Numerical investigations for the influence of the axial gap on the use of clocking effect

Clocking effect has great potential in improving the efficiency of turbomachinery. Based on knowledge, 2-D unsteady numerical investigations were further performed to understand the influence of axial gap on the use of clocking effect. One 1.5 stage turbine cascade with stator/rotor/stator configuration was adopted as a numerical test case. The results show that different axial gaps have obvious effects on optimum clocking positions, and the aerodynamic efficiency benefits vary greatly with different axial gaps. Besides, efficiency curves versus clocking positions can be improved globally by changing rotor position from the middle of two stator rows or by reducing the distance between two stators in axial direction.