Boundary Layer Loss Reduction of Cascade Flow by Wide Chord

Abstract

In actual turbomachinery, the wider chord cascade sometimes shows a higher aerodynamic efficiency than the shorter chord one. This study tries to ascertain the underlying physical mechanism of the wide chord advantage mentioned above in terms of the boundary layer loss reduction. It is verified the boundary layer loss has the characteristics of the chord to the power of -1/n ( n > 1), therefore, the wide chord can reduce it. Next, by CFD, it is verified the boundary layer loss is surely reduced by the wide chord. Consequently it is verified the wide chord is effective to reduce the viscous loss in actual turbomachinery.