Comparison Between Measured and Predicted Wall Temperatures in a Gas Turbine Combustor

On of the major considerations in the development of advanced gas turbine engines are increased thrust to weight ratio and reduced development and operating costs. Improvements in engine thrust require an increase in combustion chamber heat release and inlet pressures. However, increasing the amount of heat release will also result in an increase in the radiative heat flux to the combustion chamber walls, proving detrimental to the operational life time of the combustor. To maximise combustor life, different cooling devices can be incorporated into the combustion chamber design. The effectiveness with which these devices are implemented is important and in the absence of a reliable predictive numerical tools, is difficult to quantify without undertaking expensive and timely testing. A computer analysis tool, based on a network model approach, has previously been developed to analyse airflow distributions in complex combustor geometries. A recent variant of this model has incorporated the Discrete Transfer radiation model, along with other convective and conductive sub-models, to account for heat transfer. These models have been validated against thermocouple measurements of wall temperature obtained in a sectored research combustor. The results of this comparison indicate that, whilst the model is capable of predicting the trends in wall temperature, it is currently unable to reproduce the magnitude of wall temperature with a greater accuracy than 80 K. However, the versatility of the discrete transfer model suggests that further improvements in accuracy are possible.