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. 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 language||English (US)|
|Title of host publication||Heat Transfer|
|Publisher||American Society of Mechanical Engineers (ASME)|
|State||Published - 2020|
|Event||ASME Turbo Expo 2020: Turbomachinery Technical Conference and Exposition, GT 2020 - Virtual, Online|
Duration: Sep 21 2020 → Sep 25 2020
|Name||Proceedings of the ASME Turbo Expo|
|Conference||ASME Turbo Expo 2020: Turbomachinery Technical Conference and Exposition, GT 2020|
|Period||9/21/20 → 9/25/20|
Bibliographical noteFunding Information:
The authors would like to acknowledge Solar Turbines Incorporated for their financial support and would like to thank Alex Li for his assistance in the laboratory.
Copyright © 2020 Solar Turbines Incorporated
Copyright 2021 Elsevier B.V., All rights reserved.
- Film Cooling
- Impingement Vortex
- Secondary Flows
- Turbine Aerodynamics
- Turbine Heat Transfer