Active Flow Control for Low-Pressure Turbines

Recent applications of active flow control to the low-pressure turbine section of a gas turbine are reviewed and evaluated. Unique aspects of the low-pressure turbine flow environment such as freestream turbulence, secondary flows, and unsteady wakes create challenges for flow control that must be considered during design and implementation. Applications of four different active flow control mechanisms to two challenging flow phenomena (separation and secondary flows) are described in detail. Although significant work is yet required before a viable active flow control implementation can be fielded, several mechanisms show considerable promise.