VGRIDSG: An unstructured surface grid generation program

This report contains an overview of the VGRIDSG unstructured surface grid generation program. The VGRIDSG program was created from the VGRID3D unstructured grid generation program developed by Vigyan, Inc. The purpose of this report is to document the changes from the original VGRID3D program and to describe the capabilities of the new program

A comparison using APPL and PVM for a parallel implementation of an unstructured grid generation program

Efforts to parallelize the VGRIDSG unstructured surface grid generation program are described. The inherent parallel nature of the grid generation algorithm used in VGRIDSG was exploited on a cluster of Silicon Graphics IRIS 4D workstations using the message passing libraries Application Portable Parallel Library (APPL) and Parallel Virtual Machine (PVM). Comparisons of speed up are presented for generating the surface grid of a unit cube and a Mach 3.0 High Speed Civil Transport. It was concluded that for this application, both APPL and PVM give approximately the same performance, however, APPL is easier to use

NOx Control Options and Integration for US Coal Fired Boilers Quarterly Report

This report summarizes the research that has been performed by Reaction Engineering International (REI) during the last three months on demonstrating and evaluating low NOx control strategies and their possible impact on boiler performance for firing US coals. The focus of our efforts during the last six months have been on: (1) Field Tests for RRI at the Conectiv BL England Station Unit No.1, a 130 MW cyclone fired boiler; (2) Extending our Computational Fluid Dynamics (CFD) based NOx model to accommodate the chemistry for Rich Reagent Injection (RRI) in cyclone fired boilers; (3) Applying the NOx model to evaluate RRI systems integrated into a boiler with Over Fired Air (OFA) and Selective Non-Catalytic Reduction (SNCR); (4) Field Tests of the REI Corrosion Probe at the Conectiv BL England Station Unit No.1; (5) Commence engineering study of ammonia adsorption mechanisms for Fly Ash; (6) Presentation of current program accomplishments and plans for future work to DoE staff members at NETL-FE (Pittsburgh); and (7) Presentation of preliminary field test results for RRI to EPRI CNCIG

CFD modeling for entrained flow gasifiers

presentationIn this paper we have described a CFD based modeling tool for entrained flow coal gasifiers. The model contains sub-models to properly model the reaction kinetics of coal gasification at high pressure, high solids loading and slagging walls. Comparisons between values predicted by our CFD model and modeling studies performed by other research groups have shown good agreement. Although the models have been demonstrated for oxygen blown, pressurized systems the same model could be applied to air-blown or atmospheric systems. Future work will focus on using the model to investigate generic improvements for the operation and design of entrained flow gasifiers

PVP2002-1542 A NEWTON-KRYLOV BASED SOLVER FOR MODELING FINITE RATE CHEMISTRY

ABSTRACT To date, computational fluid dynamics (CFD) codes aimed at solving practical engineering problems involving chemically reacting flow have incorporated relatively simple descriptions of the chemical mechanisms involved. Techniques are now available to create reduced mechanisms that faithfully represent detailed chemical descriptions over an appropriate range of conditions using many fewer species. However, including reduced mechanisms into a CFD analysis typically leads to numerical difficulties. In a recent project, a new modeling tool was created that utilizes a combination of state-of-the-art techniques used by Reaction Engineering International (REI) for modeling finite rate chemistry in chemically reacting flows using reduced mechanisms with emerging Newton-Krylov methods for solving systems of non-linear equations. For tests problems ranging from geometrically simple combustion problems to full-scale utility boiler simulations, the NewtonKrylov solver has reduced the CPU time to achieve a solution by up to 60% compared to our traditional Picard iteration method. This paper discusses the implementation of the Newton-Krylov solver into the REI combustion code, the impact of parameters on the performance of the Newton-Krylov solver for solving problems using reduced mechanisms, and demonstration of the Newton-Krylov solver on full-scale utility boiler NOx simulations

A Computational Workbench Environment For Virtual Power Plant Simulation

In this paper we describe our progress toward creating a computational workbench for performing virtual simulations of Vision 21 power plants. The workbench provides a framework for incorporating a full complement of models, ranging from simple heat/mass balance reactor models that run in minutes to detailed models that can require several hours to execute. The workbench is being developed using the SCIRun software system. To leverage a broad range of visualization tools the OpenDX visualization package has been interfaced to the workbench. In Year One our efforts have focused on developing a prototype workbench for a conventional pulverized coal fired power plant. The prototype workbench uses a CFD model for the radiant furnace box and reactor models for downstream equipment. In Year Two and Year Three, the focus of the project will be on creating models for gasifier based systems and implementing these models into an improved workbench. In this paper we describe our work effort for Year One and outline our plans for future work. We discuss the models included in the prototype workbench and the software design issues that have been addressed to incorporate such a diverse range of models into a single software environment. In addition, we highlight our plans for developing the energyplex based workbench that will be developed in Year Two and Year Three