Benefits of Rake and Skew for Turbulence Ingestion Noise

Turbulent flow through a fan or pump produces a broadband spectrum of unsteady lifting forces on the blades. These forces cause undesirable blade stresses, blade vibration and sound. Jonson (1994) has shown that broadband improvements can be obtained by adding rake and skew to the stacking line of rotor blade sections. This paper adds understanding to those experimental results, and shows that benefits can be reliably predicted using analytical methods.Copyright © 2003 by ASME