Chapter 1 Introduction 1.1 Research Motivation 1.2 Objectives Chapter 2 Literature Review 2.1 Introduction 2.2 Hydrodynamic Characterizations 2.3 CFD Modeling Approaches 2.4 Closure Model 2.5 Summary Chapter 3 Numerical Study of Special Ball Packed Bed Reactor 3.1 Experiments Data Collection 3.2 Development of the Numerical Model 3.3 Results and Discussion 3.4 Conclusions Chapter 4 Numerical Simulations of a Structured Packed Bed 4.1 CFD Model Development 4.2 Results and Discussion 4.3 Conclusions Chapter 5 Development of Macro-scale Model 5.1 Macro-scale Model Description 5.2 Modified Closure Model 5.3 Results of a New Closure Model 5.4 Conclusions Chapter 6 Conclusions Nomenclature References