Some 200 years after the original invention, internal design of
a Stirling engine has come to be considered a specialist task,
calling for extensive experience and for access to sophisticated
computer modelling. The low parts-count of the type is negated by
the complexity of the gas processes by which heat is converted to
work. Design is perceived as problematic largely because those
interactions are neither intuitively evident, nor capable of being
made visible by laboratory experiment. There can be little doubt
that the situation stands in the way of wider application of this
elegant concept.
Stirling Cycle Engines re-visits the design challenge,
doing so in three stages. Firstly, unrealistic expectations are
dispelled: chasing the Carnot efficiency is a guarantee of
disappointment, since the Stirling engine has no such pretentions.
Secondly, no matter how complex the gas processes, they embody a
degree of intrinsic similarity from engine to engine. Suitably
exploited, this means that a single computation serves for an
infinite number of design conditions. Thirdly, guidelines resulting
from the new approach are condensed to high-resolution design
charts - nomograms.
Appropriately designed, the Stirling engine promises high
thermal efficiency, quiet operation and the ability to operate from
a wide range of heat sources. Stirling Cycle Engines offers
tools for expediting feasibility studies and for easing the task of
designing for a novel application.
Key features:
* Expectations are re-set to realistic goals.
* The formulation throughout highlights what the thermodynamic
processes of different engines have in common rather than what
distinguishes them.
* Design by scaling is extended, corroborated, reduced to the use
of charts and fully Illustrated.
* Results of extensive computer modelling are condensed down to
high-resolution Nomograms.
* Worked examples feature throughout.
Prime movers (and coolers) operating on the Stirling cycle are
of increasing interest to industry, the military (stealth
submarines) and space agencies. Stirling Cycle Engines fills
a gap in the technical literature and is a comprehensive manual for
researchers and practitioners. In particular, it will support
effort world-wide to exploit potential for such applications as
small-scale CHP (combined heat and power), solar energy conversion
and utilization of low-grade heat.
Autorentext
Allan J. Organ, formerly of University of Cambridge, UK - now retired.
Before his retirement Allan J. Organ was a lecturer at the University of Cambridge, specializing in thermodynamics and gas dynamics of the Stirling cycle machine and regenerator.He has studied stirling cycle machines throughout his career and is a leading authority in the field. As well as his teaching work, he has acted as a consultant in this area for numerous companies including Hymatic Ltd, Premier Precision Ltd, Lucas Aerospace Ltd, British Aerospace PLC, as well as for the Ministry of Defense.
Zusammenfassung
Some 200 years after the original invention, internal design of a Stirling engine has come to be considered a specialist task, calling for extensive experience and for access to sophisticated computer modelling. The low parts-count of the type is negated by the complexity of the gas processes by which heat is converted to work. Design is perceived as problematic largely because those interactions are neither intuitively evident, nor capable of being made visible by laboratory experiment. There can be little doubt that the situation stands in the way of wider application of this elegant concept.
Stirling Cycle Engines re-visits the design challenge, doing so in three stages. Firstly, unrealistic expectations are dispelled: chasing the Carnot efficiency is a guarantee of disappointment, since the Stirling engine has no such pretentions. Secondly, no matter how complex the gas processes, they embody a degree of intrinsic similarity from engine to engine. Suitably exploited, this means that a single computation serves for an infinite number of design conditions. Thirdly, guidelines resulting from the new approach are condensed to high-resolution design charts nomograms.
Appropriately designed, the Stirling engine promises high thermal efficiency, quiet operation and the ability to operate from a wide range of heat sources. Stirling Cycle Engines offers tools for expediting feasibility studies and for easing the task of designing for a novel application.
Key features:
- Expectations are re-set to realistic goals.
- The formulation throughout highlights what the thermodynamic processes of different engines have in common rather than what distinguishes them.
- Design by scaling is extended, corroborated, reduced to the use of charts and fully Illustrated.
- Results of extensive computer modelling are condensed down to high-resolution Nomograms.
- Worked examples feature throughout.
Prime movers (and coolers) operating on the Stirling cycle are of increasing interest to industry, the military (stealth submarines) and space agencies. Stirling Cycle Engines fills a gap in the technical literature and is a comprehensive manual for researchers and practitioners. In particular, it will support effort world-wide to exploit potential for such applications as small-scale CHP (combined heat and power), solar energy conversion and utilization of low-grade heat.
Inhalt
About the Author xi
Foreword xiii
Preface xvii
Notation xix
1 Stirling myth - and Stirling reality 1
1.1 Expectation 1
1.2 Myth by myth 2
1.3 ...and some heresy 7
1.4 Why this crusade? 7
2 R eflexions sur le cicle de Carnot 9
2.1 Background 9
2.2 Carnot re-visited 10
2.3 Isothermal cylinder 11
2.4 Specimen solutions 14
2.5 'Realistic' Carnot cycle 16
2.6 'Equivalent' polytropic index 16
2.7 R eflexions 17
3 What Carnot efficiency? 19
3.1 Epitaph to orthodoxy 19
3.2 Putting Carnot to work 19
3.3 Mean cycle temperature difference, eTx = T - Tw 20
3.4 Net internal loss by inference 21
3.5 Why no p-V diagram for the 'ideal' Stirling cycle? 23
3.6 The way forward 23
4 Equivalence conditions for volume variations 25
4.1 Kinematic configuration 25
4.2 'Additional' dead space 27
4.3 Net swept volume 32
5 The optimum versus optimization 33
5.1 An engine from Turkey rocks the boat 33
5.2 ...and an engine from Duxford 34
5.3 Schmidt on Schmidt 36
5.4 Crank-slider mechanism again 41
5.5 Implications for engine design in general 42
6 Steady-flow heat transfer correlations 45
6.1 Turbulent - or turbulent? 45
6.2 Eddy dispersion time 47
6.3 Contribution from 'inverse modelling' 48
6.4 Contribution from Scaling 50
6.5 What turbulence level? 52
7 A question of adiabaticity 55
7.1 Data 55
7.2 The Archibald test 55
7.3 A contribution from Newton 56
7.4 Variable-volume space 57
7.5 D esax e 59
7.6 Thermal diffusion - axi-symmetric case 60
7.7 Convection versus diffusion 61
7.8 Bridging the gap 61
7.9 Interim deductions 64
8 More adiabaticity 65
8.1 'Harmful' dead space 65
8.2 'Equivalent' steady-flow closed-cycle regenerative engine 66
8.3 'Equivalence' 68
8.4 Simulated performance 68
8.5 Conclusions 70
8.6 Solution algorithm 71
9 Dynamic Similarity 73
9.1 D…