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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 heat transfer. 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.

In this thesis, improved and faster CFD based aero-thermo-mechanical methods that can be used to optimize engine configurations early in the design process are described. Axisymmetric models of 3D non-axisymmetric features such as protrusions, holes and honeycomb liners are developed for use in this context, and 3D unsteady CFD is used to investigate the flow physics. Initially, the research focussed on modelling of a rotor-stator disc cavity. Steady CFD validations for a plane disc and for a disc with protrusion were carried out and a simplified body force model was developed for including the 3D effects of rotating and stationary bolts into the axisymmetric CFD models. The simplified rotor bolt model was verified and validated by comparing the results with Sussex Windage rig test data and 3D CFD data. The simplified stator bolt model was verified using 3D CFD results. The simplified rotor bolt model was found to predict the drag and windage heat transfer with reasonable accuracy compared to 3D sector CFD results. However, 3D sector CFD under-predicts the high core flow swirl and the adiabatic disc surface temperature inboard of the bolt, compared to experimental data. In the second part of the study, unsteady Reynolds averaged Navier-Stokes (URANS) calculations of the rotating bolts cases were performed in order to better understand the flow physics. Although the rotor-stator cavity with bolts is geometrically steady in the rotating frame of reference, it was found that the rotor bolts generate unsteadiness which creates time-dependent rotating flow features within the cavity. A systematic parametric study is presented giving insight into the influence of the bolt number and the cavity geometric parameters on the time dependent flow within the cavity. The URANS calculations were extended to a high pressure turbine (HPT) rear cavity to show possible unsteady effects due to rotating bolts in an engine case. Following this, the body force model was adapted to model the rotating hole velocity changes and flow through honeycomb liners. The honeycomb and hole models were verified by comparing the results with available experimental data and 3D CFD calculations. In the final part of the study, coupled FE-CFD calculations for a preliminary design whole engine thermo-mechanical (WETM) model for a transient square cycle was performed including the effects of non-axisymmetric features. Six cavities around the HPT disc were modelled using CFD. The coupled approach provides more realistic physical convective heat transfer boundary conditions than the traditional approach. The unvalidated baseline thermo-mechanical model results were verified using the high fidelity coupled FE-CFD solution. It was demonstrated that the FE-CFD coupled calculations with axisymmetric modelling of 3D features can be achieved in a few days time scale suitable for preliminary engine design. The simplified CFD based methods described in this thesis could reduce the computational time of transient coupled FE-CFD calculations several orders of magnitude and may provide results as accurate as 2DFE-3DCFD coupled calculations.

This thesis presents a new framework that enables a better integrated and industry-wide approach to the sustainable design and operation of swimming pools in the UK. The framework addresses current issues in the swimming industry by proposing a restructuring of the regulatory and guidance structure to make use of existing pieces of UK legislation. A combination of a new approved code of practice for swimming pools incorporating risk-based assessments and changes to existing approved documents for building efficiency is proposed as an effective method of engaging all stakeholders. The industrial setting of the research enabled a practical evaluation of the current UK guidance and regulation. The need for additional performance indicators to improve the management of compliance with recommendations is identified. The Water Exchange Deficit is proposed as a new performance indicator to support the water management of a facility. In addition, the relationship between activity type and the impact on water quality is examined and discussed. An enhanced methodology for the prediction of the water demand of a facility has also been generated. This methodology incorporates newly published findings in relation to the nature of bather contamination and operational variables relating to evaporation rates and chemical dosing. In addition to the contributions above, the modelling of pool hydraulics was also undertaken to assess operational consequences of the existing implementation of industry guidance. A fundamental conflict was identified between the two key recommendations that should be adopted in relation to the design of pool hydraulics. Computational fluid dynamics and small-scale physical modelling approaches were used to show that the use of well-mixed hydraulics is effective at distributing chemicals but can also potentially increase the risk of exposure to disinfectant-resistant pathogens. The availability of new treatment technologies may present the opportunity for wholesale changes to the overall strategy of pool water treatment.