12 – STATOR LOSSES

Publisher Summary This chapter discusses the stator losses. Stator losses are similar in nature to those occurring in rotor blading. The decrease in fan efficiency as a result of the loss in total head as the air passes through the stators is, for an average case, of the order of 3%. Tip clearance losses can be avoided with proper sealing; as a result, the annulus drag component will probably be smaller than the accuracy with which efficiency can be estimated. Straighteners may sometimes be installed downstream of a prerotator-rotor design arrangement for the express purpose of removing the residual swirl resulting from off-design operation. The data that have been published on the drag of accelerating and decelerating stators that is prerotators and straighteners differ somewhat in their method of presentation. In view of the relative unimportance of the precise value of the drag, and as the total drag coefficients are of the same order of magnitude in each case, a common set of data have been adopted.