A Summary of Computations of Ingestion at the University of Bath

Rim seals in gas turbines are used to reduce the potentially
damaging ingestion of hot gas into the rotor-stator wheel-space of a
turbine stage. Sealing air, bled from the compressor, is also used to
reduce or prevent ingestion, but this can be at the expense of stage
efficiency.
This paper summarises recent research into the computation of
the fluid dynamics and heat transfer of ingestion carried out at the
University of Bath. 3D Unsteady Reynolds-averaged Navier-
Stokes (URANS) simulations have been carried out, and much
more economical simplified steady state computational models
have also been tested. The results of the computations are compared
with experimental measurements (also made at the University) of
pressure, tracer gas concentration based sealing effectiveness, swirl
and heat transfer for different generic and also engine-
representative rim seals. The computations allow insight into
the flow physics of ingestion and factors affecting the most efficient
use of sealing air, as well as providing information to support the
development of the theoretical models of ingestion that are useful
to engine designers. The experimental test facility permits measurement
and ranking of sealing effectiveness for a range of different
rim seal configurations.