Preface

Computational fluid dynamic (CFD) simulation is a trans-disciplinary technique across fluid mechanics, mathematical algorithms, and computer science. This technique was based on finite difference methods (FDM) and finite element methods (FEM) by iteratively solving the partial differential governing equations (mass equation, momentum equation, and energy equation), and providing the numerical results. The temporal and spatial solutions from the CFD simulation could accurately reproduce the real flow phenomenon, and all the key information of a flow can be captured for further analysis. This alleviates the trouble of measuring the flow information by experimental tests, and solves numerous practical problems in industry with higher precision and much lower cost. CFD simulation is a computation-intensive process. With the rapid development of high-performance computers (HPC) in recent decades, CFD application has made substantial progress in different fields such as mechanical engineering, chemical engineering, environmental engineering, and thermal engineering.

This book, "Computational Fluid Dynamic Simulations", collects the recent work of leading researchers, and the contents covers a variety of theoretical studies as well as experimental validation. Despite the interdisciplinary nature of the different applications involved, there is a common need for identifying the distribution of fluid dynamic parameters and detecting its effects. The advances described by the participating authors have significantly helped accomplish this point. For instance, Rincón-Casado et al. employed ANSYS-CFX to obtain the air temperature distribution in a room with an air conditioning unit mounted on an internal wall, which facilitates further analysis of comfort level and energy demand. Adewumi et al. presents an essential study of scale analysis and double diffusive free convection boundary layer laminar flow of low Prandtl fluids over an inclined wall, and investigated the velocity, concentration, and thermal boundary layer thicknesses in a series of geometrical conditions. Velázquez Ortega applied the Lattice Boltzmann Method to study the flow of a non-Newtonian fluid between two plates. Li et al. presented a review study of the interface schemes within the scope of the Lattice Boltzmann Method for conjugate transport between multi-phases or different materials. Flores-Hidalgo et al. conducted a case study of the photocatalytic degradation of water pollutants, and analyzed the effects of pressure and velocity distribution in the photocatalytic reactors with the assistance of CFD. Termizi et al. investigated the effect of inlet velocity toward mixing intensity over two different microchannel configurations. The CFD profile showed inlet velocity has significance effects on the mixing performance and provided information on the mixing length requirement to achieve complete mixing. Druetta studied the enhanced oil recovery process by solving a set of momentum and mass conservation equations in a reservoir simulator. Loya et al. developed a flight dynamic model for aircraft using CFD, which was then used to optimize the aerodynamic performance. This study successfully demonstrated how CFD is a great tool for designing a flight dynamic model of an unknown aircraft. To improve their efficiencies and understand the performance of hydrokinetic turbines, Chica et al. used CFD to analyze the fluid dynamic parameters and power generation efficiency of turbines with complex geometries. Ochiai et al. presented a multi-phase CFD model for oil lubricated

high-speed journal bearings. This CFD analysis of the two-phase flow of VOF with vapor pressure and surface tension allowed for the calculation of the gaseous-phase area and temperature of the journal bearing under flooded and starved lubrication conditions. Vilag et al. performed a simulation of a complex process taking place in the combustion chamber of a gas turbine. This work not only showed good agreement between CFD simulations and experiments, but also provided detailed information from inside the gas turbine such as temperature field, component fraction, and velocity which allowed for further analysis and deeper understanding of the combustion process.

During the preparation of this book, all the participating authors spent significant efforts in composing the chapters with their extraordinary knowledge and high motivation, and performed serious revision where needed. Without their ongoing support the publication of this book would not have been possible. The time that they have taken away from their busy schedules to contribute to this book was valuable and greatly appreciated. Also, my appreciation is especially dedicated to Ms. Rebekah Pribetic who helped me in every editing step throughout the entire publishing process.

> **Guozhao Ji** Dalian University of Technology, Dalian, People's Republic of China

> > **Jiujiang Zhu** University of Wuyi, China

Section 1

Basics of Computational

Fluid Dynamics Simulation

Section 1
