Simulating HFIR Core Thermal Hydraulics Using 3D-2D Model Coupling

Simulating HFIR Core Thermal Hydraulics Using 3D-2D Model Coupling PDF Author:
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Languages : en
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A model utilizing interdimensional variable coupling is presented for simulating the thermal hydraulic interactions of the High Flux Isotope Reactor (HFIR) core at Oak Ridge National Laboratory (ORNL). The model s domain consists of a single, explicitly represented three-dimensional fuel plate and a simplified two-dimensional coolant channel slice. In simplifying the coolant channel, and thus the number of mesh points in which the Navier-Stokes equations must be solved, the computational cost and solution time are both greatly reduced. In order for the reduced-dimension coolant channel to interact with the explicitly represented fuel plate, however, interdimensional variable coupling must be enacted along all shared boundaries. The primary focus of this paper is in detailing the collection, storage, passage, and application of variables across this interdimensional interface. Comparisons are made showing the general speed-up associated with this simplified coupled model.

Simulating HFIR Core Thermal Hydraulics Using 3D-2D Model Coupling

Simulating HFIR Core Thermal Hydraulics Using 3D-2D Model Coupling PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
A model utilizing interdimensional variable coupling is presented for simulating the thermal hydraulic interactions of the High Flux Isotope Reactor (HFIR) core at Oak Ridge National Laboratory (ORNL). The model s domain consists of a single, explicitly represented three-dimensional fuel plate and a simplified two-dimensional coolant channel slice. In simplifying the coolant channel, and thus the number of mesh points in which the Navier-Stokes equations must be solved, the computational cost and solution time are both greatly reduced. In order for the reduced-dimension coolant channel to interact with the explicitly represented fuel plate, however, interdimensional variable coupling must be enacted along all shared boundaries. The primary focus of this paper is in detailing the collection, storage, passage, and application of variables across this interdimensional interface. Comparisons are made showing the general speed-up associated with this simplified coupled model.

2D Thermal Hydraulic Analysis and Benchmark in Support of HFIR LEU Conversion Using COMSOL.

2D Thermal Hydraulic Analysis and Benchmark in Support of HFIR LEU Conversion Using COMSOL. PDF Author:
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Category :
Languages : en
Pages :

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Book Description
The research documented herein was funded by a research contract between the Research Reactors Division (RRD) of Oak Ridge National Laboratory (ORNL) and the University of Tennessee, Knoxville (UTK) Mechanical, Aerospace and Biomedical Engineering Department (MABE). The research was governed by a statement of work (SOW) which clearly defines nine specific tasks. This report is outlined to follow and document the results of each of these nine specific tasks. The primary goal of this phase of the research is to demonstrate, through verification and validation methods, that COMSOL is a viable simulation tool for thermal-hydraulic modeling of the High Flux Isotope Reactor (HFIR) core. A secondary goal of this two-dimensional phase of the research is to establish methodology and data base libraries that are also needed in the full three-dimensional COMSOL simulation to follow. COMSOL version 3.5a was used for all of the models presented throughout this report.

Complex Geometry Creation and Turbulent Conjugate Heat Transfer Modeling

Complex Geometry Creation and Turbulent Conjugate Heat Transfer Modeling PDF Author:
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Languages : en
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The multiphysics capabilities of COMSOL provide the necessary tools to simulate the turbulent thermal-fluid aspects of the High Flux Isotope Reactor (HFIR). Version 4.1, and later, of COMSOL provides three different turbulence models: the standard k-{var_epsilon} closure model, the low Reynolds number (LRN) k-{var_epsilon} model, and the Spalart-Allmaras model. The LRN meets the needs of the nominal HFIR thermal-hydraulic requirements for 2D and 3D simulations. COMSOL also has the capability to create complex geometries. The circular involute fuel plates used in the HFIR require the use of algebraic equations to generate an accurate geometrical representation in the simulation environment. The best-estimate simulation results show that the maximum fuel plate clad surface temperatures are lower than those predicted by the legacy thermal safety code used at HFIR by approximately 17 K. The best-estimate temperature distribution determined by COMSOL was then used to determine the necessary increase in the magnitude of the power density profile (PDP) to produce a similar clad surface temperature as compared to the legacy thermal safety code. It was determined and verified that a 19% power increase was sufficient to bring the two temperature profiles to relatively good agreement.

RELAP5-3D Thermal Hydraulics Computer Program Analysis Coupled with DAKOTA and STAR-CCM+ Codes

RELAP5-3D Thermal Hydraulics Computer Program Analysis Coupled with DAKOTA and STAR-CCM+ Codes PDF Author: Oscar Artajerjes Rodriguez
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Category :
Languages : en
Pages :

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kRELAP5-3D has been coupled with both DAKOTA and STAR-CCM+ in order to expand the capability of the thermal-hydraulic code and facilitate complex studies of desired systems. In the first study, RELAP5-3D was coupled with DAKOTA to perform a sensitivity study of the South Texas Project (STP) power plant during steady-state and transient scenarios. The coupled software was validated by analyzing the simulation results with respect of the physical expectations and behavior of the power plant, and thermal-hydraulic parameters which caused greatest sensitivity where identified: inlet core temperature and reactor thermal power. These variables, along with break size and discharge coefficients, were used for further investigation of the sensitivity of the RELAP5-3D LOCA transient simulation under three difference cases: two inch break, six inch break, and guillotine break. Reactor thermal power, core inlet temperature, and break size were identified as producing the greatest sensitivity; therefore, future research would include uncertainty quantification for these parameters. In the second study, a small scale experimental facility, designed to study the thermal hydraulic phenomena of the Reactor Cavity Cooling System (RCCS) for a Very High Temperature Reactor (VHTR), was used as a model to test the capabilities of coupling Star-CCM+ and RELAP5-3D. This chapter discusses the capabilities and limitations of the STAR-CCM+/RELAP5-3D coupling, and a simulation, on the RCCS facility, was performed using STAR-CCM+ to study the flow patterns where expected complex flow phenomena occur and RELAP5-3D for the complete system. The code showed inability to perform flow coupling simulations and it is unable, at this time, to handle closed loop systems. The thermal coupling simulation was successful and showed congruent qualitative results to physical expectations. The locations of large fluid vortices were located specifically in the pipes closest to the inlet of the bottom manifold. In conclusion, simulations using coupled codes were presented which greatly improved the capabilities of RELAP5-3D stand-alone and computational time required to perform complex thermal-hydraulic studies. These improvements show greatly benefit for industrial applications in order to perform large scale thermal-hydraulic systems studies with greater accuracy while minimizing simulation time. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/148410

Energy Research Abstracts

Energy Research Abstracts PDF Author:
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 548

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Modelling Organs, Tissues, Cells and Devices

Modelling Organs, Tissues, Cells and Devices PDF Author: Socrates Dokos
Publisher: Springer
ISBN: 3642548016
Category : Technology & Engineering
Languages : en
Pages : 504

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Book Description
This book presents a theoretical and practical overview of computational modeling in bioengineering, focusing on a range of applications including electrical stimulation of neural and cardiac tissue, implantable drug delivery, cancer therapy, biomechanics, cardiovascular dynamics, as well as fluid-structure interaction for modelling of organs, tissues, cells and devices. It covers the basic principles of modeling and simulation with ordinary and partial differential equations using MATLAB and COMSOL Multiphysics numerical software. The target audience primarily comprises postgraduate students and researchers, but the book may also be beneficial for practitioners in the medical device industry.

Applications of Research Reactors

Applications of Research Reactors PDF Author: International Atomic Energy Agency
Publisher: International Atomic Energy Agency
ISBN: 9789201450104
Category : Science
Languages : en
Pages : 108

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Book Description
This publication is a comprehensive study that reviews the current situation in a great number of applications of research reactors. It revises the contents of IAEA TECDOC-1234, The Applications of Research Reactors, giving detailed updates on each field of research reactor uses worldwide. Reactors of all sizes and capabilities can benefit from the sharing of current practices and research enabled via this updated version, which describes the requirements for practicing methods as diverse as neutron activation analysis, education and training, neutron scattering and neutron imaging, silicon doping and radioisotope production, material/fuel irradiation and testing, and some others. Many underutilised research reactors can learn how to diversify their technical capabilities, staff and potential commercial partners and users seeking research reactor services and products. The content of the publication has also been strengthened in terms of current issues facing the vast majority of research reactors by including sections describing user and customer relations as well as strategic planning considerations.

Monthly Catalog of United States Government Publications

Monthly Catalog of United States Government Publications PDF Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages :

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Hydraulic Power System Analysis

Hydraulic Power System Analysis PDF Author: Arthur Akers
Publisher: CRC Press
ISBN: 1420014587
Category : Science
Languages : en
Pages : 401

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Book Description
The excitement and the glitz of mechatronics has shifted the engineering community's attention away from fluid power systems in recent years. However, fluid power still remains advantageous in many applications compared to electrical or mechanical power transmission methods. Designers are left with few practical resources to help in the design and

Monthly Catalogue, United States Public Documents

Monthly Catalogue, United States Public Documents PDF Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1012

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