This book presents the results of scientific research performed over the past two decades by the authors. The book discusses some issues of separated laminar flows that are of great practical interest for the development of new technologies using microchannel flows, where separation zones can form. Of particular interest is the complex mechanism of flow separation with superimposed high external turbulence. The challenges of finding the optimal location for the cavities and fins on heat exchange surfaces are also considered. This is an important fundamental and practical problem when creating new schemes of efficient heat exchangers in various power plants. A wide class of problems of turbulent flow in tubes with flow separation is considered. These data will be useful in engineering estimates of the thermal–hydraulic efficiency of various heat transfer intensifiers. This book focuses on the analysis of thermal characteristics of separated flows, as well as the possibility of controlling the intensity of heat exchange processes, from the point of view of both their intensification and their suppression.
Author(s): Viktor I. Terekhov, Aleksey Yu. Dyachenko, Yaroslav J. Smulsky, Tatyana V. Bogatko, Nadezhda I. Yarygina
Series: Heat and Mass Transfer
Publisher: Springer
Year: 2022
Language: English
Pages: 234
City: Cham
Preface
References
Contents
Nomenclature
Indices
1 The State of the Art in Research into the Hydrodynamics and Heat Transfer of Separated Flows
1.1 Introduction
1.2 Contemporary Simulation Level of Separated Flows
1.3 Recent Advances in the Experimental Study of Separated Flows
References
2 Separation of a Laminar Boundary Layer
2.1 Introduction
2.2 Flow and Heat Transfer in Laminar Flow Around 2D Obstacles
2.3 Influence of Dynamic and Thermal Prehistory on the Development of Laminar Separated Flow Behind a Step and Cavity
2.4 Flow Separation and Reattachment at a Permeable Surface
References
3 Features of the Development of a Turbulent Separated Flow Behind a Step and a Rib at a Changed External Turbulence
3.1 Experimental Research Methods and Facilities
3.1.1 Aerodynamic Tube and Models for Studying the Flow Behind a Single Rib and Step
3.1.2 Model of Streamlining for a Rectangular Cavity with Inclined Side Walls
3.1.3 Experimental Set-Up Used to Measure an Inclined Rib and Rib System
3.1.4 Main Measuring Instrumentation and Data Processing Methods
3.1.5 Tracer Visualisation Method
3.2 Heat Transfer in a Separated Flow Behind a Backward-Facing Step Under Natural and Increased Turbulence of the Main Flow
3.2.1 Separated Flow Dynamics Behind Steps of Different Heights
3.2.2 Heat Transfer in the Separated Flow Behind a Step
3.3 Flow Separation Behind a Step with an Inclined Wall
3.4 Effect of External Turbulence on the Dynamic Characteristics and Heat Transfer Enhancement Behind a Single Rib
3.5 Effect of High, Closely Spaced Ribs on Heat Transfer
References
4 Flow and Heat Transfer Behind a Rib Installed at an Angle to the Flow
4.1 Development of a Separated Flow Behind a Rib for Varying Incidence Angle
4.2 Heat Transfer in a System of Ribs Located at an Angle to the Flow
4.2.1 Flow Around the Rib System for Turbulised Flow
References
5 Flow and Heat Transfer in Cavities
5.1 Three-Dimensional Structure of the Flow in Cavities
5.2 Cavities with Inclined Walls: Features of Heat Transfer
5.3 Effect of the Degree of Incoming Flow Turbulence on Heat Transfer in Cavities
5.4 Passive Control of Heat Transfer Inside Cavities
References
6 Effect of Separated Zones on Vortex Formation and Turbulent Heat Transfer in a Round Pipe
6.1 Effect of Dynamic Prehistory on Heat Transfer in a Separated Flow
6.2 Effect of Thermal Prehistory on Heat Transfer at Flow Separation
6.3 Separated Flow Structure and Heat Transfer Depending on the Ratio of Pipe Expansion
6.4 Enhancement of Heat Transfer When Streamlining Obstacles of Various Shapes
6.5 Thermohydraulic Efficiency of a Diaphragm in a Pipe
6.6 Separated Flow in an Axisymmetric Diffuser After Sudden Pipe Expansion
References
7 Flow Separation in the Field of the Longitudinal Pressure Gradient
7.1 Introduction
7.2 Numerical Study of the Separated Flow Development in a Longitudinal Pressure Gradient Field
7.3 Experimental Installation and Technique
7.4 Experimental Results
7.5 Analysis of Results and Discussion
References
8 Interference of Separated Flows at Various Scales
8.1 Methods of Separated Flow Control
8.2 Experimental Set-Up
8.3 Flow Dynamics
8.4 Heat Transfer Under Interference of Separated Flows
References
