A NEW TEST RIG FOR FILM COOLING EXPERIMENTS ON TURBINE ENDWALLS

摘要

Endwall film cooling has been subject to many investigations over the past years. Since the coolant is injected into the wall boundary layer, it is primarily affected by the complex three-dimensional flow structure which is developed near the endwall inside turbine bladings. Little information can be found in the literature about how load variation affects endwall film cooling. As the secondary flow, driven by the circumferential and radial pressure gradient, is intensified with higher cascade load, strong interaction of the coolant injected in the near-wall cross flow is expected. Therefore, an airfoil cascade rig has been designed with an endwall cooling configuration containing multiple rows of expanded film holes. The film rows are combined to groups which can be supplied with different types of coolant gas through individual plenum cavities.