A boundary layer control device was designed to change significantly the case-wall boundary layer thickness entering a large-scale, multistage axial compressor. The device was intended to double the boundary layer thickness in order to evaluate the influence of the inlet boundary layer in controlled tip clearance experiments being conducted on the compressor. The boundary layer characteristics expected to be produced by the control device were predicted empirically and experimental verification was required. Kiel, cobra, and impact probes were used in the experiments and pressures were recorded manually using water manometers. The geometry of the boundary layer control device, an annular array of spires, was derived from shapes developed for simulating the atmospheric boundary layer in large rectangular section wind tunnels. A significantly thicker boundary layer was measured in the compressor than was intended. However, the results were interpreted and recommendations were made for geometry changes necessary to achieve the intended control for the tip clearance investigation. Keywords: Axial flow compressor blades; Boundary layer spires; Boundary layer control; Theses. (EDC)
展开▼
