国际机械系统动力学学报(英文)最新文献_第7页

Multiple control of thermoelectric dual-function metamaterials 热电双功能超材料的多重控制

国际机械系统动力学学报(英文) Pub Date : 2023-05-12 DOI: 10.1002/msd2.12070

Pengfei Zhuang, Jiping Huang

{"title":"Multiple control of thermoelectric dual-function metamaterials","authors":"Pengfei Zhuang, Jiping Huang","doi":"10.1002/msd2.12070","DOIUrl":"https://doi.org/10.1002/msd2.12070","url":null,"abstract":"Thermal metamaterials based on transformation theory offer a practical design for controlling heat flow by engineering spatial distributions of material parameters, implementing interesting functions such as cloaking, concentrating, and rotating. However, most existing designs are limited to serving a single target function within a given physical domain. Here, we analytically prove the form invariance of thermoelectric (TE) governing equations, ensuring precise controls of the thermal flux and electric current. Then, we propose a dual-function metamaterial that can concentrate (or cloak) and rotate the TE field simultaneously. In addition, we introduce two practical control methods to realize corresponding functions: one is a temperature-switching TE rotating concentrator cloak that can switch between cloaking and concentrating; the other is an electrically controlled TE rotating concentrator that can handle the temperature field precisely by adjusting external voltages. The theoretical predictions and finite-element simulations agree well with each other. This work provides a unified framework for manipulating the direction and density of the TE field simultaneously and may contribute to the study of thermal management, such as thermal rectification and thermal diodes.","PeriodicalId":60486,"journal":{"name":"国际机械系统动力学学报(英文)","volume":"3 2","pages":"127-135"},"PeriodicalIF":0.0,"publicationDate":"2023-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/msd2.12070","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50130416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

Development of new electromagnetic suspension–based high-speed Maglev vehicles in China: Historical and recent progress in the field of dynamical simulation 中国新型电磁悬挂高速磁悬浮车辆的发展——动力学仿真领域的历史与最新进展

国际机械系统动力学学报(英文) Pub Date : 2023-03-26 DOI: 10.1002/msd2.12069

Sansan Ding, Peter Eberhard, Georg Schneider, Patrick Schmid, Arnim Kargl, Yong Cui, Ullrich Martin, Xin Liang, Chao Huang, Markus Bauer, Florian Dignath, Qinghua Zheng

引用次数: 0

Effect of coronary artery dynamics on the wall shear stress vector field topological skeleton in fluid–structure interaction analyses 流体-结构相互作用分析中冠状动脉动力学对壁剪切应力矢量场拓扑骨架的影响

国际机械系统动力学学报(英文) Pub Date : 2023-03-16 DOI: 10.1002/msd2.12068

Harry J. Carpenter, Mergen H. Ghayesh, Anthony C. Zander, Peter J. Psaltis

{"title":"Effect of coronary artery dynamics on the wall shear stress vector field topological skeleton in fluid–structure interaction analyses","authors":"Harry J. Carpenter, Mergen H. Ghayesh, Anthony C. Zander, Peter J. Psaltis","doi":"10.1002/msd2.12068","DOIUrl":"https://doi.org/10.1002/msd2.12068","url":null,"abstract":"In this paper, we investigate the impact of coronary artery dynamics on the wall shear stress (WSS) vector field topology by comparing fluid–structure interaction (FSI) and computational fluid dynamics (CFD) techniques. As one of the most common causes of death globally, coronary artery disease (CAD) is a significant economic burden; however, novel approaches are still needed to improve our ability to predict its progression. FSI can include the unique dynamical factors present in the coronary vasculature. To investigate the impact of these dynamical factors, we study an idealized artery model with sequential stenosis. The transient simulations made use of the hyperelastic artery and lipid constitutive equations, non-Newtonian blood viscosity, and the characteristic out-of-phase pressure and velocity distribution of the left anterior descending coronary artery. We compare changes to established metrics of time-averaged WSS (TAWSS) and the oscillatory shear index (OSI) to changes in the emerging WSS divergence, calculated here in a modified version to handle the deforming mesh of FSI simulations. Results suggest that the motion of the artery can impact downstream patterns in both divergence and OSI. WSS magnitude is also decreased by up to 57% due to motion in some regions. WSS divergence patterns varied most significantly between simulations over the systolic period, the time of the largest displacements. This investigation highlights that coronary dynamics could impact markers of potential CAD progression and warrants further detailed investigations in more diverse geometries and patient cases.","PeriodicalId":60486,"journal":{"name":"国际机械系统动力学学报(英文)","volume":"3 1","pages":"48-57"},"PeriodicalIF":0.0,"publicationDate":"2023-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/msd2.12068","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50135224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Wave control of a flexible space tether based on elastic metamaterials 基于弹性超材料的柔性空间系链波浪控制

国际机械系统动力学学报(英文) Pub Date : 2023-03-16 DOI: 10.1002/msd2.12067

Yexiong Huang, Enmin Chen, Jialiang Sun, Dongping Jin

引用次数: 1

Nonlinear stochastic dynamics of an array of coupled micromechanical oscillators 耦合微机械振荡器阵列的非线性随机动力学

国际机械系统动力学学报(英文) Pub Date : 2023-03-13 DOI: 10.1002/msd2.12066

Maria I. Katsidoniotaki, Ioannis Petromichelakis, Ioannis A. Kougioumtzoglou

{"title":"Nonlinear stochastic dynamics of an array of coupled micromechanical oscillators","authors":"Maria I. Katsidoniotaki, Ioannis Petromichelakis, Ioannis A. Kougioumtzoglou","doi":"10.1002/msd2.12066","DOIUrl":"https://doi.org/10.1002/msd2.12066","url":null,"abstract":"The stochastic response of a multi-degree-of-freedom nonlinear dynamical system is determined based on the recently developed Wiener path integral (WPI) technique. The system can be construed as a representative model of electrostatically coupled arrays of micromechanical oscillators, and relates to an experiment performed by Buks and Roukes. Compared to alternative modeling and solution treatments in the literature, the paper exhibits the following novelties. First, typically adopted linear, or higher-order polynomial, approximations of the nonlinear electrostatic forces are circumvented. Second, for the first time, stochastic modeling is employed by considering a random excitation component representing the effect of diverse noise sources on the system dynamics. Third, the resulting high-dimensional, nonlinear system of coupled stochastic differential equations governing the dynamics of the micromechanical array is solved based on the WPI technique for determining the response joint probability density function. Comparisons with pertinent Monte Carlo simulation data demonstrate a quite high degree of accuracy and computational efficiency exhibited by the WPI technique. Further, it is shown that the proposed model can capture, at least in a qualitative manner, the salient aspects of the frequency domain response of the associated experimental setup.","PeriodicalId":60486,"journal":{"name":"国际机械系统动力学学报(英文)","volume":"3 1","pages":"3-11"},"PeriodicalIF":0.0,"publicationDate":"2023-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/msd2.12066","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50131801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

A stall diagnosis method based on entropy feature identification in axial compressors 基于熵特征识别的轴流压缩机失速诊断方法

国际机械系统动力学学报(英文) Pub Date : 2023-02-03 DOI: 10.1002/msd2.12064

Yang Liu, Juan Du, Jichao Li, Yang Xu, Junqiang Zhu, Chaoqun Nie

{"title":"A stall diagnosis method based on entropy feature identification in axial compressors","authors":"Yang Liu, Juan Du, Jichao Li, Yang Xu, Junqiang Zhu, Chaoqun Nie","doi":"10.1002/msd2.12064","DOIUrl":"https://doi.org/10.1002/msd2.12064","url":null,"abstract":"A stall diagnosis method based on the entropy feature extraction algorithm is developed in axial compressors. The reliability of the proposed method is determined and a parametric sensitivity analysis is experimentally conducted for two different types of compressor stall diagnoses. A collection of time-resolved pressure sensors is mounted circumferentially and along the chord direction to measure the dynamic pressure on the casing. Results show that the stall and prestall precursor embedded in the dynamic pressures are identified through nonlinear feature perturbation extraction using the entropy feature extraction algorithm. Further analysis demonstrates that the prestall precursor with the peak entropy value is related to the unsteady tip leakage flow for the spike-type stall diagnosis. The modal wave inception with increasing amplitude is identified by the considerable increase of the entropy value. The flow field in the tip region indicates that the modal wave corresponds to the flow separation in the suction side of the rotor blade. The warning time is 100–300 rotor revolutions for both types of stall diagnoses, which is beneficial for stall control in different axial compressors. Moreover, a parametric study of the embedding dimension m, similar tolerance n, similar radius r, and data length N in the fuzzy entropy method is conducted to determine the optimal parameter setting for stall diagnosis. The stall warning based on the entropy feature extraction algorithm provides a new stall diagnosis approach in the axial compressor with different stall types. This stall warning can also be adopted as an online stability monitoring index when using the concept of active stall control.","PeriodicalId":60486,"journal":{"name":"国际机械系统动力学学报(英文)","volume":"3 1","pages":"73-84"},"PeriodicalIF":0.0,"publicationDate":"2023-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/msd2.12064","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50123950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Dynamic characteristics of large permanent magnet direct-drive generators considering electromagnetic–structural coupling effects 考虑电磁-结构耦合效应的大型永磁直驱发电机的动态特性

国际机械系统动力学学报(英文) Pub Date : 2023-02-02 DOI: 10.1002/msd2.12065

Qinkai Han, Xueping Xu, Zhihong Zhang, Yifeng Yan, Chao Peng, Fulei Chu

{"title":"Dynamic characteristics of large permanent magnet direct-drive generators considering electromagnetic–structural coupling effects","authors":"Qinkai Han, Xueping Xu, Zhihong Zhang, Yifeng Yan, Chao Peng, Fulei Chu","doi":"10.1002/msd2.12065","DOIUrl":"https://doi.org/10.1002/msd2.12065","url":null,"abstract":"Dynamic characteristics of large permanent magnet direct-drive generators (PMDGs) considering electromagnetic–structural coupling effects are analyzed in this study. Using the conformal mapping method, the scalar magnetic potential of the air gap magnetic field considering the slot effect is calculated. On the basis of the discrete current element and magnetic equivalent circuit model, the local magnetic saturation effect of the stator and rotor is quantitatively simulated and the air gap magnetic field intensity distribution is obtained via numerical simulation. A series of uniformly distributed equivalent electromagnetic springs are introduced to develop an electromagnetic–structural coupling finite element PMDG model. The proposed air gap field analysis method is verified by the finite element analysis results. On the basis of the test platform for the Goldwind 1.5 MW PMDG, both modal and dynamic response tests for the stator/rotor coupling system are conducted, and the results are compared with the natural frequencies, mode shapes, and vibration responses obtained using the numerical model. The effects of the air gap length and rotor speed on the natural frequencies of the coupling system are analyzed. The proposed model has the potential to accurately evaluate the PMDG vibration energy, avoiding resonance points, and maintaining stable operations of the unit.","PeriodicalId":60486,"journal":{"name":"国际机械系统动力学学报(英文)","volume":"3 1","pages":"25-38"},"PeriodicalIF":0.0,"publicationDate":"2023-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/msd2.12065","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50117916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Free vibration of functionally graded sandwich plates in thermal environments 热环境中功能梯度夹层板的自由振动

国际机械系统动力学学报(英文) Pub Date : 2023-01-13 DOI: 10.1002/msd2.12063

Dongdong Li, Zongbai Deng, Guoping Chen

引用次数: 4

Nonlinear stochastic dynamics research on a Lorenz system with white Gaussian noise based on a quasi-potential approach 基于拟势方法的高斯白噪声Lorenz系统的非线性随机动力学研究

国际机械系统动力学学报(英文) Pub Date : 2022-12-31 DOI: 10.1002/msd2.12062

Yong Huang

{"title":"Nonlinear stochastic dynamics research on a Lorenz system with white Gaussian noise based on a quasi-potential approach","authors":"Yong Huang","doi":"10.1002/msd2.12062","DOIUrl":"https://doi.org/10.1002/msd2.12062","url":null,"abstract":"Environmental noise can lead to complex stochastic dynamical behaviors in nonlinear systems. In this paper, a Lorenz system with the parameter region with two stable fixed points and a chaotic saddle subject to white Gaussian noise is investigated as an example. Noise-induced phenomena, such as noise-induced quasi-cycle, three-state intermittency, and chaos, are observed. In the intermittency process, the optimal path used to describe the transition mechanism is calculated and confirmed to pass through an unstable periodic orbit, a chaotic saddle, a saddle point, and a heteroclinic trajectory in an orderly sequence using generalized cell mapping with a digraph method constructively. The corresponding optimal fluctuation forces are delineated to uncover the effects of noise during the transition process. Then the process will switch frequently between the attractors and the chaotic saddle as noise intensity increased further, that is, noise induced chaos emerging. A threshold noise intensity is defined by stochastic sensitivity analysis when a confidence ellipsoid is tangent to the stable manifold of the periodic orbit, which agrees with the simulation results. It is finally reported that these results and methods can be generalized to analyze the stochastic dynamics of other nonlinear mechanical systems with similar structures.","PeriodicalId":60486,"journal":{"name":"国际机械系统动力学学报(英文)","volume":"3 1","pages":"85-94"},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/msd2.12062","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50148835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A localized Fourier collocation method for 2D and 3D elliptic partial differential equations: Theory and MATLAB code 二维和三维椭圆型偏微分方程的局部傅里叶配置方法:理论和MATLAB代码

国际机械系统动力学学报(英文) Pub Date : 2022-12-13 DOI: 10.1002/msd2.12061

Yan Gu, Zhuojia Fu, Mikhail V. Golub

引用次数: 3