- Артикул:00-01050467
- Автор: Thomas Kamps
- ISBN: 1-900371-91-X
- Обложка: Мягкая обложка
- Издательство: TRAPLET (все книги издательства)
- Город: UK
- Страниц: 111
- Год: 2005
- Вес: 279 г
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Книга на английском языке.
The idea of the gas turbine can be traced back to a patent filed by the Frenchman Guillaume in the year 1921, and is therefore quite old. However, it was many years before it proved possible to put the principle into practice in the form of the jet engine. In the late nineteen-thirties Hans-Joachim Pabst von Ohain and Sir Frank Whittle succeeded virtually simultaneously in applying the principle to construct a working engine.
It has taken us modellers a great deal more time to bring the idea to fruition. Too complex and too much trouble - that was always the verdict. Now and then rumours of successful model-scale gas turbines filtered to the outside world, but in many cases the engines were only capable of running when their constructor was dreaming.
As a result we in the model world were truly astonished to learn that amateurs had actually managed to produce working jet engines using relatively straightforward methods. The key to success lay not so much in high-level precision manufacture, but in simplicity and careful matching of individual components. As Kurt Schreckling has shown with his engines, if the design is right, then it is possible to use a wooden compressor wheel and still achieve a thrust: weight ratio comparable to that of a full-size aircraft jet engine.
However how do we go about designing a working jet engine? What special characteristics have to be considered? How do these engines work, anyway? This book attempts to answer these questions and many others, with the overall aim of helping you to understand this new type of engine. As such it is really aimed at the beginner to jets, but don't give up if you are already familiar with that special kerosene fragrance; you will still find a few useful ideas here even if you already have some experience of jet engines.
Contents
Introduction
How do jet engines work?
The open gas turbine process
The question of efficiency
The development history of the jet engine
It all started in the 1930s
The robust jet engines of the 1950s
Prototypes for model jet engines
Drone engines and APUs (Auxiliary Power Units)
Hyper-charging
Early model jet engines
Max Dreber’s Baby Mamba
The Swedish PAL system and its successor Turbomin
Kurt Schreckling’s FD series
Turborec T240 from JPX
Model jet engines to date
1.1. The J-450 by Sophia Precision
1.2. AMT - Advanced Micro Turbines
1.3. The KJ 66
1.4. The Artes-Turbines
1.5. The Jet Cat model turbine
1.6. The Smallest Engines
1.7. Turboprop and Shaft Power Engines
Chapter 1 The Component Parts of a Model Jet Engine
Special features of small gas turbines
Combustion
Rotor design
Gap losses
Conclusions relating to the model jet engine
The compressor
The radial compressor
Typical calculation for a radial compressor
Turbocharger compressors
The compressor characteristic graph
Diffuser wheels
Example of calculating the diffuser system
The surge limit
The axial compressor
Example calculation: axial compressor stage
The combustion chamber
Design and function of the combustion chamber
The question of fuel
Mixture formation
The significance of re-circulation zones
Turbine stage and exhaust cone
How the turbine stage works
Axial turbine or radial turbine?
Design and vector diagrams of an axial turbine
Typical calculation: turbine design for a model jet engine
Centrifugal loads on the rotor wheel
The exhaust cone
The shaft of a model jet engine
Calculating the critical rotational speed
Chapter 2 A Home-made Model Jet Engine
Introduction
What tools Will I need?
Selecting materials
The compressor wheel
Constructing the engine
Making the shaft
The sbaft tunnel and hearing
The turbine nozzle guide vane system
The turbine wheel
Balancing
The compressor system
The combustion chamber
The housing
Assembling the components
Running the engine for the first time
Bench running stand for kerosene operation
Pumps, tanks and other equipment
Running the engine on kerosene
General instructions for different compressors
Optimising the performance of model jet engines
Chapter 3 The Engine in Practice
Safety: the First Commandment
Measuring the engine's performance data
Rotational speed pressure and thrust
Measurements for the advanced operator
Using jet engines in model aircraft
Fundamental special features
How jet engines behave in flight
Air intake design
Cooling the fuselage
Auxiliary Equipment
Particular problems encountered in jet-powered flight
Thrust delay
Gyroscopic effects
Fault-finding
What the sound of the engine tens you
Exceeding the pressure limit (surging)
A standard problem
Excessively high exhaust gas temperature
Maintenance and repair
Checking the hearings
Cleaning the engine
Bibliography
Notes
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