An investigation was conducted on sheet metal, circular-arc com-pressor inlet guide vanes in an annular cascade with untapered walls to determine the effect of solidity on turning through a "blade row. Guide vanes of 30° and 40° camber were investigated over a range of solidity from 0.7 to 4.0. The variation in turning with solidity, in the form of a curve of the ratio of turning angle to camber angle plotted against solidity, was compared with similar curves obtained from several two-dimensional methods.nAn equation similar in form to Constant's rule, which may be used to predict turning angles in cascades of configuration similar to that of this investigation, was obtained from the data. This equation plotted in the form of turning-angle correction based on a reference solidity may be used to extend the applicability of existing guide-vane data and design rules to other solidities. Because the change in turning angle produced by a change in solidity is probably little affected by blade-thickness distribution and cascade configuration, this turning-angle-correction curve can probably be applied to normal compressor-inlet guide-vane cascade configurations using blades with a circular-arc mean line.nSurveys made downstream of the guide vanes indicated that lower solidities than those presently used (about 1.5) may be employed without exceeding loading limitations (for the inlet Mach number of 0.35 of this investigation).
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