Abstract:
The research study focuses on the idea of simulation of an Integrated Full
Electric Propulsion System. The simulation required the development of a gas
turbine performance model that could predict the dynamic behaviour of the
engine in response to a fluctuation of electrical load. For this purposes it was
necessary to evaluate the thermodynamic working process of the gas turbine
and a computer code was created. A design point model written in FORTRAN
77 had been transformed to predict the steady state and transient
performance of a two-shaft gas turbine and single shaft gas turbine. The
models were based on the thermodynamic law of conservation of mass. For
the model of the two-shaft gas turbine controls system equations had been
derived from off-design analysis and implemented as handles for operation.
Both the models were then transformed to a direct link library for the
SIMULINK® package. They were further implemented with an electrical
network model to form a high-fidelity prime mover-electrical networkpropulsion
drive interface with which a complete systems analysis was done
to understand the response of the three systems in parallel.
In a second part heat exchanger modelling had to be performed so as to
create a gas turbine model of an intercooled-recuperated engine. This was
done for the steady state behaviour and sizing problem of heat exchangers.
The models were run parallel to the steady state code as a validation
exercise. Due to time and project restraints the complete incorporation of the
models with the gas turbine code was not performed and only a uni-directional
system of heat exchanger was created. Over all the period of research
parametric studies had been done for comparison of various aspects of
performance.
The high fidelity model of the prime mover-electrical network highlighted the
reasons for studying the impact of the propulsion drive and electrical network
load dynamics on the operation of the prime movers and vice versa. The loss-of-propulsion-load scenario case study has demonstrated the capabilities of
the integrated model, showing clear interactions between the individual
subsystems. The interface can now be used to analyse novel types of gas
turbine engines in the future. The method adopted to simulate transient
performance of gas turbines was useful in understanding the impact of bleed
air on current and novel cycles. Finally the task of heat exchanger simulation
emphasized the need to create better and accurate models to understand the
impact of its behaviour on the gas turbine.
