開領域移流分散問題への無限要素法の適用

抄録

It was shown that a enormous error could appear when convection-dispersion nroblems in infinite domains were solved by Galerkin finite element method assuming an infinite domain by a finite one. Infinite elements suggested by Bettess which easily satisfy boundary conditions at infinity were applied to some convectiondispersion problems and their applicability was examined. Following conclusions were obtained on the problems about a continuous point source in an infinite domain. The best attenuation length contained in a weighting function for infinite elements was found to be proportional to√D_xD_y/v, where D_x and D_y were dispersion coefficients for x and y direction respectively and v, the flow rate. Infinite elements were efficiently applicable to the steady and unsteady problems under the uniform flow fields and the steady problem under the nonuniform flow field.