检索结果-南通市图书馆

A CFD study on the hydrodynamic response of a small-scale ice floe induced by a passing ship

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of hydrodynamics 2024年第2期36卷 290-299页

作者： Zongyu Jiang Spyros Hirdaris Sasan Tavakoli Mikko Suominen Pentti Kujala Marine and Arctic Technology Department of Mechanical EngineeringAalto UniversityEspooFinland Global Ship Systems Centre ABS Hellenic SM LLC.AthensGreece Department of Infrastructure Engineering The University of MelbourneMelbourneAustralia

A Reynolds averaged Navier-Stokes(RANS)computational fluid dynamics(CFD)model is built to investigate the hydrodynamic response of a circular ice floe under the influence of a passing ship in calm *** ship,mirroring the KRISO Container Ship’s hull design,progresses near an ice floe whose diameter is 30%of the ship’s length and its thickness is 3 *** ship advances at a constant speed,which is handled by using the overset mesh *** study focuses on the ice floe’s motions and the hydrodynamic forces induced by three speeds and three transverse distances of the passing *** reveal that ship-generated wakes notably influence the ice floe’s motions,with a greater influence on sway than ***,the ship’s speed and proximity distinctly affect the ice floe’s motions.

关键词： hydrodynamics ship-ice interactions ice floe Reynolds averaged Navier-Stokes(RANS)computational fluid dynamics(CFD)

Mass transfer enhancement and hydrodynamic performance with wire mesh coupling solid particles in bubble column reactor

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第3期67卷 195-205页

作者： Chuanjun Di Jipeng Dong Fei Gao Guanghui Chen Pan Zhang Jianlong Li Key Laboratory of Multiphase Flow Reaction and Separation Engineering of Shandong Province College of Chemical EngineeringQingdao University of Science and TechnologyQingdao 266042China College of Electromechanical Engineering Qingdao University of Science and TechnologyQingdao 266043China

It is of vital significance to investigate mass transfer enhancements for chemical engineering *** work focuses on investigating the coupling influence of embedding wire mesh and adding solid particles on bubble motion and gas-liquid mass transfer process in a bubble *** image velocimetry(PIV)technology was employed to analyze the flow field and bubble motion behavior,and dynamic oxygen absorption technology was used to measure the gas-liquid volumetric mass transfer coefficient(kLa).The effect of embedding wire mesh,adding solid particles,and wire mesh coupling solid particles on the flow characteristic and kLa were analyzed and *** results show that the gas-liquid interface area increases by 33%-72%when using the wire mesh coupling solid particles strategy compared to the gas-liquid two-phase flow,which is superior to the other two strengthening *** with the system without reinforcement,kLa in the bubble column increased by 0.5-1.8 times with wire mesh coupling solid particles method,which is higher than the sum of kLa increases with inserting wire mesh and adding particles,and the coupling reinforcement mechanism for affecting gas-liquid mass transfer process was discussed to provide a new idea for enhancing gas-liquid mass transfer.

关键词： Fluid mechanics Bubble Mass transfer Wire mesh coupling solid particles Particle image velocimetry hydrodynamics

Simulating the Escaping Atmosphere of GJ 436 b with Two-fluid Magnetohydrodynamic Models

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第6期24卷 273-286页

作者： Lei Xing Jianheng Guo Chuyuan Yang Dongdong Yan Yunnan Observatories Chinese Academy of SciencesKunming 650216China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory for Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650216China International Centre of Supernovae Yunnan Key LaboratoryKunming 650216China

Observations of transmission spectra reveal that hot Jupiters and Neptunes are likely to possess escaping atmospheres driven by stellar *** models predict that magnetic fields may exert significant influences on the atmospheres of hot ***,the escaping atmospheres are not entirely ionized,and magnetic fields only directly affect the escape of ionized components within *** the chemical reactions between ionized components and neutral atoms,as well as collision processes,magnetic fields indirectly impact the escape of neutral atoms,thereby influencing the detection signals of planetary atmospheres in transmission *** order to simulate this process,we developed a magnetohydrodynamic multi-fluid model based on MHD code *** an initial exploration,we investigated the impact of magnetic fields on the decoupling of H^(+)and H in the escaping atmosphere of the hot Neptune *** to the strong resonant interactions between H and H^(+),the coupling between them is tight even if the magnetic field is *** course,alternatively,our work also suggests that merging H and H^(+)into a single flow can be a reasonable assumption in MHD simulations of escaping ***,our simulation results indicate that under the influence of magnetic fields,there are noticeable regional differences in the decoupling of H^(+)and *** the increase of magnetic field strength,the degree of decoupling also *** heavier particles such as O,the decoupling between O and H^(+)is more *** findings provide important insights for future studies on the decoupling processes of heavy atoms in the escaping atmospheres of hot Jupiters and hot Neptunes under the influence of magnetic fields.

关键词： magnetohydrodynamics(MHD) planets and satellites:atmospheres hydrodynamics

A data-driven model of drop size prediction based on artificial neural networks using small-scale data sets

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第2期66卷 71-83页

作者： Bo Wang Han Zhou Shan Jing Qiang Zheng Wenjie Lan Shaowei Li Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084China State Key Laboratory of Heavy Oil Processing China University of Petroleum(Beijing)Beijing 102249China State Key Laboratory of Chemical Engineering Tsinghua UniversityBeijing 100084China

An artificial neural network(ANN)method is introduced to predict drop size in two kinds of pulsed columns with small-scale data *** training,the deviation between calculate and experimental results are 3.8%and 9.3%,*** ANN model,the influence of interfacial tension and pulsation intensity on the droplet diameter has been *** size gradually increases with the increase of interfacial tension,and decreases with the increase of pulse *** can be seen that the accuracy of ANN model in predicting droplet size outside the training set range is reach the same level as the accuracy of correlation obtained based on experiments within this *** two kinds of columns,the drop size prediction deviations of ANN model are 9.6%and 18.5%and the deviations in correlations are 11%and 15%.

关键词： Artificial neural network Drop size Solvent extraction Pulsed column Two-phase flow hydrodynamics

Littoral landforms of Lake Hulun and Lake Buir(China and Mongolia):Wind-driven hydro-sedimentary dynamics and resulting clastics distribution

在线全文

学校读者我要写书评

暂无评论

Journal of Palaeogeography 2024年第2期13卷 309-326页

作者： Li Wang Mathieu Schuster Shi-Wei Xin Florin Zainescu Xin-Yu Xue Joep Storms Jan-Hendrik May Alexis Nutz Helena van der Vegt Guilherme Bozetti Zai-Xing Jiang School of Energy Resources China University of Geosciences(Beijing)Beijing100083China Universite de Strasbourg CNRSENGEESInstitut Terre et Environnement de StrasbourgUMR 70635 Rue DescartesStrasbourgFrance Tamsag Mongolia(XIX)Ltd. PetroChinaDaqing 163000China CEREGE Aix-Marseille UniversitéCNESIRDCollege de FranceINRAAix en ProvenceFrance School of Marine Science Sun Yat-sen UniversityZhuhai 519083China Delft University of Technology Department of Geoscience and EngineeringDelfthe Netherlands School of Geography Earth and Atmospheric SciencesUniversity of Melbourne253 Elgin St.CarltonVIC 3053Australia Deltares Delfthe Netherlands SCMF Faculty of GeographyUniversity of Bucharest1 N.Balcescu Blv.BucharestRomania

Two rectangular-shaped lakes,Lake Hulun and Lake Buir,located at the boundary between China and Mongolia,only c.75 km apart and therefore experiencing similar wind fields,have been studied based on satellite images and field surveys in order to compare their geomorphological and sedimentological *** wind-driven hydrodynamics,which have a significant effect on the development of littoral landforms and on sediment distribution,have been discussed for the two similar lakes that experienced a prevailing wind perpendicular to their long axis.A conceptual model related to wind-driven water bodies and sediment distribution is ***-influenced to wave-dominated deltas,beaches,spits,and eolian dune deposits develop around these two lakes,with a strikingly similar distribution *** features locally inform the longshore drift and help reconstruct the water circulation induced by wind *** the NW prevailing wind regime,the spits developed on the SW coast with a NW—SE extension,which was influenced by the NW—SE longshore *** same influence was observed in the delta extension in the NE *** differences lie in the presence of fan deltas in the NW region of Lake Hulun,but not in Lake ***,the width of the beach and eolian deposits on the downwind coast of Lake Hulun is three times greater than that of Lake Buir which were caused by the differences in sediment supply and wind fetch between the two *** Hulun and Lake Buir provide two reliable examples to understand the relationship among the wind field,provenance,hydrodynamics,landforms,and asymmetrical distribution of clastics in elongated *** also represent relevant modern analogs,which may also be of guiding significance to wind-driven sand body prediction in lacustrine basins.

关键词： Wind-driven lakes Fetch Sedimentary facies hydrodynamics Geomorphology Spits Shoreline Lake Hulun Lake Buir

Perturbing the Stable Accretion Disk in Kerr and 4D Einstein–Gauss–Bonnet Gravities: Comprehensive Analysis of Instabilities and Dynamics

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第8期24卷 3-21页

作者： Orhan Donmez College of Engineering and Technology American University of the Middle East

The study of a disturbed accretion disk holds great significance in the realm of astrophysics,as such events play a crucial role in revealing the nature of disk structure,the release of energy,and the generation of shock ***,they can help explain the causes of X-ray emissions observed in black hole accretion disk *** this paper,we perturb the stable disk formed by spherical accretion around Kerr and Einstein–Gauss–Bonnet(EGB) black *** perturbation reveals one-and two-armed spiral shock waves around the black *** find a strong connection between these waves and the black hole spin parameter (a/M) and the EGB coupling constant (α).Specifically,we find that as α increases in the negative direction,the dynamics of the disk and the waves become more ***,we observe that the angular momentum of the perturbing matter significantly affects mass accretion and the oscillation of the arising shock *** allows us to observe changes in QPO frequencies,particularly,perturbations with angular momentum matching the observed C-type low-frequency QPOs of the GRS 1915+105 ***,we conclude that the possibility of the occurrence of shock waves within the vicinity of GRS 1915+105 is substantial.

关键词： accretion accretion disks black hole physics hydrodynamics shock waves X-rays: binaries

Flow Regimes in Bubble Columns with and without Internals: A Review

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Fluid Dynamics & Materials Processing 2024年第2期20卷 239-256页

作者： Ayat N.Mahmood Amer A.Abdulrahman Laith S.Sabri Abbas J.Sultan Hasan Shakir Majdi Muthanna H.Al-Dahhan Department of Chemical Engineering University of Technology-IraqBaghdadIraq Chemical and Petroleum Industries Engineering Department Al-Mustaqbal University CollegeBabylonIraq Department of Chemical and Biochemical Engineering Missouri University of Science and TechnologyRollaUSA

hydrodynamics characterization in terms ofﬂow regime behavior is a crucial task to enhance the design of bubble column reactors and scaling up related *** review presents recent studies on the typicalﬂow regimes established in bubble *** effort is also provided to introduce relevant deﬁnitions pertaining to thisﬁeld,namely,that of“void fraction”and related(local,chordal,cross-sectional and volumetric)*** studies involving different parameters that affect design and operating conditions are also discussed in *** the second part of the review,the attention is shifted to cases with internals of various types(perfo-rated plates,bafﬂes,vibrating helical springs,mixers,and heat exchanger tubes)immersed in the bubble *** is shown that the presence of these elements has a limited inﬂuence on the global column ***,they can make the homogeneousﬂow regime more stable in terms of transition gas velocity and transi-tion holdup *** last section is used to highlight gaps which have not beenﬁlled yet and future directions of investigation.

关键词： hydrodynamics ﬂow regime bubble column heat-exchanging internals

Application of Regional Ocean Modeling System for hydrodynamics in Binh Cang-Nha Trang Bay, Vietnam

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Marine Science 2019年第1期1卷 1-6页

作者： Pham Xuan Duong Phan Minh-Thu Bui Hong Long Dept.Marine Physics Institute of OceanographyVietnam Academy of Science and Technology (VAST)Nha TrangVietnam Dept.Marine Ecology Institute of OceanographyVASTNha TrangVietnam Graduate University of Science and Technology VASTVietnam

Based on the data collected at the Cau Da station, the Regional Ocean Modeling System (ROMS) is applied for hydrodynamics (e.g. circulation and temperature-salinity) in Binh Cang - Nha Trang Bay, Vietnam. The results present the several cases of hydrodynamic regimes in the Bay during two mainly monsoon seasons (northeast and southwest monsoons). The clearly hydrodynamic regime occurs in the bay due to the impacts of rivers and monsoon conditions. These changes could be contributed to the hydrodynamic systems and water exchanges, that support basic scientific information for sustainable development of Binh Cang - Nha Trang bay.

关键词： ROMS Binh Cang – Nha Trang Bay hydrodynamics

Unraveling the Quantum Web: The Vortex Theory of Mass and Matter Formation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of High Energy Physics, Gravitation and Cosmology 2024年第3期10卷 1195-1225页

作者： Nader Butto Dgania Petah Tikva Israel

Mass plays a role in many physical phenomena, including the behavior of subatomic particles, the formation and behavior of stars and galaxies, and gravitational interactions between objects. The density of vacuum, 9.5 × 10−27 kg/m3, is a crucial parameter in the theory of cosmic inflation and is responsible for the accelerated expansion of the universe in its early stages. This vacuum energy interacts with matter and manifests itself as mass, which can be described as flow and vortex formation using the laws of hydrodynamics. The vortex model of elementary particles, in conjunction with the laws of hydrodynamics, provides an elegant explanation for the origin of mass and the relationship between mass and energy, with profound implications for the behavior of objects at high velocities and strong gravitational fields. The vacuum behaves as a compressible superfluid, thus elementary particles can be described as vortices of the vacuum. The equations of hydrodynamics for vortices can be applied to describe the nature and value of the mass of particles. The implications of understanding the nature of mass are vast and profound. From elucidating the fundamental properties of particles to informing the design of advanced materials and technologies, this knowledge is indispensable. It drives advancements across numerous fields, transforming both our theoretical understanding and practical capabilities. Continued research into the nature of mass promises to unlock further insights, fostering innovation and expanding the frontiers of science and technology.

关键词： Dark Energy Dark Matter Vacuum Mass Subatomic Particles Cosmic Inflation Virtual Particles Vortex Formation hydrodynamics Density