Computation of flow and heat transfer in rotating cavities
This thesis records an investigation into the flow and heat transfer
occurring in a rapidly rotating cylindrical cavity, which forms a simple
model of the space between two compressor discs in a gas turbine engine.
The main effort has been directed towards the development and application
of a computer program for the solution of the governing equations. In
addition, analytical solutions for laminar flow between two infinite
rotating discs have also been derived, and some temperature data from a
test engine have been analysed to obtain estimates of the rate of convective
The computer program, which is based on a standard finite difference
technique for the calculation of recirculating two-dimensional flow,
incorporates two novel features. Step changes in grid size have been
employed to economise on the total number of grid points required, and
the solution for the pressure field is given special treatment in order to
obtain convergence of the iterative method at-high rotational speeds.
Laminar flow predictions are presented for radial throughflow and for
the buoyancy-induced recirculation in a sealed'cavity. Comparisons with
experimental and analytical results confirm the accuracy of the numerical
work, and the additional information that is available from the numerical
solutions has given a-useful insight into the nature of the flow.
Numerical results for turbulent flow in a rotating cavity, obtained
using a two equation model of turbulence, did not agree with experimental
measurements. Subsequent attempts to reproduce other workers' numerical
predictions for the flow between a rotating and a stationary disc, and
the flow caused by a disc rotating in an infinite environment, also
failed to produce agreement.