Influence of diffusion coefficient on crystallization process is considered in a crystallization physical model. A phase field method is employed to study influence of random nucleation rates and nucleation radii on microstructure and growth kinetics in primary crystallization process. It shows that the number of grain crystal of primary crystallization increases with the increase of initial nucleation rate, and the crystal size of primary crystallization decreases with the increase of initial nucleation rate. The crystallization fraction increases with evolution time and initial nucleation rate. The greater the initial nucleation rate, the higher the crystallization fraction. With different initial nucleation radii, the quantity and size of grains in the primary crystallization process remains basically unchanged with the increase of evolutionary time. The crystallization fraction increases with the increase of evolutionary time. The growth index corresponding to different initial nucleation rates and initial nucleation radii is less than 1, which means random nucleation rate and random nucleation radius have no significant effect on the crystallization mode. The crystallization modes are primary crystallization. Control of random nucleation rate and initial nucleation radius changes effectively microstructure of the primary crystallization. The grain size and crystallization fraction affect properties of the alloy directly.

Flows past a pair of rotating circular cylinders in tandem arrangement at Re=100 are studied numerically.Multi-block lattice Boltzmann method(LBM) is used.Basic features of vortex shedding and forces acting on rotating circular cylinders are studied with comprehensive analysis of impact of cylindrical center spacing ratio S/D and rotational speed α.There exists a critical rotating speed at S/D=1.2,exceeding which the former cylinder produces a negative Magnus lift;As S/D=2,flow field emerges a second unstable mode similar to a single rotating cylinder;At relative large spacings(S/D=4、6),vortex sheds between cylinders.Wake flows of the later cylinder present a variety of forms of 2S、2S^*、2P、P+S and so on.

Ground state of plutonium dioxide in electric fields ranging from-0.005 to 0.005 a.u. are optimized using density functional theory DFr/B3LYP with SDD for Pu and 6-311 + G^* for O. Excitation energies in electric fields are calculated with time-dependent DFT method. It is shown that electronic state, total energy, molecular geometry, dipole moment and excitation energy are strongly dependent on the strength of applied electric field. Dependence of excitation energies on applied electric field strength agrees approximately with that proposed by Grozema. Spectra of the first five excited states are in the region of visible-infrared-far infrared with wavelength ranging from 501.47 to 10 291.5nm.

The energies, equilibrium geometries and harmonic frequencies of X¹∑_g⁺, A¹∑_u⁺ and B¹Ⅱ_u, of molecule Na₂ are calculated by the GSUM (Group Sum of Operators) method of SAC/SAC-CI using basis sets 6-311 ++ g, 6-311g^** and cc-PVTZ. It is found that 6-311g^** is suitable for energy calculation of molecule Na₂. The potential curves of ground states and excited states are scanned by the SAC/6-311g^** and SAC-CI/6-311g^** methods, respectively. A least square is fitted to a Murrell-Sorbie function.The spectroscopy constants (B_e, α_e, ω_e, and ω_eX_e) are calculated and show good agreement with experiment. It is believed that Murrell-Sorbie function and the SAC/SAC-CI method are suitable for ground states and for low-lying excited states as well.

To explore the effect of discretization scheme on the simulation results,both the QUICK scheme and the hybrid scheme are applied to the numerical simulation of turbulent flow in a swirl combustor with coaxial jets. The computation adopts the k-εmodel for the closure of turbulence. It is seen that the gas axial and tangential velocities and the root mean square of gas axial fluctuating velocity calculated by utilizing the QUICK scheme agree well with the measured test data, while the calculated results by using the hybrid scheme show obvious deviations from the measurement.

The numerical solution of the dynamical equations of the α-Helix Protein molecular chain is discussed by means of the initial condition on the continuous approximation soliton solution.It is discovered that lifetime of the soliton is limited even if no influence of the thermal vibration acts on.

For the purpose of developing swirl combustors with high combustion efficiency and low pollutant emission, a numerical simulation of swirling turbulent flows in a swirl combustor with coaxial jet interactions is performed. A new algebraic Reynolds stress model and the QUICK discretization scheme are utilized in the present calculations. The simulated results of swirling turbulent flows in the combustor for both cases of the coswirl jets and the counterswirl jets are in agreement with the experiment data in terms of the time-averaged gas axial velocity, tangential velocity and static pressure.

Using the Lagrangian analysis of particle motion and PDF(Probability Density Distribution Function) method,an improved the second-order-moment model of particle-phase is proposed.Based on the Lagrangian stochastic two-phase motion equations, using the stochastic-process analysis and the signal-system analysis, the obtained particle-phase PDF transport equation,the two-fluid model equations and the basic version of two-phase fluctuation velocity correlation are in agreement with those obtained by other investigators.However,significant improvement is made for the closure model.The crossing-trajectory effect,continuity effect,inertia effect and the anisotropic turbulence have been taken into account to simulate the interaction time between the particle and the fluid turbulence seen by the particles.

The premixed turbulent reacting flow in an axisymmetric sudden-expansion combustor has been numerically simulated. The k-ε turbulent transport model and the EBU-Arrhenius turbulent reaction model are utilized for the closure of the time-averaged governing equations. The calculated results cover the time-averaged gas flow field, species mass fraction and temperature distributions for the premixed reacting flow in the sudden-expansion combustor. The EBU-Arrhenius model is discussed and evaluated based on the comparisons between the calculated results and the measured data.

A mathematical model of pulverized coal combustion is formulated and developed based on a particle continuum-trajectory model.An overall iterative solution procedure for reactive two-phase flows is also proposed.The corresponding CCVC computer code has been developed for calculating two-dimensional, recirculating,reactive,two-phase turbulent flows.It is utilized to numerically simulate the pulverized coal combustion in a combustor of large velocity difference jets which at plesent is widely used in coal fired boilers.

In this paper, the rezoning technique for Lagrangian meshes is discussed with equidistant principle. A Rezoning threshold value η and fourstep rezoning methed are applied. According to volume ratio, the concerned parameters of meshes between new and old one are redistributed conservatively. The numerical tests show that in order to improve the effect of rezone, not only the position of inner mesh points but also the position of bourdary points are needed to be readjusted.

In this paper, basic thought on simulating slide motion of Wilkins have been applied to Solve problem of two intersecting Slide lines. The programing for inferaction between flying plate and target have been made and fwo numerical examples have been given.

In this paper, from basic thought of Wilkins method, the computational method of J-(radial) slide line have been discussed in two dimensonal fluid-elastic-plastic flow with axial symmetry.The programing for interaction between flying plate and target have been made and two examples of numerical sumilation have been given.