Tip Clearance Influence on Aerodynamic Damping Maps

摘要: This paper aims to investigate the influence of tip clearance on aerodynamic damping maps an oscillating low pressure turbine (LPT) unshrouded blade row. Full-scale time-marching RANS CFD simulations in ANSYS CFX® v.16.2 employing models with 0%, 1%, 2% and 3% span are adopted. Tip flow leads a significant for torsion mode shape least stable IBPA = 45°. No trend local work coefficient observed suction side, although increasing gap stabilizing side. Aerodynamic constructed each gap. Torsion axes forward portion airfoil found be more than its aft counterparts. Bending dominated shapes cascade tangential direction. Finally, small changes flutter characteristics few pitching axis locations.