摘要:

AbstractA conducting dusty gas flow in the presence of a given applied magnetic field is modelled by an initial boundary value problem. The continuous dependence of solutions backward in time to this model is studied. The electric and induced magnetic fields are assumed to be negligible and the dust particles are non‐conducting. A uniqueness result is also derive

ISSN:0170-4214    

DOI:10.1002/mma.1670120302

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractIn this paper we investigate the direct problem associated with the scattering of ‘plane waves’ from an object submerged in an ocean of finite depth. An integral representation for the Dirichlet problem is found, from which a formula for the far‐field pattern evolves.A density theorem is established concerning the set of all far‐field patterns. This theorem is essential for the reconstruction of the submerged object, the ‘inverse’ problem [2

ISSN:0170-4214    

DOI:10.1002/mma.1670120303

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractThe problem of two‐dimensional seepage from a non‐linear channel through a homogeneous medium underlain at a finite depth by a drain will be considered. A new approach is given, transforming the seepage problem to a non‐linear singular integral equation for which the unique existence of the solution is proved. The free boundaries of the seepage region can be described expli

ISSN:0170-4214    

DOI:10.1002/mma.1670120304

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractIn this article we present the solution of linear partial differential equations of the form ∂tf= L̂f, for initial value problems. Also the solution of some diffusion equations will be discuss

ISSN:0170-4214    

DOI:10.1002/mma.1670120305

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractThe solution of the three‐dimensional mixed boundary value problem for the Laplacian in a polyhedral domain has special singular forms at corners and edges. A ‘tensor‐product’ decomposition of those singular forms along the edges is derived. We present a strongly elliptic system of boundary integral equations which is equivalent to the mixed boundary value problem. Regularity results for the solution of this system of integral equations are given which allow us to analyse the influence of graded meshes on the rate of convergence of the corresponding boundary element Galerkin solutions. We show that it suffices to refine the mesh only towards the edges of the surfaces to regain the optimal rate of conv

ISSN:0170-4214    

DOI:10.1002/mma.1670120306

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractThe Neumann problem for Laplace's equation in a polygonal domain is associated with the exterior Dirichlet problem obtained by requiring the continuity of the potential through the boundary. Then the solution is the simple layer potential of the chargeqon the boundary.qis the solution of a Fredholm integral equation of the second kind that we solve by the Galerkin method. The chargeqhas a singular part due to the corners, so the optimal order of convergence is not reached with a uniform mesh. We restore this optimal order by grading the mesh adequately near the corners. The interior Dirichlet problem is solved analogously, by expressing the solution as a double layer potential.

ISSN:0170-4214    

DOI:10.1002/mma.1670120307

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractIt is shown that solutions of the equations of thermoelasticity in general will develop singularities in finite time.

ISSN:0170-4214    

DOI:10.1002/mma.1670120308

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

ISSN:0170-4214    

DOI:10.1002/mma.1670120301

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY