Unsteady Aerodynamics and Forces Characteristics of Dual Row Control Stage with Partial Admission Condition

Abstract

Unsteady aerodynamic performance and forces on the rotor blades of dual row control stage with partial admission condition were numerically investigated using three-dimensional unsteady Reynolds-Averaged Navier-Stokes (URANS) and The rotor blades were subject to large unsteady and periodic forces while traveling along the circumferential direction. The magnitude and direction of the unsteady forces on the rotor blades were significantly influenced by the rotor blades entering or leaving the admission arcs. The spectrum analysis of the excitation forces on the rotor blades show that the high amplitudes caused by partial admission were at low multiples of rotational frequency.