An Algebraic Multiscale Solver (AMS) for the pressure system of equations arising from incompressible flow in heterogeneous porous media is developed. The algorithm allows for several independent preconditioning stages to deal with the full spectrum of errors. In addition to the fine-scale system of equations, AMS requires information about the superimposed (dual) coarse grid, which is used for...

Event flow graphs used in the context of performance monitoring combine the scalability and low overhead of profiling methods with lossless information recording of tracing tools. In other words, they capture statistics on the performance behavior of parallel applications while preserving the temporal ordering of events. Event flow graphs require significantly less storage than regular event tr...

An objective of the High Performance Computing and Communication Program at the NASA Langley Research Center is to demonstrate multidisciplinary shape and sizing optimization of a complete aerospace vehicle configuration by using high-fidelity finiteelement structural analysis and computational fluid dynamics aerodynamic analysis in a distributed, heterogeneous computing environment that includ...

Shape memory alloys (SMA) are widely employed as sensors and actuators. The need for precise control requires reliable modeling techniques involving, e.g., prescribed stresses and temperatures. These parameters are always inherently coupled in SMA. Various models are in use to characterize the non-linear hysteretic behavior of SMA; among them some that do not provide a means to incorporate true...

Three-dimensional collapse of and steady flow through finite-length elastic tubes are studied numerically. The Navier-Stokes equations coupled with large, nonlinear deformation of the elastic wall are solved by using the finiteelement software, FIDAP. Three-dimensional solid elements are used for the elastic wall, allowing us to specify any wall thickness required. Plane-strain results for the ...

Accurate knowledge of water fluxes in the vadose zone of watersheds is important for applications such as water resources management and climate forecasting. Most, if not all, large-scale studies follow a pragmatic approach where simplifying assumptions have to be made regarding problem formulation and estimation of hydraulic properties. This study investigates simplifications in both regards t...