Assessment of Combustor Working Environments

In order to assess the remaining life of gas turbine critical components, it is vital to accurately define the aerothermodynamic working environments and service histories. As a part of a major multidisciplinary collaboration program, a benchmark modeling on a practical gas turbine combustor is successfully carried out, and the two-phase, steady, turbulent, compressible, reacting flow fields at both cruise and takeoff are obtained. The results show the complicated flow features inside the combustor. The airflow over each flow element of the combustor can or liner is not evenly distributed, and considerable variations, ±25%, around the average values, are observed. It is more important to note that the temperatures at the combustor can and cooling wiggle strips vary significantly, which can significantly affect fatigue life of engine critical components. The present study suggests that to develop an adequate aerothermodynamics tool, it is necessary to carry out a further systematic study, including validation of numerical results, simulations at typical engine operating conditions, and development of simple correlations between engine operating conditions and component working environments. As an ultimate goal, the cost and time of gas turbine engine fleet management must be significantly reduced. 1. Motivation It is a promising approach to assess the remaining life of gas turbine critical components, based on their service history (flight operating conditions and sensor readings), by applying aerothermodynamics, structural and material analysis models. It is consistent with condition-based maintenance (CBM) of gas turbine engines, that is, maintenance actions would be performed only when they are required. As a result, the expense of maintenance/repair of an engine fleet can be reduced, the engine operation can be made more reliable, and service life can be extended. This approach has been investigated by researchers from various disciplines under a major collaboration program [1]. One of the subprograms is the development of an aero-thermodynamics model. The model will provide more realistic distributions of temperature and pressure or loads for safety/cost critical components from engine operational conditions and sensor readings. Furthermore, it will also provide an environment for the assessment of current and enhanced sensor suites and the prediction of degraded operation with wear/damage or control changes. With the required thermal flow information, structural and material analyses can be performed, and the remaining life of engine components can