Engineering Science and Technology-An International Journal-Jestech最新文献_第7页

Air side thermal and hydraulic performance assessment of skived, louver, offset honeycomb, and metal foam finned mini-channel heat exchangers 楔形，百叶，偏移蜂窝和金属泡沫翅片微型通道热交换器的空气侧热和水力性能评估

IF 5.4 2区工程技术 Q1 ENGINEERING, MULTIDISCIPLINARY

Engineering Science and Technology-An International Journal-Jestech

Pub Date : 2025-12-01 Epub Date: 2025-12-02 DOI: 10.1016/j.jestch.2025.102242

Bahadır Doğan , M. Mete Ozturk , Levent Turhan

This study presents a comparative performance evaluation of mini-channel compact heat exchangers, focusing on four distinct extended surface configurations of skived plate fin, louver fin, metal foam, and offset honeycomb. The experiments are conducted in an air tunnel, where the Re number of the airflow ranges from 100–1400, and a constant surface temperature is maintained using a water bath. To ensure a fair comparison, all four configurations are tested under identical conditions. The performance of each configuration is assessed in terms of air-side heat transfer coefficient, pressure drop, Colburn j-factor, and friction factor. In addition to these conventional performance indicators, the heat exchangers are further evaluated using the heat transfer index with respect to friction power, both with and without accounting for compactness. According to the findings, although the cell-based configurations consistently outperform the plate-fin configurations under all conditions, the metal foam and offset honeycomb each demonstrate superiority in different performance metrics. While the heat transfer coefficient reaches approximately 110 W/(m²K) for the metal foam configuration, the offset honeycomb achieves up to 100 W/(m²K) within the same flow range. When evaluated based on the heat transfer index considering compactness, the performance order shifts, with offset honeycomb and metal foam providing values of 60.08 kW/(m³K) and 56.76 kW/(m³K), respectively. Under all tested conditions, the louver configuration, although the most commonly utilized extended surface in conventional applications, falls short of achieving the performance levels demonstrated by the novel designs introduced in this study.

本研究对小型通道紧凑型热交换器的性能进行了比较评估，重点研究了四种不同的扩展表面结构：刨花板翅片、百叶翅片、金属泡沫和偏移蜂窝。实验在风洞中进行，气流的雷诺数在100-1400之间，用水浴保持表面温度恒定。为了确保公平的比较，在相同的条件下测试了所有四种配置。根据空气侧传热系数、压降、科尔伯恩j系数和摩擦系数来评估每种配置的性能。除了这些常规的性能指标外，热交换器还使用与摩擦功率有关的传热指标进行进一步评估，包括考虑和不考虑紧凑性。根据研究结果，尽管基于单元的配置在所有条件下都优于板鳍配置，但金属泡沫和偏移蜂窝在不同的性能指标上都表现出优势。金属泡沫结构的传热系数约为110 W/(m2K)，而偏移蜂窝在相同流量范围内的传热系数可达100 W/(m2K)。当考虑紧凑性的传热指数时，性能顺序发生变化，偏移蜂窝和金属泡沫的值分别为60.08 kW/(m3K)和56.76 kW/(m3K)。在所有测试条件下，百叶窗配置，虽然在传统应用中最常用的扩展表面，未能达到本研究中介绍的新设计所展示的性能水平。

{"title":"Air side thermal and hydraulic performance assessment of skived, louver, offset honeycomb, and metal foam finned mini-channel heat exchangers","authors":"Bahadır Doğan , M. Mete Ozturk , Levent Turhan","doi":"10.1016/j.jestch.2025.102242","DOIUrl":"10.1016/j.jestch.2025.102242","url":null,"abstract":"<div><div>This study presents a comparative performance evaluation of mini-channel compact heat exchangers, focusing on four distinct extended surface configurations of skived plate fin, louver fin, metal foam, and offset honeycomb. The experiments are conducted in an air tunnel, where the <em>Re</em> number of the airflow ranges from 100–1400, and a constant surface temperature is maintained using a water bath. To ensure a fair comparison, all four configurations are tested under identical conditions. The performance of each configuration is assessed in terms of air-side heat transfer coefficient, pressure drop, Colburn <em>j</em>-factor, and friction factor. In addition to these conventional performance indicators, the heat exchangers are further evaluated using the heat transfer index with respect to friction power, both with and without accounting for compactness. According to the findings, although the cell-based configurations consistently outperform the plate-fin configurations under all conditions, the metal foam and offset honeycomb each demonstrate superiority in different performance metrics. While the heat transfer coefficient reaches approximately 110 W/(m<sup>2</sup>K) for the metal foam configuration, the offset honeycomb achieves up to 100 W/(m<sup>2</sup>K) within the same flow range. When evaluated based on the heat transfer index considering compactness, the performance order shifts, with offset honeycomb and metal foam providing values of 60.08 kW/(m<sup>3</sup>K) and 56.76 kW/(m<sup>3</sup>K), respectively. Under all tested conditions, the louver configuration, although the most commonly utilized extended surface in conventional applications, falls short of achieving the performance levels demonstrated by the novel designs introduced in this study.</div></div>","PeriodicalId":48609,"journal":{"name":"Engineering Science and Technology-An International Journal-Jestech","volume":"72 ","pages":"Article 102242"},"PeriodicalIF":5.4,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145694181","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

Novel multi-functional and compact waveguide filter based on various meta-resonators for C-band applications c波段应用中基于各种元谐振器的新型多功能紧凑波导滤波器

IF 5.4 2区工程技术 Q1 ENGINEERING, MULTIDISCIPLINARY

Engineering Science and Technology-An International Journal-Jestech

Pub Date : 2025-12-01 Epub Date: 2025-12-09 DOI: 10.1016/j.jestch.2025.102213

Abdullah Genc , Habib Dogan

This paper presents the design, fabrication, and performance analysis of a novel, multi-functional WGF for C-band (4.90–7.05 GHz) applications. The novel WR-159 WG structure is precisely fabricated from Al6065 material by the CNC milling method, and also meta-resonator structures designed in different sizes and geometries are fabricated from low-loss Duroid/RT 5880 substrate material with help of LPKF. Thanks to the designed single WR-159 WG structure, the WGF with four different functions is experimentally realized using a set of meta-resonators that can be mounted and dismounted. These four functions are bandpass/bandstop, narrow/medium/wide bandwidth, shifting operating frequency (5.5, 6, and 6.5 GHz), and filter order (n = 1–7). Filter performance has been verified through simulations and measurements with a vector network analyzer (VNA). For each WGF designed for different functions, simulated and measured performance results, such as for center frequency (f₀), return loss (RL), insertion loss (IL), fractional bandwidth (FBW), and quality factor (Q) are compared, and they have good agreement with each other. The proposed modular structure offers a low-cost and versatile alternative that can replace commercial filters.

本文介绍了一种用于c波段（4.90-7.05 GHz）应用的新型多功能WGF的设计、制造和性能分析。以Al6065材料为基材，采用数控铣削的方法精确制备了新型WR-159元谐振腔结构，并在乐普科的帮助下，以低损耗Duroid/RT 5880基材制作了不同尺寸和几何形状的元谐振腔结构。利用设计的WR-159单模谐振器结构，利用一组可安装和拆卸的元谐振器，实验实现了具有四种不同功能的WGF。这四个功能是带通/带阻、窄/中/宽带宽、移位工作频率（5.5、6和6.5 GHz）和滤波器阶数（n = 1-7）。通过矢量网络分析仪（VNA）的仿真和测量，验证了滤波器的性能。针对不同功能设计的WGF，比较了中心频率（f0）、回波损耗（RL）、插入损耗（IL）、分数带宽（FBW）、质量因子(Q)等性能的仿真和实测结果，结果吻合较好。所提出的模块化结构提供了一种低成本和多功能的替代方案，可以取代商用过滤器。

{"title":"Novel multi-functional and compact waveguide filter based on various meta-resonators for C-band applications","authors":"Abdullah Genc , Habib Dogan","doi":"10.1016/j.jestch.2025.102213","DOIUrl":"10.1016/j.jestch.2025.102213","url":null,"abstract":"<div><div>This paper presents the design, fabrication, and performance analysis of a novel, multi-functional WGF for C-band (4.90–7.05 GHz) applications. The novel WR-159 WG structure is precisely fabricated from Al6065 material by the CNC milling method, and also <em>meta</em>-resonator structures designed in different sizes and geometries are fabricated from low-loss Duroid/RT 5880 substrate material with help of LPKF. Thanks to the designed single WR-159 WG structure, the WGF with four different functions is experimentally realized using a set of <em>meta</em>-resonators that can be mounted and dismounted. These four functions are bandpass/bandstop, narrow/medium/wide bandwidth, shifting operating frequency (5.5, 6, and 6.5 GHz), and filter order (n = 1–7). Filter performance has been verified through simulations and measurements with a vector network analyzer (VNA). For each WGF designed for different functions, simulated and measured performance results, such as for center frequency (f<sub>0</sub>), return loss (RL), insertion loss (IL), fractional bandwidth (FBW), and quality factor (Q) are compared, and they have good agreement with each other. The proposed modular structure offers a low-cost and versatile alternative that can replace commercial filters.</div></div>","PeriodicalId":48609,"journal":{"name":"Engineering Science and Technology-An International Journal-Jestech","volume":"72 ","pages":"Article 102213"},"PeriodicalIF":5.4,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145747889","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

Switching oscillation-based fractional-domain high-sensitive diagnosis of machine turn insulation degradation 基于开关振荡的电机匝绝缘退化分数域高灵敏度诊断

IF 5.4 2区工程技术 Q1 ENGINEERING, MULTIDISCIPLINARY

Engineering Science and Technology-An International Journal-Jestech

Pub Date : 2025-12-01 Epub Date: 2025-11-10 DOI: 10.1016/j.jestch.2025.102224

Muhammad Usman Sardar, Toomas Vaimann, Lauri Kütt, Bilal Asad, Ants Kallaste

Stator turn insulation degradation is a significant cause of failure in electric machines fed by high-frequency switching power electronic devices, making early-stage detection challenging due to weak fault characteristic signatures. This paper presents a novel non-invasive monitoring framework that integrates a proposed low-to-high-frequency parametric grey-box model (GBM) of the motor with advanced signal processing techniques. Key electrical parameters of the motor are extracted using optimal fitting with impedance spectroscopy, which represent frequency-dependent behaviors influenced by insulation degradation. To enhance detection sensitivity, the method employs an optimized fractional Fourier transform at the optimal order, coupled with a customized resonance-centred Mel filter bank (FRFT-RMFB). Experimental results on a 0.75 kW induction motor with controlled insulation degradation, implemented by parallel capacitive loading, show a higher improvement in early-stage fault sensitivity. The proposed FRFT‑RMFB method enhances the sensitivity of turn insulation state estimation by nearly sevenfold compared with the conventional Fourier transform approach. The proposed framework is lightweight, generalized, and well-suited for real-time predictive maintenance, effectively minimizing false alarms in safety–critical applications such as industrial drives, electric vehicles, and high-speed rail systems. This work contributes to a new direction in frequency-domain diagnostics, combining accurate parametric modeling with high-resolution spectral feature extraction for early detection of insulation faults.

定子匝绝缘退化是由高频开关电力电子器件供电的电机故障的重要原因，由于故障特征特征较弱，使得早期检测具有挑战性。本文提出了一种新的无创监测框架，该框架将电机的低高频参数灰盒模型（GBM）与先进的信号处理技术相结合。通过阻抗谱优化拟合提取电机的关键电气参数，这些参数代表了受绝缘退化影响的频率依赖行为。为了提高检测灵敏度，该方法采用最优阶的优化分数傅里叶变换，再加上定制的以共振为中心的Mel滤波器组（FRFT-RMFB）。实验结果表明，采用电容并联负载控制绝缘退化的0.75 kW异步电动机的早期故障灵敏度有较高的提高。与传统的傅里叶变换方法相比，提出的FRFT - RMFB方法将匝绝缘状态估计的灵敏度提高了近7倍。所提出的框架是轻量级的、通用的，非常适合实时预测性维护，有效地减少了工业驱动、电动汽车和高速铁路系统等安全关键应用中的误报。该工作将精确的参数建模与高分辨率的频谱特征提取相结合，为早期检测绝缘故障开辟了频域诊断的新方向。

{"title":"Switching oscillation-based fractional-domain high-sensitive diagnosis of machine turn insulation degradation","authors":"Muhammad Usman Sardar, Toomas Vaimann, Lauri Kütt, Bilal Asad, Ants Kallaste","doi":"10.1016/j.jestch.2025.102224","DOIUrl":"10.1016/j.jestch.2025.102224","url":null,"abstract":"<div><div>Stator turn insulation degradation is a significant cause of failure in electric machines fed by high-frequency switching power electronic devices, making early-stage detection challenging due to weak fault characteristic signatures. This paper presents a novel non-invasive monitoring framework that integrates a proposed low-to-high-frequency parametric grey-box model (GBM) of the motor with advanced signal processing techniques. Key electrical parameters of the motor are extracted using optimal fitting with impedance spectroscopy, which represent frequency-dependent behaviors influenced by insulation degradation. To enhance detection sensitivity, the method employs an optimized fractional Fourier transform at the optimal order, coupled with a customized resonance-centred Mel filter bank (FRFT-RMFB). Experimental results on a 0.75 kW induction motor with controlled insulation degradation, implemented by parallel capacitive loading, show a higher improvement in early-stage fault sensitivity. The proposed FRFT‑RMFB method enhances the sensitivity of turn insulation state estimation by nearly sevenfold compared with the conventional Fourier transform approach. The proposed framework is lightweight, generalized, and well-suited for real-time predictive maintenance, effectively minimizing false alarms in safety–critical applications such as industrial drives, electric vehicles, and high-speed rail systems. This work contributes to a new direction in frequency-domain diagnostics, combining accurate parametric modeling with high-resolution spectral feature extraction for early detection of insulation faults.</div></div>","PeriodicalId":48609,"journal":{"name":"Engineering Science and Technology-An International Journal-Jestech","volume":"72 ","pages":"Article 102224"},"PeriodicalIF":5.4,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145529362","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

A novel mixed Rayleigh distribution model using PID based search algorithm for wind energy applications 基于PID搜索算法的混合瑞利分布模型在风能应用中的应用

IF 5.4 2区工程技术 Q1 ENGINEERING, MULTIDISCIPLINARY

Engineering Science and Technology-An International Journal-Jestech

Pub Date : 2025-12-01 Epub Date: 2025-11-21 DOI: 10.1016/j.jestch.2025.102239

Hilmi Aygün , Bayram Köse

Accurate modeling of wind speed distributions is a critical prerequisite for reliable wind energy assessment, system optimization, and long-term performance prediction. Conventional probability distribution functions exhibit notable deviations between the observed and estimated wind speed frequency distributions, indicating their limited capability in capturing the actual variability of wind regimes. To address this gap, this study introduces, for the first time in the wind energy domain, the application of a Mixed Rayleigh distribution in combination with a PID-based metaheuristic optimization algorithm (PSA) for parameter estimation. The proposed approach was tested at three measurement stations: Karaburun, Mersinkoy, and Gelibolu, using extensive wind speed datasets. Comparative analyses were conducted between PSA based Rayleigh, Mixed Rayleigh, and Weibull models, alongside conventional Moment and Maximum Likelihood methods. The proposed model achieved the lowest Sum Square Error (SSE) (0.0016) and Root Mean Square Error (RMSE) (0.0091) in Karaburun, the lowest SSE (0.0014) and RMSE (0.0075) in Gelibolu, and consistently high determination coefficients (R² ≈ 0.9999) across all regions. Additionally, the model yielded the lowest Mean Absolute Percentage Error (MAPE) based on Wind Power Density (WPD) (4.11 %) in Mersinköy and relatively low MAPE values based on Average Wind Speed (3.74 % and 3.26 %) in Karaburun and Mersinköy, respectively. In particular, the Mixed Rayleigh model demonstrated superior flexibility, resulting in improved fitting accuracy and reduced estimation errors. Overall, the findings highlight the methodological novelty and practical potential of combining hybrid distribution functions with advanced optimization algorithms.

风速分布的准确建模是可靠的风能评估、系统优化和长期性能预测的关键先决条件。传统的概率分布函数在观测到的风速频率分布和估计的风速频率分布之间存在显著的偏差，表明它们在捕捉风况的实际变异性方面的能力有限。为了解决这一差距，本研究首次在风能领域引入了混合瑞利分布与基于pid的元启发式优化算法（PSA）相结合的参数估计应用。该方法在Karaburun、Mersinkoy和Gelibolu三个观测站进行了测试，使用了大量的风速数据集。在基于PSA的瑞利、混合瑞利和威布尔模型以及传统的矩和最大似然方法之间进行了比较分析。该模型在卡拉布润的和方误差（SSE）（0.0016）和均方根误差（RMSE）（0.0091）最低，在格里博卢的SSE（0.0014）和均方根误差（RMSE）（0.0075）最低，并且在所有地区都具有较高的决定系数（R2≈0.9999）。此外，该模型基于风力密度（WPD）的平均绝对百分比误差（MAPE）在Mersinköy最低（4.11%），而基于平均风速的MAPE值在卡拉布伦和Mersinköy相对较低（3.74%和3.26%）。特别是，混合瑞利模型显示出优越的灵活性，从而提高了拟合精度，减少了估计误差。总的来说，这些发现突出了将混合分布函数与先进的优化算法相结合的方法的新颖性和实际潜力。

{"title":"A novel mixed Rayleigh distribution model using PID based search algorithm for wind energy applications","authors":"Hilmi Aygün , Bayram Köse","doi":"10.1016/j.jestch.2025.102239","DOIUrl":"10.1016/j.jestch.2025.102239","url":null,"abstract":"<div><div>Accurate modeling of wind speed distributions is a critical prerequisite for reliable wind energy assessment, system optimization, and long-term performance prediction. Conventional probability distribution functions exhibit notable deviations between the observed and estimated wind speed frequency distributions, indicating their limited capability in capturing the actual variability of wind regimes. To address this gap, this study introduces, for the first time in the wind energy domain, the application of a Mixed Rayleigh distribution in combination with a PID-based metaheuristic optimization algorithm (PSA) for parameter estimation. The proposed approach was tested at three measurement stations: Karaburun, Mersinkoy, and Gelibolu, using extensive wind speed datasets. Comparative analyses were conducted between PSA based Rayleigh, Mixed Rayleigh, and Weibull models, alongside conventional Moment and Maximum Likelihood methods. The proposed model achieved the lowest Sum Square Error (SSE) (0.0016) and Root Mean Square Error (RMSE) (0.0091) in Karaburun, the lowest SSE (0.0014) and RMSE (0.0075) in Gelibolu, and consistently high determination coefficients (R<sup>2</sup> ≈ 0.9999) across all regions. Additionally, the model yielded the lowest Mean Absolute Percentage Error (MAPE) based on Wind Power Density (WPD) (4.11 %) in Mersinköy and relatively low MAPE values based on Average Wind Speed (3.74 % and 3.26 %) in Karaburun and Mersinköy, respectively. In particular, the Mixed Rayleigh model demonstrated superior flexibility, resulting in improved fitting accuracy and reduced estimation errors. Overall, the findings highlight the methodological novelty and practical potential of combining hybrid distribution functions with advanced optimization algorithms.</div></div>","PeriodicalId":48609,"journal":{"name":"Engineering Science and Technology-An International Journal-Jestech","volume":"72 ","pages":"Article 102239"},"PeriodicalIF":5.4,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145579476","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

New ACCWOA algorithm based on the acceleration mechanism for solving engineering design problems and global optimization 基于加速机制的ACCWOA算法求解工程设计问题及全局优化

IF 5.4 2区工程技术 Q1 ENGINEERING, MULTIDISCIPLINARY

Engineering Science and Technology-An International Journal-Jestech

Pub Date : 2025-12-01 Epub Date: 2025-11-17 DOI: 10.1016/j.jestch.2025.102202

Ahmed Noori Algburi, Isa Avci

The Accelerated Whale Algorithm (ACCWOA) is a new version of the Whale Optimization Algorithm (WOA) that incorporates a velocity factor into the individuals. The WOA is a nature-inspired metaheuristic algorithm widely applied to solve engineering problems, which uses shrinking and spiral insertion movements to exploit the solution, and random search to discover new solutions. This algorithm suffers from slow convergence in early iterations, a lack of fine-tuned local search, stagnation in local optima, a lack of mechanisms to maintain diversity, and a lack of historical learning. To address these limitations, this work proposes an acceleration technique that mimics the rapid movement of whales as they pursue their prey. Acceleration technology utilizes the velocity equation to achieve accelerated convergence, enhanced exploitation, improved diversity retention, dynamic behavior, increased scalability and stability, and emergent memory capabilities. The algorithm was evaluated on standard benchmarks, IEEE CEC-2014 and CEC-2017 suites, and five engineering design problems: spring, three-bar truss, pressure vessel, welded beam, and cantilever beam. Results show that ACCWOA achieves rapid convergence, accurate solutions, and competitive efficiency compared to state-of-the-art methods.

加速鲸鱼算法（ACCWOA）是鲸鱼优化算法（WOA）的新版本，它将速度因素纳入个体。WOA是一种受自然启发的元启发式算法，广泛应用于解决工程问题，它使用收缩和螺旋插入运动来挖掘解，并使用随机搜索来发现新的解。该算法在早期迭代中收敛缓慢，缺乏微调的局部搜索，局部最优停滞，缺乏保持多样性的机制，以及缺乏历史学习。为了解决这些限制，这项工作提出了一种加速技术，模仿鲸鱼在追捕猎物时的快速运动。加速技术利用速度方程来实现加速收敛、增强开发、改进多样性保留、动态行为、增强可扩展性和稳定性以及应急存储能力。该算法在标准基准、IEEE CEC-2014和CEC-2017套件以及弹簧、三杆桁架、压力容器、焊接梁和悬臂梁五个工程设计问题上进行了评估。结果表明，与最先进的方法相比，ACCWOA实现了快速收敛，准确的解决方案和具有竞争力的效率。

{"title":"New ACCWOA algorithm based on the acceleration mechanism for solving engineering design problems and global optimization","authors":"Ahmed Noori Algburi, Isa Avci","doi":"10.1016/j.jestch.2025.102202","DOIUrl":"10.1016/j.jestch.2025.102202","url":null,"abstract":"<div><div>The Accelerated Whale Algorithm (ACCWOA) is a new version of the Whale Optimization Algorithm (WOA) that incorporates a velocity factor into the individuals. The WOA is a nature-inspired metaheuristic algorithm widely applied to solve engineering problems, which uses shrinking and spiral insertion movements to exploit the solution, and random search to discover new solutions. This algorithm suffers from slow convergence in early iterations, a lack of fine-tuned local search, stagnation in local optima, a lack of mechanisms to maintain diversity, and a lack of historical learning. To address these limitations, this work proposes an acceleration technique that mimics the rapid movement of whales as they pursue their prey. Acceleration technology utilizes the velocity equation to achieve accelerated convergence, enhanced exploitation, improved diversity retention, dynamic behavior, increased scalability and stability, and emergent memory capabilities. The algorithm was evaluated on standard benchmarks, IEEE CEC-2014 and CEC-2017 suites, and five engineering design problems: spring, three-bar truss, pressure vessel, welded beam, and cantilever beam. Results show that ACCWOA achieves rapid convergence, accurate solutions, and competitive efficiency compared to state-of-the-art methods.</div></div>","PeriodicalId":48609,"journal":{"name":"Engineering Science and Technology-An International Journal-Jestech","volume":"72 ","pages":"Article 102202"},"PeriodicalIF":5.4,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145579475","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

Investigation of power injection capability and leakage current of H6-II type inverter with different modulation techniques 不同调制技术下H6-II型逆变器功率注入能力和漏电流的研究

IF 5.4 2区工程技术 Q1 ENGINEERING, MULTIDISCIPLINARY

Engineering Science and Technology-An International Journal-Jestech

Pub Date : 2025-12-01 Epub Date: 2025-10-30 DOI: 10.1016/j.jestch.2025.102210

Pelin Turkmen, Emre Ozkop

The increasing adoption of grid-connected photovoltaic systems necessitates highly efficient and cost-effective inverter solutions. Transformerless inverters offer significant advantages in this regard, including enhanced efficiency, reduced cost, and compact size. However, their widespread deployment faces critical challenges, particularly concerning the management of leakage current and the growing demand for reactive power injection capabilities to support grid stability. This study investigates the performance of a single-phase transformerless inverter topology under various modulation strategies to address these challenges.

We evaluate the inverter’s ability to inject both active and reactive power, analyzing key performance indicators such as efficiency, total harmonic distortion, common mode voltage, and leakage current. The research explores the impact of different modulation techniques, including both conventional and novel approaches, as well as various signal and carrier wave configurations. Our findings aim to provide crucial insights into optimizing inverter design and operation for grid-connected applications, contributing to the development of more reliable and efficient renewable energy systems. This work is particularly motivated by the need to mitigate leakage current issues and enhance reactive power support in these essential power conversion devices, thereby facilitating their broader integration into modern electrical grids.

越来越多的并网光伏系统需要高效和经济的逆变器解决方案。无变压器逆变器在这方面具有显著的优势，包括提高效率，降低成本和紧凑的尺寸。然而，它们的广泛部署面临着严峻的挑战，特别是涉及到泄漏电流的管理和对支持电网稳定的无功功率注入能力日益增长的需求。本研究探讨了单相无变压器逆变器拓扑结构在各种调制策略下的性能，以解决这些挑战。我们评估了逆变器注入有功和无功功率的能力，分析了效率、总谐波失真、共模电压和漏电流等关键性能指标。该研究探讨了不同调制技术的影响，包括传统方法和新方法，以及各种信号和载波配置。我们的研究结果旨在为优化并网应用的逆变器设计和运行提供重要见解，有助于开发更可靠、更高效的可再生能源系统。这项工作的主要动机是需要减轻泄漏电流问题，增强这些基本功率转换设备的无功功率支持，从而促进它们更广泛地集成到现代电网中。

{"title":"Investigation of power injection capability and leakage current of H6-II type inverter with different modulation techniques","authors":"Pelin Turkmen, Emre Ozkop","doi":"10.1016/j.jestch.2025.102210","DOIUrl":"10.1016/j.jestch.2025.102210","url":null,"abstract":"<div><div>The increasing adoption of grid-connected photovoltaic systems necessitates highly efficient and cost-effective inverter solutions. Transformerless inverters offer significant advantages in this regard, including enhanced efficiency, reduced cost, and compact size. However, their widespread deployment faces critical challenges, particularly concerning the management of leakage current and the growing demand for reactive power injection capabilities to support grid stability. This study investigates the performance of a single-phase transformerless inverter topology under various modulation strategies to address these challenges.</div><div>We evaluate the inverter’s ability to inject both active and reactive power, analyzing key performance indicators such as efficiency, total harmonic distortion, common mode voltage, and leakage current. The research explores the impact of different modulation techniques, including both conventional and novel approaches, as well as various signal and carrier wave configurations. Our findings aim to provide crucial insights into optimizing inverter design and operation for grid-connected applications, contributing to the development of more reliable and efficient renewable energy systems. This work is particularly motivated by the need to mitigate leakage current issues and enhance reactive power support in these essential power conversion devices, thereby facilitating their broader integration into modern electrical grids.</div></div>","PeriodicalId":48609,"journal":{"name":"Engineering Science and Technology-An International Journal-Jestech","volume":"72 ","pages":"Article 102210"},"PeriodicalIF":5.4,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145425128","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

Dipping microcapillary-based droplet fabrication: Multiscale and structurally diverse droplets with programmable real-time size control 浸渍微毛细管液滴制造：多尺度和结构多样的液滴与可编程的实时尺寸控制

IF 5.4 2区工程技术 Q1 ENGINEERING, MULTIDISCIPLINARY

Engineering Science and Technology-An International Journal-Jestech

Pub Date : 2025-12-01 Epub Date: 2025-11-06 DOI: 10.1016/j.jestch.2025.102223

Dong Min Ji , Armando Ramos-Sebastian , Yung-Taek Ouh , Changho Yu , Sung Hoon Kim

This study presents an innovative “off-chip” droplet manufacturing system, which operates through hydrodynamic interactions between an adjustable flow from a microcapillary and its periodic immersion into a continuous phase. This method circumvents the limitations of conventional microfluidic chips, which are costly and complex to produce, and suffer from restricted control over droplet size. The novel system facilitates the instantaneous alteration of droplet diameters, ranging from approximately one centimeter to several tens of micrometers (77 µm). It employs a slowly rotating continuous phase to prevent droplet agglomeration and precisely manage their sedimentation location. A theoretical model is proposed, linking the radius of the produced droplets to the flow rate of the dispersed phase and the dipping frequency of the microcapillary. This model has been corroborated through computational simulations and empirical experiments. Furthermore, the system has demonstrated proficiency in producing Janus-type and multi-emulsion droplets by simply modifying the geometry of the microcapillary. The absence of microchannel confinement enables the arrangement of droplets into intricate structures, showcasing the system’s unique capacity to utilize both dispersed and continuous phases for creating functional materials with complex multidimensional droplets.

本研究提出了一种创新的“片外”液滴制造系统，该系统通过微毛细管的可调节流量与其周期性浸入到连续相之间的流体动力学相互作用来工作。这种方法绕过了传统微流控芯片的局限性，传统微流控芯片生产成本高、复杂，而且对液滴大小的控制有限。该新型系统有助于液滴直径的瞬时改变，范围从大约一厘米到几十微米（77 µm）。它采用了一个缓慢旋转的连续相，以防止液滴团聚，并精确地管理他们的沉降位置。提出了一个理论模型，将液滴的半径与分散相的流速和微毛细管的倾斜频率联系起来。通过计算模拟和实验验证了该模型的正确性。此外，该系统已经证明了通过简单地修改微毛细管的几何形状来生产双面型和多乳液液滴的能力。由于没有微通道限制，使得液滴能够排列成复杂的结构，展示了该系统利用分散相和连续相来创建具有复杂多维液滴的功能材料的独特能力。

{"title":"Dipping microcapillary-based droplet fabrication: Multiscale and structurally diverse droplets with programmable real-time size control","authors":"Dong Min Ji , Armando Ramos-Sebastian , Yung-Taek Ouh , Changho Yu , Sung Hoon Kim","doi":"10.1016/j.jestch.2025.102223","DOIUrl":"10.1016/j.jestch.2025.102223","url":null,"abstract":"<div><div>This study presents an innovative “off-chip” droplet manufacturing system, which operates through hydrodynamic interactions between an adjustable flow from a microcapillary and its periodic immersion into a continuous phase. This method circumvents the limitations of conventional microfluidic chips, which are costly and complex to produce, and suffer from restricted control over droplet size. The novel system facilitates the instantaneous alteration of droplet diameters, ranging from approximately one centimeter to several tens of micrometers (77 µm). It employs a slowly rotating continuous phase to prevent droplet agglomeration and precisely manage their sedimentation location. A theoretical model is proposed, linking the radius of the produced droplets to the flow rate of the dispersed phase and the dipping frequency of the microcapillary. This model has been corroborated through computational simulations and empirical experiments. Furthermore, the system has demonstrated proficiency in producing Janus-type and multi-emulsion droplets by simply modifying the geometry of the microcapillary. The absence of microchannel confinement enables the arrangement of droplets into intricate structures, showcasing the system’s unique capacity to utilize both dispersed and continuous phases for creating functional materials with complex multidimensional droplets.</div></div>","PeriodicalId":48609,"journal":{"name":"Engineering Science and Technology-An International Journal-Jestech","volume":"72 ","pages":"Article 102223"},"PeriodicalIF":5.4,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145475331","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

Investigation of structural behavior in natural and synthetic fiber reinforced multilayer composites based on resin and additives 基于树脂和添加剂的天然和合成纤维增强多层复合材料的结构性能研究

IF 5.4 2区工程技术 Q1 ENGINEERING, MULTIDISCIPLINARY

Engineering Science and Technology-An International Journal-Jestech

Pub Date : 2025-12-01 Epub Date: 2025-11-29 DOI: 10.1016/j.jestch.2025.102240

Samet Karabulut, Kaan Kaysadı, Faruk Gümüş

In our study, jute natural fiber and glass fiber were preferred as reinforcing elements. Epoxy, vinyl ester, and polyester were selected as matrix materials, and sodium hydroxide and magnesium hydroxide were used as additives. When the results were analyzed, the samples produced with epoxy yielded good results in tensile and elongation tests compared to the others, while the average values remained the same in bending and impact tests. The presence of additives was also observed in the SEM images and EDS results.

在我们的研究中，首选黄麻天然纤维和玻璃纤维作为增强元素。以环氧树脂、乙烯基酯和聚酯为基体材料，以氢氧化钠和氢氧化镁为助剂。结果分析表明，与其他样品相比，环氧树脂样品在拉伸和延伸试验中取得了良好的结果，而在弯曲和冲击试验中平均值保持不变。在SEM图像和EDS结果中也观察到添加剂的存在。

引用次数: 0

Linear Doherty power amplifier design based on adaptive input signal power control 基于自适应输入信号功率控制的线性多尔蒂功率放大器设计

IF 5.4 2区工程技术 Q1 ENGINEERING, MULTIDISCIPLINARY

Engineering Science and Technology-An International Journal-Jestech

Pub Date : 2025-12-01 Epub Date: 2025-12-05 DOI: 10.1016/j.jestch.2025.102247

Zhiqing Liu , Ye Zhong , Zhijiang Dai

In modern wireless communication systems, the trade-off between efficiency and linearity in Doherty power amplifiers (DPAs) remains a critical challenge. To address this, a novel Schottky diode-based input matching network is presented for peaking power amplifiers (PAs) which leverages a dual optimization mechanism: (1) adaptive gate DC bias adjustment via Schottky rectification, enabling Class B operation in high-power regions to enhance DPA linearity; and (2) nonlinear impedance modulation to suppress premature peaking PA activation in low-power regions, thereby improving back-off efficiency. Based on this structure, an asymmetric DPA is designed and manufactured, with continuous wave test results showing that saturation efficiency is higher than 50%, saturated output power reaches more than 43.4 dBm, and the back-off efficiency of 9 dB is 41.2%–55.6% in the operating band of 0.75–1.25 GHz. The adjacent channel power ratio (ACPR) of the PA is tested using a 20 MHz quadrature amplitude modulation (QAM) signal with a PAPR of 9 dB, and the test results show that, in the band of 1.0–1.3 GHz, the ACPR is −38.1 to −34.0 dBc and average efficiency is from 34.2%–45.5% at an average output power of 36 dBm, which verifies that the designed DPA has good linearity performance.

在现代无线通信系统中，Doherty功率放大器（dpa）的效率和线性度之间的权衡仍然是一个关键的挑战。为了解决这个问题，提出了一种新的基于肖特基二极管的峰值功率放大器（pa）输入匹配网络，该网络利用双重优化机制：(1)通过肖特基整流自适应栅极直流偏置调整，使B类工作在高功率区域，提高DPA线性度；(2)非线性阻抗调制，抑制低功率区域PA的过早峰值激活，从而提高退退效率。基于该结构设计并制造了非对称DPA，连续波测试结果表明，在0.75 ~ 1.25 GHz工作频段，饱和效率高于50%，饱和输出功率大于43.4 dBm， 9db的回退效率为41.2% ~ 55.6%。采用PAPR为9 dB的20 MHz正交调幅（QAM）信号对该放大器的邻道功率比（ACPR）进行了测试，测试结果表明，在1.0 ~ 1.3 GHz频段，平均输出功率为36 dBm时，ACPR为−38.1 ~−34.0 dBc，平均效率为34.2% ~ 45.5%，验证了所设计的DPA具有良好的线性性能。

{"title":"Linear Doherty power amplifier design based on adaptive input signal power control","authors":"Zhiqing Liu , Ye Zhong , Zhijiang Dai","doi":"10.1016/j.jestch.2025.102247","DOIUrl":"10.1016/j.jestch.2025.102247","url":null,"abstract":"<div><div>In modern wireless communication systems, the trade-off between efficiency and linearity in Doherty power amplifiers (DPAs) remains a critical challenge. To address this, a novel Schottky diode-based input matching network is presented for peaking power amplifiers (PAs) which leverages a dual optimization mechanism: (1) adaptive gate DC bias adjustment via Schottky rectification, enabling Class B operation in high-power regions to enhance DPA linearity; and (2) nonlinear impedance modulation to suppress premature peaking PA activation in low-power regions, thereby improving back-off efficiency. Based on this structure, an asymmetric DPA is designed and manufactured, with continuous wave test results showing that saturation efficiency is higher than 50%, saturated output power reaches more than 43.4 dBm, and the back-off efficiency of 9 dB is 41.2%–55.6% in the operating band of 0.75–1.25 GHz. The adjacent channel power ratio (ACPR) of the PA is tested using a 20 MHz quadrature amplitude modulation (QAM) signal with a PAPR of 9 dB, and the test results show that, in the band of 1.0–1.3 GHz, the ACPR is −38.1 to −34.0 dBc and average efficiency is from 34.2%–45.5% at an average output power of 36 dBm, which verifies that the designed DPA has good linearity performance.</div></div>","PeriodicalId":48609,"journal":{"name":"Engineering Science and Technology-An International Journal-Jestech","volume":"72 ","pages":"Article 102247"},"PeriodicalIF":5.4,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145693537","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 and experimental investigation of the seismic behavior of rigid steel beam-to-hollow circular column connections using a steel box 钢箱梁-空心圆柱连接抗震性能的数值与试验研究

IF 5.4 2区工程技术 Q1 ENGINEERING, MULTIDISCIPLINARY

Engineering Science and Technology-An International Journal-Jestech

Pub Date : 2025-12-01 Epub Date: 2025-11-15 DOI: 10.1016/j.jestch.2025.102233

Abdulrahman Kamil Aakool AL-Hureshat , Mehrzad TahamouliRoudsari , AllahReza Moradi Garoosi , Mohsen Oghabi

Rigid beam-to-circular steel column connections have always attracted the attention of researchers and design codes due to their geometric complexity and construction challenges. In this study, the use of a steel box at the connection region is proposed for joining I-shaped sections to hollow circular columns. This method offers advantages such as simplified detailing and eliminates the need for continuity plates or doubler plates. The initial design of the experimental specimens was performed numerically, and then three specimens exhibiting superior performance were selected for experimental investigation. The experimental studies examined the effect of the configuration of column-to-box and beam-to-box stiffeners on their seismic performance. Subsequently, further numerical studies were conducted on the experimentally superior specimen. After validating the numerical model, the effect of the steel box thickness on the connection with various beam and column sections was evaluated. The aim of this part was to determine the minimum required thickness for the steel box, beyond which further increases would not affect the results. Additionally, the rigidity of the connection was also investigated. The experimental results indicated that the model with internal box stiffeners aligned with the beam flanges provided the highest strength, ductility, and elastic stiffness. Parametric analyses indicated that rigid behavior and full beam capacity can be ensured when the steel box thickness is at least 1.4 times the beam flange thickness.

钢梁与圆钢柱的刚性连接由于其几何复杂性和施工难度，一直受到研究人员和设计规范的关注。在本研究中，建议在连接区域使用钢箱将工字截面连接到空心圆形柱。这种方法的优点是简化了细节，并且不需要连续版或加倍版。通过数值方法对试验试件进行初步设计，选取性能较好的3个试件进行试验研究。试验研究考察了柱对箱和梁对箱加强筋结构对其抗震性能的影响。随后，对实验上较优的试样进行了进一步的数值研究。在验证了数值模型的基础上，评估了钢箱厚度对不同梁柱截面连接的影响。这部分的目的是确定钢盒所需的最小厚度，超过该厚度的进一步增加不会影响结果。此外，还对连接的刚度进行了研究。试验结果表明，内箱型加劲筋与梁缘对齐的模型具有最高的强度、延性和弹性刚度。参数分析表明，当钢箱厚度至少为梁翼缘厚度的1.4倍时，可以保证梁的刚性性能和全梁承载力。

{"title":"Numerical and experimental investigation of the seismic behavior of rigid steel beam-to-hollow circular column connections using a steel box","authors":"Abdulrahman Kamil Aakool AL-Hureshat , Mehrzad TahamouliRoudsari , AllahReza Moradi Garoosi , Mohsen Oghabi","doi":"10.1016/j.jestch.2025.102233","DOIUrl":"10.1016/j.jestch.2025.102233","url":null,"abstract":"<div><div>Rigid beam-to-circular steel column connections have always attracted the attention of researchers and design codes due to their geometric complexity and construction challenges. In this study, the use of a steel box at the connection region is proposed for joining I-shaped sections to hollow circular columns. This method offers advantages such as simplified detailing and eliminates the need for continuity plates or doubler plates. The initial design of the experimental specimens was performed numerically, and then three specimens exhibiting superior performance were selected for experimental investigation. The experimental studies examined the effect of the configuration of column-to-box and beam-to-box stiffeners on their seismic performance. Subsequently, further numerical studies were conducted on the experimentally superior specimen. After validating the numerical model, the effect of the steel box thickness on the connection with various beam and column sections was evaluated. The aim of this part was to determine the minimum required thickness for the steel box, beyond which further increases would not affect the results. Additionally, the rigidity of the connection was also investigated. The experimental results indicated that the model with internal box stiffeners aligned with the beam flanges provided the highest strength, ductility, and elastic stiffness. Parametric analyses indicated that rigid behavior and full beam capacity can be ensured when the steel box thickness is at least 1.4 times the beam flange thickness.</div></div>","PeriodicalId":48609,"journal":{"name":"Engineering Science and Technology-An International Journal-Jestech","volume":"72 ","pages":"Article 102233"},"PeriodicalIF":5.4,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145529275","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