Multi-objective genetic algorithms are implemented to optimize airfoil shape for obtaining greater laminar range and weaker shock wave drag simultaneously by using a shock control bump. Non dominated solutions of this two-objective optimization problem indicate that aerodynamic performances of airfoils trade-off between delay of profile's transition location and increased intensity of shock wave due the bump installed at upper surface of airfoil.

To enforce accurate displacement constraints,essential boundary conditions and interface continuity conditions in mesh-less method are treated as Multi-Point Constraints (MPC) of displacement,which are illustrated by using SPH (Smoothed Particle Hydrodynamics) method incorporated with algebraic master-slave relations.An example of linear elastic problem of representative volume element in matrix-inclusion composite is presented.Numerical tests show that the proposed algebraic master-slave method leads to higher accuracy and wider application than the penalty function method.

A wavelet-homotopy hybrid inversion algorithm for inverse problem of ground penetrating radar (GPR) is proposed.Wavelet is applied to separate inverse problem into different scales.In the maximum scale,initial value of the next scale is found by a homotopy method.In other scales,iteration process is carried out to obtain the global minimum point.The algorithm takes advantages of wavelet analysis and homotopy inversion method.It shows high capability of global search.

We propose a "state of art"tetrahedron sampling scheme based on a nonlocal pseudopotential bandstructure calculation and linear energy interpolation in each tetrahedron cell.In this approach,a relatively small amount of tetrahedrons are produced automatically and the Brillouin integration is calculated with higher precision and efficiency.In an application to diamond materials of Si and Ge,optimized nonuniform meshes are obtained automatically in the 1/48 irreducible wedge of the brillouin zone.A complement is given for the integrality of the present tetrahedron DOS expression and the DOS's for the first and second conductance band of Si and Ge are obtained with this grid and the supplemented expression.

Propagation of light in a supersonic flat turbulence boundary layer is numerically analyzed. The flow characteristics are studied according to the optic wave-front variance. The mass-weight averaging N-S equations are adopted as the governing equations of flow, and a two-equation turbulent model is employed. Light propagation is described by paraxial wave equations and solved by a phase-screen method combined with the FFT technique, Light intensity distribution and phase aberrations are given in order to show the optic aberrations as well as the flow characteristics.

The solid mechanical behaviors and the fracture process of laminated composite material with non-uniform material properties are simulated by the finite element method.All layers possess non-homogeneity, which is described by proper statistical distributions.In the 3-D discretization,the non-uniformity consists in a variety of elastic constants in each element.When the displacement or loading increases gradually, discretized element fails one by one randomly and the equivalent curve of strain vs. stress reflects complex non-linearity.Under the given conditions, the variation of strain and stress field and the fracture process are obtained through numerical simulations in which different elements fail in a random sequence until the specimen is fractured totally as the displacement or loading increases gradually. In the test runs, the material consists of about 14 to 15 layers. Thousands of elements are used in test examples presented in this paper. The relations between equivalent stresses and strain, got by simulation, is in qualitative agreement with test results in [11,12], especially for the phenomena of strain softening. Our investigations can serve as an explanation of strain softening of heterogeneous material.

By using Linearization method in little time interval, from the heat conduition equation with the 1st-order phasetransformations, the foundation equations of Finite Elememts in solidifications of Metals is established in the paper. The numerical analog on symetric problem in solidification of a grayiron in sandform is obtained by means of triangular element, and the results tallies the corresponding test well.

In this paper, Norsette Method is used to solve the non-steady heat conduction problem. This method prevents the "oscillation" of numerical solution effectively.

This paper presents an unfactored efficient algorithm for 3-D Euler equationsbased on the implicit flux-splitting and the line Gauss-Seidel iteration. In the algorithm the explicit terms on the right side of the discretization equation are treated in second order accuracy and to solve the implicit discretization equation one back-and-forth sweep in the main flow direction is taken and an alternating direction line G-S interation is carried out in the other two directions. The numerical calculations of 3-D transonic cascade inviscid blow tave shown that the algorithm has a quite high convergent rate.

A hybrid method [1] is used to solve the wave of 3-D low Reynolds flow in an elastc pipe. The flow region is divided into far field and near fielf. In far field the solutions can be expressed by series expansions[2], while in the near field FEM could be used. 3-D eigen-functions must be taken into account. The corresponding eigen values are calculated numerically. It is shown that except the fundamental eigen functions which are just the 2-D ones, the others decrease very quickly. So 2-D eigen functions are enough for many cases.