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A CONSERVATIVE COUPLED FLOW/transport model WITH ZERO MASS ERROR

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Journal of Hydrodynamics 2009年第2期21卷 166-175页

作者： BAI Lu-hai JIN Sheng State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology Dalian 116024China

A fully conservative form applied to a coupled system of two-dimensional water flow and solute motion is presented. A cell-centred finite volume method based on Roe＇s approximate Riemann solver with unstructured grids is formulated. The bed slope source terms are discretized following an upwind approach and a semi-implicit treatment is used for the friction source terms. The centered discretization of the diffusion terms is in an implicit way. It is shown that this numerical technique reproduces almost exactly the steady state of still water and enables to achieve zero numerical errors in unsteady flow over configurations with strong variations on bed slope. The model ensures a global conservation and positive values of both water level and solute concentration. Numerical results show the effectiveness of the model in solute transport over real complex geometries.

关键词： transport model shallow water flow coupled model wetting/drying conditions conservation complex topography

Investigating the elliptic anisotropy of identified particles in p-Pb collisions with a multi-phase transport model

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Nuclear Science and Techniques 2024年第2期35卷 160-169页

作者： Si-Yu Tang Liang Zheng Xiao-Ming Zhang Ren-Zhuo Wan School of Mathematical and Physical Sciences Wuhan Textile UniversityWuhan 430200China School of Mathematics and Physics China University of Geosciences(Wuhan)Wuhan 430074China Key Laboratory of Quark and Lepton Physics(MOE)and Institute of Particle Physics Central China Normal UniversityWuhan 430079China Hubei Key Laboratory of Digital Textile Equipment Wuhan Textile UniversityWuhan 430200China School of Electronic and Electrical Engineering Wuhan Textile UniversityWuhan 430200China

The elliptic azimuthal anisotropy coefficient(v_(2))of the identified particles at midrapidity(|η|<0.8)was investigated in p-Pb collisions at√s_(NN)=5.02 TeV using a multi-phase transport model(AMPT).The calculatio... 详细信息

The elliptic azimuthal anisotropy coefficient(v_(2))of the identified particles at midrapidity(|η|transport model(AMPT).The calculations of differential v_(2)based on the advanced flow extraction method of light flavor hadrons(pions,kaons,protons,andΛ)in small collision systems were extended to a wider transverse momentum(p_(T))range of up to 8 GeV/c for the first *** string-melting version of the AMPT model provides a good description of the measured p_(T)-differential v_(2)of the mesons but exhibits a slight deviation from the baryon v_(2).In addition,we observed the features of mass ordering at low p_(T)and the approximate number-of-constituentquark(NCQ)scaling at intermediate p_(T).Moreover,we demonstrate that hadronic rescattering does not have a significant impact on v_(2)in p-Pb collisions for different centrality selections,whereas partonic scattering dominates in generating the elliptic anisotropy of the final *** study provides further insight into the origin of collective-like behavior in small collision systems and has referential value for future measurements of azimuthal anisotropy.

关键词： Azimuthal anisotropy Small collision systems transport model

An Accurate Multimoment Constrained Finite Volume transport model on Yin-Yang Grids

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Advances in Atmospheric Sciences 2013年第5期30卷 1320-1330页

作者：李兴良沈学顺彭新东肖锋庄照荣陈春刚 State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences Center of Numerical Weather Prediction China Meteorological Administration Department of Energy Sciences Tokyo Institute of Technology School of Human Settlement and Civil Engineering Xi'an Jiaotong University

A global transport model is proposed in which a multimoment constrained finite volume （MCV） scheme is applied to a Yin-Yang overset grid. The MCV scheme defines 16 degrees of freedom （DOFs） within each element to build a 2D cubic reconstruction polynomial. The time evolution equations for DOFs are derived from constraint conditions on moments of line-integrated averages （LIA）, point values （PV）, and values of first-order derivatives （DV）. The Yin-Yang grid eliminates polar singularities and results in a quasi-uniform mesh. A limiting projection is designed to remove nonphysical oscillations around discontinuities. Our model was tested against widely used benchmarks; the competitive results reveal that the model is accurate and promising for developing general circulation models.

关键词： transport model Yin-Yang grid finite volume method high-order scheme

Application of microscopic transport model in the study of nuclear equation of state from heavy ion collisions at intermediate energies

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Frontiers of physics 2020年第4期15卷 133-151页

作者： Yong-Jia Wang Qing-Feng Li School of Science Huzhou UniversityHuzhou 313000China Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China

The equation of state(EOS)of nuclear matter,i.e.,the thermodynamic relationship between the binding energy per nucleon,temperature,density,as well as the isospin asymmetry,has been a hot topic in nuclear physics and astrophysics for a long *** knowledge of the nuclear EOS is essential for studying the propertics of muclei,the structure of neutron stars,the dynamics of heavy ion collision(HIC),as well as neutron star *** offers a unique way to create muclear matter with high density and isospin asymmetry in terrestrial laboratory,but the formed dense nuclear matter exists only for a very short period,one cannot measure the nuclear EOS directly in ***,transport models which often incorporate phenomenological potentials as an input are utilized to deduce the EOS from the comparison with the observables mcasured in *** ultrarelativistic quantum molecular dynamics(UrQMD)model has been widely employed for investigating HIC from the Fermi energy(40 MeV per nucleon)up to the CERN Large Hadron Collider energies(TeV).With further improvement in the nmuclear mean-field potential term,the collision term,and the cluster recognition term of the UrQMD model,the newly measured collective flow and nuclear stopping data of light charged particles by the FOPI Collaboration can be *** this article we highlight our recent results on the studies of the muclear EOS and the muclear symmetry energy with the UrQMD *** opportunities and challenges in the extraction of the nuclear EOS from transport models and HIC experiments are discussed.

关键词： muclear equation of state symmetry energy heavy ion collision transport model

The effect of Lorentz-like force on collective flows of K+in Au+Au collisions at 1.5 Ge V/nucleon

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Science China(Physics,Mechanics & Astronomy) 2018年第6期61卷 24-29页

作者： YuShan Du YongJia Wang QingFeng Li Ling Liu School of Science Huzhou University School of Physics science and Technology Shenyang Normal University Institute of Modern Physics Chinese Academy of Sciences

Producing kaon mesons in heavy-ion collisions at beam energies below their threshold energy is an important way to investigate the properties of dense nuclear matter. In this study, based on the newly updated version of the ultrarelativistic quantum molecular dynamics model, we introduce the kaon-nucleon(KN) potential, including both the scalar and vector(also dubbed Lorentz-like)aspects. We revisit the influence of the KN potential on the collective flow of K+mesons produced in Au+Au collisions at Elab= 1.5 Ge V/nucleon and find that the contribution of the newly included Lorentz-like force is very important, particulary for describing the directed flow of K+. Finally, the corresponding Kao S data of both directed and elliptic flows can be simultaneously reproduced well.

关键词： kaon flow heavy-ion collision transport model kaon-nucleon potential

Dynamical effects of spin-dependent interactions in low- and intermediate-energy heavy-ion reactions

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Frontiers of physics 2015年第6期10卷 7-22页

作者： Jun Xu Bao-An Li Wen-Qing Shen Yin Xia Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201800 China Kavli Institute for Theoretical Physics China Chinese Academy of Sciences Beijing 100190 China Department of Physics and Astronomy Texas A&M University Commerce Commerce TX 75429-3011 USA University of Chinese Academy of Sciences Beijing 100049 China

It is well known that noncentral nuclear forces, such as the spin-orbital coupling and the tensor force, play important roles in understanding many interesting features of nuclear structures. However, their dynamical effects in nuclear reactions are poorly known because only the spin-averaged observables are normally studied both experimentally and theoretically. Realizing that spin-sensitive observables in nuclear reactions may convey useful information about the in-medium properties of noncentral nuclear interactions, besides earlier studies using the time-dependent Hartree-Fock approach to understand the effects of spin-orbital coupling on the threshold energy and spin polarization in fusion reactions, some efforts have been made recently to explore the dynamical effects of noncentral nuclear forces in intermediate-energy heavy-ion collisions using transport models. The focus of these studies has been on investigating signatures of the density and isospin dependence of the form factor in the spin-dependent single-nucleon potential. Interestingly, some useful probes were identified in the model studies but so far there are still no data to compare with. In this brief review, we summarize the main physics motivations as well as the recent progress in understanding the spin dynamics and identifying spin-sensitive observables in heavy-ion reactions at intermediate energies. We hope the interesting, important, and new physics potentials identified in the spin dynamics of heavy-ion collisions will stimulate more experimental work in this direction.

关键词： heavy-ion collisions transport model spin-orbit interaction tensor force polarization

Fragment emission and critical behavior in light and heavy charged systems

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Chinese Physics C 2021年第1期45卷 215-225页

作者： Samiksha Sood Rohit Kumar Arun Sharma Sakshi Gautam Rajeev K.Puri Department of Physics Panjab UniversityChandigarh 160014India Department of Physics G.D.College.BillawarJammu 185204India

We study the emission of fragments in central collisions of light and heavily charged systems of^4+Ar+^45 Sc and^s4Kr+^197 Au,respectively,using the Quantum Molecular Dynamics(QMD)model as the primary *** fragments are identified using an energy based clusterization algorithm,i.e.,the Simulated Annealing Clusterization Algorithm(SACA).The charge distributions of intermediate mass fragments[3≤Zf≤12]are fitted with power-law(∝Zf^-τ)and exp on ential(∝e^-λZf)fits in order to extract the parametersτandλ,whose minimum values are also sometimes linked with the onset of fragmentation or the critical point for a liquid-gas phase *** parameters such as the normalized second moment,,average size of the second largest cluster,phase separation parameter(Sp),bimodal parameter(P),information entropy(H),and Zipfs law are also analyzed to find the exact energy of the onset of *** detailed analysis predicts that an energy point exists between 20-23.1 MeV/nucleon,which is very close to the experimentally observed value of 23.9 MeV/nucleon for the^40Ar+^45Sc *** also find that the critical energy deduced using Zipfs law is higher than those predicted from other critical ***,no minimum is found for t values of the highly charged system of^84Kr+^197Au,in agreement with experimental findings and various theoretical *** observe that the QMD+SACA model calculations are in agreement with the experimental *** agreement supports our results regarding the energy point of the liquid-gas phase transition and the onset of fragmentation.

关键词： heavy-ion collisions transport model clusterization algorithm Monte-Carlo technique li・quid-gas phase transition

On Aircraft Lift and Drag Reduction Using V Shaped Riblets

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Fluid Dynamics & Materials Processing 2021年第5期17卷 899-915页

作者： Zihai Geng Jinsheng Cai Yubiao Jiang Weiguo Zhang Aviation College of Northwestern Polytechnical University Xi’an710072China China Aerodynamic Research and Development Center Mianyang621000

Reducing drag during take-off and nominal(cruise)conditions is a problem of fundamental importance in aeronautical *** studies have demonstrated that v-shaped symmetrical riblets can effectively be used for turbulence control,with those with dimensionless depth h+=15 and dimensionless width s+=15 having the best drag reduction *** the present study,experimental tests have been conducted considering two models of the same size,one with smooth surface,the other with v-shaped riblets of the h+=15 and s+=15 *** results show that for an angle of attack in the 8°~20°range(take-off stage),the maximum lift coefficient can be increased by 22%.For angle of attack between 8°and 14°,a drag reduction effect can be produced using riblets,which increases with the Reynolds number,leading to a decrease in the drag coefficient maximum of 36%.Flow visualization experiments have been carried out by means of Laser Induced fluorescence.

关键词： transport model V-shaped riblet lifting drag reduction flow visualization

A review of numerical modeling research on the marine oil spill

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Marine Science Bulletin 2013年第2期15卷 71-86页

作者：蔡扬牟林李欢宋军迟永祥管承扬李程国家海洋局南海预报中心广东广州510300 国家海洋信息中心天津300171 中国海洋大学山东青岛266100

Recently, as the oceanic activities are more and more frequently carried out, marine oil spill accidents bring to enormous harm to the economy and society in China, especially in the Offshore China. Marine oil spill is one kind of serious disasters which severely damages the marine environment. Aiming at the improvement of the emergency response system and response ability for the oil spill, the relative technologies on oil spill response are developed. This paper briefly introduces the developments and achievements of the oil spill numerical models, including the oil spill spreading model, the oil spill transport model, the oil particle model as well as the oil spill weathering model, which provide the theoretic criterions for the future work on the oil spill predicting and response.

关键词： oil spill spreading model transport model weathering model oil particlemodel