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基于SBFE虚粒子边界的结构入水数值模拟
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作者 李上明 赵梓斌 《兵器装备工程学报》 CSCD 北大核心 2021年第12期153-158,共6页
通过联合比例边界有限元法(SBFEM)和光滑粒子法(SPH),提出了一种基于SPH框架下新的无反射边界—SBFE虚粒子边界,该SBFE虚粒子边界能够准确的模拟边界波的透射过程,能够以较小计算域模拟无穷域的特征,从而显著地提高SPH算法模拟无穷域流... 通过联合比例边界有限元法(SBFEM)和光滑粒子法(SPH),提出了一种基于SPH框架下新的无反射边界—SBFE虚粒子边界,该SBFE虚粒子边界能够准确的模拟边界波的透射过程,能够以较小计算域模拟无穷域的特征,从而显著地提高SPH算法模拟无穷域流体的计算效率。最后,将SBFE虚粒子边界应用于无穷水域的结构入水数值模拟,验证了SBFE虚粒子边界模拟无穷域流体的准确性。 展开更多
关键词 SBFEM SPH SBFE虚粒子边界 无反射边界 结构入水
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带气囊结构航行体入水回收动力学特性研究 被引量:1
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作者 职明洋 燕国军 +1 位作者 孙龙泉 王鹏霄 《力学学报》 EI CAS CSCD 北大核心 2024年第4期943-959,共17页
针对大尺度模型入水航行体的回收问题,为避免结构入水下落产生的过大入水深度对发射平台的安全造成威胁,并提升模型航行体的回收效率.文章设计了一种带气囊的航行体结构,认为气囊自空中释放并与航行体同步入水,经上浮后确保结构回收,并... 针对大尺度模型入水航行体的回收问题,为避免结构入水下落产生的过大入水深度对发射平台的安全造成威胁,并提升模型航行体的回收效率.文章设计了一种带气囊的航行体结构,认为气囊自空中释放并与航行体同步入水,经上浮后确保结构回收,并给出了模型具体的设计参数.同时基于耦合欧拉-拉格朗日(CEL)算法建立了带气囊结构入水回收的数值计算模型,结合相关球体入水以及AUV头段入水试验结果,验证了数值方法的有效性并选取了本模型的无关性网格尺度.在此基础上,开展了不同气囊体积下航行体垂直入水回收的计算,选取了该结构对应的最佳气囊体积.随后,针对不同入水参数(入水速度、攻角以及气囊固定位置)进行了带气囊结构航行体入水回收过程的对比分析.研究结果表明,气囊体积对回收效率的提升具有正相关作用,且在体积的选取中应兼顾回收效率与气囊内压响应;入水速度的增加诱导系统运动规模同步增加,不利于回收的进行;入水攻角以及气囊固定位置的不同造成不同阶段航行体偏转运动的差异,气囊固定在航行体中部且较大的入水攻角有利于航行体模型的入水回收. 展开更多
关键词 航行体回收 结构入水 气囊 姿态偏转 耦合欧拉-拉格朗日方法
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基于修正任意拉格朗日-欧拉算法的结构体入水仿真
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作者 曹力飞 李炳彦 刘艳 《探测与控制学报》 CSCD 北大核心 2023年第2期30-36,共7页
针对显示动力学算法在结构体入水的流固耦合数值计算过程中计算效率低的问题,提出基于冲击修正的任意拉格朗日欧拉(C-ALE)算法的结构体入水计算方法,该方法引入贯穿量C对任意拉格朗日欧拉方法进行修正,采用流体域与固体域定步长交替计... 针对显示动力学算法在结构体入水的流固耦合数值计算过程中计算效率低的问题,提出基于冲击修正的任意拉格朗日欧拉(C-ALE)算法的结构体入水计算方法,该方法引入贯穿量C对任意拉格朗日欧拉方法进行修正,采用流体域与固体域定步长交替计算的方法进行求解。对比结构体入水过程外场试验结果和采用相同输入条件和网格模型的ALE算法计算结果,可以得出针对结构体入水过程的求解,C-ALE算法比ALE算法具有更小的计算误差和更快的收敛速度。 展开更多
关键词 显式动力学 流固耦合 结构入水
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2D刚体椭圆头结构高速撞水模拟 被引量:5
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作者 郑金伟 宗智 《鱼雷技术》 2008年第2期9-12,共4页
2D刚体椭圆头结构高速撞击水面会受到来自水面的冲击力,由于撞水过程中会引起自由液面大幅波动和流固接触界面的非线性,载荷的大小很难使用常规动力学方法求解。本文利用ANSYS/LS-DYNA软件中的ALE算法对椭圆头结构高速入水问题进行了模... 2D刚体椭圆头结构高速撞击水面会受到来自水面的冲击力,由于撞水过程中会引起自由液面大幅波动和流固接触界面的非线性,载荷的大小很难使用常规动力学方法求解。本文利用ANSYS/LS-DYNA软件中的ALE算法对椭圆头结构高速入水问题进行了模拟,数值结果表明,在某一入水角度下,加速度峰值和入水速度呈幂次关系,压力峰值随着入水速度的增大而增大,入水角度在35°时压力峰值最大。 展开更多
关键词 结构入水 自由液面 流固接触界面 数值仿真 ALE算法
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基于FPM方法的入水问题数值模拟研究
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作者 王敏 马小晶 +1 位作者 陈尉 张博文 《应用力学学报》 CAS CSCD 北大核心 2023年第1期199-210,共12页
结构体入水作为一个高度非线性的冲击动力学问题,广泛存在于船舶海洋和军事等工程领域,因此,对该问题进行精确而高效的数值模拟是十分必要。采用有限质点法(finite particle method,FPM),结合无反射边界,数值模拟研究了二维结构体入水... 结构体入水作为一个高度非线性的冲击动力学问题,广泛存在于船舶海洋和军事等工程领域,因此,对该问题进行精确而高效的数值模拟是十分必要。采用有限质点法(finite particle method,FPM),结合无反射边界,数值模拟研究了二维结构体入水的动态过程。通过分析楔形体入水所受的垂向力、速度和压力,并与相关文献结果对比分析,验证了该方法的有效性。在此基础上,对不同工况下的入水问题进行了模拟,研究了不同尺寸、形状、初速度和质量等情况下,结构入水冲击时垂向力和速度随时间的变化规律,以及不同时刻下压力响应的变化趋势。研究结果表明:楔形体的底升角尺寸、结构体形状、入水初速度和质量等因素都会直接影响结构体入水的力学特性,为入水结构体的力学设计提供了参考。 展开更多
关键词 FPM 无反射边界 数值模拟 结构入水 力学特性
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Influence of inflow conditions on the hydrodynamic characteristics of floating photovoltaic membrane structures
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作者 Zhang Puyang Zhang Linyang +2 位作者 Xiong Lichao Le Conghuan Ding Hongyan 《Journal of Southeast University(English Edition)》 EI CAS 2024年第4期363-371,共9页
The floating photovoltaic membrane prototype developed by Ocean Sun was selected as a reference object,and a 1∶40 scale laboratory model was designed and produced to further explore the impact of inflow conditions on... The floating photovoltaic membrane prototype developed by Ocean Sun was selected as a reference object,and a 1∶40 scale laboratory model was designed and produced to further explore the impact of inflow conditions on the hydrodynamic properties of the membrane structure.By conducting free attenuation tests,results showed that the inflow has only a slight effect on the natural frequencies of the heave,pitch,and surge of the membrane structure.This finding shows that the dynamic properties of the membrane structure remain essentially stable under different inflow conditions.The results of further regular and irregular wave hydrodynamic experiments show that,compared with the control group,the response of the membrane structure under inflow conditions in terms of heave,pitch,surge,and heave acceleration motions is relatively gentle,whereas the response of the membrane structure to the mooring force is strong.Especially when the waves are irregular,the inflow conditions have a more significant impact on the membrane structure,which may lead to more complex response changes in the structure.Therefore,in the actual engineering design process,the impact of inflow conditions on the behavior of the membrane structure must be fully considered,and appropriate engineering measures must be taken to ensure the safety and stability of the structure. 展开更多
关键词 floating photovoltaic MEMBRANE hydrodynamic characteristic INFLOW
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塔河油田奥陶系岩溶古暗河岩溶期机械充填特征 被引量:1
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作者 张慧涛 杨敏 +3 位作者 汪彦 杨德彬 徐珊 刘洁 《石油地质与工程》 CAS 2021年第6期12-17,24,共7页
塔河油田岩溶古暗河的结构类型呈多样性,几何特征存在较大差异,一直制约着古暗河油藏的开发。在岩心、常规测井、成像测井和钻录井资料综合分析的基础上,建立古暗河岩溶期机械充填的识别标志,然后分析裂缝、断裂、表层落水洞+断裂、深... 塔河油田岩溶古暗河的结构类型呈多样性,几何特征存在较大差异,一直制约着古暗河油藏的开发。在岩心、常规测井、成像测井和钻录井资料综合分析的基础上,建立古暗河岩溶期机械充填的识别标志,然后分析裂缝、断裂、表层落水洞+断裂、深部落水洞四种不同的古暗河入水口结构类型,阐明其运动特征、对岩溶水的作用、水流流动方向以及对砂泥质等充填物的携带能力。在机械充填物识别和入水口结构研究的基础上,总结出落水洞–断裂–管道、断裂–厅堂、裂缝–管道三种不同岩溶组合形态,并分析了其机械充填原因、地震和测井识别方法、生产特征,指出断裂–厅堂型是有利的岩溶组合形态,是后期开发的重点对象。 展开更多
关键词 塔河油田 古暗河 岩溶组合形态 入水结构 机械充填
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不同姿态下救生艇高空自由下落的动力学特性 被引量:1
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作者 张大朋 严谨 赵博文 《船舶与海洋工程》 2022年第6期18-24,共7页
救生艇从高空自由下落到水面上的过程是典型的结构物入水问题。以一艘刚性充气艇为计算模型,基于动态重叠网格法对该艇在某高度处以不同姿态自由下落的过程进行数值模拟,得出其在下落过程中的垂向速度、加速度和下落距离等物理量的变化... 救生艇从高空自由下落到水面上的过程是典型的结构物入水问题。以一艘刚性充气艇为计算模型,基于动态重叠网格法对该艇在某高度处以不同姿态自由下落的过程进行数值模拟,得出其在下落过程中的垂向速度、加速度和下落距离等物理量的变化情况。对比分析结果表明:初始下落姿态决定着救生艇入水后的运动状态,横倾在艇宽方向上的运动比较剧烈,艏倾和艉倾在艇长方向上的运动比较剧烈;救生艇艏倾入水时的埋艏现象和甲板上浪现象比较严重;通过调整艇体下落时的初始姿态,可改变其入水角度,有效减缓甲板上浪。 展开更多
关键词 救生艇 结构入水 自由下落 数值模拟
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Numerical Simulation of the Water Entry of a Structure in Free Fall Motion 被引量:1
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作者 Qingtong Chen Baoyu Ni +1 位作者 Shuping Chen Jiangguang Tang 《Journal of Marine Science and Application》 2014年第2期173-177,共5页
To solve the problems concerning water entry of a structure, the RANS equations and volume of fluid (VOF) method are used. Combining the user-defined function (UDF) procedure with dynamic grids, the water impact o... To solve the problems concerning water entry of a structure, the RANS equations and volume of fluid (VOF) method are used. Combining the user-defined function (UDF) procedure with dynamic grids, the water impact on a structure in free fall is simulated, and the velocity, displacement and the pressure distribution on the structure are investigated. The results of the numerical simulation were compared with the experimental data, and solidly consistent results have been achieved, which validates the numerical model. Therefore, this method can be used to study the water impact problems of a structure. 展开更多
关键词 STRUCTURE free fall motion water impact RANSequations VOF water entry
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The Empirical Analysis of the Impacts of Income Distribution Gap on Consumption Demand:Based on the Statistic Data of Chinese Urban Residents in 2000-2010
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作者 Qian Long Zhao Yong Zhong Sheng 《Chinese Journal of Population,Resources and Environment》 2012年第4期116-120,共5页
This paper analyzes the impact of income distribution gap on consumption demand from a theoretical view,and draws the conclusion that there is an inverse relationship between income distribution gap and consumption de... This paper analyzes the impact of income distribution gap on consumption demand from a theoretical view,and draws the conclusion that there is an inverse relationship between income distribution gap and consumption demand.Then,the paper finds that the existing widening income distribution gap in China has a negative impact on consumption demand,but this is not the key factor for the insufficient consumption demand because of the low level of per capital income.At last,it suggests that governments should improve the income level of entire residents and adjust income distribution structure simultaneously. 展开更多
关键词 income distribution gap consumption demand elas- ticity coefficient substitution effects
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The pore structure of tight limestone-Jurassic Ziliujing Formation, Central Sichuan Basin, China 被引量:1
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作者 Liu Yun-Long Zhang Yuan-Zhong +1 位作者 Wang Yong-Jun Wang Li-Geng 《Applied Geophysics》 SCIE CSCD 2018年第2期165-174,361,共11页
The pore structure of the tight limestone in the Daanzhai Member of the Ziliujing Formation, Jurassic System, in central Sichuan Basin, China, is complex but essential to the exploration and development of tight oil. ... The pore structure of the tight limestone in the Daanzhai Member of the Ziliujing Formation, Jurassic System, in central Sichuan Basin, China, is complex but essential to the exploration and development of tight oil. The pore structure of the tight limestone is studied by using scanning electron microscopy (SEM), nitrogen adsorption, high-pressure mercury intrusion, and nuclear magnetic resonance (NMR). The experimental results suggest that the pores are mainly slit pores and mesopores and macropores contribute to the pore volume and specific surface. The displacement pressure, average pore size, and homogeneity coefficient correlate with porosity and permeability and can be used to evaluate the pore structure. The full pore-size distribution was obtained by combining nitrogen adsorption and high-pressure mercury intrusion. We find that the limestone mainly contains mesopores with diameter of 2-50 nm. The T2 distribution was converted into pore-size distribution, well matching the full pore-size distribution. The relation between T2 and pore size obeys a power law and the geometric mean of T2 correlates with the pore structure and can be used in the pore structure evaluation. 展开更多
关键词 Tight oil LIMESTONE pore structure nitrogen adsorption mercury intrusion nuclear magnetic resonance
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Numerical simulation of the floor water-inrush in working face influenced by fault structure
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作者 程久龙 曹吉胜 +2 位作者 许进鹏 于师建 田丽 《Journal of Coal Science & Engineering(China)》 2007年第3期230-233,共4页
Used numerical simulation method to study the floor water-inrush mechanism in working face which was influenced by fault structure, and set up many kinds of models and performs numerical calculation by fully using lar... Used numerical simulation method to study the floor water-inrush mechanism in working face which was influenced by fault structure, and set up many kinds of models and performs numerical calculation by fully using large finite element soft-ANSYS and element birth-death method. The results show that the more high the underground water pressure, the more big the floor displacement and possibility of water-inrush; the floor which has fault structure is more prone to water-inrush than the floor which not has fault structure, the floor which has multi-groups cracks is more prone to water-inrush than the floor which has single-group cracks. The numerical simulation result forecasts the water-inrush in working face preferably. 展开更多
关键词 floor water-inrush numerical simulation fault structure
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Study on the Influencing Factors of the Aquatic Products Consumption in China
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作者 Yiyang LIU Jian GAO 《International Journal of Technology Management》 2013年第4期72-75,共4页
In this paper, an econometric model for the aquatic products consumption of urban residents was established, aiming at investigating the different effects of seven factors (urban residents' annual disposable income,... In this paper, an econometric model for the aquatic products consumption of urban residents was established, aiming at investigating the different effects of seven factors (urban residents' annual disposable income, annual consumption quantity of pork and poultry and related byproducts, family structure, aging level, educational background, having meals out of home, and the number of retail chains stores) on the aquatic products consumption quantity of urban residents. The result of the model showed urban residents' annual disposable income and having meals out of home play the greatest effect on the consumption of aquatic products, followed by the number of retail chains stores; family structure plays a negative effect on the consumption of aquatic products. Also, the analysis shows not only the prices of the aquatic products as well as substitutes should be considered and also the quantity of the meals consumed by residents out of home and the number of retail chains stores should be used as important associated factors in studying the change trend of aquatic products consumption, and simultaneously the effect of family structure on the consumption quantity of aquatic products should be taken seriously, so that the aquatic products consumption of Chinese residents should be further promoted and also the aquatic products market can attain a development. 展开更多
关键词 The Consumption of Aquatic Products Influencing Factors ECONOMETRICS
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波浪条件下空投AUV入水数值模拟 被引量:4
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作者 赵庆新 丁忠军 《华中科技大学学报(自然科学版)》 EI CAS CSCD 北大核心 2021年第1期128-132,共5页
针对波浪条件下空投自主式水下运载器(AUV)低速入水(伞降或低空空投)工况,采用计算流体力学方法进行数值模拟.计算了5套不同分辨率网格的AUV入水情况,证明了所采用的网格设置能很好地满足AUV入水数值模拟.分析了AUV在波峰、波谷等不同... 针对波浪条件下空投自主式水下运载器(AUV)低速入水(伞降或低空空投)工况,采用计算流体力学方法进行数值模拟.计算了5套不同分辨率网格的AUV入水情况,证明了所采用的网格设置能很好地满足AUV入水数值模拟.分析了AUV在波峰、波谷等不同入水点处受力情况.入水点在波峰和波谷处AUV受力较大,且这两点处x方向上受力变化趋势是相反的,主要原因是水面上水质点圆周运动速度和迁移速度叠加导致的合速度方向不一致.分析了不同波浪参数和风速对AUV受力的影响,不同波浪参数和风速对AUV垂向受力影响极小,而对横向受力影响较大;相比于静水入水,波浪条件下入水受力更大.产生这些现象的主要原因是波面上水质点的横向运动. 展开更多
关键词 空投自主式水下运载器(AUV) 波浪条件 结构入水 流体力学 数值模拟
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Structural analysis of [Bmim]_2CuCl_4 ionic liquids in the presence of water and ethanol by XAFS technique
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作者 Fangling Jiang Cheng Li +3 位作者 Haiying Fu Yaxing Wang Xiaojing Guo Guozhong Wu 《Science China Chemistry》 SCIE EI CAS CSCD 2015年第4期716-721,共6页
The structure of [Bmim]2CuCl4 ionic liquids (Bmim: 1-butyl-3-methylimidazolium) with different ratios of H2O and C2H5OH was investigated using X-ray absorption fine structure (XAFS) technique. In this study, XAFS... The structure of [Bmim]2CuCl4 ionic liquids (Bmim: 1-butyl-3-methylimidazolium) with different ratios of H2O and C2H5OH was investigated using X-ray absorption fine structure (XAFS) technique. In this study, XAFS was employed to directly probe the conformational variations of copper ions in [Bmim]2CuCl4 with the addition of either water or ethanol. XAFS analysis confirmed that the structure of ionic liquids gradually transformed from tetrahedral to octahedral configuration with the increase in ratio of H2O. Our results also showed that water molecules coordinated with the copper ions of [Bmim]2CuCl4, leading to the conformational change in ionic liquids. However, the XAFS spectra of [Bmim]zCuCIa/C2H5OH indicated no coordination of anhydrous ethanol with the copper ions of [Bmim]2CuC14. The structure of [Bmim]2CuCl4 ionic liquids is maintained as the tetrahedral configuration in presence of ethanol. Therefore, anhydrous ethanol causes little variation in the structure of ionic liquids and it is a good solvent for the dilution of ionic liquids. 展开更多
关键词 ionic liquids WATER ETHANOL XAFS
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