Reynolds and Mach number simulation of Apollo and Gemini re-entry and comparison with flight

Reynolds and Mach numbers simulation of Apollo and Gemini reentry compared with flight dat

Building top management muscle in a slow growth environment: How different is better at Greyhound Financial Corporation

The turbulence experienced in the 1980s in the U.S. business environment has led to something of a motivational crisis among corporate managers. Increased competition, budget constraints, and changing demographics are forcing companies into adopting strategies geared toward downsizing and flatter organizational structures. While corporate America probably has begun to accept its leaner profile, it has not yet successfully addressed the issue of how to keep the best managerial talent tuned in and turned on in an era of dwindling resources. This article describes and assesses one corporation\u27s efforts to maintain top-managerial motivation through a unique form of job swapping called the Muscle Building program at Greyhound Financial Corporation in Phoenix, Arizona. Muscle building. a top-management job rotation program, helps prevent career gridlock, fosters management diversity, and provides for top-management succession. Hidden costs and benefits of the program and issues concerning its implementation are discussed

Inertial Coupling Method for particles in an incompressible fluctuating fluid

We develop an inertial coupling method for modeling the dynamics of point-like 'blob' particles immersed in an incompressible fluid, generalizing previous work for compressible fluids. The coupling consistently includes excess (positive or negative) inertia of the particles relative to the displaced fluid, and accounts for thermal fluctuations in the fluid momentum equation. The coupling between the fluid and the blob is based on a no-slip constraint equating the particle velocity with the local average of the fluid velocity, and conserves momentum and energy. We demonstrate that the formulation obeys a fluctuation-dissipation balance, owing to the non-dissipative nature of the no-slip coupling. We develop a spatio-temporal discretization that preserves, as best as possible, these properties of the continuum formulation. In the spatial discretization, the local averaging and spreading operations are accomplished using compact kernels commonly used in immersed boundary methods. We find that the special properties of these kernels make the discrete blob a particle with surprisingly physically-consistent volume, mass, and hydrodynamic properties. We develop a second-order semi-implicit temporal integrator that maintains discrete fluctuation-dissipation balance, and is not limited in stability by viscosity. Furthermore, the temporal scheme requires only constant-coefficient Poisson and Helmholtz linear solvers, enabling a very efficient and simple FFT-based implementation on GPUs. We numerically investigate the performance of the method on several standard test problems...Comment: Contains a number of corrections and an additional Figure 7 (and associated discussion) relative to published versio

Hydrodynamics of Suspensions of Passive and Active Rigid Particles: A Rigid Multiblob Approach

We develop a rigid multiblob method for numerically solving the mobility problem for suspensions of passive and active rigid particles of complex shape in Stokes flow in unconfined, partially confined, and fully confined geometries. As in a number of existing methods, we discretize rigid bodies using a collection of minimally-resolved spherical blobs constrained to move as a rigid body, to arrive at a potentially large linear system of equations for the unknown Lagrange multipliers and rigid-body motions. Here we develop a block-diagonal preconditioner for this linear system and show that a standard Krylov solver converges in a modest number of iterations that is essentially independent of the number of particles. For unbounded suspensions and suspensions sedimented against a single no-slip boundary, we rely on existing analytical expressions for the Rotne-Prager tensor combined with a fast multipole method or a direct summation on a Graphical Processing Unit to obtain an simple yet efficient and scalable implementation. For fully confined domains, such as periodic suspensions or suspensions confined in slit and square channels, we extend a recently-developed rigid-body immersed boundary method to suspensions of freely-moving passive or active rigid particles at zero Reynolds number. We demonstrate that the iterative solver for the coupled fluid and rigid body equations converges in a bounded number of iterations regardless of the system size. We optimize a number of parameters in the iterative solvers and apply our method to a variety of benchmark problems to carefully assess the accuracy of the rigid multiblob approach as a function of the resolution. We also model the dynamics of colloidal particles studied in recent experiments, such as passive boomerangs in a slit channel, as well as a pair of non-Brownian active nanorods sedimented against a wall.Comment: Under revision in CAMCOS, Nov 201

Archeological Survey Of The Proposed Mary Rhodes Water Pipeline (Phase II) From The Colorado River To The Navidad-Lavaca River Authority\u27s West Water Delivery System, Jackson And Matagorda Counties Texas

In August 2010 and February–April 2012, personnel with Prewitt and Associates, Inc., performed an archeological survey for the proposed Mary Rhodes water pipeline (Phase II) in Jackson and Matagorda Counties, Texas. The work was done for Freese and Nichols, Inc., and the City of Corpus Christi under Texas Antiquities Permit No. 5688. Field survey targeted the most likely locations for Native American sites, consisting of the 24-acre pump station tract on the Colorado River and 5.35 km of pipeline route at 11 stream crossings, as well as several potential historic localities identified through analysis of historic maps and aerial photographs. In total, 56 shovel tests and 58 backhoe trenches were excavated. A single archeological site was found. This site, 41MG136, is an elevated railroad bed on the floodplain of the Colorado River that was built in the first decade of the twentieth century and abandoned by 1989. It is not considered eligible for listing in the National Register of Historic Places or designation as a State Archeological Landmark. No further archeological work is recommended

Phase Field Modeling of Fracture and Stress Induced Phase Transitions

We present a continuum theory to describe elastically induced phase transitions between coherent solid phases. In the limit of vanishing elastic constants in one of the phases, the model can be used to describe fracture on the basis of the late stage of the Asaro-Tiller-Grinfeld instability. Starting from a sharp interface formulation we derive the elastic equations and the dissipative interface kinetics. We develop a phase field model to simulate these processes numerically; in the sharp interface limit, it reproduces the desired equations of motion and boundary conditions. We perform large scale simulations of fracture processes to eliminate finite-size effects and compare the results to a recently developed sharp interface method. Details of the numerical simulations are explained, and the generalization to multiphase simulations is presented

The New World challenge : Performance trends in wine production in major wine-exporting countries in the 2000s and their implications for the Australian wine industry

© 2014 UniCeSV, University of Florence. Anderson, K., Nelgen, S., 2011. Global Wine Markets, 1961 to 2009: A Statistical Compendium. University of Adelaide Press, Adelaide publication of an index of revealed comparative advantage suggests that the Australian wine industry had come under increased competition from other "New World" producers in the first decade of this century. We examine this influence by comparing the transformation of wine grapes into wine volume and value in the 11 largest wine-exporting countries during the years, 2000-2009. Our focus is on the challenge issued by other New World producers from the Southern Hemisphere to Australian producers, and the continuing challenge to Old World global supremacy by New World producers and its response. Four performance measures are used this study. Two key trends are evident. First, all countries migrated to higher price points, albeit with differing degrees of success: slightly declining productivity in transforming wine grapes into wine output was over whelmed by price/quality effects, leading to substantial gains in transforming wine grapes in to wine value. Second, New World producers plus Portugal and Spain were much more successful in achieving gains in their export value proposition than they were in extracting value in their domestic markets. Results show that Australian wine producers had lost some of their competitive advantage during the 2000s as their pre- existing strategy dominated by the export of high-volume wines by large companies at low to medium price points, and their reliance on a reputation for reliable good quality for the price point was beginning to fail in the face of competition from both New World and Old World producers. Acknowledgement of this outcome has led to a good deal of introspection, and recognition of the need to promote the wine regions of Australia, based on higher-quality wines,and to select and promote quality indicators