A BOUNDARY ELEMENT METHOD WITH LOWER-ORDER SINGULARITY

In this paper, a lower-order singular BEM based on original BEM is presented by introduccing a new variable of angle. In the new method, kernel of force is the same as kernel of displacement which is only singularity of InR ( R is the distance between a source and a field point ) . Hence, it results in a new BEM formulation, whose singularity is lower than that of the original BEM formulation. What's more, in calculating stress, it eliminates the boundary-layer effect in the main. A software which is based on lower-order singular formulation is used to analysis the bar of 300T coiningmachine, its result is coincident with that obtained by the original BEM and photo-elastic experiment.     

A CLASS OF SINGULAR CAUCHY PROBLEM FOR A QUASILINEAR HYPERBOLIC EQUATION

This paper studies a class of singular Cauchy problem for aquasilinear hyperbolic equation and shows that there exists a uniquely stablesolution by quasi-differential operators.     

MAXIMUM PRINCIPLE AND NONTRIVAL SOLUTION FOR A STATIONARY WAVE EQUATION

The boundary-value problem of a non-linear equation is discussed. A necessary condition for existence of nontrival solution and a maximum priciple are proved.     

THE STUDY ON CHARACTERISTICS OF ELASTIC WAVE PROPAGATION IN ROCKS UNDER COMPLICATED STRESS STATES

This paper is aimed at investigating the acoustic properties of rock mass under the three-dimentional different stress states, and is presented to discuss emphatically the characteristics of the acoustic wave propagation and the stress-velocity relation in both rocks (sandstone and limestone) under uniaxial and true triaxial compression. The results indicate three regions in which the acoustic velocities and the strains change with the stresses are approximately similar under different stress states; and the acoustic velocity-stress relations for elastic rocks may be represented by different interdependence coefficients under uniaxial compression. At a time, The acoustic measurement method of rock mass stresses and the horizontal tectonic stress are discussed.     

STUDY OF SOLUTION METHODS FOR SEPARATOR EQUATIONS OF HIGH GRADIENT MAGNETIC SEPARATION

In this paper, an analytical solution,approximate solution of initial retention, steady-state solution and numerical solution of separator equations of high gradient magnetic separation are discussed. A backward-vave method used to improve the steady-state solution and Treanor-four order Taylor numerical method are suggested for magnetic separator equations and are compared with experimental results.     

AN OPTIMIZATION METHOD FOR SOLVING THE BOUNDARY WALUE QUESTION OF DIFFERENTIAL EQUATIONS

This paper presents an optimization method for solving the boundary value question of a differential equation on the basis of the trial-and-error method and the optimization method. As compared with the differential method, this method has some advantages such as quiker velocity at count, higher precision(especially at the boundary points) and can be widely used.     

THE CALCULATION OF FLOW USING SEMI-IMPLICIT METHOD FOR PRESSURE-LINKED EQUATIONS

This paper briefly introduces Patankar-Spalding Method, which is systematical, active and widely applicable in numerical heat transfer and fluid flow. The corresponding dependent variables, diffusivities and source terms for the general differential equations under all circumstances are explained. By using this method the calculation of two-dimentional Poiseuiue Flow and Couette Flow compared with exact solutions are proved to be high precision. with two-dimentional path-flow in the heat convertor intersification devices as an example, the tilted method is used with FORTRAN 77 programming, and the calculation is done on a SIEMENS 7570c minicomputer.     

PARALLEL ALGORITHMS FOR A LARGE SPARSE SYSTEM OF LINEAR EQUATIONS

ABS algorithms new agorithm is introduced with the discussions of the sparse structuere of the projection matrixes and the reorder methods of equations. To apply ABS algorithm on qarallel computer, the parallel ABSalgorithu is also discussed with numerical examples and the time need for the computation.     

NUMERICAL SOLUTIONS OF SHOCK WAVE FOCUSING WITH CCW METHOD

By the use of a numerical scheme of chisnell-Chester-Whitham Method (CCW), some numerical solutions to the problems of shock wave focusing are completed successfully and simply.     

A Non-overlapping Domain Decomposition Method for Scattering Problems

In this paper, a domain decomposition method for the exterior Helmholtz problem is investigated. The unboundary domain is divided into some non overlapping subdomains. The natural integral operator is used as the artificial boundary conditions on the exterior boundary of the computational domains. The convergence of the algorithm is given in the sense of energy norm. Finally, the discrete problem is discussed and some numerical examples are presented.     

A Class of Exact Solution for RLW-Burgers Equation

A class of analytic solution for RLW Burgers equation and KdV Burgers equation are given which include results of some papers.These solutions can be expressed as some linear combination of solutions of Burgers equation and RLW equation or KdV equation which correct conclusion in some paper.     

THE ANALYTICAL EQUATIONS OF HYDRO-THERMAL POWER SYSTEM ECONOMIC DISPATCH

The paper developes the analytical equations of the power economic dispatch by using the modified coordination equation, it also developes the explicit functional relation between the hydro-coal conversion factor and the daily water consumption. Using these expressions,the calculating amount of the hydro-thermal system economic dispatch is greatly reduced and the convergency is much better. Finally a numerical example is given to show these advantages.     

DETERMING THE RELIABILITY OF A MEMBER WITH CRACK ACCORDING TO THE INFORMATION FROM FLAW-DETECTION WITH ULTRASONIC WAVE

Using the flaw-detecting with ultrasonic wave one may know the equivalant area of a crack that burys in the member. If the crack is ellipse shaped, the equivalant area is constant, and the distribution function of its major semiaxle and the plane strain fracture toughness of the material are given, then we would get the probability of reliability of the member under the uniform tension. In this condition, a formula of calculating the probability would be provided in this paper. Because a simple and enough precise approximate function has been introduced the formula in the paper is simple in shape and easy to use.