Archive

25 January 1999, Volume 16 Issue 1 Previous Issue    Next Issue

---

For Selected:

Download Citations EndNote Ris BibTeX

Toggle Thumbnails

Select

The effects of grid aspect ratio on the efficiency of implicit multigrid method and its improvement Tang Zhili 1999, 16(1): 1-6.  Abstract ( )   PDF (246KB) ( )   The effects of grid aspect ratio on the efficiency of implicit multigrid method have been analysed theoretically. The results indicate that the algorithm affects convergence on highly stretched or non unifirm grids. The improvement ways are introduced, and the validations are also been discussed. Finally the comparison of convergence between the original model and the improved one is presented.

Select

Numerical simulation of the melting in an enclosure with three discrete flush mounted heat sources Jiang Hongli, Chen Zhongqi, Xu Tongmo, Hui Shien 1999, 16(1): 7-12.  Abstract ( )   PDF (234KB) ( )   The numerical simulation of melting heat transfer in an enclosure with three discrete flush mounted heat sources on one of its vertical walls and all the other walls insulted is studied by means of the enthalpy method. Numerical results are compared with previous experimental and numerical ones.

Select

Analytic investigation of steady state heat conduction problem of anisotropic rectangular cantilever plate Zhang Chengzong, Wang Anwen, Zhang Xiangming 1999, 16(1): 13-16.  Abstract ( )   PDF (159KB) ( )   The analytic solution for anisotropic steady state heat conduction is applied to analyse the anisotropic rectangular cantilever plate with one edge of nonuniformed boundary temperature and other edges of convection at the first time.The effect of piy angle on the temperature distributions is discussed.With the increasement of the anisotropic angle,the gradient of temperature in the plate is increased.Numerical results show there is the lowest gradient of temperature in the cantilever plate with 0° anisotropic angle.

Select

Numerical simulation of a time resolved electron microscope Li Shuhong, Niu Hanben 1999, 16(1): 17-24.  Abstract ( )   PDF (333KB) ( )   The simulation of a time resolved electron microscope is discussed.Temporal resolution and spatial resolution power are evaluated by computing the motion of transmission eletrons emitted from the sample in the combination of static magnetic field and dynamic electric field.The design methods,including the calculation of magnetic field,dynamic electric magnetic field,electron trajectory tracing and spatial and temporal spread functions,are also involved.The simulation demonstrates that 6 framing images with the size of φ=10mm,temporal resolution of 100ps and spatial resolution of 100Å have been achieved in the time resolved electron microscope.

Select

New tvd schemes for linear hyperbolic equations Ni Hangen, Wang Jiasong, Jin Sheng 1999, 16(1): 25-30.  Abstract ( )   PDF (227KB) ( )   It is shown that there are partial TVD regions after analyzing Lax Wendroff and Warming Beam schemes from the TVD conditions of hyperbolic equation. Based on which, new second order accurate TVD schemes of three or four grids in space are constructed in order to keep second order accuracy near the extreme points. Finally a comparative study is presented to solve linear hyperbolic equation by the new and old TVD schemes.

Select

Temperature field control with gas transpiration Yang Xueshi, Guo Yingjun, Wu Jingang 1999, 16(1): 31-38.  Abstract ( )   PDF (283KB) ( )   By using the compressible and permeable theory, it presents a mathematical model of closed loop control with gas transpiration and surface erosion. Its numerical solution is achieved. The series of pressure pl as a control parameter is given. It also points out, when the pressure of the control parameter is constant or the transpiration coolant is incompressible, the problem will be back to ref.[2]

Select

The reduction of mesh distortion by the use of node couple method Duan Qingsheng, Yuan Guoxing, Wang Lihua 1999, 16(1): 39-44.  Abstract ( )   PDF (245KB) ( )   A method of couple node velocity is given for reducing distortion of quadrilateral mesh in Lagrangian numerical computation of two dimensional compressible hydrodynamics. It is verified that this method is equivalent to introducing four order smooth term with dissipation property in the momentum equation, thus it plays a role of damping the unphysical oscillation of velocity.

Select

A new numerical method of solving the point reactor neutron kinetics equations Chen Changyou 1999, 16(1): 45-53.  Abstract ( )   PDF (324KB) ( )   A new numerical method of solving the point reactor neutron kinetics equations by using the technique of first order Taylor polynomials for the approximation of neutron density in integral of one step is presented. The full implicit formulation is used to overcome the stiffness of the equations and to guarantee the necessary exactness of solution. The numerical results show that for reasonable reactivity inputs, a sufficient accuracy can be achieved in first order polynomial approach presented here. When the reactivity is given, this method can provide a straighforward computation procedure for solving reactor dynamics problems.

Select

The numerical calculation of direct current field character of overburden failure Cheng Jiulong, Liu bin, Yu Shijian, Xu Shizhe, Zhu Lu 1999, 16(1): 54-58.  Abstract ( )   PDF (221KB) ( )   The overburden failure causes the changes of the constant electric field,and the resistivity is the main parameter in these changes.2D finite element method (FEM) is used to simulate the resistivity distribution of overburden by building the mathematics models of the overburden electrical parameter changes.The calculation indicates that the resistivity varies with the electrical character of the rock in cracked zone and caving zone caused by overburden failure,and the resistivity method used in monitoring the overburden failure is practical in principle.

Select

High accurate algorithm of associated legendre functions Zhu shide, Xiang Anping, Yang Jin 1999, 16(1): 59-65.  Abstract ( )   PDF (256KB) ( )   A high accurate algorithm of calculating the associated Legendre functions for integral order and complex degree is presented. On a microcomputer and using double precision, the calculated results indicate the precision of at least 9 significant digits is attained.

Select

A two dimensional adaptive numerical grids generation method and its realization Xu Tao, Shui Hongshou 1999, 16(1): 66-76.  Abstract ( )   PDF (812KB) ( )   A two dimentional adaptive numerical grids generation method and its particular realization is discussed. During Computational Fluid Dynamics, because the control values of adaptive grids-numerical solution is given in the descrite form, it needs to interpolate these values to get the continuous control functions. This paper discussed these interpolation techniques, and given some efficient adaptive grids. At last, a two dimentional fluid dynamics example was also given.

Select

The extending of monte carlo technique for morse code Yang Jinan, Pei Lucheng 1999, 16(1): 77-83.  Abstract ( )   PDF (262KB) ( )   This paper studies the Monte Carlo Technique for MORSE code. Three new techniques are added for transmitted probability calculation in spherical geometry. It extends the ability and reliability of MORSE code.

Select

Highly excited state structure of beryllium isoelectronic sequence with j=2 and odd parity Zhao Cuilan, Wang Zhiwen 1999, 16(1): 84-88.  Abstract ( )   PDF (195KB) ( )   This paper caculated the highly excited states with J=2 and odd parity of the beryllium isoelectronic sequence by using the eigenchannel quantum defect theory (EQDT).It obtained the EQDT parameters Uiα and μα,of Be like systems from BeⅠ to OⅤ,as functions of effective nuclear charge.These results indicate that the differences between eigenquantum defects of different channels,which characterize the channel interactions,gradually diminish along this sequence.This isoelectronic behaviour is caused by the competition between electronic and spin orbit interaction along the evaluated with EQDT parameters as input.As a numerical example,the Lu Fano plots of BeⅠ is given as wall.

Select

A boundary spline solution method for potential flow around a 2-d semi infinite body Shen Min, Deng Kang 1999, 16(1): 89-93.  Abstract ( )   PDF (191KB) ( )   In terms of Cauchy's integral formula of analytical complex function and the three order spline function of complex variable, a general boundary solution method is presented for solving the complex potential field of the flow field around a 2D semi infinite body. The pressure coefficient distribution on the cylinder surface by the present method is in good agreement with Acrivous' result for the flow problem around a circular cylinder.

Select

Numerical method for solving relativistic hydro dynamics equation with quark frament effect Wang Lilian, Li Panlin, Xu Mengjie 1999, 16(1): 94-98.  Abstract ( )   PDF (198KB) ( )   A numerical method is given to solve the relavtivistic equations with source terms by finite difference method, QGP phase transition taken into account.The numerical experiments verifies the effectiveness of the method.

Select

A new strategy of grid adaption in 2d unstructured mesh Cheng Juan, Huang Mingke 1999, 16(1): 99-103.  Abstract ( )   PDF (367KB) ( )   A new method for adaptive refinement of 2D unstructured grids generated by advancing front technique is presented.Some small triangle units are arranged on the place where mesh needs to be refined,and all the sides of these units are regarded as a part of the initial front.During the advancing process,near the above mentioned units,the cells are naturally generated from small to large.For the flow with shock,in the mesh graph,a quite clear shock picture is formed.

Select

Improvement on calculation of sensitivity distribution of capacitance sensor Yan Hua, Xu Hui, Shao Fuque, Wang Shi 1999, 16(1): 104-108.  Abstract ( )   PDF (189KB) ( )   An improved algorithm based on finite element method to calculate the sensitivity distribution of capacitance sensor is presented. By fast generating of global siffness matrix and fast calculating capacitance values, the calculation speed of sensitivity distribution is raised.

Select

Fishbase:a special dbms prototype for cavity design Yan Xiaowei, Fan Mingwu 1999, 16(1): 109-112.  Abstract ( )   PDF (149KB) ( )   A special DBMS prototype is developed for applying in the design of accelerator cavity, i.e.the FISHBASE.It has an interface similar to that of FOXBASE.For the calculation of electromagnetic field in the cavity,the code of SUPERFISH has been transplanted.