Meccanica最新文献_第4页

Study on the flow characteristics of air-to-solid ratios for pneumatic conveying of wheat based on computational fluid dynamics: discrete element method 基于计算流体力学的小麦气力输送气固比流动特性研究：离散元法

IF 2.1 3区工程技术

Meccanica Pub Date : 2025-06-20 DOI: 10.1007/s11012-025-02021-2

Zhenglong Liang, Pan Zhang, Baicheng Li, Ting Yang, Guochun Liu

{"title":"Study on the flow characteristics of air-to-solid ratios for pneumatic conveying of wheat based on computational fluid dynamics: discrete element method","authors":"Zhenglong Liang, Pan Zhang, Baicheng Li, Ting Yang, Guochun Liu","doi":"10.1007/s11012-025-02021-2","DOIUrl":"10.1007/s11012-025-02021-2","url":null,"abstract":"<div><p>To optimize the efficiency and stability of wheat pneumatic conveying systems, this study systematically analyzed the flow characteristics under varying air-to-solid ratios using the CFD-DEM (Computational Fluid Dynamics—Discrete Element Method) approach. The results demonstrate that as the gas velocity increases, the flow regime within the pipe transitions progressively from plug flow to dune flow, and ultimately to stratified flow. The standard deviation of inlet pressure fluctuations was highest under dune flow conditions, followed by plug flow, and lowest during stratified flow, while the system stability showed the inverse trend. Wheat particle velocity is highest under stratified flow conditions, followed by dune flow, and lowest during plug flow. The distribution of wheat particles transitions from a fully filled pipe state to a depositional state at the pipe bottom. Increasing the wheat feed rate reduced both the particle velocity growth rate and system stability. This study demonstrates the critical role of the air-to-solid ratio in regulating flow regimes to influence conveying stability and efficiency, providing direct guidance for optimizing air-to-solid ratio settings in wheat processing lines.</p></div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":"60 5","pages":"1461 - 1476"},"PeriodicalIF":2.1,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145167819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Correction: Efficient and simplified numerical contact model for the braking simulation of a magnetic track brake 修正：磁轨道制动器制动仿真的高效简化数值接触模型

IF 2.1 3区工程技术

Meccanica Pub Date : 2025-06-19 DOI: 10.1007/s11012-025-02018-x

Emin Kocbay, Alois Steininger, Andreas Pavicsics, Eray Arslan, Johannes Edelmann

引用次数: 0

Prediction of the profile of a vertical air-entraining vortex 垂直气流涡旋廓线的预测

IF 2.1 3区工程技术

Meccanica Pub Date : 2025-06-17 DOI: 10.1007/s11012-025-02006-1

Yasameen Mansoor A. Al-Hakeem, Kerem Taştan, Nevzat Yıldırım

{"title":"Prediction of the profile of a vertical air-entraining vortex","authors":"Yasameen Mansoor A. Al-Hakeem, Kerem Taştan, Nevzat Yıldırım","doi":"10.1007/s11012-025-02006-1","DOIUrl":"10.1007/s11012-025-02006-1","url":null,"abstract":"<div><p>Air-core vortices occurring at intakes cause efficiency losses, vibrations, operational difficulties, and erosion at affiliated water-conveying structures. Air-core vortices are in the forms of non-air entraining vortex (air-core vortex in suspension) and air-entraining vortex. The profile of an air-core vortex is considered to be one of the main characteristics of the vortex. There are available semi-empirical formulas for the profile of a vertical non-air entraining vortex (air-core vortex in suspension) occurring at a vertically-flowing downward intake. However, there is no available developed formula relating to the profile of a vertical air-entraining vortex occurring at a vertically-flowing downward intake because the height, radii, and other physical quantities of the imaginary section of the air-entraining vortex downstream of the intake entrance are not measurable. Therefore, the profile of a vertical air-entraining vortex needs to be predicted. In the present study, by modifying the available formula relating to the profile of a non-air-entraining vortex and incorporating available test data, a practical methodology is developed for predicting the profile of a vertical air-entraining vortex. This study provides a practical formula and a chart to determine the necessary parameters to predict the profile of a vertical air-entraining vortex. The validation of the proposed methodology is examined and checked with available test data relating to the profile of a vertical air-entraining vortex occurring at a vertically-flowing downward intake. The results of the present study are in good agreement with available test data relating to the profile of vertical air-entraining vortices (the coefficient of determination is between 0.976 and 0.995).</p></div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":"60 5","pages":"1445 - 1459"},"PeriodicalIF":2.1,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145166438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Dynamic homogenization of multi-layered lattice-like metamaterials with alternate chiral microstructure 具有交替手性微观结构的多层晶格类超材料的动态均匀化

IF 2.1 3区工程技术

Meccanica Pub Date : 2025-06-16 DOI: 10.1007/s11012-025-01966-8

Andrea Bacigalupo, Paolo Badino, Luigi Gambarotta

{"title":"Dynamic homogenization of multi-layered lattice-like metamaterials with alternate chiral microstructure","authors":"Andrea Bacigalupo, Paolo Badino, Luigi Gambarotta","doi":"10.1007/s11012-025-01966-8","DOIUrl":"10.1007/s11012-025-01966-8","url":null,"abstract":"<div><p>This paper presents a dynamic continualization technique for a multi-layer beam-lattice metamaterial with an alternating chiral microstructure, where each layer is reciprocally interconnected through the insertion of pins. The study analyzes the dispersive properties of the system and its potential applications as a meta-filter, highlighting how the enhanced continualization technique introduced can capture the dispersive properties of stratified systems with chiral geometry. This approach makes it possible to derive higher-order gradient-type continuum models that yield dispersion spectra close to those obtained through a discrete Lagrangian treatment, without encountering dynamic instability effects due to thermodynamic inconsistency. These aspects are further investigated through the presentation of application examples, specifically concerning a stratified tetrachiral waveguide. A key finding of the studied examples is related to the passive/active tunability of the system, specifically in relation to the stiffness of the pin which determines significant influences on the dispersion spectra. To complete the analysis, a further example is finally proposed in which the waveguide is subjected to harmonic excitation, revealing how variations in the parameters can affect wave polarizations.</p></div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":"60 8","pages":"2197 - 2221"},"PeriodicalIF":2.1,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11012-025-01966-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145230187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Morphology analysis of a thin elastic ring under gravity for configuration design of rolling soft robots 重力作用下薄弹性环的形态分析，用于滚动软机器人的构型设计

IF 2.1 3区工程技术

Meccanica Pub Date : 2025-06-12 DOI: 10.1007/s11012-025-01994-4

Fei Dang, Kunyi Peng, Pengfei Yang, Zhiying Liu, Xiangpan Zheng

引用次数: 0

Energy absorption of sustainable lattice structures under static compression 静压缩下可持续晶格结构的能量吸收

IF 2.1 3区工程技术

Meccanica Pub Date : 2025-06-07 DOI: 10.1007/s11012-025-02003-4

Sören Bieler, Kerstin Weinberg

引用次数: 0

An energy-stepping Markov Monte Carlo method 一种能量步进马尔可夫蒙特卡罗方法

IF 2.1 3区工程技术

Meccanica Pub Date : 2025-06-06 DOI: 10.1007/s11012-025-01997-1

Ignacio Romero, Michael Ortiz

引用次数: 0

Experimental and simulation study on temperature rise prediction of spiral bevel gears based on similarity theory 基于相似理论的螺旋锥齿轮温升预测的实验与仿真研究

IF 2.1 3区工程技术

Meccanica Pub Date : 2025-06-03 DOI: 10.1007/s11012-025-02005-2

Xi-Qing Zheng, Yuan Zi, Hui-Qing Lan

{"title":"Experimental and simulation study on temperature rise prediction of spiral bevel gears based on similarity theory","authors":"Xi-Qing Zheng, Yuan Zi, Hui-Qing Lan","doi":"10.1007/s11012-025-02005-2","DOIUrl":"10.1007/s11012-025-02005-2","url":null,"abstract":"<div><p>The temperature rise of the tooth surface in spiral bevel gears plays a crucial role in lubrication performance and surface failure. However, existing studies primarily investigate scuffing by analyzing tooth surface temperature through experiments and simulations, without using similarity theory to examine comparable systems. By leveraging similarity theory, researchers efficiently translate insights from controlled experiments to real-world applications, fostering innovation while conserving resources. Similarity theory is used in the study to analyze the temperature rise of the tooth surface, and it is possible to determine that gears in different systems may exhibit analogous thermal behavior under specific scaling conditions. A thermal fluid–structure coupled model is employed to conduct a precise analysis of the original system for thermal assessment and experimental validation. Similarity theory effectively predicts tooth surface temperature rise and optimizes lubrication strategies. Notably, the temperature rise is more pronounced near the tooth crest. The maximum temperature in the similarity model reaches 140.59 °C, while that in the original model is 134.5 °C. The deviation between simulation and experimental results for the original model is 6.43%, and the discrepancy between the original and similarity models remains within 4.53%. This similarity-based modeling approach accurately captures the thermal behavior of analogous systems, significantly reducing the cost of manufacturing test gears and the workload associated with tooth surface temperature experiments and simulations.</p></div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":"60 5","pages":"1393 - 1410"},"PeriodicalIF":2.1,"publicationDate":"2025-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145161559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Crashworthiness assessment of NASA CRM wing in single and multiple bird strikes scenarios NASA CRM机翼在单次和多次鸟击场景下的耐撞性评估

IF 2.1 3区工程技术

Meccanica Pub Date : 2025-06-02 DOI: 10.1007/s11012-025-02002-5

Hussain Saad, Yang Pei

{"title":"Crashworthiness assessment of NASA CRM wing in single and multiple bird strikes scenarios","authors":"Hussain Saad, Yang Pei","doi":"10.1007/s11012-025-02002-5","DOIUrl":"10.1007/s11012-025-02002-5","url":null,"abstract":"<div><p>Numerous aircraft accidents involving bird flocks have occurred in aviation. Existing literature and the airworthiness certification standards are primarily focused on single bird-strike assumption. The present study addresses the possibility of bird flock incident and investigates the crashworthiness of NASA Common Research Model wing subjected to single and multiple bird strikes, using a coupled Finite Element Method and Smooth Particle Hydrodynamics approach. The numerical bird model is validated and the influence of equation of state (EOS) models, porosity and contact loads variation against the target structure’s shape, is reported. Two locations along the span i.e. towards the wing root and the wing tip, are considered for impact investigation, with emphasis on comparative penetration, energy absorption capability and potential damage to the main spar. Results revealed that the impact loads and impulse for the curved leading-edge section to reduce by more than half compared to the flat plate. The Gruneisen EOS provided a good correlation with experimental data, while adding porosity to the Polynomial EOS significantly reduced pressure peaks. Analyzing different flock orientation scenarios, the vulnerability of wing tip to multiple bird strikes was observed, leading to main spar damage. While single bird strikes may not cause critical damage, bird flocks pose a significant threat to aircraft safety, emphasizing the need for incorporating bird flock scenarios into aircraft design considerations.</p></div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":"60 5","pages":"1371 - 1392"},"PeriodicalIF":2.1,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145161167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Seismic fragility of free-standing rocking-sliding rigid blocks under earthquake excitation 地震作用下独立岩滑刚性块体的地震易损性

IF 2.1 3区工程技术

Meccanica Pub Date : 2025-05-30 DOI: 10.1007/s11012-025-01986-4

Nicola A. Nodargi, Paolo Bisegna

{"title":"Seismic fragility of free-standing rocking-sliding rigid blocks under earthquake excitation","authors":"Nicola A. Nodargi, Paolo Bisegna","doi":"10.1007/s11012-025-01986-4","DOIUrl":"10.1007/s11012-025-01986-4","url":null,"abstract":"<div><p>The seismic fragility of free-standing rigid blocks under earthquake excitation is investigated, focusing on the combined effect of rocking and sliding in their dynamic response. A variational-based formulation of the non-smooth contact dynamics method is employed for the problem solution, requiring the solution of a quadratic programming problem at each time step in the three unknown block scalar velocities. Such an approach efficiently captures all possible block response modes, including rocking, sliding, rocking-sliding, and free flight. The seismic fragility of both slender and stocky blocks is evaluated through a multiple-stripe analysis, introducing overturning-sliding fragility curves that account for overturning and excessive-sliding limit states. Numerical validation against benchmark results confirms the accuracy of the proposed formulation, showing that while a no-sliding assumption is reliable for slender blocks, it may prove unsafe for stocky blocks, even assuming high friction at the foundation. The resulting overturning-sliding fragility curves highlight the dependence of the block response on the normalized friction coefficient, defined as the ratio of the friction coefficient to the block slenderness. Blocks with a normalized friction coefficient below unity exhibit an isolation effect, preventing overturning at the cost of significant sliding. Conversely, blocks with normalized friction coefficient above unity undergo rocking-sliding or pure-rocking motion, which can lead to overturning. Accordingly, the overturning-sliding fragility curves are determined by the interplay between overturning and excessive-sliding limit states, as governed by a prescribed sliding displacement capacity. For typical values of the friction coefficient at the block-foundation interface, slender blocks are largely unaffected by sliding, whereas overturning-sliding or sliding fragility curves are crucial for accurately assessing the seismic performance of stocky blocks.</p></div>","PeriodicalId":695,"journal":{"name":"Meccanica","volume":"60 8","pages":"2411 - 2435"},"PeriodicalIF":2.1,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145230465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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