UNSTEADY AERODYNAMIC ANALYSIS OF SUPERSONIC THROUGH-FLOW FAN WITH VIBRATING BLADES UNDER NON-ZERO MEAN LOADING

摘要

The double linearization concept is applied to a rotating annular cascade model operating at supersonic axial velocity. It is assumed that each blade vibrates with infinitesimal displacement amplitude under small but non-zero mean loading. Vibration modes normal and parallel to the blade chord are considered. Numerical results indicate that the mean loading effects play a crucial role on the aerodynamic instability of the blade motion. The bending motion can be unstable due to the presence of mean loading. Both the steady performance and the flutter boundary are highly sensitive to the blade camber. The bending motion instability is substantially influenced also by the chordwise component of the blade motion. Some numerical results compared with strip theory predictions demonstrate significant three-dimensional effects on the unsteady aerodynamic force under non-zero mean loading. (C) 1996 Academic Press Limited [References: 17]