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Cover -- Title Page -- Copyright -- Contents -- Preface -- Acknowledgments -- List of Acronyms -- List of Symbols -- Chapter 1 Introduction -- 1.1 What Is a Mixed‐flow Pump? -- 1.2 Types of Mixed‐flow Pumps -- 1.3 Agricultural and Industrial Applications of Pumps -- 1.4 Summary -- References -- Chapter 2 Basic Concepts and Theory of Mixed‐flow Pumps -- 2.1 Basic Flow and Performance Parameters -- 2.1.1 Volume Flow Q -- 2.1.2 Head H -- 2.1.3 Speed n -- 2.1.4 NPSH -- 2.1.5 Power and Efficiency -- 2.2 Typical Type of Flows in the Mixed‐flow Pumps -- 2.2.1 Tip Leakage Flow -- 2.2.2 Rotating Stall -- 2.2.3 Cavitation Flow -- 2.3 Summary -- Nomenclature -- References -- Chapter 3 Brief Review of Computational Fluid Dynamics -- 3.1 CFD as a Flow Simulation Tool -- 3.2 Geometry Modeling -- 3.3 Mesh Generation -- 3.4 Governing Equations of Fluid Dynamics -- 3.5 Simulation of Turbulent Flows -- 3.6 Turbulence Modeling -- 3.6.1 Standard k− Model -- 3.6.2 Shear Stress Transport (SST) k−ω Model -- 3.6.3 Spalart-Allmaras (SA) Model -- 3.6.4 Wray-Agarwal (WA) Model -- 3.6.5 Detached Eddy Simulation Model -- 3.6.6 Large Eddy Simulation (LES) Model -- 3.7 Numerical Solution Algorithms -- 3.7.1 Numerical Discretization Method -- 3.7.2 Flow Field Solution Method -- 3.8 Near‐wall Flow Treatment -- 3.9 Boundary Conditions -- 3.10 Uncertainty Analysis -- 3.11 Summary -- Nomenclature -- References -- Chapter 4 Pump Performance Analysis Methods -- 4.1 Entropy Production Analysis -- 4.2 Vortex Identification and Vorticity Transport -- 4.2.1 Vortex Identification -- 4.2.1.1 Q‐Criterion -- 4.2.1.2 Regularized Helicity Method -- 4.2.2 Vorticity Transport -- 4.3 Transient Flow Analysis Using the Wavelet Method -- 4.4 Summary -- References -- Chapter 5 Experimental Methods, Data, and Analysis -- 5.1 External Characteristics Experiment -- 5.1.1 Test Equipment and Instruments.
5.1.2 Test Method for External Flow Characteristics of the Pump -- 5.1.3 Uncertainty Analysis of the Experiment -- 5.1.4 Test Results for External Flow Characteristics of the Pump -- 5.2 Experiment for Measuring Pressure Fluctuations -- 5.2.1 Experimental Procedure -- 5.2.2 Wavelet Transform of Pressure Pulsation for Different Tip Clearances -- 5.2.3 Coherence of Pressure Pulsation for Different Tip Clearances -- 5.3 PIV Measurement -- 5.3.1 Basic Principles of PIV Measurement -- 5.3.2 The PIV Image Processing System -- 5.3.3 PIV Measurement Criteria -- 5.3.4 PIV Testing Instruments and System -- 5.3.5 PIV Test Method -- 5.3.5.1 Selection and Addition of Tracer Particles -- 5.3.5.2 Calibration Apparatus -- 5.3.5.3 Lens Group, Camera Fixing, and Adjustment -- 5.3.5.4 Shooting Section of the Dynamic and Static Interference Flow Field -- 5.3.5.5 Positions of the Equipment and the Shooting Sections -- 5.3.6 Analysis of the PIV Results for the Flow Field of the Front Shaft Section of the Impeller Inlet -- 5.3.7 Relative Velocity Distribution at the Monitoring Lines in Different Phases at the Impeller Inlet and Outlet Under the Part‐loading Conditions -- 5.4 Orbit of Shaft Centerline -- 5.4.1 Measurement of the Spindle Axis Trajectory -- 5.4.2 Characteristics of Vibrations of the Shaft System -- 5.4.3 Original Axis Trajectory Diagram and Time‐domain Diagram -- 5.4.4 Decomposition and Refinement of the Rotor Axis‐centered Trajectory -- 5.4.5 Flow Spectrum Analysis -- 5.4.6 Effect of the Rotor-Stator Interaction on the Shaft Vibration -- 5.5 Summary -- References -- Chapter 6 CFD Simulations of a Mixed‐flow Pump Using Various Turbulence Models -- 6.1 Comparison and Validation of Numerical Results from Three Two‐equation Turbulence Models (SST k-ω, k-ω, and Standard k- ) -- 6.1.1 Comparison of Energy Performance.
6.1.2 Comparison of CFD Results with Phase‐Averaged Velocity Predictions from PIV -- 6.1.3 Flow Field Under Incipient Stall Condition -- 6.2 Application of Wray-Agarwal (WA) One‐Equation Turbulence Model -- 6.2.1 Energy Performance Comparison -- 6.2.2 Comparison of the Flow Field in the Rotor-Stator Interaction Zone Using Different Turbulence Models -- 6.2.3 Comparison of Eddy Viscosity Variable R & -- equals -- k/ω in the Pump Using the Four Turbulence Models (SST k-ω, k-ω, k- , and WA) -- 6.3 Summary -- References -- Chapter 7 Tip Leakage Flow In a Mixed‐flow Pump -- 7.1 Energy Characteristics -- 7.1.1 Comparison of Energy Performance of the Pump for Various Tip Clearances -- 7.1.2 Distribution of the Total Entropy Production in the Pump for Various Tip Clearances -- 7.1.3 Local Entropy Production Rate in the Impeller -- 7.1.4 Local Entropy Production Rate in the Guide Vane -- 7.2 Flow Structures -- 7.2.1 Vortex Patterns in the Blade Rim Region of the Pump for Various Tip Clearances -- 7.2.2 Tip Leakage Vortex (TLV) Intensity and the Vortex Core Distribution -- 7.3 Unsteady Flow Characteristics -- 7.3.1 Time‐domain Analysis of the Pressure Pulsations -- 7.3.2 Frequency‐domain Analysis of the Pressure Pulsation -- 7.4 Transient Flow Field Due to Rotor-Stator Interaction (RSI) -- 7.4.1 Flow Fields Before the RSI Zone -- 7.4.2 Flow Fields in the RSI Zone -- 7.4.3 Pressure Fluctuation in Partial‐loading Conditions -- 7.4.3.1 Time‐domain Analysis -- 7.4.3.2 Frequency‐domain Analysis -- 7.5 Summary -- References -- Chapter 8 Rotational Stall in a Mixed‐flow Pump -- 8.1 Energy Characteristics -- 8.1.1 Energy Performance of the Pump Along the Axial Flow Direction -- 8.1.2 Energy Loss Mechanism Under Stall Condition -- 8.1.2.1 Theoretical Analysis of Head Drop in Saddle Area -- 8.1.2.2 Flow Distribution in Each Channel.
8.1.2.3 Region of the Maximum Energy Loss in the Impeller -- 8.2 Flow Structure in the Critical and Deep Stall Conditions -- 8.2.1 Flow Structure in the Impeller in the Design, Critical, and Deep Stall Conditions -- 8.2.2 Key Factors Causing the Energy Loss -- 8.2.2.1 Influence of the Inlet Swirl on Energy Loss -- 8.2.2.2 Influence of the Tip Leakage Vortex on the Energy Loss -- 8.2.2.3 Influence of the Stall Vortex on the Energy Loss -- 8.2.2.4 Influence of the Backflow Vortex on the Energy Loss -- 8.3 Effect of the Tip Clearance on the Rotating Stall -- 8.3.1 TLF Patterns and TLV Core Trajectories for Different Tip Clearances -- 8.3.2 Influence of the Inlet Swirl Flow and the TLV Characteristics -- 8.3.3 Distorted Flow in the Blade Rim Region Below the TLV -- 8.4 Propagation Characteristics of Rotating Stall -- 8.4.1 Pressure Fluctuation Characteristics of the Flow in the Stall Condition -- 8.4.2 Correlation Between the Transient Flow Field and the Energy Characteristics of the Pump -- 8.4.3 Morphology and Propagation Mechanism of Rotating Stall -- 8.5 Inducements for the Circumferential Propagation of the Rotating Stall -- 8.6 A Stall Prediction Model of the Mixed‐flow Pump -- 8.6.1 Flow Characteristics During the Process of the Stall for Impellers with Different Blade Numbers -- 8.6.2 Quantitative Analysis of the Suction Surface Parameters of the Stalled Blades -- 8.6.3 The Pressure and Velocity Distributions on the Suction Side of the Blade of the Impellers with Various Blade Numbers -- 8.6.4 A Simple Stall Prediction Model -- 8.7 Summary -- References -- Chapter 9 Passive Suppression of Rotating Stall in Mixed‐flow Pump -- 9.1 Introduction -- 9.2 Impeller Blade Rim Structures for Stall Suppression -- 9.2.1 Geometries of Various Blade Rim Structures -- 9.2.2 Results of Numerical Calculations for Various Blade Rim Structures.
9.2.2.1 Comparison of the External Characteristics of the Pump for Various Blade Rim Structures -- 9.2.2.2 Influence of Blade Rim Geometry on the Flow Field in Rim Clearance Region -- 9.2.2.3 Influence of Blade Rim Structure on the Inlet Flow Angle of the Impeller -- 9.2.2.4 Distribution of Vortex Structures in the Impeller with Different Rim Structures -- 9.3 Influence of the Circumferential Spokes -- 9.3.1 The Structure of "O‐Spoke" -- 9.3.2 Analysis of Results -- 9.3.2.1 External Characteristics Analysis -- 9.3.2.2 Analysis of the Flow Field in Various Cross‐Sectional Areas of the Pump -- 9.3.2.3 Flow Field Analysis in the Impeller Shroud Region -- 9.3.2.4 Energy Performance Analysis Based on the Entropy Generation Theory -- 9.3.2.5 Analysis of the Blade Height Section Flow Field -- 9.4 Summary -- References -- Chapter 10 Cavitation in a Mixed‐flow Pump -- 10.1 Numerical Model -- 10.1.1 Cavitation Model -- 10.1.2 Numerical Simulation Setup and Boundary Conditions -- 10.1.3 Cavitation Test Procedure -- 10.1.4 Comparison of Numerical Simulations and Cavitation Test Results -- 10.2 Flow Characteristics of the Mixed‐flow Pump Under Cavitation -- 10.2.1 Blade Surface Load Distribution -- 10.2.2 Trajectory of TLV for Different Values of NPSHa -- 10.2.3 Evolution of the Transient Flow Trajectory of the TLV and Tip Cavitation Flow -- 10.3 Analysis of Cavitation Energy Characteristics -- 10.3.1 Analysis of Pump Energy Characteristics -- 10.3.2 Analysis of Energy Loss in the End Wall Region of the Pump Caused by the TLV‐Induced Cavitation -- 10.3.3 Effect of Cavitation on the Output Power of the Pump -- 10.3.4 Effect of Cavitation on Energy Losses in the Pump -- 10.4 Summary -- References -- Chapter 11 Analysis of the Vortex Dynamics Characteristics in the Tip Region of the Mixed‐flow Pump Under Cavitation.
11.1 The Tip Leakage Flow Characteristics Under Cavitation.
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Mixed-Flow Pumps : Modeling, Simulation, and Measurements
