Blade design data for axial-flow fans and compressors

exmerlmental lnvestiKation to"obtain blade design data for high-efficiency axial-flow fans and compressors was carried out in a two-di.menslonallow-speed cascade tunnel at the Langley laboratory of the NACA.The effects of csmbm, solidity, and stagger on blade tu~ntng angle and the shape of pressure distributions were ~etermined for a f~mily of five low-drag airfoils.These airfoils were cambered for free-air lift coefficient I'romO to 1.8 and were Investigate& at stag~ers of 450 and 600 and sollditles of 1.0 and 1.5.Blade design charts for axial-flow fans and compressors were prepared that give the camber and angle-of-attack setting for any ' desired turning angle.Blades chosen from these design charts operate with an essentially flat pressure distrlbutlon.A test in a single-stagG test blower showed that the maximum efficiency occurs near the point at which the pres?ure d~.etributionis flat.Empirical equations are given b~which the perfomnance of an airfoil in cascade similar to those investigated may be predicted with sufficient accuracy for blade design.=.