An efficient method for solving the mixed direct-inverse problem of the transonic rotational flow in plane casades

The method in [1] has been extended to the case of rotational flow in this paper. A new method for dealing with the shock wave is presented. This method has the advantages of both the shock-fitting and the shock capturing methods. The direct problem and the mixed direct-inverse problem of the rotational flow in a transonic plane cascade at both design and off design conditions are solved, and the results show that the present method has rapid convergence rate and high accuracy even for the flow with moderately strong shocks. The calculations have been carried out on the DPS-8 computer, and for the direct problem, only 50–80 iterations are needed, and 50–80 seconds of CPU time are required.     

Exponential Stability to a Contact Problem of Partially Viscoelastic Materials

In this paper we study models for contact problems of materials consisting of an elastic part (without memory) and a viscoelastic part, where the dissipation given by the memory is effective. We show that the solution of the corresponding viscoelastic equation decays exponentially to zero as time goes to infinity, provided the relaxation function also decays exponentially, no matter how small is the dissipative part of the material.     

A theoretical solution of cylindrical shells for axisymmetric plain strain elastodynamic problems

A method is developed for the transient responses of axisymmetric plain strain problems of cylindrical shells subjected to dynamic loads. Firstly, a special function was introduced to transform the inhomogeneous boundary conditions into the homogeneous ones. Secondly, using the method of separation of variables, the quantity that the displacement subtracts the special function was expanded as the multiplication series of Bassel functions and time functions. Then by virtue of the orthogonal properties of Bessel functions, the equation with respect to the time variable was derived, of which the solution is easily obtained. The displacement solution was finally obtained by adding the two parts mentioned above. The present method can avoid the integral transform and is fit for arbitrary loads. Numerical results are presented for internally shocked isotropic and cylindrically isotropic cylindrical shells and externally shocked cylinders, as well as for an externally shocked, cylindrically isotropic cylindrical shell that is fixed at the internal surface. Contributed by Ding Hao-jiang Foundation item: the National Natural Science Foundation of China (10172075) Biography: Ding Hao-jiang (1934-)     

Coupled Groundwater Flow and Transport in Porous Media. A Conservative or Non-conservative Form?

A new formulation for the modeling of density coupled flow and transport in porous media is presented. This formulation is based on the development of the mass balance equation by using the conservative form. The system of equations obtained by coupling the flow and transport equations using a state equation is solved by a combination of the mixed hybrid finite element method (MHFEM) and the discontinuous finite element method (DFEM). The former is applied in order to solve the flow equation and the dispersive part of the transport equation, whilst the latter is used to solve the advective part of the transport equation. Although the advantages of the MHFEM are known (efficiency calculation of velocity field and continuity of fluxes from one element to an adjacent one), its application in a classical development form (volumetric fluxes as unknowns) leads to the non-conservative version of the mass balance equation. The associated matrix of the system of equations obtained by hybridization is positive definite but non-symmetrical. By using a new approach (mass fluxes as unknowns) the conservative form of the continuity equation is preserved and the associated matrix of the system of equations obtained by hybridization becomes symmetrical. When applied to Elder's problem involving a strong density contrast, this new approach, with a lower calculation cost, leads to similar or identical results to those found in the specialized literature. The comparison between the conservative and non-conservative formulations solved with the same MHFEM and DFEM combination emphasizes the rigor and the pertinence of this new approach. Furthermore, we show the existence of a limit refinement defining the stability of the numerical solution for Elder's problem.     

Quasi-Equilibrium Problems and Constrained Multiobjective Games in Generalized Convex Space

ＩｎｔｒｏｄｕｃｔｉｏｎＬｅｔＸａｎｄＹｂｅｎｏｎｅｍｐｔｙｓｅｔｓａｎｄ2 ＸｂｅｔｈｅｆａｍｉｌｙｏｆａｌｌｓｕｂｓｅｔｓｏｆＸ .ＬｅｔＴ :Ｘ→Ｙｂｅａｓｉｎｇｌｅ＿ｖａｌｕｅｄｍａｐｐｉｎｇ ,Ａ :Ｘ→ 2 Ｘｂｅａｓｅｔ＿ｖａｌｕｅｄｍａｐｐｉｎｇ ,ψ :Ｘ×Ｙ×Ｘ→Ｒ∪ ±∞ ａｎｄｆ:Ｘ×Ｙ→Ｒ∪ ±∞ ｂｅｔｗｏｆｕｎｃｔｉｏｎｓ.Ｔｈｅｇｅｎｅｒａｌｑｕａｓｉ＿ｅｑｕｉｌｉｂｒｉｕｍｐｒｏｂｌｅｍＧＱＥＰ (Ｔ ,Ａ ,ψ)ｉｓｔｏｆｉｎｄ ^ｘ∈Ｘｓｕｃｈｔｈａｔ^ｘ∈Ａ( ^ｘ) ,ψ( ^ｘ ,Ｔ^ｘ ,ｙ)≤ 0…     

Convergence of a Modified SLP Algorithm for the Extended Linear Complementarity Problem

ＩｎｔｒｏｄｕｃｔｉｏｎＷｅｃｏｎｓｉｄｅｒｔｈｅｅｘｔｅｎｄｅｄｌｉｎｅａｒｃｏｍｐｌｅｍｅｎｔａｒｉｔｙｐｒｏｂｌｅｍ (ＸＬＣＰ)ｉｎｔｒｏｄｕｃｅｄｂｙＭａｎｇａｓａｒｉａｎａｎｄＰａｎｇ[1](ａｌｓｏｓｅｅＹｅ[2 ]) :Ｆｉｎｄａｖｅｃｔｏｒ(ｘ ,ｙ) ∈Ｒ2ｎｓｕｃｈｔｈａｔＭｘ-Ｎｙ∈Ｋ ,ｘＴｙ=0 ,　ｘ≥ 0 ,ｙ≥ 0 ,( 1 )ｗｈｅｒｅＭ ,Ｎ ∈Ｒｍ×ｎａｒｅｇｉｖｅｎ ,ａｎｄＫｉｓａｐｏｌｙｈｅｄｒａｌｓｅｔｉｎＲｍｄｅｆｉｎｅｄｂｙＫ :=ｕ∈Ｒｍ｜Ｇｕ≥ｇ ,　　Ｇ∈Ｒｌ×ｍ,ｇ∈Ｒｌ.Ｔｈｉｓｐｒｏ…     

A New Algorithm of Time Stepping in Dynamic Viscoelastic Problems

ＩｎｔｒｏｄｕｃｔｉｏｎＡｎｕｍｂｅｒｏｆｍａｔｅｒｉａｌｓｉｎｅｎｇｉｎｅｅｒｉｎｇｃａｎｂｅｃｌａｓｓｉｆｉｅｄｉｎｔｈｅｃａｔａｌｏｇｏｆｖｉｓｃｏｅｌａｓｔｉｃｉｔｙ ,ｉｎｃｌｕｄｉｎｇｒｏｃｋ ,ｓｏｉｌ,ｐｏｌｙｍｅｒ,ａｎｄＥＲ ＭＲｍａｔｅｒｉａｌｓｅｔｃ .[Ｃｈｒｉｓｔｅｎｓｅｎ 1 982 [1],ＴＡＯ 1 999[2 ]] .Ｔｈｅｄｙｎａｍｉｃａｎａｌｙｓｉｓｏｆｖｉｓｃｏｅｌａｓｔｉｃｐｒｏｂｌｅｍｓｉｓｒｅｌａｔｅｄｔｏｔｈｅｔｉｍｅｄｅｐｅｎｄｅｎｔｓｏｌｕｔｉｏｎｓ.Ｅｖｅｎｔｈｏｕｇｈｄｉ…     

The Asymptotic Behavior of Solution for the Singularly Perturbed Initial Boundary Value Problems of the Reaction Diffusion Equations in a Part of Domain

Ｔｈｅａｕｔｈｏｒｓｓｔｕｄｉｅｄａｃｌａｓｓｏｆｓｉｎｇｕｌａｒｌｙｐｅｒｔｕｒｂｅｄｐｒｏｂｌｅｍｓｉｎ [1 ] -[7] .Ｎｏｗｗｅｒａｉｓｅａｃｌａｓｓｏｆｓｉｎｇｕｌａｒｌｙｐｅｒｔｕｒｂｅｄｐｒｏｂｌｅｍｓｏｎａｐａｒｔｏｆｄｏｍａｉｎ .Ｃｏｎｓｉｄｅｒｔｈｅｆｏｌｌｏｗｉｎｇｉｎｉｔｉａｌｂｏｕｎｄａｒｙｖａｌｕｅｐｒｏｂｌｅｍｆｏｒｔｈｅｒｅａｃｔｉｏｎｄｉｆｆｕｓｉｏｎｅｑｕａｔｉｏｎｓ　　ｕｔ-λε(ｘ) ( μ(ｕ)ｕｘ) ｘ Ｋｘ(ｕ) ｆ(ｘ ,ｔ,ｕ) =0 ,(ｔ,ｘ) ∈ ( 0 ,Ｔ)× ( ( 0 ,α) ∪ (…     

Kustaanheimo–Stiefel变量与二体问题的正规化

本文叙述Kustaanheimo–Stiefel变量及其从四元数发展形成的过程,以及Kustaanheimo–Stiefel变换在二体问题正规化中的应用。

     

Wavelet multiresolution interpolation Galerkin method for nonlinear boundary value problems with localized steep gradients

The wavelet multiresolution interpolation for continuous functions defined on a finite interval is developed in this study by using a simple alternative of transformation matrix. The wavelet multiresolution interpolation Galerkin method that applies this interpolation to represent the unknown function and nonlinear terms independently is proposed to solve the boundary value problems with the mixed Dirichlet-Robin boundary conditions and various nonlinearities, including transcendental ones, in which the discretization process is as simple as that in solving linear problems, and only common two-term connection coefficients are needed. All matrices are independent of unknown node values and lead to high efficiency in the calculation of the residual and Jacobian matrices needed in Newton’s method, which does not require numerical integration in the resulting nonlinear discrete system. The validity of the proposed method is examined through several nonlinear problems with interior or boundary layers. The results demonstrate that the proposed wavelet method shows excellent accuracy and stability against nonuniform grids, and high resolution of localized steep gradients can be achieved by using local refined multiresolution grids. In addition, Newton’s method converges rapidly in solving the nonlinear discrete system created by the proposed wavelet method, including the initial guess far from real solutions.