The integrability character of nonlinear equations of motion of two-dimensional gravity with dynamical torsion and bosonic string coupling is studied in this paper. The space-like and time-like first integrals of equa...The integrability character of nonlinear equations of motion of two-dimensional gravity with dynamical torsion and bosonic string coupling is studied in this paper. The space-like and time-like first integrals of equations of motion are also found.展开更多
A new theoretical model is formulated to describe internal movement mechanisms of the sand ridges and sand waves based on the momentum equation of a solid-liquid two-phase flow under a shear flow. Coupling this equati...A new theoretical model is formulated to describe internal movement mechanisms of the sand ridges and sand waves based on the momentum equation of a solid-liquid two-phase flow under a shear flow. Coupling this equation with two-dimensional shallow water equations and wave reflection-diffraction equation of mild slope, a two-dimensional coupling model is established and a validation is carried out by observed hydrogeology, tides,waves and sediment. The numerical results are compared with available observations. Satisfactory agreements are achieved. This coupling model is then applied to the Dongfang 1-1 Gas Field area to quantitatively predict the movement and evolution of submarine sand ridges and sand waves. As a result, it is found that the sand ridges and sand waves movement distance increases year by year, but the development trend is stable.展开更多
A two-dimensional coupled model of the cellular automaton(CA)and the lattice Boltzmann method(LBM)was developed to simulate the solute dendrite growth of Fe-C-Mn-S alloy in the presence of forced convection.The model ...A two-dimensional coupled model of the cellular automaton(CA)and the lattice Boltzmann method(LBM)was developed to simulate the solute dendrite growth of Fe-C-Mn-S alloy in the presence of forced convection.The model describes the transport phenomenon by the evolution of moving pseudo-particles distribution functions and utilizes the LBM to solve fluid flow and solute transport under forced convection numerically.Based on the solute field calculated by the CA technique,the dynamics of dendrite growth were determined by the previously proposed local solute balance method.The accuracy of the forced convection dendrite growth model was verified by comparing the CA-LBM model with Lipton-Glicksman-Kurz analytical model.It is revealed that the dendrite symmetry structure is destroyed compared to free diffusion,and the upstream arm is more developed than the downstream arm of the dendrite.The enriched solute segregates more at the downstream side than at the upstream side of the dendrite.The length of the upstream dendrite arm increases firstly and then becomes stable with the increase in the flow velocity,the dendrite necking is restrained,and the vertical dendrite arm becomes longer.展开更多
文摘The integrability character of nonlinear equations of motion of two-dimensional gravity with dynamical torsion and bosonic string coupling is studied in this paper. The space-like and time-like first integrals of equations of motion are also found.
基金The National Natural Science Foundation of China under contract No.51079095the Science Fund for Creative Research Groups of the National Natural Science Foundation of China under contract No.51021004
文摘A new theoretical model is formulated to describe internal movement mechanisms of the sand ridges and sand waves based on the momentum equation of a solid-liquid two-phase flow under a shear flow. Coupling this equation with two-dimensional shallow water equations and wave reflection-diffraction equation of mild slope, a two-dimensional coupling model is established and a validation is carried out by observed hydrogeology, tides,waves and sediment. The numerical results are compared with available observations. Satisfactory agreements are achieved. This coupling model is then applied to the Dongfang 1-1 Gas Field area to quantitatively predict the movement and evolution of submarine sand ridges and sand waves. As a result, it is found that the sand ridges and sand waves movement distance increases year by year, but the development trend is stable.
基金funded by the National Natural Science Foundation of China(Grant Nos.52074071 and U1660204)Fundamental Research Funds for the Central Universities of China(Grant No.N172502006)Liaoning Revitalization Talents Program(Grant No.XLYC1802032).
文摘A two-dimensional coupled model of the cellular automaton(CA)and the lattice Boltzmann method(LBM)was developed to simulate the solute dendrite growth of Fe-C-Mn-S alloy in the presence of forced convection.The model describes the transport phenomenon by the evolution of moving pseudo-particles distribution functions and utilizes the LBM to solve fluid flow and solute transport under forced convection numerically.Based on the solute field calculated by the CA technique,the dynamics of dendrite growth were determined by the previously proposed local solute balance method.The accuracy of the forced convection dendrite growth model was verified by comparing the CA-LBM model with Lipton-Glicksman-Kurz analytical model.It is revealed that the dendrite symmetry structure is destroyed compared to free diffusion,and the upstream arm is more developed than the downstream arm of the dendrite.The enriched solute segregates more at the downstream side than at the upstream side of the dendrite.The length of the upstream dendrite arm increases firstly and then becomes stable with the increase in the flow velocity,the dendrite necking is restrained,and the vertical dendrite arm becomes longer.
