The first stage turbine of a modern gas turbine is subjected to high thermal loads which lead to a need for aggressive cooling schemes to protect its components from melting. Endwalls are particularly challenging to cool due to the complex system of secondary flows near them that wash the protective film coolants into the mainstream. This paper shows that without including combustor cooling, the complex secondary flow physics are not representative of modern engines. Aggressive injection of all cooling flows upstream of the passage is expected to interact and change passage aerodynamics and, subsequently, mixing and transport of coolants. This study describes, experimentally, the aero-thermal interaction of cooling flows near the endwall of a first stage nozzle guide vane passage. The test section involves an engine-representative combustor-turbine interface geometry, combustor coolant flow and endwall film cooling flow injected upstream of a linear cascade. The approach flow conditions represent flow exiting a cooled, low-NOx combustor. This first part of this two-part study aims to understand the complex aerodynamics near the endwall through detailed measurements of passage three-dimensional velocity fields with and without endwall film cooling. The aerodynamic measurements reveal a dominant vortex in the passage, named here as the Impingement Vortex, that opposes the passage vortex formed at the airfoil leading edge plane. This Impingement Vortex completely changes our description of flow over a modern film cooled 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
- Passage Vortex
- Secondary Flows
- Turbine Aerodynamics