| Summary: | Although gas turbine engines are designed to use dry air as the working fluid,
the great demand over the last decades for air travel at several altitudes and
speeds has increased aircraft’s exposure to inclement weather conditions.
Although, they are required to perform safely under the effect of various
meteorological phenomena, in which air entering the engine contains water,
several incidents have been reported to the aviation authorities about power
loss during flight at inclement weather. It was understood that the rain ingestion
into a gas turbine engine influences the performance of the engine and
particular the compressor and the combustor.
The effects of water ingestion on gas turbine engines are aerodynamic,
thermodynamic and mechanical. These effects occur simultaneously and affect
each other. Considering the above effects and the fact that they are timedependent,
there are few gas turbine performance simulation tools, which take
into account the water ingestion phenomenon.
This study is a new research of investigating theoretically the water ingestion
effects on a gas turbine performance. It focuses on the aerodynamic and
mechanical effects of the phenomenon on the compressor and the combustor.
The application of Computational Fluid Dynamics (CFD) is the basic
methodology to examine the details of the flow in an axial compressor and how
it is affected by the presence of water. The calculations of water film thickness,
which is formed on the rotor blade, its motion (direction and speed) and the
extra torque demand, are provided by a code created by the author using
FORTRAN programming language. Considering the change in blade’s profile
and the wavy characteristics of the liquid film, the compressor’s performance
deterioration is calculated.
The compressor and combustor’s deterioration data are imported to a gas
turbine simulation code, which is upgraded to calculate overall engine’s
performance deterioration. The results show a considerable alteration in
engine’s performance parameters and arrive at the same conclusions with the
relevant experimental observations.
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