Design of the Blade Geometry of Swept Transonic Fans by 3D Inverse Design

The application of sweep in the design of transonic fans has been shown to be an effective method of controlling the strength and position of the shock wave at the tip of transonic fan rotors, and the control of corner separations in stators. In rotors sweep can extend the range significantly. However, using sweep in conventional design practice can also result in a change in specific work and therefore pressure ratio. As a result, laborious iterations are required in order to recover the correct specific work and pressure ratio. In this paper, the blade geometry of a transonic fan is designed with sweep using a 3D inverse design method in which the blade geometry is computed for a specified distribution of blade loading. By comparing the resulting flow field in the conventionally and inversely designed swept rotors, it is shown that it is possible to apply sweep without the need to iterate to maintain pressure ratio and specific work when using the inverse method.Copyright © 2003 by ASME