WSC 2005

WSC 2005 Final Abstracts

General Applications B Track

Monday 10:30:00 AM 12:00:00 PM
General Applications of Simulation I

Chair: Renzo Shamey (NC State University)

A Stochastic Model for Planning Swine Facilities
Lluis M. Plà-Aragonés (University of Lleida)

A simulation model and its application for planning swine facilities are presented. Swine production is becoming more and more specialized, hence the sizing of a farm producing piglets is the main strategic decision concerning farmers who invest in sow production, since a farm comprises a big range of facilities with many possible sizes. The classical approach is deterministic, including sometimes some security margins without considering variations in future sow performance or in the management policy. The stochastic model presented here has revealed practical differences with respect to deterministic approaches. As result, simulation is useful to determine accurately the capacity, improve farm design, prevent practical problems and fit housing cost. Furthermore, the implementation in Extend allows potential users to perform efficiently different kinds of analyses.

Simulating Uncertainty in Mass Balance Modeling for Fresh Water Reservoirs. Case Study: Deer Creek Reservoir, Utah, U.S.A.
Ahmad M. Salah, Paul J. Fields, and A. Woodruff Miller (Brigham Young University)

Simple mass balance techniques can be used to build a zero-dimensional model for a fresh water reservoir to quantify the amount of water and certain pollutants flowing into and out of the system. Yet, great uncertainty is involved in the environmental and hydrological factors related to a reservoir and it is useful to build a model that incorporates uncertainty. A generic mass balance model was built for a hypothetical reservoir and applied to Deer Creek Reservoir in Utah. Simulation was used to model the stochastic nature of the inflows and outflows to estimate the distribution of water volume and pollutant concentrations. The historical observations and simulated values were shown to be in good agreement. The model can therefore be used to manage the performance of the reservoir. The modeling process is not site specific, thus it can be used to model any reservoir provided that there are enough data.

Numerical Simulation of Dyebath and the Influence of Dispersion Factor on Dye Transport
Renzo Shamey (North Carolina State University) and Xiaoming Zhao and Roger H. Wardman (Heriot-Watt University)

In order to model the mass transfer in a fluid, a “dispersion” model is frequently used. When the flow behavior does not drastically deviate from plug flow, the model performs well. The dispersive flow properties of liquids within fibrous textile assemblies however, have not been fully explored. In the mass transfer model, the dispersive flow is assumed to reduce the concentration gradient of dye liquor flowing through the package. This paper illustrates the influence of dispersion term on dye transport based on numerical simulation of dyebath. The transfer of dye through the package is described by a set of time-dependent partial differential equations, which govern convection, dispersion, and adsorption of dyes in the dyebath and across the yarn package. The simulation results prove, theoretically, that the inclusion of the dispersion term in the dyeing model improves the results of the dyeing process in terms of dye uptake and levelness.