| dc.description.abstract | Radial gas turbines engines have established prominence in the field of small turbomachinery
because of their simplicity, relatively high performance and installation
features. Thus they have been used in a variety of applications such as generator sets,
small auxiliary power units (APu), air conditioning of aircraft cabins and hybrid
electric vehicles turbines.
The current research describes the design, manufacturing, construction and testing a
radial type small gas turbine. The aim was to design and build the engine to drive
directly a high-speed permanent magnet alternator running at 60000 rpmand
developing a maximum of 60 W. This direct coupling arrangement produces a
portable, light, compact, reliable and environment friendly power generator. These
features make the generator set very attractive to use in many applications including
emergency power generation for hospitals, in areas of natural disasters such as floods
and earthquakes, in remote areas that cannot be served from the national grid, oil rigs,
and in confined places of limited spaces.
It is important to recognize that the design of the main components, that is, the inward
flow radial UFR turbines, the centrifugal compressor and the combustion chamber
involve consideration of aero-dynamics, thermodynamics, fluid mechanics, stress
analysis, vibration analysis, selection of bearings, selection of suitable materials and
the requirements for manufacturing. These considerations are all inter-linked and a
procedure has been followed to reach an optimum design.
This research was divided into three phases: phase I dealt with the complete design of
the inward radial turbine, the centrifugal compressor, the power transmission shaft, the
selection of combustion chamber and the bearing housing including the selection of
bearings. Phase 2 dealt with mechanical consideration of the rotating components that
is stress, thermal and vibration analyses of the turbine rotor, the impeller and the
rotating shaft, respectively. Also it dealt with the selection of a suitable fuel and oil
lubrication systems and a suitable starting system.
Phase 3 dealt with the manufacturing of the gas turbine components, balancing the
rotating components, assembling the engine and finally commissioning and then
testing the engine.
The current work in this thesis has put the light on a new design methodology on
determining the optimum principal dimensions of the rotor and the impeller. This
method, also, has defined the optimum number of blades and the axial length of the
rotor and the impeller. Mathematical models linking the performance parameters and
the design variables for the turbine and the compressor have been developed to assist
in carrying out parametric studies to study the influence of the design parameters on
the performance and on each other. Also, a new graphical matching procedure has
been developed for the gas turbine components. This technique can serve as a valuable
tool to determine the operating range and the engine running line. Furthermore, it
would decide whether the gas turbine engine operates in a region of satisfactory
compressor and turbine efficiencies | en_US |
