Spacer grid assembly supporting the nuclear fuel rods is an important concern in the design of structural components of a Pressurized Water Reactor (PWR). The spacer grid is composed by springs and dimples which are formed from a strip sheet by means of blanking and stamping processes. In this paper, the blanking process and tooling parameters are evaluated by means of a 2D plane-strain finite ...

We consider the problem of constructing spatial finite difference approximations on an arbitrary fixed grid which preserve any number of integrals of the partial differential equation and preserve some of its symmetries. A basis for the space of of such finite difference operators is constructed; most cases of interest involve a single such basis element. (The “Arakawa” Jacobian is such an elem...

In this paper a time-dependent moving-grid method is described to numerically solve time-dependent partial differential equations (PDEs) in one space dimensions involving fine scale structures such as steep moving fronts, emerging steep layers, pulses and shocks. Smoothing in the spatial direction is employed to control grid clustering and expansion. Additional smoothing in the temporal directi...

A simple expression for the Smagorinsky length scale is derived using arguments in physical space. This expression is sensitive to the choice of the basis functions employed in a numerical method and can be used with the finite volume or the finite element method on fully unstructured grids and meshes. For a polynomial basis, the dependence of the Smagorinsky length scale on the order of comple...

We develop multiscale mortar mixed finite element discretizations for second order elliptic equations. The continuity of flux is imposed via a mortar finite element space on a coarse grid scale, while the equations in the coarse elements (or subdomains) are discretized on a fine grid scale. The polynomial degree of the mortar and subdomain approximation spaces may differ; in fact, the mortar sp...

In this paper, we propose a two-grid finite element method for solving coupled partial differential equations, e.g., the Schrödinger-type equation. With this method, the solution of the coupled equations on a fine grid is reduced to the solution of coupled equations on a much coarser grid together with the solution of decoupled equations on the fine grid. It is shown, both theoretically and num...

This paper presents SGrid, a service-oriented model for the Semantic Grid. Each Grid service in SGrid is a Web service with certain domain knowledge. A Web services oriented wrapper generator has been implemented to automatically wrap legacy codes as Grid services exposed as Web services. Each wrapped Grid service is supplemented with domain ontology and registered with a Semantic Grid Service ...