| Summary: | Turbine blade cooling via internal cooling channels is a very important aspect in
modern-day gas turbine cycles. The need for blade cooling stems from the fact
that higher cycle efficiencies requires higher maximum temperatures and
therefore also higher turbine inlet temperatures. In order to evaluate the effects of
these cooling flows on the cycle as a whole under various load conditions, it is
necessary to simulate the compressible flow with heat transfer within the
channels. The main objective of this study is to develop a mathematical model to
simulate the steady-state compressible flow in the radial cooling channels of a
simple rotating disc and to determine a temperature distribution in the disc. The
disc's axis of rotation is vertical and it contains six equally spaced cooling
channels through which air is dispersed radially outward.
The steady-state compressible equations for the fluid flow in a rotating pipe were
derived from first principals. The generated heat transfer in the rotating pipe was
then coupled incrementally to a system of temperature conduction equations. It
was then possible to determine a three dimensional temperature distribution in
the rotating disc. The study also included an experimental validation of the flow
model under adiabatic conditions.
An inlet loss factor was empirically determined from data obtained from the
experimental test bench. It was found that the inlet loss factor is a function of the
inlet radial velocity component divided by the inlet tangential velocity component.
Finally, it was shown that the results obtained from the theoretical model are in
good agreement with the data obtained from the experimental test bench. === Thesis (M.Ing. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2004.
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