摘要:
The invention relates to an axial turbine (1) for a gas turbine comprising a rotor blade cascade that is formed from rotor blades (2) having, respectively, a front edge (3) and a radially outer, free-standing (13) blade tip, and an annular space wall (11) that surrounds the rotor blade cascade and that has an annular space inner side (12), enabling the annular space wall to be arranged directly adjacent to the blade tip forming a radial gap between the covering of the blade tip and the annular space inner side. The invention is characterised in that the blade tips are designed aerodynamically such that when the axial turbine is in operation, the area of the blade tip with the highest pressure load is disposed in the region of the front edges, and the rotor blades in the region of their front edges have a radial elevation (16) and the annular space wall comprises, on the annular space inner side, a peripheral radial recess (15) that interacts with the radial elevations such that a gap width minimum is established in the direction of the main through flow of the axial turbine when seen in the region of the front edge.