Multipoint Inverse Design of an Infinite Cascade of Airfoils

Tbis paper describes a method for the design of an infinite cascade in incompressible Dow. The method is bued on conformaJ mapping and does aJlow for multipoint design. The cascade blade to be determined is divided into a desired number of segments. Over each segment. the velocity distribution is prescribed together with an inlet or outlet Dow angle at which this velocity distribution is to be achieved. In this way multipoint design requirements can be met. It is necessary to satisfy 5everaJ conditions that arise to guarantee compatibility with the inlet and outlet Dow 85 well 85 dosure of the cascade blade. Satisfaction of these conditions does not necessarily result in a cascade with aU of the desired characteristics. For example. the cascade blades may be bulbous or crossed. Through Newton iteration. however. the desired characteristics may be prescribed directly. Four examples will be iUustrated to demoustrate the capability of the method.