Tests Concerning Novel Designs of Blades for Axial Compressors PARTⅠ. BLADES DESIGNED FOR INCREASED WORK AT ROOT AND TIP PARTⅡ. BLADES DESIGNED TO OPERATE IN A PARABOLIC AXIAL VELOCITYnDISTRIBUTION

摘要

Investigation of the flow between the blade rows in a research compressor with conventional HalfVortex blades has shown a rapid stage-to-stage build-up of the annulus boundary layer. The axial velocity distribution under these conditions bears no resemblance to the straight-line distribution which is usually assumed in design so the incidence angles at both root and tip probably give rise to considerable secondary losses.nTwo sets of blades were designed therefore, with the object of minimizing these effects. The first set was designed with an increased work input at the root and tip of the blades in order to re-energies the boundary layer and prevent axial-velocity profile deterioration. The second set was designed using as a design assumption a mathematical approximation to the axial-velocity profiles found experimentally at various stages in a conventional compressor.