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A 2-D plain strain CFD/FEM model to simulate thermal shocks and stresses in a turbine blade has been set up using the commercially available software FLUENT and NASTRAN. The model was validated against the experimental data of Bohn et. al. and used to simulate real test cases. The steady state numerical model was set up for a single Mark II nozzle guide vane using the correct boundary conditions to resolve the flow field. A combined laminar and turbulent model was developed in FLUENT that was used to highly accurately predict the pressure, temperature and heat transfer coefficient distribution on the blade surface as well as the temperature distribution on the cooling holes inside the blade. The resulting temperature profiles on the blade and cooling holes were used as boundary conditions for the FEM analysis to resolve the internal temperature and stress profiles. The pressure, temperature and heat transfer distribution on the blade, from FLUENT, were compared to those from Bohn et. al. The predicted pressure distribution was exact with the experimental results and the predicted temperature distribution had an average overprediction of 1.4 % on both the pressure and suction side. The internal temperature profile predicted by NASTRAN was correctly predicted with an average over-prediction of 2 %. The stress contours were accurately predicted with the stress magnitude varying by 17 % to that of Bohn et. al. The reason for the difference between the MSC.NASTRAN and Bohn et. al. stress results is believed to be purely solver related. Bohn et al. used a FEM package called MSC.MARClMentat. With the steady state model validated, transient test cases were simulated that represent typical operational data. The mission profile was obtained for the T-56 engine found on the C130 cargo plane. The model was used to simulate the test case where the turbine inlet temperature (TIT) varied with time. The simulation results showed that stress was proportional to TIT, where changes in the TIT were seen later in the stress curve, due to conduction in the blade. Steep TIT changes, such as shock loads affected stress later than gentler TIT changes. Thus, the FLUENT / NASTRAN model was successfully validated, and used to simulate a flight mission profile. The goal to calculate quality unsteady stress profiles was achieved and forms the boundary conditions for thermal fatigue calculations. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, 2005.

The ability of an organisation to change and adapt is critical. The process of change however tends to be more challenging than expected during initial planning. Organisations frequently rush into change initiatives; these often result in unintended consequences which may subsequently lead to many change efforts being unsuccessful. There is much contention around issues of participation and communication, and current theory and models are criticised for being inadequate. The skills base of employees and managers are also often inadequate to deal with proposed changes. Problems are seldom handled effectively, thereby decreasing an organisation’s ability to engage in learning. Simulations have proven beneficial in enabling participants from various backgrounds to meaningfully engage by learning from experience. The safety of the environment enables participants to explore ideas and strategies, with the aim of developing abstract thinking by observing and reflecting on experiences from the simulation. This exploratory study therefore set out to investigate how and specifically in which ways simulations can play a role in change management. Relevant literature in the areas of change management, learning, systems thinking, complexity theory and simulations were examined to establish a theoretical grounding. The empirical component of this study focused on the fisheries system in the Western Cape province of South Africa. A qualitative research approach and purposive sampling were employed. Fifteen semi-structured, face-to-face interviews were conducted. Observations and secondary data in the form of archival data, and other relevant organisational documents were also analysed. Subsequent data analysis was then used to uncover the various pertinent issues. A simulation was thereafter designed, piloted with students, and then conducted twice with some of the stakeholders in the fisheries context. This study is significant in understanding how interactive simulations contribute to change management. The main findings from this study indicate that simulation use illustrated how the various stakeholders in a system interact, and how their actions and decisions influence each other. The findings also revealed that simulations were particularly effective in a multiplestakeholder scenario, and could show the role that mental models and stakeholder perceptions play. The findings indicated that simulations could successfully place emphasis on developing capabilities, and highlight how approaches towards communication and participation influence outcomes. General implications based on the findings were derived for change and simulation theory, as well as for the fisheries context. The simulation may be used in other areas of natural resource management, as well as general stakeholder scenarios. It may also be effective in a general organisational setting to re-examine the conventional way of approaching change. / Thesis (M.Com.)-University of KwaZulu-Natal, Westville, 2009. / MCM.