11 – STATOR DESIGN

Publisher Summary This chapter discusses the stator design. Prerotators and straighteners can be treated in a manner similar to that used for rotor blades. A prerotator accelerates the air as it introduces a tangential velocity component, thus, producing a static pressure drop across the stator. It is, thus, less critical in design than the straightener vane and therefore, lower solidities and higher lift coefficients are possible. When the swirl velocity is small, a simple solution evolved at the N.P.L. is often employed. This consists in using stators with a gap/chord ratio of unity, the stators being so arranged that in a purely axial flow there is no lift on the stators, that is, the no-lift line of the section is parallel with the fan axis. Provided the stators are not stalled, all swirls can be removed with a single stator setting.