Session: 32-07 Loss Reduction for Axial Turbines

Submission Number: 178205

Part-Span Suction Surface Slot Injection for Variable Area Turbine With Active Flow Control 

Experiments and computational work have shown the feasibility of utilizing active flow control to throttle the core mass flow through a nozzle guide vane. This enables a variable area turbine without the complexity of mechanically swiveling vanes. Previous experiments in a small-scale singular nozzle guide vane passage identified a 2D suction surface slot design which balanced performance and losses. A three-passage transonic linear cascade with the OSU vane geometry was built to study these fluidic actuators in an environment nearer to that of an engine. The OSU vane axial chord is 53.5mm with a solidity of 1.2 and a span of 50.8mm.  The full-span suction surface slot design, at an injection pressure ratio of one, was capable of reducing core mass flow by 15.1%, blocking 1.9 times the injected mass flow and generating 1.5 times more total pressure loss than when the actuator is off. It was identified in exit plane five-hole probe surveys that slot injection near the endwalls was less effective at restricting the flow due to the dominant secondary flowfield. Accordingly, the slot was truncated to comprise just the central 50% of the vane span. This part-span slot design at PR=1 reduced core mass flow by 13.8%, blocking 2.8 times the injected mass flow, thus improving the effectiveness of the suction surface slot actuation by 50%. Complementary studies using 3D RANS CFD are used to identify the physics associated with this significant increase in effectiveness.

Presenting Author: Jeffrey Bons The Ohio State University

Presenting Author Biography: Dr. Bons received his PhD in Aeronautical and Astronautical Engineering from MIT in 1997. Prior to this, he worked for 4 years at the Air Force Research Laboratory in Dayton Ohio. From 1997-2002 he was an assistant professor at the Air Force Institute of Technology (AFIT) in Dayton, Ohio and from 2002-2007 he was an associate professor in the Department of Mechanical Engineering at Brigham Young University (BYU) in Provo, Utah. He has been part of the Aerospace Engineering faculty at OSU since 2007.

Authors:

Cole Westrick The Ohio State University
Corey Mays The Ohio State University
Bethany Thompson The Ohio State University
Jeffrey Bons The Ohio State University