Design of an Aggressive Flow-controlled Turbine Duct

Paper in proceeding, 2008

Demands on improved efficiency, reduced emissions and noise restrictions result in the need for very high by-pass ratio turbo-fan engines. Large fans and small high-pressure cores require aggressive intermediate transition ducts connecting the low-pressure and high-pressure systems. In the present work the design of an aggressive flow-controlled turbine duct is presented. A number of vortex generators are installed in a turbine duct to control the boundary layer. The objective is to suppress the existing separation and thus minimize overall duct loss. In doing so the turbine duct design space will be extended toward more aggressive configurations. By using response surface methodology, together with design of experiments based on computational fluid dynamics (CFD), an optimum flow control arrangement is determined. A vortex generator model was adopted in order to be able to investigate a large number of different configurations. The vortex generator installation is optimized with respect to vortex generator position, height, length and angle of attack.