Fluid Mechanics and Thermodynamics of Turbomachinery

by DIXON

• ISBN13: 9780750678704
• ISBN10: 0750678704
• Edition: 5th
• Format: Paperback
• Copyright: 2005-02-23
• Publisher: Elsevier Science

Summary

The new edition will continue to be of use to engineers in industry and technological establishments, especially as brief reviews are included on many important aspects of Turbomachinery, giving pointers towards more advanced sources of information. For readers looking towards the wider reaches of the subject area, very useful additional reading is referenced in the bibliography. The subject of Turbomachinery is in continual review, and while the basics do not change, research can lead to refinements in popular methods, and new data can emerge. This book has applications for professionals and students in many subsets of the mechanical engineering discipline, with carryover into thermal sciences; which include fluid mechanics, combustion and heat transfer; dynamics and vibrations, as well as structural mechanics and materials engineering.

Table of Contents

PREFACE TO THE FIFTH EDITION	xi
PREFACE TO THE FOURTH EDITION	xiii
PREFACE TO THE THIRD EDITION	xv
ACKNOWLEDGEMENTS	xvii
LIST OF SYMBOLS	xix
1. Introduction: Dimensional Analysis: Similitude	1	(23)
Definition of a turbomachine	1	(2)
Units and dimensions	3	(2)
Dimensional analysis and performance laws	5	(1)
Incompressible fluid analysis	6	(1)
Performance characteristics	7	(1)
Variable geometry turbomachines	8	(2)
Specific speed	10	(2)
Cavitation	12	(3)
Compressible gas flow relations	15	(1)
Compressible fluid analysis	16	(4)
The inherent unsteadiness of the flow within turbomachines	20	(1)
References	21	(1)
Problems	22	(2)
2. Basic Thermodynamics, Fluid Mechanics: Definitions of Efficiency	24	(32)
Introduction	24	(1)
The equation of continuity	24	(1)
The first law of thermodynamics-internal energy	25	(1)
The momentum equation-Newton's second law of motion	26	(4)
The second law of thermodynamics-entropy	30	(1)
Definitions of efficiency	31	(4)
Small stage or polytropic efficiency	35	(7)
Nozzle efficiency	42	(2)
Diffusers	44	(10)
References	54	(1)
Problems	55	(1)
3. Two-dimensional Cascades	56	(38)
Introduction	56	(1)
Cascade nomenclature	57	(1)
Analysis of cascade forces	58	(2)
Energy losses	60	(1)
Lift and drag	60	(2)
Circulation and lift	62	(1)
Efficiency of a compressor cascade	63	(1)
Performance of two-dimensional cascades	64	(1)
The cascade wind tunnel	64	(2)
Cascade test results	66	(3)
Compressor cascade performance	69	(3)
Turbine cascade performance	72	(1)
Compressor cascade correlations	72	(8)
Fan blade design (McKenzie)	80	(3)
Turbine cascade correlation (Ainley and Mathieson)	83	(5)
Comparison of the profile loss in a cascade and in a turbine stage	88	(1)
Optimum space-chord ratio of turbine blades (Zweifel)	89	(1)
References	90	(2)
Problems	92	(2)
4. Axial-flow Turbines: Two-dimensional Theory	94	(51)
Introduction	94	(1)
Velocity diagrams of the axial turbine stage	94	(1)
Thermodynamics of the axial turbine stage	95	(2)
Stage losses and efficiency	97	(1)
Soderberg's correlation	98	(2)
Types of axial turbine design	100	(2)
Stage reaction	102	(2)
Diffusion within blade rows	104	(4)
Choice of reaction and effect on efficiency	108	(1)
Design point efficiency of a turbine stage	109	(4)
Maximum total-to-static efficiency of a reversible turbine stage	113	(2)
Stresses in turbine rotor blades	115	(6)
Turbine flow characteristics	121	(2)
Flow characteristics of a multistage turbine	123	(2)
The Wells turbine	125	(7)
Pitch-controlled blades	132	(7)
References	139	(1)
Problems	140	(5)
5. Axial-flow Compressors and Fans	145	(32)
Introduction	145	(1)
Two-dimensional analysis of the compressor stage	146	(2)
Velocity diagrams of the compressor stage	148	(1)
Thermodynamics of the compressor stage	149	(1)
Stage loss relationships and efficiency	150	(1)
Reaction ratio	151	(1)
Choice of reaction	151	(1)
Stage loading	152	(1)
Simplified off-design performance	153	(2)
Stage pressure rise	155	(1)
Pressure ratio of a multistage compressor	156	(1)
Estimation of compressor stage efficiency	157	(5)
Stall and surge phenomena in compressors	162	(5)
Control of flow instabilities	167	(1)
Axial-low ducted fans	168	(1)
Blade element theory	169	(2)
Blade element efficiency	171	(2)
Lift coefficient of a fan aerofoil	173	(1)
References	173	(1)
Problems	174	(3)
6. Three-dimensional Flows in Axial Turbomachines	177	(31)
Introduction	177	(1)
Theory of radial equilibrium	177	(2)
The indirect problem	179	(8)
The direct problem	187	(1)
Compressible flow through a fixed blade row	188	(1)
Constant specific mass flow	189	(2)
Off-design performance of d stage	191	(1)
Free-vortex turbine stage	192	(2)
Actuator disc approach	194	(4)
Blade row interaction effects	198	(1)
Computer-aided methods of solving the through flow problem	199	(2)
Application of Computational Fluid Dynamics (CFD) to the design of axial turbomachines	201	(1)
Secondary flows	202	(3)
References	205	(1)
Problems	205	(3)
7. Centrifugal Pumps, Fans and Compressors	208	(38)
Introduction	208	(1)
Some definitions	209	(2)
Theoretical analysis of a centrifugal compressor	211	(1)
Inlet casing	212	(1)
Impeller	212	(1)
Conservation of rothalpy	213	(1)
Diffuser	214	(1)
Inlet velocity limitations	214	(1)
Optimum design of a pump inlet	215	(2)
Optimum design of a centrifugal compressor inlet	217	(5)
Slip factor	222	(5)
Head increase of a centrifugal pump	227	(2)
Performance of centrifugal compressors	229	(8)
The diffuser system	237	(3)
Choking in a compressor stage	240	(2)
References	242	(1)
Problems	243	(3)
8. Radial Flow Gas Turbines	246	(44)
Introduction	246	(1)
Types of inward flow radial turbine	247	(2)
Thermodynamics of the 90 deg IFR turbine	249	(2)
Basic design of the rotor	251	(1)
Nominal design point efficiency	252	(4)
Mach number relations	256	(1)
Loss coefficients in 90 deg IFR turbines	257	(1)
Optimum efficiency considerations	258	(5)
Criterion for minimum number of blades	263	(3)
Design considerations for rotor exit	266	(4)
Incidence losses	270	(3)
Significance and application of specific speed	273	(3)
Optimum design selection of 90 deg IFR turbines	276	(2)
Clearance and windage losses	278	(1)
Pressure ratio limits of the 90 deg IFR turbine	279	(1)
Cooled 90 deg IFR turbines	280	(2)
A radial turbine for wave energy conversion	282	(3)
References	285	(2)
Problems	287	(3)
9. Hydraulic Turbines	290	(33)
Introduction	290	(1)
Hydraulic turbines	291	(3)
The Pelton turbine	294	(9)
Reaction turbines	303	(1)
The Francis turbine	304	(6)
The Kaplan turbine	310	(3)
Effect of size on turbomachine efficiency	313	(2)
Cavitation	315	(4)
Application of CFD to the design of hydraulic turbines	319	(1)
References	320	(1)
Problems	320	(3)
10. Wind Turbines	323	(54)
Introduction	323	(2)
Types of wind turbine	325	(4)
Growth of wind power capacity and cost	329	(1)
Outline of the theory	330	(1)
Actuator disc approach	330	(7)
Estimating the power output	337	(1)
Power output range	337	(1)
Blade element theory	338	(8)
The blade element momentum method	346	(7)
Rotor configurations	353	(7)
The power output at optimum conditions	360	(1)
HAWT blade selection criteria	361	(2)
Developments in blade manufacture	363	(1)
Control methods (starting, modulating and stopping)	364	(5)
Made tip shapes	369	(1)
Performance testing	370	(1)
Performance prediction codes	370	(1)
Comparison of theory with experimental data	371	(1)
Peak and post-peak power predictions	371	(2)
Environmental considerations	373	(1)
References	374	(3)
Bibliography	377	(1)
Appendix 1. Conversion of British and US Units to SI Units	378	(1)
Appendix 2. Answers to Problems	379	(4)
Index	383