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25 December 1985, Volume 2 Issue 4 Previous Issue    Next Issue

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THE COMPUTATION OF SATURATED-UNSATURATED WATER TABLE FLOW USING DIFFERENCE MESH OF IRREGULAR CONVEX POLYGON Lei Guang-yao, Zhang Suo-chun, Gao Ji 1985, 2(4): 387-397.  Abstract ( )   PDF (681KB) ( )   For the computation of saturated-unsaturated water table flow, a kind of difference scheme of irregular convex polygon mesh is developed. Using this method, saturated-unsaturated seepage flow is calculated to AKAI's sand model and KOM-ADA's reservoir model. The results obtained here are compared with results ob -tained from computations in which rectangled difference meshes were used. The applicableness and accuracy of this method are also discussed.

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THE SOLUTION OF UNSTEADY OPEN CHANNEL FLOW BY THE STOCHASTIC METHOD Huang Ke-zhong, Li Gi-ze 1985, 2(4): 398-404.  Abstract ( )   PDF (520KB) ( )   Stochastic hydraulics is a new development in the research of hydraulics. By coupling a stochastic model with a deterministic model, the computation of unsteady open channel flow is studied. Saint Venant equations are used as the sys -tern model. We use stochastic models for the inputs including roughness, cross-section, hydraulic radius and so on. The outputs of discharge and water level varyingwith time and location are stochastic. An unsteady flow in the downstream ofZhexi Water Power Station is calculated by this method as above, and the resultsare compared with the observed data.

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COMPUTATION FOR DEVIATION OF PSEUDORANDOM NUMBERS Li Zuo-xin, Lu Qing-tang 1985, 2(4): 405-412.  Abstract ( )   PDF (413KB) ( )   This Paper by use of the distribution theorems of pseudorandom Points by the author and devolped Method of Separated Regions gives a precise Substitufion of Separated Regions of Bands (SSRB) and acquires more simple and precise deviation expression of two dimesions for pseudorandom numbers.

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NUMERICAL CALCULATIONS FOR RESISTIVE HRLICAL INSTABILITY OF CURRENT-CARRYING PLASMA COLUMN WITH FREE BOUNDARY Gong Ye, Ma Teng-cai 1985, 2(4): 413-418.  Abstract ( )   PDF (343KB) ( )   In this paper we employ a two-step implicit difference scheme to study numerically ths resistive helical instability of current-carrying plasma column with free boundary. It is found that the wider and higher of the plasma temperature profile, the better linear stabilization of the tearing mode m=2 will be, The results agree with experimental one.

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NUMERICAL SOLUTION OF INNER STOKES FLOWS WITH ARBITRARY BOUNDARIES Han Qing-shu, Yang De-quan 1985, 2(4): 419-429.  Abstract ( )   PDF (555KB) ( )   In this paper the problem of inner Stokes flows with arbitrary boundaries is considered using Green's function method[1].The Stokes equations are converted to linear boundary integral equations and the domain of solution is decreased by one dimension.The integral equations are resolved numerically and the surface-stress force is determined.Numerical solution of sample test problems indicate the superior accuracy, computational efficiencies and wide flexibility in handling very complex geometry.

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A SELF-CONSISTENT METHOD FOR CALCULATING THE INTERNAL ELECTROMAGNETIC PULSE IN THE TWO-DIMENSIONAL CYLINDRICAL CAVITY (III) Wang Yu-zhi, Wang Tai-chun 1985, 2(4): 430-442.  Abstract ( )   PDF (783KB) ( )   This paper is the continuity of the reference [1] and [2], is also last a paper of those works. Its subject are to solve the equations of the primary electrons with Lagranican method.At the same time,numerrccal results are given by PIC, Eulerian and Lagrangean method. we compare those results with the results of the non-self-consintent method when electric field intensity E>105v/M,the results of the self-consistent method is nearer when electric field intensity E≤105v/M, the results of self-consistent rather nice coincide with the results of non-self-consistent method.

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SALTATION MODEL OF SAND AND ITS NUMERICAL ANALYSIS Liu shao-zhong, Yang shao-hua, Ling Yu-quan 1985, 2(4): 443-453.  Abstract ( )   PDF (690KB) ( )   The Velocity distribution of the atmospheric turbulence boundary layer of the Earth Was calculated. Based on the calculation of the threshold friction speed of saltation and the turbulence boundary-xayer, the extent of the boundary layer where saltation may occure was obtained. The rotation moment of force which plays an important role in the movement of sand consists of lift and interparticle force in the early stage of saltation.The duration and the strength of the moment of force were calculated.The trajectory and the movement parameters of saltation were obtained. All results of calculation tully with the experiment results.

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PARTICLE SIMULATION RESEARCH OF PLASMA PARAMETRIC HEATING CAUSED BY STRONG LASER Liu Cheng-hai, Zhang Jia-tai, Zhang Shu-guiYu, Shu-Zhen, Liang Hua-xiang, Xu Lin-bao 1985, 2(4): 454-461.  Abstract ( )   PDF (554KB) ( )   We have studied parametric heating caused by electric field of strong laser with frequence which is a little higher than plasma frequence(w0=1.1Wp)by use one and half dimensional CIC scheme. Results shown that both the ion-acoustic instabilities and the oscillation two-stream instabilities are stimulated together, nonlinear saturation show some fine structures, plasma is heated strongly and tur-blent spectra after saturetion fllows a typical power law.

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A AXISYMMETRIC FINGERING PROBLEM SOLVED BY FEM Cao Nian-zheng, Chen Yao-song 1985, 2(4): 462-468.  Abstract ( )   PDF (391KB) ( )   A low Reynolds unmber flow in a pipe with an air plug is studied by FEM, The incompressibility is treated with penalty function. The nonlinear free surface is found by iteration of its position with updated critical streamline,The ultimate free surface and its relative plug radius β=0.645 is obtained and seems very nice as compared to experimental values.

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NUMERICAL SIMULATION ON TWO INTERSECTING SLIDE LINES Zhou Lian-sheng, Bei Xin-yuan, Zhang Zhi-jie 1985, 2(4): 469-473.  Abstract ( )   PDF (309KB) ( )   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.

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STRONGLY IMPLICIT PROCEDURE APPLIED TO TRANSONIC STREAM EQUATIONS AND NEW APPROACH TO DETERMINATION OF DENSITY-FIDLD Wang Bao-Guo 1985, 2(4): 474-481.  Abstract ( )   PDF (493KB) ( )   A set of equations governing the fluid flow along a given S1 stream surface is solved by the use of artificial compressibility and with a new iterative algorithm between the two variables stream function ψ and density ρ.The set of equations consists of a stream function equation and a new first-order partial differential equation for density derived from the continuity equation, momentum equation, and Bernoulli's equation.A strongly implicit approximate factorization algorithm (SI) of multidimensional partial differential equations is used in numerical solutions of this set of equations.By the method proposed in this paper, the problem of non-uniqueness of density in traditional stream function method is avoided.A number of transonic cascades are calculated and given herein to demonstrate the capability of the present method.

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THE DECONFINMENT TRANSITION AT FINITETEMPE RATURES IN THE SU (2) LATTICEGAUGETHEORY WITH SINACTION Li Wen-zhu, Dong Shao-jing 1985, 2(4): 482-484.  Abstract ( )   PDF (190KB) ( )   Using Monte Carlo techniques we study the SU(2) lattice gauge theory with Sin 1-Sin(TrUp/2) action at finite temperatures.A deconfinement transition at high temperature is observed. The critical point is Tc=334±40Mev, which is consistent with that obtained by using Wilson's action and others.

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APPLICATION OF GEAR METHOD TO A SET OF STIFF ORDINARY DIFFERENTIAL EQUATIONS Zhao Huai-guo 1985, 2(4): 485-488.  Abstract ( )   PDF (235KB) ( )   A set of stiff ordinary differential equations in power supply for poloidal field of noncircular takamak is solved using Gear method. Gear method, self-adju stable step length and Self-Variable power are described in detail. Compared to single step method, Gear method spends less time.

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ACCURATE SOLUTION OF THE ORR-SOMMERFELD EIGENVALUE EQUATION Wang Fa-min 1985, 2(4): 489-497.  Abstract ( )   PDF (539KB) ( )   The Orr-Sommerfeld equation is solved numerically using a finite element method and the LR matrix eigenvalue algorithm.The results of great accuracy are obtained, by choosing higher order Hermite polynomials to be basis functions and making element distribution according to the physical character of the flow existed in the region.The method is applied to the stability of plane Poiseuille flowi It is found that the critical Reynolds nnmber is 5772.2218 and, it is computed that the neutral curve in the range of Reynolds number from Rc to 1010 farabove than those obtained before