Finite integration method is employed to solve convection-diffusion equations. For diffusion-dominated convection-diffusion problems, numerical results show that finite integration method is more than one and two orders of magnitude better in accuracy than QUICK scheme and central differencing scheme, respectively. We find that finite integration method can be improved by introducing a weighting parameter in numerical quadrature. By appropriately adjusting the parameter, modified finite integration method is at least more than four orders of magnitude better in accuracy than traditional finite volume method for convection-dominated flows. Furthermore, even coarse grids are utilized to divide flow domain modified finite integration method has not lead to unphysical oscillations in convection-dominated convection-diffusion problem, which demonstrates a good stability of the method.

Collision and coalescence among drops is an important phenomena in gas/drop two-phase flows. To study change of number of drops caused by collision and coalescence,a special flow field is considered in which liquid phase consists of two classes of drops with big or small sizes. Probability for collision and coalescence between a big drop and a small drop is derived. Considering three factors of immigration,emigration and collision of drops,a model of birth-death process is proposed for number of drops located in a fixed observation region,and relevant unconditional probability model equation is deduced. Finally,stationary distribution is obtained. As an illustration,mass creament of a falling rain drop is calculated.

To investigate scattering characteristics of expanded graphite in 3 millimeter waves, with method of moment formule of radar cross section (RCS) are established based on electromagnetic scattering of finite length and conductivity cylinder. Average RCS of expanded graphite and its jamming decoy are calcutated. RCS of graphite and chaff jamming decoy are measured through field experiment. It shows that expanded graphite have some scattering ability in 3 millimeter wave. Average RCS of single expanded graphite particle is 0.867 6 mm² as its radius and length are 0.12 mm and 1.5 ram, respectively. RCS of chaff is 7.4 times of expanded graphite as interfering material mass are same. Expanded graphite is difficult to implement in the style of chaff decoy deception jamming on guided weapons.

A model for flow in a 3-dimensional 3-phase anisotropic oil reservoir is established and applied to reservoir development.The model includes a complete anisotropic permeability tensor.It characterizes the anisotropic permeability distribution with different principal directions in different regions.It calculates the fluid flow,the residual oil distribution and the pressure distribution in anisotropic reservoirs accurately.

A new concept of pulse tube refrigerator using gap regenerator as its regenerator is suggested.The physical model of this pulse tube refrigerator is established.The influences of frequency,gap width,opening of orifice and double inlet valves on the refrigerator performance have been analyzed by numerical calculation based on the finite difference method.It shows that in the pulse tube refrigerator with a gap regenerator, the optimum frequency,optimum openings of orifice and double inlet valves are less than those of the pulse tube refrigerator with screen-matrix regenerator.

This paper, based on the characteristics of the Three Gorges Cascade Hydroelectric System, establishes a new short term economic scheduling network model for a cascaded hydroelectric system that transmits power to multiregions. A method combined with linear and nonlinear minimum cost network flow algorithms is used to solve the problem of load dispatch among the cascaded plants. In this paper, the short path algorithm with the data structure which is marked to arcs of the network saves the computational time and the storage space. The result that is computed on the microprocessor IMB PC/XT with FORTRAN language programs indicates that the model and the algorithm is the paper are correct.