Session: 32-07 Endwall and Secondary Flows

Paper Number: 154078

Performance of Adjoint-Optimized Contoured Endwalls for Multiple Off-Design Purge Flow Rates in Axial Turbines 

Endwall contouring in gas turbines has become a critical area of research aimed at improving aerodynamic efficiency and reducing secondary flow losses. As modern gas turbine designs push the boundaries of performance, secondary flows—generated by pressure gradients between rotor and stator components and wall-bounded viscous effects—contribute significantly to overall efficiency losses. By optimizing the endwall geometry, particularly through non-axisymmetric contouring, it is possible to mitigate these detrimental flows and enhance turbine performance. Recent application of the adjoint method of optimization in turbomachinery has generated novel endwall designs that push turbine performance higher.
In this paper, an adjoint-based optimization approach is utilized within commercially available software to aerodynamically optimize the blade endwall of a cooled high-pressure turbine through targeted contouring. A series of computational fluid dynamics (CFD) simulations has been conducted on a full turbine stage in a high-pressure production engine to assess the effects of these optimizations when the turbine is operating at a different condition than that used for optimization. Particular emphasis is placed on the performance of the endwall optimization at off-design rim seal purge conditions. Comparisons between an array of optimized endwalls and the baseline geometry are made, providing insight into how endwall contouring decreases aerodynamic loss across the purge rate range tested. It was found that all contours optimized for a given purge condition improved efficiency across all purge conditions, with contours optimized for higher purge conditions decreasing the sensitivity of efficiency with purge flow rate.

 

Presenting Author: Austin Hendrickson The Ohio State University

Presenting Author Biography: Austin is a 4th year graduate student from the Ohio State University going for his PhD in Aerospace Engineering. His primary research interests include turbomachinery aerodynamics, heat transfer, and CFD.

Authors:

Austin Hendrickson The Ohio State University
Spencer Sperling Honeywell Aerospace Technologies
Bao Nguyen Honeywell Aerospace Technologies
Richard Celestina Honeywell Aerospace Technologies
Jong Liu Honeywell Aerospace Technologies
Hakan Aksoy Honeywell Aerospace Technologies
Jeremy Nickol Honeywell Aerospace Technologies
Randall Mathison The Ohio State University
Evan Sears The Ohio State University