Flow measurements in a first stage nozzle cascade having endwall contouring, leakage and assembly features

J. D. Piggush, Terrence W Simon

Research output: Contribution to conferencePaper

6 Scopus citations

Abstract

This work supports new gas turbine designs for improved performance by evaluating the use of endwall contouring in a cascade that is representative of a first stage stator passage. Contouring accelerates the flow, reducing the thickness of the endwall inlet boundary layer to the turbine stage and reducing the strength of secondary flows within the passage. Reduction in secondary flows leads to less mixing in the endwall region. This allows improved cooling of the endwall and airfoil surfaces with injected and leakage flows. The present paper documents component misalignment and leakage flow effects on the aerodynamic losses within a passage having one contoured and one straight endwall. Steps on the endwall and leakage flows through the endwall can lead to thicker endwall boundary layers, stronger secondary flows and possibly additional vortex structures in the passage. The paper compares losses with steps of various geometries and leakage of various flow rates to assess their importance on aerodynamic losses in this contoured passage. In particular, features associated with the combustor-to-turbine transition piece and the slashface gap, a gap between two vane segments on the vane platform, are addressed. An n-factorial study is used to quantify the importance of such effects on aerodynamic losses.

Original languageEnglish (US)
Pages345-357
Number of pages13
DOIs
StatePublished - Nov 23 2005
EventASME Turbo Expo 2005 - Gas Turbie Technology: Focus for the Future - Reno-Tahoe, NV, United States
Duration: Jun 6 2005Jun 9 2005

Other

OtherASME Turbo Expo 2005 - Gas Turbie Technology: Focus for the Future
CountryUnited States
CityReno-Tahoe, NV
Period6/6/056/9/05

Keywords

  • Contouring
  • Endwall
  • Film cooling
  • Heat transfer
  • Leakage
  • Nozzle
  • Secondary flows
  • Turbine vane

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    Piggush, J. D., & Simon, T. W. (2005). Flow measurements in a first stage nozzle cascade having endwall contouring, leakage and assembly features. 345-357. Paper presented at ASME Turbo Expo 2005 - Gas Turbie Technology: Focus for the Future, Reno-Tahoe, NV, United States. https://doi.org/10.1115/GT2005-68340