Aero-Thermal Aspects of Film Cooled Nozzle Guide Vane Endwall—Part 2: Thermal Measurements

Mahmood H. Alqefl, Kedar P Nawathe, Pingting Chen, Rui Zhu, Yong W. Kim, Terrence W. Simon

Research output: Contribution to journalArticlepeer-review

4 Scopus citations


Flow over gas turbine endwalls is complex and highly three-dimensional. As boundaries for modern engine designs are pushed, this already-complex flow is affected by aggressive application of film cooling flows that actively interact. This two-part study describes, experimentally, the aero-thermal interaction of cooling flows near the endwall of a first-stage nozzle guide vane passage (NGV). The approach flow conditions represent flow exiting a low-NOx combustor. The test section includes geometric and cooling details of a combustor-turbine interface in addition to endwall film cooling flows injected upstream of the passage. The first part of this study describes in detail, the passage aerodynamics as affected by injection of cooling flows. It reveals a system of secondary flows, including the newly discovered Impingement Vortex, which redefines our understanding of the aerodynamics of flow in a modern, film-cooled, first-stage vane row. The second part investigates, through thermal measurements, the distribution, mixing, and disruption of cooling flows over the endwall. Measurements are made with and without active endwall film cooling. Descriptions are made through adiabatic surface effectiveness measurements and correlations with in-passage velocity (presented in part one) and thermal fields. Results show that the newly discovered impingement vortex has a positive effect on coolant distribution through passage vortex suppression and by carrying the coolant to hard-to-cool regions in the passage, including the pressure surface near the endwall.

Original languageEnglish (US)
Article number121010
JournalJournal of Turbomachinery
Issue number12
StatePublished - Dec 2021

Bibliographical note

Funding Information:
This work was supported by Solar Turbines Incorporated.

Publisher Copyright:
Copyright © 2021 by ASME


  • Combustor coolant
  • Effusion cooling
  • Endwall aerodynamics
  • Endwall cooling
  • Film cooling
  • Impingement vortex
  • Louver cooling
  • Passage vortex
  • Secondary flows
  • Turbine aerodynamics
  • Turbine heat transfer


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