIF":3.8,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143155031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Micro-mechanism of basal stresses in steady rock-ice mixture flows: Insights from 2D DEM simulations

IF 3.8 2区工程技术 Q1 ENGINEERING, CIVIL

Cold Regions Science and Technology

Pub Date : 2024-12-04 DOI: 10.1016/j.coldregions.2024.104383

Quan Zhang , Li-jun Su , Zhi-bo Dong , Yong-liang Pan

Rock-ice avalanches developing in high-altitude and cold regions typically result in massive destruction due to their exceptionally high impact force and long run-out distance. Comprehensively analyzing the basal stresses generated by this granular process is essential for understanding mechanical behaviors such as erosion and entrainment. However, the current understanding of the basal stresses generated by rock-ice mixture flows remains incomplete. In this paper, a series of miniature 2D steady flows of spherical rock-ice particles on a bumpy subsurface were conducted using DEM to provide physical insights for hazard risk management. Simulation results indicate that the kinetic energy of rock-ice mixture flows reach a steady state after the segregation reaches a stable state along the depth direction. The probability density functions of basal stresses exhibit Gaussian-like distributions in the simulations, suggesting that the interactions between rock-ice particles and the base are characterized as identical and independent events. Positive correlations exist between normalized stress fluctuations (the maximum and standard deviation of stress) and the ice content. Additionally, normalized stress fluctuations exhibit positive correlations with the free volume per spherical particle (a metric for quantitatively characterizing the free space surrounding spherical particles, which in turn influences the random particle motion) and the modified granular temperature, which includes both translational and rotational components. This highlights the significance of granular thermal motion in rock-ice mixture flows.

{"title":"Micro-mechanism of basal stresses in steady rock-ice mixture flows: Insights from 2D DEM simulations","authors":"Quan Zhang , Li-jun Su , Zhi-bo Dong , Yong-liang Pan","doi":"10.1016/j.coldregions.2024.104383","DOIUrl":"10.1016/j.coldregions.2024.104383","url":null,"abstract":"<div><div>Rock-ice avalanches developing in high-altitude and cold regions typically result in massive destruction due to their exceptionally high impact force and long run-out distance. Comprehensively analyzing the basal stresses generated by this granular process is essential for understanding mechanical behaviors such as erosion and entrainment. However, the current understanding of the basal stresses generated by rock-ice mixture flows remains incomplete. In this paper, a series of miniature 2D steady flows of spherical rock-ice particles on a bumpy subsurface were conducted using DEM to provide physical insights for hazard risk management. Simulation results indicate that the kinetic energy of rock-ice mixture flows reach a steady state after the segregation reaches a stable state along the depth direction. The probability density functions of basal stresses exhibit Gaussian-like distributions in the simulations, suggesting that the interactions between rock-ice particles and the base are characterized as identical and independent events. Positive correlations exist between normalized stress fluctuations (the maximum and standard deviation of stress) and the ice content. Additionally, normalized stress fluctuations exhibit positive correlations with the free volume per spherical particle (a metric for quantitatively characterizing the free space surrounding spherical particles, which in turn influences the random particle motion) and the modified granular temperature, which includes both translational and rotational components. This highlights the significance of granular thermal motion in rock-ice mixture flows.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"231 ","pages":"Article 104383"},"PeriodicalIF":3.8,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143154422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Intelligent characterization and robustness quantification of frozen soil strength images using a multi-module fusion strategy

IF 3.8 2区工程技术 Q1 ENGINEERING, CIVIL

Cold Regions Science and Technology

Pub Date : 2024-12-02 DOI: 10.1016/j.coldregions.2024.104384

Xun Wang , Zhaoming Yao , Hang Wei

In frozen wall engineering, traditional detection methods are difficult to implement for real-time monitoring of strength parameters, due to their intermittent nature. This makes it difficult to provide timely warnings and effective responses to potential risks of frozen walls, highlighting the urgent need for a method that can continuously and accurately monitor the strength of frozen walls. An image data-driven intelligent identification method for frozen soil strength based on convolutional neural networks is proposed. By capturing images of cured samples from multiple angles and conducting uniaxial compressive strength tests, the collected strength data were divided into 12 categories, creating an image dataset for deep learning model training. A Resnet-34 deep learning model combined with global attention and downsampling showed excellent performance in comparison with a series of basic models, with an accuracy of 93.3 % and no overfitting. The accuracy of the deep learning model was assessed using adversarial attack and defense strategies, serving as an indicator of robustness. The improved model exhibited better robustness in comparative analyses. Using SHapley Additive exPlanations (SHAP) value analysis, the feature extraction process of the convolutional neural network in recognizing frozen soil strength was investigated and clarified, confirming the model's ability to identify and extract key features in frozen soil images, such as particle size, texture, cracks, and ice crystal distribution patterns. This technology offers a cutting-edge method for real-time tracking of frozen wall conditions and early disaster warnings, significantly enhancing the safety and success rate of construction projects under freezing conditions.

{"title":"Intelligent characterization and robustness quantification of frozen soil strength images using a multi-module fusion strategy","authors":"Xun Wang , Zhaoming Yao , Hang Wei","doi":"10.1016/j.coldregions.2024.104384","DOIUrl":"10.1016/j.coldregions.2024.104384","url":null,"abstract":"<div><div>In frozen wall engineering, traditional detection methods are difficult to implement for real-time monitoring of strength parameters, due to their intermittent nature. This makes it difficult to provide timely warnings and effective responses to potential risks of frozen walls, highlighting the urgent need for a method that can continuously and accurately monitor the strength of frozen walls. An image data-driven intelligent identification method for frozen soil strength based on convolutional neural networks is proposed. By capturing images of cured samples from multiple angles and conducting uniaxial compressive strength tests, the collected strength data were divided into 12 categories, creating an image dataset for deep learning model training. A Resnet-34 deep learning model combined with global attention and downsampling showed excellent performance in comparison with a series of basic models, with an accuracy of 93.3 % and no overfitting. The accuracy of the deep learning model was assessed using adversarial attack and defense strategies, serving as an indicator of robustness. The improved model exhibited better robustness in comparative analyses. Using SHapley Additive exPlanations (SHAP) value analysis, the feature extraction process of the convolutional neural network in recognizing frozen soil strength was investigated and clarified, confirming the model's ability to identify and extract key features in frozen soil images, such as particle size, texture, cracks, and ice crystal distribution patterns. This technology offers a cutting-edge method for real-time tracking of frozen wall conditions and early disaster warnings, significantly enhancing the safety and success rate of construction projects under freezing conditions.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"231 ","pages":"Article 104384"},"PeriodicalIF":3.8,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143155347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Research on controlling measures of snowdrifts around Arctic ground-based buildings through shape optimization

IF 3.8 2区工程技术 Q1 ENGINEERING, CIVIL

Cold Regions Science and Technology

Pub Date : 2024-12-02 DOI: 10.1016/j.coldregions.2024.104382

Qingwen Zhang , Guolong Zhang , Ruixiang Zheng , Huamei Mo , Xudong Zhi , Jinzhi Wu , Feng Fan

Elevated structures in the Arctic region have proven effective in mitigating surrounding snowdrifts by enhancing the airflow beneath, and serve as a preferred architectural form. However, ground-based buildings still occupy the dominant position due to the constraints posed by construction costs and foundation conditions. One of the effective measures to reduce and prevent snowdrifts around such buildings is to modify their aerodynamic shapes. Therefore, this research endeavors to explore measures for controlling snowdrifts around ground-based buildings through shape optimization. Initially, the predictive accuracy of a refined Mixture model for simulating snowdrifts around ground-based structures was checked against wind tunnel test results. Based on the validated numerical model and representative Arctic meteorological conditions, the snowdrift controlling effects by changing the overall and local building shapes were investigated separately. Overall, the snow reduction and prevention effects can be effectively achieved for ground-based buildings with smoother sidewalls, such as those featuring a circular plane. Conversely, for traditional rectangular ground-based buildings, a larger downwind aspect ratio and a more inclined windward surface can significantly diminish peak snow depth. Additionally, the measures by adding windward side chamfering can effectively manage the locations of snow erosion areas, thereby enabling flexible placement of entrances and exits.

{"title":"Research on controlling measures of snowdrifts around Arctic ground-based buildings through shape optimization","authors":"Qingwen Zhang , Guolong Zhang , Ruixiang Zheng , Huamei Mo , Xudong Zhi , Jinzhi Wu , Feng Fan","doi":"10.1016/j.coldregions.2024.104382","DOIUrl":"10.1016/j.coldregions.2024.104382","url":null,"abstract":"<div><div>Elevated structures in the Arctic region have proven effective in mitigating surrounding snowdrifts by enhancing the airflow beneath, and serve as a preferred architectural form. However, ground-based buildings still occupy the dominant position due to the constraints posed by construction costs and foundation conditions. One of the effective measures to reduce and prevent snowdrifts around such buildings is to modify their aerodynamic shapes. Therefore, this research endeavors to explore measures for controlling snowdrifts around ground-based buildings through shape optimization. Initially, the predictive accuracy of a refined Mixture model for simulating snowdrifts around ground-based structures was checked against wind tunnel test results. Based on the validated numerical model and representative Arctic meteorological conditions, the snowdrift controlling effects by changing the overall and local building shapes were investigated separately. Overall, the snow reduction and prevention effects can be effectively achieved for ground-based buildings with smoother sidewalls, such as those featuring a circular plane. Conversely, for traditional rectangular ground-based buildings, a larger downwind aspect ratio and a more inclined windward surface can significantly diminish peak snow depth. Additionally, the measures by adding windward side chamfering can effectively manage the locations of snow erosion areas, thereby enabling flexible placement of entrances and exits.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"231 ","pages":"Article 104382"},"PeriodicalIF":3.8,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143154421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Investigate the adhesion behavior and mechanisms of salty ice on bitumen surface based on the ice heterogeneous nucleation kinetics and quasi-liquid layer theory

IF 3.8 2区工程技术 Q1 ENGINEERING, CIVIL

Cold Regions Science and Technology

Pub Date : 2024-11-27 DOI: 10.1016/j.coldregions.2024.104378

Yujin Yao , Wenchang Liu , Huaxin Chen , Yunhao Jiao , Teng Yuan , Jiayu Wu , Can Guo , Yongchang Wu

Understanding the freezing and adhesion properties of de-icing salt solutions is crucial for optimizing de-icing strategies in infrastructure and minimizing damage to the environment and road materials from de-icing salts. This work employed a customized ice-adhesion testing system to investigate the evolution of ice-adhesion strength (IAS) of NaCl and NaCH₃COO salts on bitumen surfaces under different concentrations and temperatures. The icing phase transition process and thermodynamic properties of the salt solution were analyzed using multi-channel temperature setting and differential scanning calorimetry (DSC). Moreover, the adhesive mechanisms of salty ice were elucidated based on heterogeneous nucleation kinetics and quasi-liquid layer (QLL) theory. The results show that even a 0.5 wt% salt solution can lower the IAS to approximately 40–50 % of the value observed with pure water. The concentration of salt solution required to achieve adhesive failure is temperature-dependent. Additionally, the latent heat of fusion (h_f) of NaCl solutions at concentrations from 0.5 to 2.5 wt% sequentially decreased by 45.3 J/g, 63.1 J/g, 79.9 J/g, 90.0 J/g, and 117.6 J/g compared to pure water. The freezing temperature (T_F) of 2.5 wt% NaCH₃COO and NaCl solutions dropped by 1.3 °C and 1.6 °C, respectively. Based on the ice nucleation kinetics, lowering the T_F and h_f leads to an increase in the nucleation energy barrier (ΔG*), with IAS showing a logarithmic correlation with ΔG*. Furthermore, the QLL transitions from droplets to a thin film as salinity increases, further reducing the contact area and IAS. This work offers novel insights into the freezing progress and adhesion mechanisms of salty ice, aiming to reduce maintenance costs and environmental damage from de-icing salts.

{"title":"Investigate the adhesion behavior and mechanisms of salty ice on bitumen surface based on the ice heterogeneous nucleation kinetics and quasi-liquid layer theory","authors":"Yujin Yao , Wenchang Liu , Huaxin Chen , Yunhao Jiao , Teng Yuan , Jiayu Wu , Can Guo , Yongchang Wu","doi":"10.1016/j.coldregions.2024.104378","DOIUrl":"10.1016/j.coldregions.2024.104378","url":null,"abstract":"<div><div>Understanding the freezing and adhesion properties of de-icing salt solutions is crucial for optimizing de-icing strategies in infrastructure and minimizing damage to the environment and road materials from de-icing salts. This work employed a customized ice-adhesion testing system to investigate the evolution of ice-adhesion strength (IAS) of NaCl and NaCH₃COO salts on bitumen surfaces under different concentrations and temperatures. The icing phase transition process and thermodynamic properties of the salt solution were analyzed using multi-channel temperature setting and differential scanning calorimetry (DSC). Moreover, the adhesive mechanisms of salty ice were elucidated based on heterogeneous nucleation kinetics and quasi-liquid layer (QLL) theory. The results show that even a 0.5 wt% salt solution can lower the IAS to approximately 40–50 % of the value observed with pure water. The concentration of salt solution required to achieve adhesive failure is temperature-dependent. Additionally, the latent heat of fusion (<em>h</em><sub><em>f</em></sub>) of NaCl solutions at concentrations from 0.5 to 2.5 wt% sequentially decreased by 45.3 J/g, 63.1 J/g, 79.9 J/g, 90.0 J/g, and 117.6 J/g compared to pure water. The freezing temperature (<em>T</em><sub><em>F</em></sub>) of 2.5 wt% NaCH₃COO and NaCl solutions dropped by 1.3 °C and 1.6 °C, respectively. Based on the ice nucleation kinetics, lowering the <em>T</em><sub><em>F</em></sub> and <em>h</em><sub><em>f</em></sub> leads to an increase in the nucleation energy barrier (ΔG*), with IAS showing a logarithmic correlation with ΔG*. Furthermore, the QLL transitions from droplets to a thin film as salinity increases, further reducing the contact area and IAS. This work offers novel insights into the freezing progress and adhesion mechanisms of salty ice, aiming to reduce maintenance costs and environmental damage from de-icing salts.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"231 ","pages":"Article 104378"},"PeriodicalIF":3.8,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143154387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Vibration-based ice monitoring of composite blades using artificial neural networks under different icing conditions

IF 3.8 2区工程技术 Q1 ENGINEERING, CIVIL

Cold Regions Science and Technology

Pub Date : 2024-11-26 DOI: 10.1016/j.coldregions.2024.104379

Jan Wittig , Georgios Tzortzinis , Niels Modler , Maria Lißner , Angelos Filippatos

Cold climates pose significant challenges for wind turbines, primarily due to icing that influence electrical energy production. Precise methods are needed to identify and predict ice distribution on blades, enabling enhanced prediction of ice accumulation based on the blade's frequency response. This study uses glass fiber reinforced plastic composite rotor blades equipped with actuators and accelerometers to measure, with a total of

1700

measurements, the response of the blade subjected to icing. Small-scale icing experiments are conducted inside a climate chamber at temperatures ranging from

- 10^{\circ} C

to

- 20^{\circ} C

with seven ice distribution profiles on the blades. The gathered data is analyzed for the effects of icing on the frequency response of the blades. Optimized artificial neural networks, using fully connected layers and convolutional layers, are proposed to predict the accumulated ice thickness on rotor blades based on the frequency response, with weighted mean absolute percentage errors of 5.1 % and 5.8 %, respectively, and to predict ice volume and ice mass with errors of 5.7 % and 4.9 %, respectively. Overall, this study investigates the effect of icing on the frequency response of composite blades with regard to ice mass and ice location, and proposes a high-performance data-driven method for ice detection and monitoring during operation.

{"title":"Vibration-based ice monitoring of composite blades using artificial neural networks under different icing conditions","authors":"Jan Wittig , Georgios Tzortzinis , Niels Modler , Maria Lißner , Angelos Filippatos","doi":"10.1016/j.coldregions.2024.104379","DOIUrl":"10.1016/j.coldregions.2024.104379","url":null,"abstract":"<div><div>Cold climates pose significant challenges for wind turbines, primarily due to icing that influence electrical energy production. Precise methods are needed to identify and predict ice distribution on blades, enabling enhanced prediction of ice accumulation based on the blade's frequency response. This study uses glass fiber reinforced plastic composite rotor blades equipped with actuators and accelerometers to measure, with a total of <span><math><mn>1700</mn></math></span> measurements, the response of the blade subjected to icing. Small-scale icing experiments are conducted inside a climate chamber at temperatures ranging from <span><math><mo>−</mo><msup><mn>10</mn><mo>∘</mo></msup><mi>C</mi></math></span> to <span><math><mo>−</mo><msup><mn>20</mn><mo>∘</mo></msup><mi>C</mi></math></span> with seven ice distribution profiles on the blades. The gathered data is analyzed for the effects of icing on the frequency response of the blades. Optimized artificial neural networks, using fully connected layers and convolutional layers, are proposed to predict the accumulated ice thickness on rotor blades based on the frequency response, with weighted mean absolute percentage errors of 5.1 % and 5.8 %, respectively, and to predict ice volume and ice mass with errors of 5.7 % and 4.9 %, respectively. Overall, this study investigates the effect of icing on the frequency response of composite blades with regard to ice mass and ice location, and proposes a high-performance data-driven method for ice detection and monitoring during operation.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":"231 ","pages":"Article 104379"},"PeriodicalIF":3.8,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143154426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Numerical study on cooling performance of the L-shaped crushed-rock embankment in permafrost regions 多年冻土区l型碎石路基冷却性能的数值研究

IF 3.8 2区工程技术 Q1 ENGINEERING, CIVIL

Cold Regions Science and Technology

Pub Date : 2024-11-26 DOI: 10.1016/j.coldregions.2024.104380

Yafang Guo , Wansheng Pei , Mingyi Zhang , Deren Liu , Ruiqiang Bai , Yanqiao Zhou , Guanji Li

In permafrost regions, crushed-rock embankments are favored for their environmental compatibility and thermal efficiency. This study introduces the innovative L-shaped crushed-rock embankment (LCRE), which features a crushed-rock layer exclusively at the base and on the sunny slope, providing a cost-effective alternative to the conventional U-shaped design. Using numerical methods, we assessed the cooling performance of the LCRE compared to other crushed-rock embankments, focusing on the impact of its geometric parameters. The findings indicate that the overall cooling performance of the LCRE is situated between that of the crushed-rock interlayer embankment and the U-shaped crushed-rock embankment, and its ability to mitigate the shady and sunny slope effect is superior to that of the U-shaped crushed-rock embankment. Additionally, our analysis reveals that increasing the horizontal width of the revetment to enhance cooling is not a cost-effective approach. The LCREs is more suitable for higher embankments than U-shaped counterparts. Despite the LCRE's advantageous thermal performance and cost benefits, its asymmetric load distribution could lead to exacerbated differential settlement, highlighting the need for further research. This study offers pivotal insights into the design and development of innovative crushed-rock embankments in permafrost regions.

在多年冻土区，碎石堤防因其环境相容性和热效率而受到青睐。本研究介绍了创新的l型碎石路基（lre），它的特点是在底部和向阳坡上只使用碎石层，为传统的u型设计提供了一种经济有效的替代方案。使用数值方法，我们评估了与其他破碎岩石堤防相比，lre的冷却性能，重点关注其几何参数的影响。研究结果表明：层间碎石路基整体降温性能介于层间碎石路基与u型碎石路基之间，且对阴、阳坡效应的缓解能力优于u型碎石路基；此外，我们的分析表明，增加驳岸的水平宽度来增强冷却并不是一种经济有效的方法。LCREs比u型路堤更适合于较高的路堤。尽管lre具有良好的热性能和成本效益，但其不对称的负载分布可能导致差异沉降加剧，这突出了进一步研究的必要性。这项研究为多年冻土区创新型碎石路堤的设计和开发提供了关键的见解。

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引用次数: 0

How strong is Snow? Spatial correlations of snowpack load bearing capacity and micromechanics from NASA SnowEx SnowMicroPen Data at Grand Mesa, Colorado

IF 3.8 2区工程技术 Q1 ENGINEERING, CIVIL

Cold Regions Science and Technology

Pub Date : 2024-11-26 DOI: 10.1016/j.coldregions.2024.104369

Molly E. Tedesche, Aaron C. Meyer, Sergey N. Vecherin, Tate G. Meehan

The mechanical and structural properties of a snowpack, at both the micro- and macro-scales, are critical to understanding how snow cover architecture evolves over each winter. Snow load bearing capacity across a landscape is extremely spatially variable, yet fundamentally important for an array of applications. Such applications include winter vehicle mobility and modeling wildlife movements, among others. In this study, we derive snowpack microstructural and micromechanical properties across Grand Mesa, Colorado using SnowMicroPenetrometer (SMP) penetration force datasets from the NASA SnowEx 2017 and 2020 field campaigns. For the first time, raw SMP data from the SnowEx campaigns are processed and analyzed to derive snow cover microparameters, using empirical and physical methods involving microstructural dimensions of the snow crystal matrix. We propose a newly created equation for an SMP-derived snow load bearing capacity micromechanical parameter. We also refine one technique for identifying top and bottom boundaries of snow profiles in SMP raw data.

The final component of this study involved an analysis of SMP-derived snow microparameter spatial variability across Grand Mesa, Colorado. Results of the statistical analyses for the two different years revealed consistency in spatial relationships. Microparameters that exhibited non-zero cross correlations included snow density, compression strength, load bearing capacity, and microstructural deflection during snow grain bond rupture.

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引用次数: 0