Time-Variant Aerodynamics of High-Turning Blade Elements

Abstract

Basic experimental data has been obtained from a linear cascade of five turbine airfoil sections undergoing torsional oscillation. A high-turning subsonic/transonic cascade was tested and both steady-state and time-variant data were obtained. A quasi-static investigation was conducted to compare static pressure distributions with the pressure distributions from the time-variant investigation. During the time-variant data acquisition, six values of interblade phase angle were investigated at each of four expansion ratios. Unsteady pressures were measured by flush-mounted Kulite pressure transducers on the center airfoil and compared with an oscillating flat-plate cascade analysis.