Considering the droplet coalescence, the motion of a group of dispersed droplets in W/O emulsion in a DC electric field is simulated. The simulation demonstrates the evolutions of droplet number, size as well as its d...Considering the droplet coalescence, the motion of a group of dispersed droplets in W/O emulsion in a DC electric field is simulated. The simulation demonstrates the evolutions of droplet number, size as well as its distribution,local concentration distribution and droplet size-velocity relation with the applied time of electric field. The simulated average droplet size is roughly consistent with the experimental value. The simulated variation of droplet number with time under several applied voltages shows that increasing voltage is more effective for raising the rate of droplet coalescence than extending exerting time. However, with the further raise of applied voltage, the improvement in droplet coalescence rate becomes less significant. The evolution of simulated droplet size–velocity relationship with time shows that the inter-droplet electric repulsion force is very strong due to larger electric charge on the droplet under higher applied voltage, so that the magnitude and the direction of droplet velocity become more random, which looks helpful to droplet coalescence.展开更多
Some cylindrically symmetric inhomogeneous viscous fluid string cosmological models with magnetic field and cosmological term A varying with time are investigated. To get the deterministic solution, it has been assume...Some cylindrically symmetric inhomogeneous viscous fluid string cosmological models with magnetic field and cosmological term A varying with time are investigated. To get the deterministic solution, it has been assumed that the expansion （θ） in the model is proportional to the eigen value σ^11 of the shear tensor σ^ij. The value of cosmological constant for the model is found to be small and positive, which is supported by the results from recent supernovae Ia observations. The effect of bulk viscosity is to produce a change in perfect fluid and hence exhibits essential influence on the character of the solution. The physical and geometric properties of the models are also discussed in presence and absence of magnetic field.展开更多
基金Supported by the Special Research Project of Fujian Province(JK2012027)the Natural Science Foundation of Fujian Province(2014J01201)
文摘Considering the droplet coalescence, the motion of a group of dispersed droplets in W/O emulsion in a DC electric field is simulated. The simulation demonstrates the evolutions of droplet number, size as well as its distribution,local concentration distribution and droplet size-velocity relation with the applied time of electric field. The simulated average droplet size is roughly consistent with the experimental value. The simulated variation of droplet number with time under several applied voltages shows that increasing voltage is more effective for raising the rate of droplet coalescence than extending exerting time. However, with the further raise of applied voltage, the improvement in droplet coalescence rate becomes less significant. The evolution of simulated droplet size–velocity relationship with time shows that the inter-droplet electric repulsion force is very strong due to larger electric charge on the droplet under higher applied voltage, so that the magnitude and the direction of droplet velocity become more random, which looks helpful to droplet coalescence.
文摘Some cylindrically symmetric inhomogeneous viscous fluid string cosmological models with magnetic field and cosmological term A varying with time are investigated. To get the deterministic solution, it has been assumed that the expansion （θ） in the model is proportional to the eigen value σ^11 of the shear tensor σ^ij. The value of cosmological constant for the model is found to be small and positive, which is supported by the results from recent supernovae Ia observations. The effect of bulk viscosity is to produce a change in perfect fluid and hence exhibits essential influence on the character of the solution. The physical and geometric properties of the models are also discussed in presence and absence of magnetic field.
基金supported in part by the National Basic Research Program (2007CB814906)the National Natural Science Foundation of China (10471103 and 10771158)+2 种基金Social Science Foundation of the Ministry of Education of China (Numerical methods for convertible bonds, 06JA630047)Tianjin Natural Science Foundation (07JCYBJC14300)the National Science Foundation under Grant No. EAR-0934747
文摘This article summarizes our recent work on uniform error estimates for various finite elementmethods for time-dependent advection-diffusion equations.
