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Analysis of multi-factor influences of tilt-to-length coupling noise in a test mass interferometer
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作者 ZHAO Meng-yuan SHEN Jia +5 位作者 PENG Xiao-dong MA Xiao-shan YANG Zhen LIU He-shan MENG Xin ZHANG Jia-feng 《中国光学(中英文)》 北大核心 2025年第3期704-714,共11页
For space-borne gravitational wave detection missions based on the heterodyne interferometry principle,tilt-to-length(TTL)coupling noise is an important optical noise source,significantly influencing the accuracy of t... For space-borne gravitational wave detection missions based on the heterodyne interferometry principle,tilt-to-length(TTL)coupling noise is an important optical noise source,significantly influencing the accuracy of the measurement system.We present a method for analyzing TTL coupling noise under the joint influence of multiple factors.An equivalent simulated optical bench for the test mass interferometer was designed,and Gaussian beam tracing was adopted to simulate beam propagation.By simulating the interference signal,it can analyze the impact of various factors on the TTL coupling noise,including positional,beam parameters,detector parameters,and signal definition factors.On this basis,a random parameter space composed of multiple influential factors was constructed within a range satisfying the analysis requirement,and the corresponding simulation results from random sampling were evaluated via variance-based global sensitivity analysis.The calculated results of the main and total effect indexes show that the test mass rotation angle and the piston effect(lateral)significantly influence the TTL coupling noise in the test mass interferometer.The analysis provides a qualitative reference for designing and optimizing space-borne laser interferometry systems. 展开更多
关键词 space interferometry optical simulation tilt-to-length coupling noise
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Accidental zero modes in a multiorbital superconductor with spin-orbital coupling
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作者 XIANG Ke WANG Da WANG Qianghua 《物理学进展》 北大核心 2025年第5期250-259,共10页
The Majorana zero modes in vortex cores are of extensive interest in the context of topological quantum computing.However,a zero-energy bound state may arise accidentally but is not necessarily a Majorana zero mode.Su... The Majorana zero modes in vortex cores are of extensive interest in the context of topological quantum computing.However,a zero-energy bound state may arise accidentally but is not necessarily a Majorana zero mode.Such accidental zero modes should be carefully ruled out in experiment in order to identify the genuine Majorana zero modes.We show that in a spin-orbital coupled multi-band superconductor,such as the iron-selenide superconductor,accidental zero modes indeed arise in the vortex core if the pairing symmetry is the so-called nodeless d-wave(defined in the absence of spin-orbital coupling).Instead,if the pairing sym-metry is s_(++)or s_(+−)with respect to the Fermi pockets split by the spin-orbital coupling,the accidental zero modes do not appear in the limit of weak spin-orbital coupling.Our results are not only important in the experimental identification of Majorana zero modes,but also provide an avenue to pinpoint the pairing symmetry of the iron-selenide superconductor. 展开更多
关键词 spin-orbital coupling Andreev approximation accidental zero mode
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Failure microscopic mechanism and damage constitutive model of dolomite under water-rock coupling interaction
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作者 SUN Xiao-ming ZHANG Jing +6 位作者 SHI Fu-kun HE Lin-sen ZHANG Yong MIAO Cheng-yu DING Jia-xu MA Li-sha ZHAO Hao-ze 《Journal of Central South University》 2025年第4期1431-1446,共16页
To investigate the effects of water and cyclic loading on dolomite’s mechanical properties during deep mining,mechanical experiments on non-pressure water absorption and cyclic loading were conducted.The findings rev... To investigate the effects of water and cyclic loading on dolomite’s mechanical properties during deep mining,mechanical experiments on non-pressure water absorption and cyclic loading were conducted.The findings reveal that the elastic modulus and Poisson ratio of dolomite fluctuate with increasing water content.The mass of water absorption is positively correlated with time and the water absorption stage can be divided into three stages:accelerated,decelerated,and stabilized stages.During this process,the number of pores in dolomite increases,while the pore diameter initially decreases and then fluctuates.Microscopic analysis shows that the proportion of mesopores first increases and then decreases,while micropores exhibit the opposite trend,and the proportion of macropores fluctuates around 0%.A model diagram of structural evolution during water absorption has been developed.Additionally,the softening process of dolomite’s water absorption strength is categorized into three stages:a relatively stable stage,an accelerated softening stage dominated by mesopore water absorption,and a decelerated softening stage characterized by micropore water absorption.A uniaxial damage constitutive model for dolomite under water influence was established based on the Weibull distribution and Mohr-Coulomb strength criterion,and experimental validation indicates its strong applicability. 展开更多
关键词 water-rock coupling DOLOMITE constitutive model MICROSTRUCTURE loading-unloading cycle
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Mechanical properties and permeability evolution of sandstone subjected to the coupling effects of chemical-seepage-stress
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作者 WANG Wei CHEN Chao-wei +3 位作者 CAO Ya-jun JIA Yun LIU Shi-fan SHEN Wan-qing 《Journal of Central South University》 2025年第2期552-565,共14页
In this study,a series of triaxial tests are conducted on sandstone specimens to investigate the evolution of their mechanics and permeability characteristics under the combined action of immersion corrosion and seepa... In this study,a series of triaxial tests are conducted on sandstone specimens to investigate the evolution of their mechanics and permeability characteristics under the combined action of immersion corrosion and seepage of different chemical solutions.It is observed that with the increase of confining pressure,the peak stress,dilatancy stress,dilatancy stress ratio,peak strain,and elastic modulus of the sandstone increase while the Poisson ratio decreases and less secondary cracks are produced when the samples are broken.The pore pressure and confining pressure have opposite influences on the mechanical properties.With the increase of the applied axial stress,three stages are clearly identified in the permeability evolution curves:initial compaction stage,linear elasticity stage and plastic deformation stage.The permeability reaches the maximum value when the highest volumetric dilatancy is obtained.In addition,the hydrochemical action of salt solution with pH=7 and 4 has an obvious deteriorating effect on the mechanical properties and induces the increase of permeability.The obtained results will be useful in engineering to understand the mechanical and seepage properties of sandstone under the coupled chemical-seepage-stress multiple fields. 展开更多
关键词 red sandstone chemical corrosion multi-field coupling mechanical characteristics permeability evolution
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Cascading failure analysis of an interdependent network with power-combat coupling
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作者 WANG Yang TAO Junyong +2 位作者 ZHANG Yun’an BAI Guanghan DUI Hongyan 《Journal of Systems Engineering and Electronics》 2025年第2期405-422,共18页
Cutting off or controlling the enemy’s power supply at critical moments or strategic locations may result in a cascade failure,thus gaining an advantage in a war.However,the exist-ing cascading failure modeling analy... Cutting off or controlling the enemy’s power supply at critical moments or strategic locations may result in a cascade failure,thus gaining an advantage in a war.However,the exist-ing cascading failure modeling analysis of interdependent net-works is insufficient for describing the load characteristics and dependencies of subnetworks,and it is difficult to use for model-ing and failure analysis of power-combat(P-C)coupling net-works.This paper considers the physical characteristics of the two subnetworks and studies the mechanism of fault propaga-tion between subnetworks and across systems.Then the surviv-ability of the coupled network is evaluated.Firstly,an integrated modeling approach for the combat system and power system is predicted based on interdependent network theory.A heteroge-neous one-way interdependent network model based on proba-bility dependence is constructed.Secondly,using the operation loop theory,a load-capacity model based on combat-loop betweenness is proposed,and the cascade failure model of the P-C coupling system is investigated from three perspectives:ini-tial capacity,allocation strategy,and failure mechanism.Thirdly,survivability indexes based on load loss rate and network sur-vival rate are proposed.Finally,the P-C coupling system is con-structed based on the IEEE 118-bus system to demonstrate the proposed method. 展开更多
关键词 cascading failure survivability analysis interdepen-dent network power-combat(P-C)coupling.
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The noise analysis and multi-physical field coupling study of high-precision SERF atomic gyroscopes
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作者 Jiaxin Liu Xusheng Lei +3 位作者 Yu Yuan Yizhe Zhou Haoying Pang Zhihong Wu 《Defence Technology(防务技术)》 2025年第8期213-224,共12页
The spin-exchange relaxation-free atomic gyroscope,with its exceptionally high theoretical precision,demonstrates immense potential to become the next-generation strategic-grade gyroscope.However,due to technological ... The spin-exchange relaxation-free atomic gyroscope,with its exceptionally high theoretical precision,demonstrates immense potential to become the next-generation strategic-grade gyroscope.However,due to technological noise,there is still a significant gap between its actual precision and theoretical precision.This study identifies the key factor limiting the precision of the SERF gyroscope as coupling noise.By optimizing the detection loop structure,a distinction between the dual-axis signals'response to optical and magnetic fields was achieved-where the optical errors responded similarly,while the response to magnetic noise was opposite.Based on the differences in the optical-magnetic response of the dual-axis signals,empirical mode decomposition was used to decompose the dual-axis gyroscope signals into multiple intrinsic mode functions,and Allan deviation analysis was applied to analyze the noise characteristics of the intrinsic mode functions over various periods.This study successfully reveals that optical errors caused by thermal-optical coupling and long-period magnetic noise induced by thermal-magnetic coupling are the dominant factors limiting the long-term stability of the SERF gyroscope.Based on these analyses,the study concludes that to achieve strategic-grade precision for the SERF gyroscope,it is essential to effectively address the noise issues caused by multi-physical field couplings. 展开更多
关键词 SERF gyroscope Empirical mode decomposition Allan deviation Noise feature recognition Multi physics field coupling
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基于CFD-DEM的斜面平台对下降管内混合颗粒流动的影响 被引量:1
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作者 孙雪峰 张德俐 +5 位作者 刘浩 高豪磊 马瑞 王芳 金德禄 易维明 《农业工程学报》 北大核心 2025年第5期240-249,共10页
为改善生物质热解过程中混合颗粒在下降管热解反应器内部流动时生物质颗粒扰动较小、混合不充分的问题,该研究探讨了管内斜面平台对陶瓷球和生物质颗粒流动的影响。以斜面平台的位置、倾斜角度和高度为试验因素,以生物质颗粒管内离散度... 为改善生物质热解过程中混合颗粒在下降管热解反应器内部流动时生物质颗粒扰动较小、混合不充分的问题,该研究探讨了管内斜面平台对陶瓷球和生物质颗粒流动的影响。以斜面平台的位置、倾斜角度和高度为试验因素,以生物质颗粒管内离散度为评判标准,通过计算流体力学与离散元法(computational fluid dynamics-discrete element method,CFD-DEM)耦合仿真对混合颗粒流动过程进行模拟,并利用粒子图像测速技术进行了验证。结果表明,斜面平台高度对生物质颗粒离散度影响最大,其次为位置和角度,最佳工作参数为斜面平台底部距下降管拐角处245 mm,高度为27 mm,角度为149°,相较于无斜面平台工况,生物质颗粒离散度提高了50.24%,进而提升了混合颗粒的混合程度。斜面平台的引入使得下降管内生物质颗粒和陶瓷球的轴向平均速度分别降低了14.38%和11.43%,平均停留时间分别升高了20.00%和5.75%,改变了无斜面平台时混合颗粒的向心流动特性,表现为抛物线形流动特性,打破了上疏下密的分布状态,使混合颗粒偏析降低,混合更为均匀。该研究结果能够为下降管式生物质热解反应器的设计与优化提供一定支持,有利于生物质快速热解技术的发展。 展开更多
关键词 生物质 下降管 计算机仿真 cfd-dem 气固两相流
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基于CFD-DEM的气送式稻麦兼用型高速播种机种子减速器设计与试验
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作者 臧英 张美林 +3 位作者 黄子顺 姜有聪 钱诚 王在满 《农业机械学报》 北大核心 2025年第5期222-234,共13页
针对气送式稻麦兼用型高速播种机作业时种子输送速度快造成投种精度低、投种不稳定等问题,设计了一种基于旋风减速原理的种子减速器。采用CFD-DEM耦合仿真方法进行单因素试验,确定主要结构因素并选取适宜尺寸区间。为确定种子减速器结... 针对气送式稻麦兼用型高速播种机作业时种子输送速度快造成投种精度低、投种不稳定等问题,设计了一种基于旋风减速原理的种子减速器。采用CFD-DEM耦合仿真方法进行单因素试验,确定主要结构因素并选取适宜尺寸区间。为确定种子减速器结构参数,基于单因素试验结果开展了Box-Behnken正交组合仿真试验,结果表明:最佳结构尺寸为圆筒直径D为82.352 mm,圆筒长度H_(t)为101.364 mm,排气口直径D_(P)为25.0002 mm,锥筒长度H_(z)为67.9025 mm,此时籼稻种子出种口流速V_(1)和种子竖直速度V_(2)分别为5.212 m/s和0.462 m/s;粳稻种子出种口流速V_(1)和种子竖直速度V_(2)分别为5.339 m/s和0.473 m/s;小麦种子出种口流速V_(1)和种子竖直速度V_(2)分别为5.341 m/s和0.408 m/s。台架验证试验结果表明,在出种口处籼稻种子竖直速度为0.411 m/s,粳稻种子竖直速度为0.452 m/s,小麦种子竖直速度为0.457 m/s,与仿真试验结果较符合。条播性能台架试验结果表明,有种子减速器时排种成条效果明显优于无种子减速器情况,而且籼稻、粳稻和小麦排量均匀性变异系数分别由无种子减速器时41.61%、25%和37.84%依次降至9.10%、8.42%和8.49%,满足种子减速器性能要求。研究结果可为后续提高气送式稻麦兼用型播种机播种性能提供指导。 展开更多
关键词 高速播种机 稻麦兼用 种子减速器 cfd-dem
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基于CFD-DEM耦合的膨化颗粒饲料气力输送机理数值分析
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作者 王昱 刘佳豪 +4 位作者 罗毅智 周星星 欧一志 齐海军 袁余 《农业机械学报》 北大核心 2025年第7期180-189,199,共11页
气力输送是水产饲喂的主要方式之一,然而目前气力输送过程中颗粒运动机理尚不清晰,以致气力输送系统的作业效率难以提升。本文以膨化颗粒饲料为对象,采用CFD-DEM气固耦合数值分析方法,构建双弯管颗粒饲料气力输送过程的数值分析模型,采... 气力输送是水产饲喂的主要方式之一,然而目前气力输送过程中颗粒运动机理尚不清晰,以致气力输送系统的作业效率难以提升。本文以膨化颗粒饲料为对象,采用CFD-DEM气固耦合数值分析方法,构建双弯管颗粒饲料气力输送过程的数值分析模型,采用Box-Behnken响应曲面法量化分析喂料速率、入口风速、弯管数对颗粒饲料料气输送比、出口速度和悬浮程度的影响。方差分析结果显示:喂料速率显著影响料气输送比。各因素对颗粒饲料末端速度影响由强到弱为入口风速、弯管数、喂料速率,各因素对颗粒饲料悬浮程度影响由强到弱为入口风速、喂料速率、弯管数。入口风速与颗粒的出口速度和颗粒在竖直方向的坐标、标准差成正比,当喂料速率小于35 g/s时入口风速对料气输送比无显著影响。随着入口风速提高,颗粒的出口速度提高,颗粒悬浮程度上升,表明气力输送系统的输送性能增强。当入口风速为20 m/s、喂料速率为27.232/s、无弯管时,料气输送比为0.966,颗粒出口速度为12.48 m/s,竖直方向坐标为-3.944 mm,标准差为8.805 mm。研究结果为提升气力输送系统的效率和优化设计提供了理论依据。 展开更多
关键词 颗粒饲料 气力输送 cfd-dem耦合 数值分析
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Investigation on the exploding foil initiators ignition enhanced by explosion-electricity coupling 被引量:1
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作者 Songmao Zhao Haotian Jian +3 位作者 Ke Wang Zheng Ning Peng Zhu Ruiqi Shen 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第12期1-11,共11页
Explosion-electricity coupling(EEC) is a technical method to induce electric energy into the plasma material produced by explosion to improve the output of explosion.Exploding foil initiator(EFI) which could produce p... Explosion-electricity coupling(EEC) is a technical method to induce electric energy into the plasma material produced by explosion to improve the output of explosion.Exploding foil initiator(EFI) which could produce plasma during electric explosion can serve as a good carrier for studying the EEC.To investigate the enhancement ability and mechanism of EEC in EFI ignition performance,a kind of EFI chips which could realize the EEC effect was designed and fabricated to observe the characteristics of current and voltage,flyer and plasma temperature during Boron Potassium Nitrate(BPN) ignition of the EFI.It was found that the EEC could enhance EFI ignition in terms of energy utilization,ignition contact surface,and high-temperature sustainability of plasma:firstly,the EEC prolonged the late time discharge(LTD) phase of the electric explosion,making the energy of capacitor effectively utilized;secondly,the EEC could create a larger area of ignition contact surface;last of all,the EEC effect enhanced its hightemperature sustainability by sustaining continuous energy input to plasma.It also was found that the ignition voltage of BPN could be reduced by nearly 600 V under the condition of 0.4 μF capacitance.The research has successfully combined EEC with EFI,revealing the behavioral characteristics of EEC and demonstrating its effective enhancement of EFI ignition.It introduces a new approach to improving EFI output,which is conducive to low-energy ignition of EFI,and expected to take the ignition technology of EFI to a new level. 展开更多
关键词 Exploding foil initiator Explosion-electricity coupling PLASMA Ignition mechanism Boron potassium nitrate
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基于CFD-DEM方法的安全壳碎片迁移流固耦合数值模拟研究
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作者 张丰弢 章静 +3 位作者 巫英伟 贺亚男 田文喜 秋穗正 《原子能科学技术》 北大核心 2025年第6期1284-1293,共10页
当核电厂发生冷却剂丧失事故(LOCA)时,破口介质的喷射过程会导致大量碎片迅速进入安全壳内部,这不仅显著增大滤网处的压降,还可能阻碍安全系统中冷却水的正常循环过程,进而影响事故后反应堆的安全运行。本文基于典型碎片迁移试验台架,... 当核电厂发生冷却剂丧失事故(LOCA)时,破口介质的喷射过程会导致大量碎片迅速进入安全壳内部,这不仅显著增大滤网处的压降,还可能阻碍安全系统中冷却水的正常循环过程,进而影响事故后反应堆的安全运行。本文基于典型碎片迁移试验台架,结合计算流体力学(CFD)与离散单元法(DEM)建立了碎片迁移分析模型,并在验证数值模型准确性的基础上,重点研究了流速变化及碎片堆积对迁移过程的影响,分析了不同流速下碎片的迁移行为及堆积特性。结果表明,入口流速及碎片堆积形态对碎片的迁移行为和迁移份额具有显著影响,低流速下,碎片因回流效应和结构件阻隔,在流道前端堆积形成静止区;而高流速下,碎片迁移距离增大,堆积发生在结构件前的低速回流区,流道边缘的回流效应使碎片向边缘迁移。碎片堆积对流道流场与压力场的影响较为局部,主要表现为碎片堆处流速减缓和迎流面局部正压区引起的压降增大。研究成果为核电厂内部碎片迁移过程的优化设计与安全评估提供了理论依据与技术支持。 展开更多
关键词 碎片迁移 流场分析 cfd-dem 堆积特性 数值模拟
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基于CFD-DEM方法的煤气化渣气流分级提炭模拟研究
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作者 李向阳 张乾 +2 位作者 李乐 白慧 黄伟 《太原理工大学学报》 北大核心 2025年第1期34-43,共10页
【目的】煤气化渣提炭分质是实现其减量化、无害化、资源化利用的重要手段,气流分级法因其能够高效处理细粒级物料且无废水、废气排放而具有独特优势。【方法】基于CFD-DEM模拟,研究卧式涡轮气流分级机内气固流动状况,探明进气方向和涡... 【目的】煤气化渣提炭分质是实现其减量化、无害化、资源化利用的重要手段,气流分级法因其能够高效处理细粒级物料且无废水、废气排放而具有独特优势。【方法】基于CFD-DEM模拟,研究卧式涡轮气流分级机内气固流动状况,探明进气方向和涡轮转向的匹配关系,明确炭颗粒和灰颗粒的流动机制。优化涡轮气流分级机中进气口方向,预测入口气速和涡轮转速对气化细渣气流分级提炭效率的影响。【结果】结果表明:涡轮气流分级机的进气方向对流场分布和气化细渣提炭效率有显著影响。切向进气口易导致在分级区和淘洗区产生相互干扰的次级漩涡,影响气化渣炭和灰颗粒分离效率。优化切向进气为垂直向上后,避免了淘洗区和分级区相互干扰,消除了涡轮和叶片之间次级漩涡,改善并稳定了分级区内的流场,提高了气化细渣提炭效率。在优化后的涡轮气流分级机中,通过匹配入口气速与涡轮转速,富炭渣产品中的炭含量可达80.95%,炭回收率可达59.83%。 展开更多
关键词 煤气化渣 气流分级机 cfd-dem 流场特性 颗粒运动特征
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基于CFD-DEM的循环阀清洁器携屑特性研究
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作者 胡伟 关宁 +3 位作者 张燕萍 徐丙贵 张金亚 朱宏武 《石油机械》 北大核心 2025年第7期42-49,共8页
在钻井过程中,低效的钻屑输运会导致环空岩屑体积分数升高、等效循环密度(ECD)增大,从而引起工具磨损和井漏等问题。为此,开发了一种新型的井眼环空循环阀清洁器。基于H-B非牛顿流体模型,采用耦合的CFD-DEM计算方法,建立了多级井眼环空... 在钻井过程中,低效的钻屑输运会导致环空岩屑体积分数升高、等效循环密度(ECD)增大,从而引起工具磨损和井漏等问题。为此,开发了一种新型的井眼环空循环阀清洁器。基于H-B非牛顿流体模型,采用耦合的CFD-DEM计算方法,建立了多级井眼环空中循环阀清洁器的携屑特性数值计算模型。分析了循环阀清洁器水眼数量、水眼直径、水眼角度以及钻杆转速对携屑性能的影响。研究结果表明:增大水眼直径和数量,提高钻杆转速,均会导致环空岩屑体积分数升高,岩屑输运效率显著降低;当水眼数量为3、直径为10 mm时,携屑效果最佳;随着水眼角度增大,岩屑输运效率先增加后减小;在水眼角度为30°时,岩屑输运效率最高;在垂直井眼中,循环阀清洁器的旋转会产生旋流效应,容易引起岩屑的螺旋运移,从而延长岩屑在井眼中的停留时间,导致岩屑输运效率显著下降;转速越大,旋流作用越强,岩屑输运效果越差。在上述最优参数下,使用该清洁器后,环空井眼流量提升了近58%,整体岩屑输运效率提升了近10%。研究结论对提高环空岩屑输运效率,确保高效、安全的油气开发具有重要意义。 展开更多
关键词 多级井眼 循环阀清洁器 岩屑输运效率 cfd-dem 水眼 钻杆转速
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基于粗粒化CFD-DEM耦合的球磨机钢球级配优化
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作者 唐良彪 涂福泉 +3 位作者 徐淼 陈向东 高路萍 白云 《烧结球团》 北大核心 2025年第2期87-94,142,共9页
球磨机在选矿过程中扮演着关键角色,其性能直接影响后续分选效率和经济收益。本文针对球磨机性能优化方法所存在的高成本和低效率问题,提出了一种基于粗粒化CFD-DEM双向耦合方法研究钢球级配对研磨效率的影响。该方法使用粗粒化模型将... 球磨机在选矿过程中扮演着关键角色,其性能直接影响后续分选效率和经济收益。本文针对球磨机性能优化方法所存在的高成本和低效率问题,提出了一种基于粗粒化CFD-DEM双向耦合方法研究钢球级配对研磨效率的影响。该方法使用粗粒化模型将原始系统中一定数量的粒子由粗粒系统中较大的粒子表示。通过模拟不同钢球级配方案,分析了不同矿石粒度的比能量消耗和球磨机总功耗。试验结果表明,推荐方案一[m(■80)∶m(■60)∶m(■30)=40∶25∶35]的总功率消耗比现场方案[m(■100)=100]低7.5%,耗散功率低5.2%,且在破碎[8,3] mm和[3.0,0.5] mm矿石颗粒时,累积比功率最高,破碎效果最佳。粗粒化CFD-DEM双向耦合方法的应用有效降低了大规模颗粒系统的计算开销,提高了球磨机研磨过程模拟的计算效率,为球磨机优化设计提供了更高效的实践指导。 展开更多
关键词 球磨机 钢球级配优化 粗粒化cfd-dem耦合 数值模拟 磨矿效率
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基于CFD-DEM耦合模型的弯管起旋装置优化及减磨效果研究
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作者 宋海豪 徐雪萌 +3 位作者 尚坤 张汉山 李炳贤 贾会梅 《包装工程》 北大核心 2025年第13期186-196,共11页
目的通过优化气力输送系统中弯管的结构,从而降低弯管磨损的问题。方法在弯管磨损中心切向处添加起旋装置,将弯管中的轴流输送转变为旋流输送。主管道轴线与起旋装置的中心轴线夹角为55°,保持弯管的气速为20 m/s,通过CFD-DEM,对比... 目的通过优化气力输送系统中弯管的结构,从而降低弯管磨损的问题。方法在弯管磨损中心切向处添加起旋装置,将弯管中的轴流输送转变为旋流输送。主管道轴线与起旋装置的中心轴线夹角为55°,保持弯管的气速为20 m/s,通过CFD-DEM,对比小麦颗粒在起旋装置气速分别为20、30、40 m/s时的流场特性。结果基于CFD-DEM对弯管内部颗粒进行运动仿真,分别对比了2种装置的静压、迹线图、旋流强度、颗粒分布图等指标,发现导流叶片式的静压将与旋流强度均大于旋流管道式,螺旋效果更优。通过建立实验平台进行实验验证,实验结果与仿真结果相吻合。结论导流叶片式更适合弯管输送,起旋效果明显,颗粒在弯管内分布均匀,整体呈螺旋前进,可以更有效地减少弯管与颗粒之间的磨损。 展开更多
关键词 粮食颗粒 旋流输送 弯管磨损 cfd-dem
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基于CFD-DEM的种子联合收获机气流清种仿真分析
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作者 夏圣博 李耀明 +2 位作者 姬魁洲 杜拓 王法政 《农机化研究》 北大核心 2025年第4期1-8,共8页
针对现有种子联合收获机在收获后籽粒输运搅龙、杂余搅龙和卸粮搅龙处会残留种子的问题,在上述部位添加了清种气流,并分析在这些机构内使用气流清理残留种粒的可行性。从螺旋搅龙转速和清种入口气流速度这两个因素对清种效果的影响进行... 针对现有种子联合收获机在收获后籽粒输运搅龙、杂余搅龙和卸粮搅龙处会残留种子的问题,在上述部位添加了清种气流,并分析在这些机构内使用气流清理残留种粒的可行性。从螺旋搅龙转速和清种入口气流速度这两个因素对清种效果的影响进行研究,开展卸粮搅龙机构内气固两相流的数值仿真,并基于计算流体力学-离散单元法(CFD-DEM)进行耦合求解,获得了清种过程中气相与颗粒相的速度分布及运动轨迹。结果表明:螺旋搅龙的运动状态对清种气流的通过性有显著影响;当螺旋搅龙处在高转速状态时,清种气流衰减速度较快,此状态下难以有效地利用气流进行清种;气流速度对清种效果影响显著,余种数量和清种所用时间随气流速度升高而降低,但当气流速度过快时会使种子撞击在螺旋搅龙叶片上产生反流和飞溅现象,从而影响清种效果。仿真表明,最优清种气流速度为50 m/s。 展开更多
关键词 种子联合收获机 气流清种 仿真分析 cfd-dem 水稻种子
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基于CFD-DEM的三级配混凝土振动响应研究
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作者 陈雨杰 田正宏 何丽平 《混凝土》 北大核心 2025年第6期23-28,共6页
为研究在插入式振捣作用下三级配混凝土的动力响应,基于计算流体动力学(CFD)和离散元(DEM)的方法,构建了三级配混凝土在振捣作用下的细观模型,分析在振捣过程中骨料配位数、位移场、转动场、速度场、能量的变化规律,结论如下:振捣过程中... 为研究在插入式振捣作用下三级配混凝土的动力响应,基于计算流体动力学(CFD)和离散元(DEM)的方法,构建了三级配混凝土在振捣作用下的细观模型,分析在振捣过程中骨料配位数、位移场、转动场、速度场、能量的变化规律,结论如下:振捣过程中,骨料配位数呈现先减小后增大的趋势,振捣结束时的骨料配位数大于振捣之前的骨料配位数;骨料竖直向位移大于水平向位移,位移变化速度前者大于后者;骨料主要发生绕Z轴的转动,同时伴随着绕X轴、Y轴的转动,其转动大致呈现先增大后趋于稳定的趋势;骨料速度大小呈现先增大后减小的趋势,速度范围前期逐步增大,后趋于稳定;骨料的平动及转动动能均呈现先增大后减小最后稳定的趋势。上述结论可为深入研究三级配混凝土振捣密实理论提供参考。 展开更多
关键词 插入式振捣 三级配混凝土 cfd-dem 骨料配位数 密实性
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Aging Characteristics of Lithium-Ion Battery Under Fast Charging Based on Electrochemical-thermalmechanical Coupling Model
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作者 Dong-Xu Zuo Pei-Chao Li 《电化学(中英文)》 CAS 北大核心 2024年第9期10-24,共15页
The aging characteristics of lithium-ion battery(LIB)under fast charging is investigated based on an electrochemical-thermal-mechanical(ETM)coupling model.Firstly,the ETM coupling model is established by COMSOL Multip... The aging characteristics of lithium-ion battery(LIB)under fast charging is investigated based on an electrochemical-thermal-mechanical(ETM)coupling model.Firstly,the ETM coupling model is established by COMSOL Multiphysics.Subsequently,a long cycle test was conducted to explore the aging characteristics of LIB.Specifically,the effects of charging(C)rate and cycle number on battery aging are analyzed in terms of nonuniform distribution of solid electrolyte interface(SEI),SEI formation,thermal stability and stress characteristics.The results indicate that the increases in C rate and cycling led to an increase in the degree of nonuniform distribution of SEI,and thus a consequent increase in the capacity loss due to the SEI formation.Meanwhile,the increases in C rate and cycle number also led to an increase in the heat generation and a decrease in the heat dissipation rate of the battery,respectively,which result in a decrease in the thermal stability of the electrode materials.In addition,the von Mises stress of the positive electrode material is higher than that of the negative electrode material as the cycling proceeds,with the positive electrode material exhibiting tensile deformation and the negative electrode material exhibiting compressive deformation.The available lithium ion concentration of the positive electrode is lower than that of the negative electrode,proving that the tensile-type fracture occurring in the positive material under long cycling dominated the capacity loss process.The aforementioned studies are helpful for researchers to further explore the aging behavior of LIB under fast charging and take corresponding preventive measures. 展开更多
关键词 Lithium-ion battery Aging characteristics Fast charging Electrochemical-thermal-mechanical coupling model
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基于CFD-DEM耦合的混凝土输送弯管冲蚀磨损数值模拟
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作者 樊新波 王桂红 +1 位作者 罗杨 刘灿 《南方农机》 2025年第S1期125-128,共4页
【目的】解决混凝土泵车弯管冲蚀磨损问题,提高施工质量与资源利用率。【方法】基于CFD-DEM耦合方法的数值模拟框架,构建了非牛顿流体-颗粒两相流耦合作用下的冲蚀分析模型,分析了弯管外侧的磨损以及曲率半径对管道磨损的影响。【结果... 【目的】解决混凝土泵车弯管冲蚀磨损问题,提高施工质量与资源利用率。【方法】基于CFD-DEM耦合方法的数值模拟框架,构建了非牛顿流体-颗粒两相流耦合作用下的冲蚀分析模型,分析了弯管外侧的磨损以及曲率半径对管道磨损的影响。【结果】1)弯管外侧75°区域为最大磨损位置,其形成机制受颗粒离心聚集、二次流输送及高冲击频率共同作用,仿真预测最大磨损速率为7.46×10-7mm/s,弯管寿命约5.2万方,与实际工程数据(4万方~6万方)基本一致;2)曲率半径(R/D)增大可显著降低颗粒冲击强度与磨损速率,有利于延长弯管寿命。【结论】本研究可为弯管几何优化与耐磨材料设计提供理论依据,对提升混凝土泵送系统的安全性与经济性具有工程指导价值。 展开更多
关键词 混凝土弯管 cfd-dem耦合 冲蚀磨损
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Investigation of the electrical performance of high-speed aircraft radomes using a thermo-mechanical-electrical coupling model
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作者 JI Jianmin WANG Wei +2 位作者 YU Huilong LIU Juan CHEN Bo 《Journal of Systems Engineering and Electronics》 CSCD 2024年第6期1397-1410,共14页
During high-speed flight,both thermal and mechani-cal loads can degrade the electrical performance of the antenna-radome system,which can subsequently affect the performance of the guidance system.This paper presents ... During high-speed flight,both thermal and mechani-cal loads can degrade the electrical performance of the antenna-radome system,which can subsequently affect the performance of the guidance system.This paper presents a method for evalu-ating the electrical performance of the radome when subjected to thermo-mechanical-electrical(TME)coupling.The method involves establishing a TME coupling model(TME-CM)based on the TME sharing mesh model(TME-SMM)generated by the tetrahedral mesh partitioning of the radome structure.The effects of dielectric temperature drift and structural deformation on the radome’s electrical performance are also considered.Firstly,the temperature field of the radome is obtained by tran-sient thermal analysis while the deformation field of the radome is obtained by static analysis.Subsequently,the dielectric varia-tion and structural deformation of the radome are accurately incorporated into the electrical simulation model based on the TME-SMM.The three-dimensional(3D)ray tracing method with the aperture integration technique is used to calculate the radome’s electrical performance.A representative example is provided to illustrate the superiority and necessity of the pro-posed method.This is achieved by calculating and analyzing the changes in the radome’s electrical performance over time dur-ing high-speed flight. 展开更多
关键词 high-speed flight thermo-mechanical-electrical(TME) TME coupling model(TME-CM) dielectric temperature drift structural deformation electrical performance
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