Experimental Study of 3D Unsteady Flow Around Oscillating Blade With Part-Span Separation

This paper documents an investigation conducted on the aerodynamic response of a turbine blade oscillating in a three-dimensional bending mode under massive tip separation. Flow separation near the tip of the blade was realized by use of a step placed upstream of the blade's leading edge. Extensive blade surface steady and unsteady pressure measurements were obtained from a test facility with clearly defined boundary conditions for a range of reduced frequency. The experiment is designed to produce detailed and reliable 3D test cases for aeroelastic applications. A complete set of steady and unsteady blade surface pressure measurements is provided for five spanwise sections at 10, 30, 50, 70, and 90 percent of span. In addition, the issue of linearity is addressed. Experimental results demonstrate a predominant linear behavior of the unsteady pressure response. [DOI: 10.1115/1.1370164]