Optimization of the Working Process of a Two-Stage HPT of a Modern GTE for Civil Aviation

Abstract

— The paper describes an optimization process of an axial two-stage high-pressure turbine (HPT) of a gas turbine engine (GTE) for a civil aviation aircraft. This turbine was optimized to increase efficiency and reduce the output swirl gradient. The original turbine has a high efficiency so no significant improvement of efficiency was found using conventional approaches. A large number of variables must be used to describe the process, and the computational model, taking into account film cooling modeling, is time consuming and computationally intensive. In this regard, direct optimization did not provide a meaningful result. For this reason, a series of optimization problems were solved by varying the parameterization schemes, the number of variable sections, the grid of finite volumes and the degree of detailing of the mathematical model. During the optimization process, the issues of ensuring the strength and service life of the blades were not considered, however, the range of changes in the geometry of the blades was chosen in such a way as to prevent a significant deterioration in the strength parameters. As a result, 2 variants of optimization of turbine geometry have been found: the first variant in which only forms of control sections of blades (2D form) changed allowed to increase efficiency by 0.37 %. The second variant in which both shape of profiles and their mutual position relative to each other were changed (2D and 3D form) allowed to increase efficiency by 0.63% at significant decrease of gradient of the flow exit angle.