Experimental study on aeroelasticity in linear oscillating compressor cascade. Part I: Unsteady aerodynamic response

An experiment is carried out to enhance the understanding of three-dimensional(3D) blade aeroelastic mechanisms and to produce the experimental data for the validation of numerical methods. Forming the first part of the two-part series, the experimental study on the aeroelastic stability of the compress oscillating cascade is presented. The tip-clearance effects on the aeroelastic response of the same cascade are identified in part II. A linear cascade experiment rig is developed. It consistes of seven prismatic controlled diffusion blades. The middle blade is driven by the crank bar mechanism to simulate a 3D bending/flapping oscillating mode. Steady and unsteady pressure measurements are performed at six spanwise sections for three reduced frequencies. Off-board pressure transducers are utilized with a transfer-function method to correct tubing errors. The tuned cascade results are constructed by using the influence coefficient method. The results illustrate the fully 3D unsteady behaviour and the significant influence of reduced frequency and inter-blade phase angle on the unsteady aerodynamic response.