Session: 12-09: Film Cooling Optimization and Novel Design

Paper Number: 154287

Adjoint Optimization of Gas Turbine Film Cooling Geometry With Elevated Mainstream Mach Number 

Adjoint based shape optimization has the potential to produce real gains in the performance of gas turbine film cooling geometry. This has been demonstrated in previous studies with incompressible mainstream Mach number, using both computational and experimental evidence. Starting from a 7-7-7 shaped film cooling hole as a baseline, the present study investigated such optimization routines using an elevated mainstream Mach number of Ma=0.75, and is the first of its kind. At this elevated Mach number, supersonic flow and shockwaves were predicted within the 7-7-7 baseline hole. How such behaviors affected the optimization was of particular interest. In addition to the optimization at elevated mainstream Mach number, a control optimization was performed at an incompressible mainstream Mach number of Ma=0.15. Both the “high-speed” and “low-speed” optimizations were performed using a hole Reynolds number Re=10,000, a blowing ratio M=2.00 and a stagnation temperature ratio TR0=0.50. Although the resulting optimizations were similar, significant differences were observed and are discussed. After generating each optimization, the resulting geometries were simulated across a wide range of conditions. Computationally, the predicted performance of both geometries was significantly higher than that of the baseline 7-7-7. Each geometry was also constructed experimentally and tested at mainstream Mach numbers of Ma = 0.15 and Ma=0.50. The high-speed optimization was the best performing geometry at both Mach numbers tested, with adiabatic effectiveness double that of the baseline 7-7-7 at elevated blowing ratios. The “low-speed” optimization did not outperform the baseline 7-7-7, as predicted flow mechanisms were not replicated in the experiments.

Presenting Author: Michael Furgeson The University of Texas at Austin

Presenting Author Biography: Michael Furgeson graduated from The University of Texas at Austin with his Ph.D. in 2024. While at UT Austin, Michael was a member of the Turbulence and Turbine Cooling Research Laboratory, working under Dr. David Bogard. Following graduation, Michael started a new role at Blue Origin as a Propulsion Analyst.

Authors:

Michael Furgeson The University of Texas at Austin
Elise Flachs The University of Texas at Austin
David Bogard The University of Texas at Austin