**Meet the editor**

Dr. Donna Post Guillen is in the Energy Systems Integration Department at the Idaho National Laboratory operated for the U.S. Department of Energy. She earned a B.S. in Mechanical Engineering from Rutgers University, an M.S. in Aeronautics from Caltech, and a Ph.D. in Engineering and Applied Science from Idaho State University. Dr. Guillen is a licensed Professional Engineer

in the State of Idaho with nearly 30 years of experience in mechanical and systems engineering. The focus of her research is on multiphase computational fluid dynamics and thermal hydraulics for sustainable energy technologies. She has authored or co-authored over 100 technical publications in the form of books, reports, journal articles and conference papers.

Contents

**Preface VII**

Alois Hoeld

**T-Junction 45**

Hernan Tinoco

Yasushi Ito

**Using CFD 155**

**Thrust Chamber 107**

Weidong Huang and Kun Li

Osama Sayed Abd El Kawi Ali

**Section 1 CFD Applications for Nuclear Reactor Safety 1**

Chapter 1 **The Coolant Channel Module CCM — A Basic Element for the**

Pervichko, Anna E. Aksenova and Sergey A. Karabasov

Chapter 3 **CFD as a Tool for the Analysis of the Mechanical Integrity of**

Chapter 4 **Thermal Hydraulics Design and Analysis Methodology for a Solid-Core Nuclear Thermal Rocket Engine**

Chapter 5 **CFD Simulation of Flows in Stirred Tank Reactors Through**

Chapter 6 **Hydrodynamic and Heat Transfer Simulation of Fluidized Bed**

**Prediction of Momentum Source 135**

**Light Water Nuclear Reactors 71**

**Section 2 General Thermal Hydraulic Applications 105**

Chapter 2 **Large Eddy Simulation of Thermo-Hydraulic Mixing in a**

**Construction of Thermal-Hydraulic Models and Codes 3**

Aleksandr V. Obabko, Paul F. Fischer, Timothy J. Tautges, Vasily M. Goloviznin, Mikhail A. Zaytsev, Vladimir V. Chudanov, Valeriy A.

Ten-See Wang, Francisco Canabal, Yen-Sen Chen, Gary Cheng and

## Contents

## **Preface XI**


Preface

ering general thermal hydraulic applications.

and properly capture the mixing properties of turbulence.

for an Accelerator Driven System.

This book covers a range of thermal hydraulic topics related, but not limited, to nuclear re‐ actors. The purpose is to present research from around the globe that serves to advance our knowledge of nuclear reactor thermal hydraulics and related areas. The focus is on comput‐ er code developments and applications to predict fluid flow and heat transfer, with an em‐ phasis on computational fluid dynamic (CFD) methods. This book is divided into two sections. The first section consists of three chapters concerning computational codes and methods applied to nuclear reactor safety. The second section consists of four chapters cov‐

The overarching theme of the first section of this book is thermal hydraulic models and co‐ des to address safety behaviour of nuclear power plants. Accurate predictions of heat trans‐ fer and fluid flow are required to ensure effective heat removal under all conditions. The section begins with a chapter discussing the theoretical development of thermal-hydraulic approaches to coolant channel analysis. These traditional methods are widely used in sys‐ tem codes to evaluate nuclear power plant performance and safety. The second chapter ex‐ amines several fully unsteady computational models in the framework of large eddy simulations implemented for a thermal hydraulic transport problem relevant to the design of nuclear power plant piping systems. A comparison of experimental data from a classic benchmark problem with the numerical results from three simulation codes is given. The third chapter addresses the issue of properly modeling thermal mixing in Light Water Nu‐ clear Reactors. A CFD approach is advocated, which allows the flow structures to develop

The second section of this book includes chapters focusing on the application of CFD to crosscutting thermal hydraulic phenomena. In line with best practices for CFD, the simula‐ tions are supported by relevant experimental data. The section begins with a chapter de‐ scribing a thermal hydraulic design and analysis methodology for a nuclear thermal propulsion development effort. Modern computational fluid dynamics and heat transfer methods are used to predict thermal, fluid, and hydrogen environments of a hypothetical solid-core, nuclear thermal engine designed in the 1960s. The second chapter in this section investigates the applicability of several CFD approaches to modeling mixing and agitation in a stirred tank reactor. The results are compared with experimentally-obtained velocity and turbulence parameters to determine the most appropriate methodology. The third chap‐ ter in this section presents the results of CFD simulations used to study the hydrodynamics and heat transfer processes in a two-dimensional gas fluidized bed. The final chapter uses CFD to predict the thermal hydraulics surrounding the design of a spallation target system

## Preface

This book covers a range of thermal hydraulic topics related, but not limited, to nuclear re‐ actors. The purpose is to present research from around the globe that serves to advance our knowledge of nuclear reactor thermal hydraulics and related areas. The focus is on comput‐ er code developments and applications to predict fluid flow and heat transfer, with an em‐ phasis on computational fluid dynamic (CFD) methods. This book is divided into two sections. The first section consists of three chapters concerning computational codes and methods applied to nuclear reactor safety. The second section consists of four chapters cov‐ ering general thermal hydraulic applications.

The overarching theme of the first section of this book is thermal hydraulic models and co‐ des to address safety behaviour of nuclear power plants. Accurate predictions of heat trans‐ fer and fluid flow are required to ensure effective heat removal under all conditions. The section begins with a chapter discussing the theoretical development of thermal-hydraulic approaches to coolant channel analysis. These traditional methods are widely used in sys‐ tem codes to evaluate nuclear power plant performance and safety. The second chapter ex‐ amines several fully unsteady computational models in the framework of large eddy simulations implemented for a thermal hydraulic transport problem relevant to the design of nuclear power plant piping systems. A comparison of experimental data from a classic benchmark problem with the numerical results from three simulation codes is given. The third chapter addresses the issue of properly modeling thermal mixing in Light Water Nu‐ clear Reactors. A CFD approach is advocated, which allows the flow structures to develop and properly capture the mixing properties of turbulence.

The second section of this book includes chapters focusing on the application of CFD to crosscutting thermal hydraulic phenomena. In line with best practices for CFD, the simula‐ tions are supported by relevant experimental data. The section begins with a chapter de‐ scribing a thermal hydraulic design and analysis methodology for a nuclear thermal propulsion development effort. Modern computational fluid dynamics and heat transfer methods are used to predict thermal, fluid, and hydrogen environments of a hypothetical solid-core, nuclear thermal engine designed in the 1960s. The second chapter in this section investigates the applicability of several CFD approaches to modeling mixing and agitation in a stirred tank reactor. The results are compared with experimentally-obtained velocity and turbulence parameters to determine the most appropriate methodology. The third chap‐ ter in this section presents the results of CFD simulations used to study the hydrodynamics and heat transfer processes in a two-dimensional gas fluidized bed. The final chapter uses CFD to predict the thermal hydraulics surrounding the design of a spallation target system for an Accelerator Driven System.

Our ability to simulate larger problems with greater fidelity has vastly expanded over the past decade. The collection of material presented in this book is but a small contribution to the important topic of thermal hydraulics. The contents of this book will interest researchers, scientists, engineers and graduate students.

> **Dr. Donna Post Guillen** Group Lead, Advanced Process and Decision Systems Department, Idaho National Laboratory, USA

**Section 1**

**CFD Applications for Nuclear Reactor Safety**

**CFD Applications for Nuclear Reactor Safety**

Our ability to simulate larger problems with greater fidelity has vastly expanded over the past decade. The collection of material presented in this book is but a small contribution to the important topic of thermal hydraulics. The contents of this book will interest researchers,

Group Lead, Advanced Process and Decision Systems Department,

**Dr. Donna Post Guillen**

Idaho National Laboratory, USA

scientists, engineers and graduate students.

VIII Preface

**Chapter 1**

**The Coolant Channel Module CCM — A Basic Element for**

The development of LWR Nuclear Power Plants (NPP) and the question after their safety behaviour have enhanced the need for adequate efficient theoretical descriptions of these plants. Thus thermal-hydraulic models and, based on them, effective computer codes played already very early an important role within the field of NPP safety research. Their objective is to describe both the steady state and transient behaviour of characteristic key parameters of a single- or two-phase fluid flowing along corresponding loops of such a plant and thus also along any type of heated or non-heated coolant channels being a part of these loops in an

Due to the presence of discontinuities in the first principle of mass conservation of a two-phase flow model, caused at the transition from single- to two-phase flow and vice versa, it turned out that the direct solution of the basic conservation equations for mixture fluid along such a coolant channel gets very complicated. Obviously many discussions have and will continue to take place among experts as to which type of theoretical approach should be chosen for the correct description of thermal-hydraulic two-phase problems when looking at the wide range of applications. What is thus the most appropriate way to deal with such a special thermal-

With the introduction of a 'Separate-Phase Model Concept' already very early an efficient way has been found how to circumvent these upcoming difficulties. Thereby a solution method has been proposed with the intention to separate the two-phases of such a mixture-flow in parts of the basic equations or even completely from each other. This yields a system of 4-, 5 or sometimes even 6-equations by splitting each of the conservation equations into two so-

> © 2013 Hoeld; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,

© 2013 Hoeld; licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

distribution, and reproduction in any medium, provided the original work is properly cited.

**the Construction of Thermal-Hydraulic Models and**

Additional information is available at the end of the chapter

**Codes**

Alois Hoeld

**1. Introduction**

adequate way.

hydraulic problem?

http://dx.doi.org/10.5772/53372

**Chapter 1**
