Gas Turbine Cycle Modeling Oriented to Component Performance Evaluation from Limited Design or test Data

This paper describes the first phase of a study aimed at setting - up a cycle model and computer program for evaluating the performance of gas turbine components having only a limited amount of data available. In this study the mathematical models of the individual components, the iterative solution algorithms and the main code blocks were set-up. To achieve a solution a simultaneous method, consisting of a constrained optimization algorithm, is utilized. A preliminary evaluation of the ranges in which parameters can vary was necessary to calibrate the method; it consisted of a sensitivity analysis made with a version of the code that employs a sequential solution method. The code may be utilized either to identify the causes of performance deviations from design values or to perform comparative analyses of gas turbine cycles when few specific design data are available. In the latter case a statistical data base for each class of machine analysed is needed as input. A future paper will present the results of work currently in progress, involving application of the code to a number of turbines, for which detail design data are available, in order to check the simultaneous solution method for a variety of machines and operating conditions.