Abstract:
This thesis first provided strategic recommendations for the research sponsor, Rolls-
Royce plc (RR) and then applied optical diagnostics to measure aero gas turbine fuel
spray properties in order to predict Oxides of Nitrogen (NOx) emissions and
combustion instability. Analysis of the large civil aero engine sector suggested possible
courses of action for RR to protect itself from short-term market volatilities and also
prepare for three long term changes in strategic operating context: air traffic growth;
tighter United Nations enforced aero engine combustion emissions legislation and entry
of civil aviation into the European Union Emissions Trading Scheme. A collaborative
game theoretic approach was explored during the pre-competitive, pre-technology,
capability acquisition aero engine design phase on unproven future technologies to
reduce R&D expenditures, development times and the costs of failure. Lean
Prevapourised Premixed combustion demands excellent spray atomisation quality to
sustain combustion efficiency, stability and to minimise pollutants. Post development
of an improved procedure to calibrate laser signals, methodology to predict NOx and
technique to optimise rig operating conditions that minimised fractional discrepancies in
two-phase flow behaviour with corresponding engine conditions, this thesis applied
quantitative Planar Laser Induced Fluorescence (PLIF) and Laser Sheet Dropsizing
(LSD) to measure the fuel placement and dropsize distribution in the near nozzle
regions of RR liquid-fuelled hybrid, airblast and pressure-swirl sprays. Measurements
were made under non-combusting, low pressure conditions and results were processed
to identify fuel injector designs that exhibited low emissions and high stability for the
Affordable Near Term Low Emissions (ANTLE) and Instability Control of Low
Emission Aero-Engine Combustors (ICLEAC) engine demonstrator programmes.
Results also provided validation data and boundary conditions for spray computational
codes. Research findings will improve RR core competencies in fuel injection research
to accelerate the development and deployment of low emissions aero engine technology.
