International Communications in Heat and Mass Transfer最新文献_第2页

Thermodynamic and thermal perspectives of failure in oscillating heat pipe 振荡热管失效的热力学和热学观点

IF 6.4 2区工程技术

International Communications in Heat and Mass Transfer Pub Date : 2025-10-10 DOI: 10.1016/j.icheatmasstransfer.2025.109745

Ashok Thapa, Maheswar Chaudhary, Ryan Gallagher, Shalabh C. Maroo

{"title":"Thermodynamic and thermal perspectives of failure in oscillating heat pipe","authors":"Ashok Thapa, Maheswar Chaudhary, Ryan Gallagher, Shalabh C. Maroo","doi":"10.1016/j.icheatmasstransfer.2025.109745","DOIUrl":"10.1016/j.icheatmasstransfer.2025.109745","url":null,"abstract":"<div><div>Oscillating heat pipes (OHPs) have garnered significant attention for thermal management applications due to their high heat transfer efficiency, ease of miniaturization, and adaptable form factor. However, their operation can be prone to failure under unpredictable heat input conditions, potentially leading to device malfunction. The mechanisms driving such failures remain poorly understood, thereby complicating efforts to reliably predict OHP performance limits. In this study, the operational limit at which OHP failure occurs is experimentally identified, and two predictive criteria—thermal convergence and the thermodynamic saturation limit—are introduced to explain and predict the onset of such failure. A 14-tube OHP is fabricated, with the evaporator and condenser sections constructed from copper tubing, and the adiabatic section made of non-conductive, transparent glass tubing. Temperature and pressure measurements are obtained from a selected tube for three working fluids: water, methanol, and ethanol. OHP failure is directly observed during experiments conducted with water as the working fluid. The predictive capability of the two criteria is validated using the experimental results for water, and subsequently applied to methanol and ethanol, enabling failure prediction without operating the OHP to the point of failure.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"169 ","pages":"Article 109745"},"PeriodicalIF":6.4,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145262860","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

Transient heat transfer characteristics and flow mechanism of two-phase closed thermosyphon 两相闭式热虹吸管的瞬态传热特性及流动机理

IF 6.4 2区工程技术

International Communications in Heat and Mass Transfer Pub Date : 2025-10-10 DOI: 10.1016/j.icheatmasstransfer.2025.109753

Wandong Bai , Zhanli Geng , Xiang Li , Lanxin Wang , Yue Shen , Wei Chen

{"title":"Transient heat transfer characteristics and flow mechanism of two-phase closed thermosyphon","authors":"Wandong Bai , Zhanli Geng , Xiang Li , Lanxin Wang , Yue Shen , Wei Chen","doi":"10.1016/j.icheatmasstransfer.2025.109753","DOIUrl":"10.1016/j.icheatmasstransfer.2025.109753","url":null,"abstract":"<div><div>The two-phase closed thermosyphon (TPCT) has shown great potential in solar thermal collectors. Despite the prevalence of internal-external conjugate heat transfer in practical TPCT applications, research on this topic remains limited. This study investigates the effects of three typical condensation cooling scenarios, heating power, and working fluid filling ratio on TPCT heat transfer characteristics. In order to reveal the underlying mechanisms, a phase change model for TPCT simulation was developed based on Lee's equation using the Nusselt's theory and the principle of thermal balance. The results indicated that the two-phase flow within the TPCT exhibits intermittent boiling, continuous boiling, and annular flow modes under the varying operational conditions. These two-phase flow patterns in turn determine the temperature behavior and overall heat transfer performance of the TPCT. This work contributes to a deeper understanding of the mechanisms governing TPCT heat transfer, thereby providing guidance for controlling operational condition in its application.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"169 ","pages":"Article 109753"},"PeriodicalIF":6.4,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145262755","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

Increasing the thermal performance of double-pipe heat exchangers by active methods: A comprehensive review 利用主动方法提高双管换热器的热性能：综述

IF 6.4 2区工程技术

International Communications in Heat and Mass Transfer Pub Date : 2025-10-10 DOI: 10.1016/j.icheatmasstransfer.2025.109837

Saif Ali Kadhim , Rassol Hamed Rasheed , Osama Abd Al-Munaf Ibrahim , Husam Abdulrasool Hasan , Farhan Lafta Rashid , Ali M. Ashour , Abdallah Bouabidi , Karrar A. Hammoodi

{"title":"Increasing the thermal performance of double-pipe heat exchangers by active methods: A comprehensive review","authors":"Saif Ali Kadhim , Rassol Hamed Rasheed , Osama Abd Al-Munaf Ibrahim , Husam Abdulrasool Hasan , Farhan Lafta Rashid , Ali M. Ashour , Abdallah Bouabidi , Karrar A. Hammoodi","doi":"10.1016/j.icheatmasstransfer.2025.109837","DOIUrl":"10.1016/j.icheatmasstransfer.2025.109837","url":null,"abstract":"<div><div>This review investigates recent advancements in active heat transfer enhancement techniques for double-pipe heat exchangers, which are widely used in industrial and energy systems due to their simple design, ease of maintenance, and operational flexibility. A typical double-pipe heat exchanger consists of one pipe inside another, enabling efficient heat exchange between two fluids. While passive methods for improving thermal performance in double-pipe heat exchangers offer limited enhancement, active techniques, such as mechanical vibration, tube rotation, fluid injection, electromagnetic fields, and acoustic excitation, have demonstrated greater effectiveness by disturbing the thermal boundary layer and inducing enhanced turbulence, leading to significantly improved heat transfer rates. This review classifies active techniques into mechanical, electromagnetic, acoustic, and thermal categories, providing detailed insights into their mechanisms, working fluids, flow regimes, and combined applications with passive elements. Experimental and numerical studies are compared based on the thermal enhancement factor, revealing that electromagnetic techniques, particularly magnetic turbulators, achieved the highest thermal enhancement factor values (above 4), especially in laminar flows. Mechanical vibration and tube rotation also demonstrated strong enhancement, with promising results when integrated with nanofluids or twisted tapes. Despite trade-offs in pressure drop and energy input, active methods show high potential for targeted heat transfer improvement in double-pipe heat exchangers, especially under controlled flow conditions. The findings serve as a benchmark for selecting optimal enhancement strategies in advanced thermal systems.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"169 ","pages":"Article 109837"},"PeriodicalIF":6.4,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145262260","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

Pulsatile hemodynamic prediction in cerebral fusiform aneurysms using proper orthogonal decomposition model and long short-term memory networks 利用正交分解模型和长短期记忆网络预测脑梭状动脉瘤的搏动血流动力学

IF 6.4 2区工程技术

International Communications in Heat and Mass Transfer Pub Date : 2025-10-10 DOI: 10.1016/j.icheatmasstransfer.2025.109833

Walid Aich , Joy Djuansjah , Ali B.M. Ali , As'ad Alizadeh , Muntadher Abed Hussein , Narinderjit Singh Sawaran Singh , Khalil Hajlaoui , Wajdi Rajhi

{"title":"Pulsatile hemodynamic prediction in cerebral fusiform aneurysms using proper orthogonal decomposition model and long short-term memory networks","authors":"Walid Aich , Joy Djuansjah , Ali B.M. Ali , As'ad Alizadeh , Muntadher Abed Hussein , Narinderjit Singh Sawaran Singh , Khalil Hajlaoui , Wajdi Rajhi","doi":"10.1016/j.icheatmasstransfer.2025.109833","DOIUrl":"10.1016/j.icheatmasstransfer.2025.109833","url":null,"abstract":"<div><div>This study presents a hybrid computational framework that combines Proper Orthogonal Decomposition (POD) with Long Short-Term Memory (LSTM) neural networks to efficiently model and forecast transient hemodynamic parameters in patient-specific cerebral fusiform aneurysm geometries. High-resolution computational fluid dynamics (CFD) simulations were performed using ANSYS-Fluent with a Casson non-Newtonian blood model, resolving flow fields including wall shear stress (WSS), oscillatory shear index (OSI), and pressure under both rest and exercise physiological conditions. POD was applied to extract dominant spatial modes, achieving over 99 % energy capture within 50 modes, thereby enabling significant model reduction. Quantitative analysis based on L2 norm differences showed low reconstruction and prediction errors, particularly for pressure and WSS components, while OSI exhibited higher variability due to its sensitivity to temporal fluctuations. Contour plots of predicted fields confirmed that the proposed model preserves critical spatial features, including high-shear and oscillatory regions relevant to aneurysmal wall degradation. The proposed POD-LSTM surrogate model offers a fast, accurate, and computationally efficient alternative to full CFD simulations, making it suitable for real-time hemodynamic analysis and patient-specific aneurysm assessment. This work lays the foundation for future integration of reduced-order Artificial Intelligence (AI) models into clinical workflows, supporting predictive diagnostics and personalized neurovascular care.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"169 ","pages":"Article 109833"},"PeriodicalIF":6.4,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145262867","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

Numerical study on heat transfer enhancement performance of a jet impingement heat sink combining with inverted trapezoidal mini-channel 结合倒梯形微通道的射流冲击散热器强化传热性能的数值研究

IF 6.4 2区工程技术

International Communications in Heat and Mass Transfer Pub Date : 2025-10-10 DOI: 10.1016/j.icheatmasstransfer.2025.109831

Ming Peng, Kai Zheng, Ke Yang, Yuyang Li, Yecheng Liu, Hong Ji, Zhixiang Xing

{"title":"Numerical study on heat transfer enhancement performance of a jet impingement heat sink combining with inverted trapezoidal mini-channel","authors":"Ming Peng, Kai Zheng, Ke Yang, Yuyang Li, Yecheng Liu, Hong Ji, Zhixiang Xing","doi":"10.1016/j.icheatmasstransfer.2025.109831","DOIUrl":"10.1016/j.icheatmasstransfer.2025.109831","url":null,"abstract":"<div><div>The pursuit of high heat flux dissipation in power electronics demands cooling solutions that transcend the performance of conventional mini-channels. This numerical study employs the <em>k</em>-<em>ε</em> turbulence model to optimize a hybrid jet impingement and mini-channel system by evaluating the cross-section shape, inclination angle, and jet number. Key findings reveal that the inverted trapezoidal channel minimizes flow resistance, reducing pressure drop by approximately 57 % compared to the straight channel. While the pressure drop of trapezoidal mini-channel is the highest, about three times that of straight channels. Field synergy analysis shows that the diverging mini-channel enhance heat transfer best. However, the inverted trapezoidal channel offers the best thermal-hydraulic performance, lowering the thermal resistance by up to 22.5 % compared with straight channel at a pressure drop of 19.5 kPa. Parametric analysis of the bottom width identifies an optimum of 0.16 mm, maintaining the peak thermal resistance below 0.48 cm<sup>2</sup>·°C/W with a lower pressure drop. Furthermore, increasing jet inlets degrades thermal resistance despite reducing the pressure drop. Single-inlet designs minimize thermal resistance via higher jet intensity. Whereas the channel with 3 inlets enhances bottom-wall temperature uniformity by 4.2 % under the mass flow rate studied.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"169 ","pages":"Article 109831"},"PeriodicalIF":6.4,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145262256","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

The dynamic characteristics of hollow droplet impacting spherical surfaces with different wettabilities 空心液滴冲击不同润湿性球面的动力学特性

IF 6.4 2区工程技术

International Communications in Heat and Mass Transfer Pub Date : 2025-10-10 DOI: 10.1016/j.icheatmasstransfer.2025.109735

Bingbing Yan, Chengbin Sun, Lijuan Qian, Li Lv

{"title":"The dynamic characteristics of hollow droplet impacting spherical surfaces with different wettabilities","authors":"Bingbing Yan, Chengbin Sun, Lijuan Qian, Li Lv","doi":"10.1016/j.icheatmasstransfer.2025.109735","DOIUrl":"10.1016/j.icheatmasstransfer.2025.109735","url":null,"abstract":"<div><div>To investigate the influence of surface wettability on impact dynamics, this study combines experimental and theoretical approaches to elucidate the complex behavior of hollow glycerol droplets impacting spherical surfaces with varying wettabilities and size ratios. Experimental observations reveal that collisions with spheres of different curvatures induce phenomena such as reflection flows, encapsulation, and bubble detachment. Unlike solid droplets, which rebound and form dome-shaped structures upon impact, hollow droplets exhibit fluid instability during spreading due to internal bubble collapse, leading to film rupture and suppression of rebound, ultimately forming “doughnut-shaped” structures. For hollow droplets composed of 25 % glycerol–water mixture, the critical Weber numbers for reflection flows traversing the internal bubble are 140 and 175 on hydrophilic and hydrophobic surfaces, respectively, increasing to 217 for 50 % glycerol solutions. The maximum reflection flow length reaches 7.11 mm in deionized water and decreases with increasing viscosity. The deviation between bubble rupture time and the time to maximum spreading is approximately 3 %, with central jet detachment occurring at t<sub>c</sub>/ <span><math><mi>τ</mi></math></span>=22.08We<sup>-0.76</sup>. Based on volume and mass conservation principles, the residual film thickness h on the spherical surface and the spreading velocity U<sub>0</sub> of the hollow droplet were predicted. Furthermore, a theoretical model incorporating gravitational effects was developed to describe the maximum spreading factor <span><math><msub><mi>β</mi><mi>m</mi></msub></math></span> on spherical surfaces, with a 7 % deviation from experimental measurements.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"169 ","pages":"Article 109735"},"PeriodicalIF":6.4,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145262257","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 temperature-controlled by phase change materials and energy analysis in a refrigerated vehicle during the door opening 冷藏车车门开启过程相变材料控温及能量分析研究

IF 6.4 2区工程技术

International Communications in Heat and Mass Transfer Pub Date : 2025-10-10 DOI: 10.1016/j.icheatmasstransfer.2025.109824

Puxian Ding , Yingsun Sun , Shiming Liu , Di Fan , Ye Feng , Xinqiang Liao

{"title":"Study on temperature-controlled by phase change materials and energy analysis in a refrigerated vehicle during the door opening","authors":"Puxian Ding , Yingsun Sun , Shiming Liu , Di Fan , Ye Feng , Xinqiang Liao","doi":"10.1016/j.icheatmasstransfer.2025.109824","DOIUrl":"10.1016/j.icheatmasstransfer.2025.109824","url":null,"abstract":"<div><div>This study investigates how phase change materials (PCMs) mitigate temperature rise and energy consumption during door openings in refrigerated vehicles at 66 % loading capacity. Numerical simulations are employed to analyze airflow patterns, thermal dynamics, and energy consumption. Key findings include: When the fan is off, external hot air enters the compartment, raising internal temperatures and impacting both the food and the PCM. With the fan on, airflow reduces direct contact between the hot air and the food, and increasing inlet velocity helps prevent excessive temperature rise. However, an inlet velocity of 3 m/s causes the air to escape the compartment, diminishing the cooling capacity of the PCM and raising the internal temperature. Baffle designs effectively block hot air, particularly in areas near the door, mitigating temperature rise and slowing food warming, thus reducing recovery energy. Higher inlet velocities increase cold energy consumption, with an inlet velocity of 3 m/s showing the highest consumption due to direct airflow from the fan. However, baffles reduce cold energy usage. The inlet velocity with 2 m/s in the baffle case is identified as optimal, balancing temperature control, food quality preservation, and lower recovery energy consumption. It also improves cold energy efficiency and reduces hot air intrusion.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"169 ","pages":"Article 109824"},"PeriodicalIF":6.4,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145262862","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

Nanoscale insights into bi-conductive surfaces: An analytical study of enhanced pool boiling performance through wettability and thermal conductivity 纳米级双导电表面的洞察：通过润湿性和导热性增强池沸腾性能的分析研究

IF 6.4 2区工程技术

International Communications in Heat and Mass Transfer Pub Date : 2025-10-10 DOI: 10.1016/j.icheatmasstransfer.2025.109746

Sina Li, Sihong He, Kejian Dong, Yuzhe Li, Song Ni, Jiyun Zhao

{"title":"Nanoscale insights into bi-conductive surfaces: An analytical study of enhanced pool boiling performance through wettability and thermal conductivity","authors":"Sina Li, Sihong He, Kejian Dong, Yuzhe Li, Song Ni, Jiyun Zhao","doi":"10.1016/j.icheatmasstransfer.2025.109746","DOIUrl":"10.1016/j.icheatmasstransfer.2025.109746","url":null,"abstract":"<div><div>Recent advancements in surface modification technologies have led to significant enhancements in heat transfer techniques for pool boiling, particularly through the use of bi-conductive surfaces. While many experimental studies have examined heat transfer on these surfaces, research at the nanoscale remains limited. This study employs molecular dynamics methods to investigate the boiling performance of bi-conductive surfaces and the combined effects of mixed wettability and conductivity on heat transfer mechanisms at the nanoscale. Our findings reveal enhanced heat transfer performance on bi-conductive surfaces, consistent with experimental observations. This enhancement is attributed to convective effects arising from uneven pressure distribution at the solid-liquid interface, as analyzed through the temperature profiles and velocity profiles of liquid atoms, heat transfer coefficient, and bubble volume. We also examine preferential bubble nucleation regions and thermal resistance on bi-conductive surfaces. Additionally, the boiling performance of surfaces with patterned structures is explored, including both biphilic and bi-conductive patterns. The combined effects of these patterns are analyzed, as modifications in surface wettability often accompany the introduction of materials with varying conductivities. The results indicate that surfaces exhibiting both biphilic and bi-conductive characteristics achieve earlier evaporation—an advantage of biphilic surfaces—during the initial boiling stage, while also demonstrating superior boiling performance—an advantage of bi-conductive surfaces—during later stages.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"169 ","pages":"Article 109746"},"PeriodicalIF":6.4,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145262255","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

An experimental study on condensation frosting characteristics on vibrating cold surfaces 振动冷表面结霜特性的实验研究

IF 6.4 2区工程技术

International Communications in Heat and Mass Transfer Pub Date : 2025-10-10 DOI: 10.1016/j.icheatmasstransfer.2025.109803

Xuan Zhang , Kailiang Li , Binfei Zhan , Qiang Yang , Zhichao Wang , Long Zhang , Mengjie Song

{"title":"An experimental study on condensation frosting characteristics on vibrating cold surfaces","authors":"Xuan Zhang , Kailiang Li , Binfei Zhan , Qiang Yang , Zhichao Wang , Long Zhang , Mengjie Song","doi":"10.1016/j.icheatmasstransfer.2025.109803","DOIUrl":"10.1016/j.icheatmasstransfer.2025.109803","url":null,"abstract":"<div><div>Frosting on cold surfaces influences the system efficiency and the role of surface vibration in frosting is not clear. This study experimentally investigates the effect of vertical vibration on the condensation frosting process on horizontal cold surfaces, especially the edge region, condensation droplet, and frost layer characteristics. An edge region with significantly larger condensation droplets is observed during the frosting process and its boundary can be quantitatively identified by analyzing the droplet distribution features. The surface vibration weakens the effect of the edge region and significantly shortens the period of droplet condensation stage. The period under a 1000 μm vibration amplitude is approximately reduced to a half of that on a stationary surface. The vibrating surfaces generally yield a larger frost layer height and growth rate. The frost layer height under a 250 μm vibration amplitude reaches 150.13 % of that on a stationary surface. As the vibration amplitude increases, the frost layer growth rate and roughness first go up and then decrease owing to the competition between the enhanced heat and mass transfer and the inertia force caused by the surface vibration. The findings provide reference for optimizing frosting control strategies.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"169 ","pages":"Article 109803"},"PeriodicalIF":6.4,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145262258","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

Optimization of piston trajectory in micro free-piston generators 微型自由活塞发电机活塞轨迹优化

IF 6.4 2区工程技术

International Communications in Heat and Mass Transfer Pub Date : 2025-10-10 DOI: 10.1016/j.icheatmasstransfer.2025.109785

Yong Liu , Xiaofeng Zhang , Fukang Ma , Zhiqiang Liu

{"title":"Optimization of piston trajectory in micro free-piston generators","authors":"Yong Liu , Xiaofeng Zhang , Fukang Ma , Zhiqiang Liu","doi":"10.1016/j.icheatmasstransfer.2025.109785","DOIUrl":"10.1016/j.icheatmasstransfer.2025.109785","url":null,"abstract":"<div><div>The miniaturization of electrical equipment and the popularity of portable devices are attractive drivers for the development of small thermal engines. However, as the size of engines shrinks, problems that can be neglected at conventional scales become prominent in micro-compact heat engines. For micro free-piston generators (MFPG), their unique flexible piston trajectories offer new ways to improve common problems of micro-compact heat engines such as flame quenching, leakage and severe heat dissipation, and they have great potential for improving the performance of micro-compact heat engines. Therefore, this paper proposes a multi-stage optimization model for the piston trajectory based on a nonlinear dynamical model coupled with an internal combustion engine and a linear motor, and it uses a Gaussian pseudospectral method and a sequential quadratic optimization algorithm to obtain an optimal solution for the piston trajectory that maximizes the indicated thermal efficiency of the system. The results show that, under different system parameters, the piston trajectory can improve the effective thermal efficiency of the system by 18.2–51.7 %, and the higher the sweeping pressure, the longer the combustion duration and the earlier the combustion onset, the more significant the effect of piston trajectory optimization on the thermal efficiency of the system.</div></div>","PeriodicalId":332,"journal":{"name":"International Communications in Heat and Mass Transfer","volume":"169 ","pages":"Article 109785"},"PeriodicalIF":6.4,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145262749","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