Session: 12-07 Optimization of Film Cooling Geometries

Paper Number: 83436

83436 - Evaluation of Adjoint Optimized Holes - Part I Baseline Performance 

 In a previous study from our laboratory, a computational adjoint based optimization method was used to design shaped film cooling holes fed by internal co-flow and cross-flow channels.  The associated RANS computations predicted that the holes optimized for use with cross-flow (X-flow_AOp) and co-flow (Co-flow_AOp) would increase adiabatic effectiveness by 150% and 200%, respectively, compared to a baseline 7-7-7 shaped hole. Only the X-flow_AOp hole was tested experimentally in this previous study.  Though the experimentally measured performance for this hole was much less than computationally predicted, it still had a 90% improved performance compared to the 7-7-7 shaped hole.  In the current study, the X-flow_AOp and Co-flow_AOp shaped holes were experimentally evaluated using measurements of adiabatic effectiveness and overall cooling effectiveness.  An internal co-flow channel with a channel velocity to mainstream velocity ratio of VR_c = 0.2 was used with coolant density ratio of 1.2.  The film cooling injection rates were varied from VR = 0.4 to 3.4 (M = 0.5 to 4). For reference, experiments were also conducted with the baseline 7-7-7 shaped hole, and a 15-15-1 shaped hole (shown in a previous study to be the optimum expansion angles for a shaped hole).  Furthermore, overall cooling effectiveness measurements were made with an engine scale models to evaluate the performance of additively  manufactured (AM)  X-flow_AOp and Co-flow_AOp holes with a realistic metal AM build.  Results from this study confirmed that the  X-flow_AOp hole had a 100% increase in adiabatic effectiveness compared to the 7-7-7 shaped hole.  However, the Co-flow_AOp hole had only a 65% increase in adiabatic effectiveness, substantially less than had been computationally predicted.  Measurements of overall cooling effectiveness for the engine-scale models and the large-scale models followed similar trends. 

Presenting Author: Daniel Gutierrez University of Texas at Austin

Presenting Author Biography: Author's name is Daniel Gutierrez. Daniel studied a Bachelor of Science in Mechanical Engineering at the University of Texas at Austin. Currently pursuing a Masters of Science in Engineering at the University of Texas at Austin, Thermal and Fluid Systems track of study, and his current position is Graduate Research Assistant under Dr. David G. Bogard's Turbulence and Turbine Cooling Research Lab (TTCRL).

Authors:

Daniel Gutierrez University of Texas at Austin
Christopher Yoon University of Texas at Austin
Michael Furgeson University of Texas at Austin
Emma Veley The Pennsylvania State University
David Bogard University of Texas at Austin
Karen Thole The Pennsylvania State University