3D investigation of heat exchange and hydrodynamics of high pressure turbine nozzle block platforms with different cooling schemes

Turbine nozzle blocks were tested and, as a result, problems of nozzle block lower platform alligatoring were detected. In the course of the research possible variants of cooling high pressure turbine nozzle block vane platforms were investigated. According to the results of 3D ANSYS CFX calculation the cooling efficiency of high pressure turbine vane platforms with film cooling and convective-film cooling were compared. Research was carried out to eliminate the alligatoring defect of the lower vane platform with convective cooling. Necessary changes in the design were made due to which the cooling air from the secondary combustion chamber area was redistributed over the surface of the turbine nozzle block lower platform. To force the gas turbine engine to the inlet gas temperature to 1800К and more, and to increase the cooling air mass flow from the secondary combustion chamber area over the platforms using convective cooling methods not requiring developed ribbing and impingement cooling, areas of the platforms, as well as zones demanding insignificant intensity of cooling are shown.