Thesis can be edited
Very easy to understandAbstract Thesis EFFECT OF CASING ROTATION ON THE PERFORMANCE OF DIFFUSER
A diffuser is a device for converting the kinetic energy of an incoming fluid into pressure efficiently. The task of a diffuser is to decelerate the flow and to regain total pressure. As the flow proceeds through the diffuser there is continuous retardation of the flow resulting in conversion of kinetic energy into pressure energy. Such a process is termed as diffusion. Diffuser forms an important part in flow machinery and structures.
The present study involves the CFD analysis of effect of casing rotation on annular diffuser performance using Fluent.. CFD analysis is conducted without swirl in an annular diffuser with the inlet velocity profile obtained experimentally. The variation in parameters i.e. Axial Velocity, Radial velocity, Swirl Velocity and Pressure Co-efficient, in the flow through annular diffuser studied along the various sections of the diffuser and also at various casing rotation speeds for a diffuser of constant length and Area Ratio. The velocity and pressure variations are calculated for different casing rotations. The various values of casing RPM studied are 200, 400, 600, 800, 1000, 1200, 1400, 1600, 1800, 2000, 2200, 2400, 2600, 2800, 3000 and 3200 rpm. In order to predict the performance characteristics of an annular diffuser, the Geometric parameters of annular diffuser are calculated for constant area ratio and length. The data is obtained with respect to a inlet velocity of 60 m/s. It is assumed that the flow is exhausted to atmosphere, so pressure at exit of diffuser is assumed to be atmospheric. The results are depicted in the form of variation of pressure coefficient along the diffuser length at different casing rotation. and velocity (axial velocity, radial velocity, swirl velocity) variation from hub to casing (along the diffuser height). These graphs are at no swirl condition and also variation of pressure coefficient with respect to casing rotation at no swirl condition. The pressure recovery coefficient at hub and casing side has been worked out.
 |
| Thesis EFFECT OF CASING ROTATION ON THE PERFORMANCE OF DIFFUSER |
CONTENTS
Candidate’s Declaration
Acknowledgement
Abstract
Contents
Lists of Figures
Nomenclature
1. INTRODUCTION
1.1 Axial Diffuser
1.2 Radial Diffuser
1.3 Curved Wall Diffuser
1.4 Annular Diffuser
1.5 Principle of Diffuser Design
1.6 Diffuser Performance Parameters
1.6.1 Geometric Parameter
1.6.2 Aerodynamic Blockage
1.6.3 Reynolds number
1.6.4 Inlet Mach number
1.6.5 Inlet Turbulence intensity
1.6.6 Effect of Compressibility
1.6.7 Effect of Compressibility on Wall Design
1.7 Design Performance Parameters
1.7.1 Static Pressure Recovery Coefficient
1.7.2 Diffuser Effectiveness
1.7.3 Total Pressure Loss Coefficient
1.7.4 Ideal Pressure Recovery
1.8 Swirling Flow
1.8.1 Physics of Swirling and Rotating Flows
1.8.2 Method of swirl generation
1.9 Motivation
2. LITERATURE REVIEW
2.1 Effect of Geometric Parameters
2.1.1 Passage Divergence and Length
2.1.2 Wall Contouring
2.2 Effects of Flow Parameters
2.2.1 Aerodynamic Blockage
2.2.2 Inlet Swirl
2.2.3 Inlet Turbulence
2.2.4 Mach number Influence
2.2.5 Reynolds Number Influence
2.2.6 Boundary Layer Parameter
2.2.7 Blowing and Injection
3. CFD ANALYSIS
3.1 Why Use CFD for analysis
3.2 Program Capabilities
3.3 Planning CFD Analysis
3.3.1 Definition of the Modeling Goals
3.3.2 Grid Generation and its Independence
3.3.3 Choice of the Computational Model
3.3.4 Choice of Physical Models
3.3.5 Determination of the Solution Procedure
3.4 Discretization of partial equations
3.5 Convergence Criteria
3.6 Simulation Procedure
3.7 FLUENT Applications
4. FLOW FIELD NUMERICAL MODELLING
4.1 Conservation principles
4.1.1 The Mass Conservation Equation
4.1.2 Momentum Conservation Equations
4.2 Turbulence Modelling
4.2.1 Choosing a Turbulence Model
4.2.2 FLUENT Turbulence models
4.3 The Standard, RNG, and Realizable k- ε Models
4.3.1 The Standard k-ε Model
4.3.2 Transport Equations for the Standard k-ε Model
4.3.3 Modeling the Turbulent Viscosity
4.3.4 The Model Constants
4.3.5 The RNG k-ε Model
4.3.6 Transport Equations for the RNG k-ε Model
4.3.7 The Realizable k-ε Model
4.3.8 Turbulence Modeling in Swirling Flows
4.3.9 Modeling Axisymmetric Flows with Swirl or Rotation
4.3.10 Modeling the Turbulent Viscosity
4.3.11 Model Constants
4.3.12 Turbulence Modeling in Swirling Flows
4.3.13 Modeling Axisymmetric Flows with Swirl or Rotation
5 RESULT AND DISCUSSION
6 RECOMMENDATIONS FOR FUTURE WORK
REFERENCES
FIGURES
APPENDIX
