Applied Thermal Engineering最新文献

{"title":"Optimization problem for in-situ heat generation estimation in lithium-ion batteries","authors":"Jean-Luc Dauvergne ,&nbsp;Artem Nikulin ,&nbsp;Edurne Jaime-Barquero ,&nbsp;Emilie Bekaert ,&nbsp;Elena Palomo Del Barrio","doi":"10.1016/j.applthermaleng.2025.126723","DOIUrl":"10.1016/j.applthermaleng.2025.126723","url":null,"abstract":"<div><div>Knowledge of the thermal behavior of a lithium-ion battery is a key factor in ensuring its optimum performance. This paper presents a novel and non-intrusive method for accurately estimating the heat generated inside a battery during operation, based solely on surface temperature measurements. The originality of the approach lies in its ability to retrieve the total internal heat sources over time, without any prior assumptions regarding their profile, number, or spatial distribution across the cell thickness by solving an optimization problem with a regularized objective function, where the input is the measured surface temperature, and the output is the time-dependent internal heat generation. This method therefore combines simple and in-situ instrumentation, without requiring other characterization devices such as calorimeters, with a powerful non-iterative estimation method. The results obtained both numerically and experimentally show high accuracy over a wide range of conditions. In numerical tests, the relative error on the total estimated energy remained below 0.03% in most cases where effective thermal properties of the cell are known. To account for uncertainties in these effective properties, an enthalpic formulation was used, and the error in the estimated total enthalpy remained below 0.3% despite significant initial biases in the input thermal properties. Experimental validation using a dummy pouch cell with a controlled heating element confirmed these results, with relative total energy estimation errors not exceeding 8.2% for purely theoretical patterns and as low as 1.6% for a heat generation profile from a real calorimetric experiment, demonstrating the reliability and robustness of the proposed method.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"274 ","pages":"Article 126723"},"PeriodicalIF":6.1,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143942584","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}

{"title":"The role of nanoparticles in combustion improvement: Performance and emission analysis of a DI diesel engine fuelled with water-in-biodiesel emulsions enhanced by mono and hybrid nanoparticles","authors":"Mhadi A. Ismael ,&nbsp;Izz Rasyad Silmyi ,&nbsp;Waqad Ul Mulk ,&nbsp;Mohammed El-Adawy ,&nbsp;A. Rashid A. Aziz ,&nbsp;M.Elamen Babiker ,&nbsp;Medhat A. Nemitallah","doi":"10.1016/j.applthermaleng.2025.126755","DOIUrl":"10.1016/j.applthermaleng.2025.126755","url":null,"abstract":"<div><div>The growing demand for cleaner and more efficient diesel engine operation has driven interest in alternative fuels and advanced additives. This study investigates the effects of incorporating mono and hybrid metal oxide nanoparticles aluminium oxide (Al₂O₃) and manganese oxide (Mn₂O₃) into a biodiesel blend (B10) and its water-emulsified form (B10W5) to enhance combustion performance, thermal efficiency, and emissions in a single-cylinder direct injection (DI) diesel engine under full-load conditions. Nanoparticles were dispersed into the fuel blends via ultrasonication, and their impacts on key engine parameters were experimentally evaluated. Al₂O₃ significantly increased the peak heat release rate (HRR) by 145 %, while Mn₂O₃ delayed ignition but enhanced post-ignition energy release. The hybrid Al₂O₃-Mn₂O₃ combination advanced ignition timing and increased peak in-cylinder pressure by 2.6–3 % compared to B10. The B10Al₂O₃-Mn₂O₃ blend with water achieved the highest indicated mean effective pressure (IMEP) of 12.2 bar, along with a 34.4 % increase in HRR, a 54.5 % rise in cumulative heat release, and 27.8 % faster combustion. It also recorded the highest indicated thermal efficiency (ITE) of 48.4 %, significantly outperforming B10. Both Al₂O₃ and Mn₂O₃ effectively reduced hydrocarbon (HC) and carbon monoxide (CO) emissions, though they slightly increased nitrogen oxides (NO_x) and carbon dioxide (CO₂) levels. B10Al₂O₃ increased NO_x emissions by 6.25 %, while B10Mn₂O₃, B10Al₂O₃-Mn₂O₃/B10W5, and B10W5Al₂O₃-Mn₂O₃ reduced NO_x by 7.21 %, 15.87 %, and 27.88 %, respectively. Overall, the findings demonstrate that integrating nanoparticles and water emulsification in biodiesel blends offers a promising strategy to enhance engine performance, boost thermal efficiency, and reduce emissions in diesel engines.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"274 ","pages":"Article 126755"},"PeriodicalIF":6.1,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143936946","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}

{"title":"A comparative study on combustion and emission characteristics of ammonia ignited by n-heptane, n-dodecane, and PODE in an optical engine","authors":"Ren Zhang ,&nbsp;Jinguang Li ,&nbsp;Lin Chen ,&nbsp;Wei Li ,&nbsp;Haiqiao Wei ,&nbsp;Jiaying Pan","doi":"10.1016/j.applthermaleng.2025.126754","DOIUrl":"10.1016/j.applthermaleng.2025.126754","url":null,"abstract":"<div><div>Combining high-reactivity fuels is acknowledged as an efficient strategy for improving ammonia combustion performance. However, there is currently a lack of direct experimental evidence regarding the suitability of various fuels and their impacts on combustion and emission characteristics. In this study, a comparative investigation was conducted to explore the influence of n-heptane, n-dodecane, and polyoxymethylene dimethyl ether (PODE) on ammonia’s combustion and emission within an optical engine. Pressure trajectories, combustion flame evolution, and nitrogen-based pollutants were addressed. Considering the poor ignition of ammonia, the high-reactivity fuel was maintained at a 30% energy ratio, and the injection timing was varied between −70 and −20 °CA aTDC. The results demonstrate that n-dodecane and PODE can enhance ammonia combustion more pronounced compared to n-heptane. Specifically, higher thermal efficiency and reduced cyclic variations are observed, alongside an extended stable operating range. Moreover, among the three highly reactive fuels, PODE exhibits optimal performance in combustion phasing and duration, leading to more complete combustion of ammonia. Combustion visualizations indicate that, when adopting PODE fuel, sequential auto-ignition becomes more prevalent, particularly at early injection timings. Regarding nitrogen-based emissions, both PODE and n-dodecane significantly reduce NH₃ and N₂O emissions, but NOx emissions increase, especially at early injection timings. Notably, PODE can achieve NOx emissions that are comparable to those of n-heptane under late injection conditions. Therefore, adopting PODE fuel with an optimized injection strategy can present substantial benefits in terms of fuel economy and reduced pollution emissions.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"274 ","pages":"Article 126754"},"PeriodicalIF":6.1,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143942586","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}

{"title":"Effect of thermal spray aluminum oxide coating on the long-term stability of pool boiling heat transfer enhancement","authors":"Mubarak Salisu ,&nbsp;Shixue Wang ,&nbsp;Yurong Yang ,&nbsp;Yu Zhu ,&nbsp;Xiaodong Wang ,&nbsp;Jingyi Zhang","doi":"10.1016/j.applthermaleng.2025.126759","DOIUrl":"10.1016/j.applthermaleng.2025.126759","url":null,"abstract":"<div><div>Boiling stability is a crucial but frequently ignored attribute when developing modified surfaces to improve phase-change heat transfer. This study investigated pool boiling on copper surfaces with various durable micro-porous thickness aluminum oxide (Al₂O₃) coatings applied using thermal spraying that improved the pool boiling stability at high heat fluxes with deionized water as the working fluid. The experiments compared the effects of surface roughness and coating thickness on the pool boiling heat transfer enhancement relative to a copper surface. Each surface underwent continuous nucleate boiling for 60 h. The wettability, morphology, and surface oxidation were assessed before and after each test. The boiling heat transfer rates on the Al₂O₃ surfaces were very stable with little degradation. The standard deviation of the heat transfer coefficient on the coated surface was 0.951 kW/m²K, while that on the copper surface was 3.184 kW/m²K for the boiling curve stability test. The pool boiling CHF was significantly higher on the coated Al₂O₃ surfaces than on the copper surfaces. The CHF on the coated rough surface was 1681.1 kW/m², 54.6 % higher than on the copper surface. Thus, these Al₂O₃ coated surfaces demonstrate considerable potential for integration into applications that demand precise heat transfer and efficient thermal management.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"274 ","pages":"Article 126759"},"PeriodicalIF":6.1,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143942581","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}

{"title":"Reaching near-isothermal compression in liquid piston with PCM inserts","authors":"Meghana Athadkar,&nbsp;Sylvie Lorente","doi":"10.1016/j.applthermaleng.2025.126758","DOIUrl":"10.1016/j.applthermaleng.2025.126758","url":null,"abstract":"<div><div>Air compression processes see a surge of interest with the growing objective of storing renewable energy at various scales, as in Compressed Air Energy Storage. This objective of this work is to develop a solution to compress air at quasi constant temperature, the gold standard in terms of thermodynamic efficiency. To this sake, phase change material (PCM) elements are inserted into the cylindrical compression chamber of a liquid piston. A theoretical approach based on scale analysis gives information on the PCM volume, the PCM elements geometry and their spacing. A three-dimensional numerical model is developed to describe heat transfer during compression. After validation with results available in the literature, the model is expanded to account for the presence of PCM inserts within the air compression chamber. The set of equations is therefore completed by solving the energy equation within the PCM elements to describe melting. A study of the impact of the number of PCM inserts is then conducted together with the distance between these elements. The results show the impact of the PCM rods spacing on the control of the average compressed air temperature. In the best-case scenario, the temperature increase is 4.5 K.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"274 ","pages":"Article 126758"},"PeriodicalIF":6.1,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143941981","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}

{"title":"External exchanges around a Chaotic Helix Exchanger in a thermal energy storage tank","authors":"Nouhaila El Hani ,&nbsp;Tom Lacassagne ,&nbsp;Souria Hamidouche ,&nbsp;André Bontemps ,&nbsp;S. Amir Bahrani","doi":"10.1016/j.applthermaleng.2025.126611","DOIUrl":"10.1016/j.applthermaleng.2025.126611","url":null,"abstract":"<div><div>This study compares the external heat transfer performances and energy efficiency of two heat exchanger geometries, Chaotic Helix Exchanger (CHE) and Helical Heat Exchanger (HHE), under varying flow rates, immersed in a thermal energy storage tank. External heat transfer performance refers to the ability of the heat exchanger to transfer heat between its surface and the surrounding fluid, which is crucial for optimizing energy efficiency in storage systems. The novelty of this work lies in the integration of chaotic advection-based heat exchangers into thermal storage systems, a topic that remains unexplored in the literature. Experimental methods involved dimensionless temperature (<span><math><mi>θ</mi></math></span>) analyses and measurements of the external heat transfer coefficient (<span><math><mi>h</mi></math></span>). Results indicated that CHE maintained a consistent and predictable heat transfer process, with <span><math><mi>θ</mi></math></span> decreasing uniformly to equilibrium across all flow rates, while HHE showed sensitivity to flow rates, with initial fluctuations in <span><math><mi>θ</mi></math></span> before stabilization. The external heat transfer coefficients were similar for both geometries at most flow rates but differed slightly at intermediate rates. Additionally, temperature ratio analysis revealed that CHE consistently maintained a uniform temperature distribution (ratio = 0.99), while HHE exhibited initial peaks and non-uniformities before stabilizing. These findings show that CHE is more efficient in maintaining uniform heat transfer and minimizing energy losses, making it the better choice for energy-efficient heat exchanger design. The enhanced thermal stability and performance of CHE directly contribute to reducing energy consumption, especially in systems requiring consistent thermal regulation.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"274 ","pages":"Article 126611"},"PeriodicalIF":6.1,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143927816","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}

{"title":"Machine learning-based performance and optimal refrigerant charge prediction for a split air conditioning system","authors":"Rajendran Prabakaran ,&nbsp;B. Gomathi ,&nbsp;A. Lalitha Saravanan ,&nbsp;P. Jeyalakshmi ,&nbsp;Dhasan Mohan Lal ,&nbsp;Sung Chul Kim","doi":"10.1016/j.applthermaleng.2025.126764","DOIUrl":"10.1016/j.applthermaleng.2025.126764","url":null,"abstract":"<div><div>Maintaining the optimal refrigerant charge and accurately predicting the performance of split-type air conditioning (STAC) systems are essential for enhancing energy efficiency and reducing carbon emissions. The adoption of the environmentally friendly refrigerant R290 as a replacement for R22 has increased due to updated regulations. However, optimizing refrigerant charge and system performance typically demands substantial research, cost, and time. To address this challenge, six machine learning (ML) models—artificial neural network (ANN), multi-layer perceptron (MLP), extreme gradient boosting (XGB), support vector regression (SVR), random forest (RF), and K-nearest neighbor (KNN)—were employed to predict STAC performance and determine the optimal refrigerant charge. For model development, the considered input features were indoor and outdoor temperatures—specifically, wet-bulb temperature (WBT), dry-bulb temperature (DBT)—and refrigerant charge. The predicted outputs were system pressure, power consumption, coefficient of performance (COP), refrigerant mass flow rate, and evaporator capacity. Correlation analysis showed a strong negative correlation between outdoor DBT and COP (−0.96), followed by indoor DBT (−0.81) and indoor WBT (−0.67). However, no perfect relationship was observed between COP and refrigerant charge, likely due to nonlinearity. Among the models, SVR, ANN, and RF performed best on smaller datasets (&lt;20 samples), while XGB demonstrated superior performance on larger datasets (&gt;40 samples). XGB outperformed MLP and RF, achieving deviations within ±5 %, a mean absolute error of 2.539, and an R² value of 0.957. The optimal refrigerant charge amounts predicted for R290 were 460 and 320 g for the existing and modified systems, respectively, 2.3 % and 3.2 % higher than the experimental values. This study underscores the potential of ML models, particularly XGB, in optimizing STAC systems using environmentally friendly refrigerants.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"274 ","pages":"Article 126764"},"PeriodicalIF":6.1,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143936993","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}

{"title":"Zero-carbon energy system for offshore Islands: Integrating freeze desalination, hydrogen storage, and fuel cells","authors":"Yuan Zhao ,&nbsp;Han Yuan ,&nbsp;Xinyu Liu ,&nbsp;Ji Zhang ,&nbsp;Jiatong Song ,&nbsp;Haibin Wang","doi":"10.1016/j.applthermaleng.2025.126702","DOIUrl":"10.1016/j.applthermaleng.2025.126702","url":null,"abstract":"<div><div>Energy supply challenges hinder the economic development of remote offshore islands, which traditionally rely on diesel generators, causing pollution, shortages, and high costs. Wind power and photovoltaics, promising renewable sources, offer solutions when integrated with technologies such as desalination, refrigeration, and power generation, tailored to local conditions. However, their fluctuating nature leads to system instability. Additionally, while freshwater and cooling energy are vital for island residents, traditional desalination is costly, and refrigeration systems often fail to meet comprehensive needs. The pursuit of low-cost desalination and effective low-temperature refrigeration is still needed. This research proposes an integral renewable energy system for islands, combining ocean thermal, wind, and solar energy, with ocean thermal energy conversion system as the stabilizer. By employing freeze desalination technology, the system achieves a joint supply of low-cost seawater desalination and low-temperature refrigeration. Additionally, the integration of freshwater, hydrogen storage, and fuel cell technology facilitates the storage and reconversion of surplus electricity, addressing temporal and spatial energy mismatches while lowering power consumption costs. This study employs multi-objective optimization to refine the configuration of the multi-energy complementary supply system, concentrating on thermodynamic and economic performance objectives. Findings show that for user electrical loads fluctuating between 2 MW and 4.5 MW, with theoretical design capacities of 2 MW for ocean thermal energy conversion system, 2.2 MW for photovoltaic, and 1.7 MW for wind turbines. Its exergy efficiency is 34.63 % with a levelized cost of power at 0.084$/kWh. Furthermore, the system can potentially reduce CO₂ emissions by approximately 2.16 × 10⁴ tons annually, demonstrating significant environmental benefits. This research offers a solution with enhanced stability and lower energy supply costs for offshore islands, contributing to the advancement of zero-carbon offshore integrated energy technologies.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"274 ","pages":"Article 126702"},"PeriodicalIF":6.1,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143927888","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}

{"title":"Parametric study on a novel steam injected inverted Brayton cycle system recovering waste heat from the internal combustion engine","authors":"Biqing Jin ,&nbsp;Junlong Liu ,&nbsp;Jing Chen ,&nbsp;Yujun Tang ,&nbsp;Jinfeng Feng ,&nbsp;Shuzhan Bai ,&nbsp;Sipeng Zhu","doi":"10.1016/j.applthermaleng.2025.126774","DOIUrl":"10.1016/j.applthermaleng.2025.126774","url":null,"abstract":"<div><div>To fully explore the potential of recovering waste heat from the turbocharged internal combustion engine, this paper proposes a novel steam injected inverted Brayton cycle (IBC) system, with the IBC subsystem recovering excess exhaust pressure energy downstream of the turbocharger turbine and the steam injection subsystem utilizing waste heat from the IBC heat exchanger. First, the configuration and thermodynamic processes of this novel system are introduced, followed by detailed descriptions of model building and validation. Next, parametric simulations for the IBC system with steam injection are carried out, and optimization of the whole combined power cycle system is present at the end. The results show that the IBC turbine size has the biggest effect on the exhaust energy distributions across two turbines, followed by the bypass valve opening and the IBC power split ratio. To fully utilize the injected steam energy, the injected location should be upstream of the turbocharger turbine rather than upstream of the IBC turbine. The total fuel economy can be improved by 7.4 % at the rated condition. Considering the case swept optimization at different engine speeds, the fuel economy at the rated speed and the maximum torque speed can be improved by 3.5 % and 2.8 %, respectively.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"274 ","pages":"Article 126774"},"PeriodicalIF":6.1,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143936991","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}

{"title":"Hydro-thermal disturbance and its impact on the bearing characteristics of bored piles in ice-rich permafrost","authors":"Qiang Gao ,&nbsp;Lin Chen ,&nbsp;Zhi Wen ,&nbsp;Zhiwei Zhou ,&nbsp;Changxin Fan ,&nbsp;Anatoli Brouchkov ,&nbsp;Alexander Zhirkov","doi":"10.1016/j.applthermaleng.2025.126652","DOIUrl":"10.1016/j.applthermaleng.2025.126652","url":null,"abstract":"<div><div>In warm, ice-rich permafrost regions, road construction confronts challenges such as frost heave, thaw settlement. Bored piles were first extensively utilized in the construction of the Qinghai-Tibet Railway. However, the effects of hydro-thermal disturbance—primarily from curing hydration heat—on the surrounding frozen soil, and its impacts on pile bearing characteristics post-refreezing, remain unclear. In this study, frozen soil’s melting-refreezing process, alongside associated moisture migration and redistribution is investigated via model experiments. By analyzing extensive field test data, how the thermal disturbance history influences the bearing characteristics of bored piles is further examined. Based on these findings, a hydro-thermal interaction mechanism between pile and surrounding frozen soil is proposed. Results indicate that thermal disturbance instigates the melting of upper ice layer, with moisture percolating downward into the soil pores along the thawed zone due to gravity. Upon refreezing, gaps at pile-ice interface and ice reallocation in the surrounding soil influence the distribution of shaft resistance. The study also reveals that pile diameter-determining the total hydration heat emission, together with the temperature and ice content of the adjacent permafrost—both impacting the thermal disturbance intensity and thawing extent, jointly shape the hydrothermal process of the pile-soil system. Higher moisture content in the soil tends to diminish shaft resistance, while larger pile diameters and higher ground temperatures augment end resistance ratio. The conclusions furnish a theoretical basis for designing and constructing bored piles in permafrost regions.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"274 ","pages":"Article 126652"},"PeriodicalIF":6.1,"publicationDate":"2025-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144068839","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}