Influence of blade-stagger departure on the migration of hot streak in turbine passage

The departures of blade machining and assembly may influence not only turbine performance, but also the migration of hot streak in turbine passage. In order to investigate the influence of these departures on the migration of hot streak and the thermal load of blade, 3-D unsteady numerical simulations of a high pressure turbine stage are carried out. Numerical results indicate that the departure of rotor blade stagger have obvious influence on circumferential migration of hot streak in rotor blade passage. The thermal loads of rotor blades are directly influenced by the changes of hot streak migration and therefore also the life-span of blades. In addition, the change of hot streak migration also result in obvious temperature variations of downstream strut passage, which may lead to measure error of engine exhaust temperature. The change of hot streak migration should be considered in turbine design and failure analyses.