Large eddy simulation of compound angle effects on cooling effectiveness and flow structure of fan-shaped holes

Ali Zamiri, Jin Taek Chung

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

Large eddy simulation (LES) was utilized to investigate the influence of applying various compound angle (CA), on film-cooling effectiveness and turbulent flow structures. The baseline cooling hole was a 7-7-7 laidback fan-shaped hole, where this hole is located at a flat plate surface with a pitchwise spacing of 6D, and the hole was inclined at 30-degrees with respect to the mainstream hot-gas flow. Five different cooling hole orientations (CA0, CA15, CA30, CA45 and CA60) were numerically simulated using a constant density ratio of 1.5 and two blowing ratios (M = 1.0 and 3.0). The time-averaged computational results for the thermal and flow fields were validated by comparison with experimental data from previous literature. The simulation results revealed that under a low blowing ratio (M = 1.0), cooling performance was not affected significantly by the compound angle, but at the higher blowing ratio there was a considerable improvement of 40% for the CA60 hole over the CA0 hole, this improvement was especially pronounced in the lateral direction. The vorticity-field investigation showed that as the compound angle increased, the magnitude of the streamwise vorticity also increased while it becoming more asymmetric. In addition, time-space evaluation and spectral analysis of the velocity fluctuations indicates higher unsteadiness and greater turbulent statistics when using holes with larger compound angles.

Original languageEnglish
Article number121599
JournalInternational Journal of Heat and Mass Transfer
Volume178
DOIs
Publication statusPublished - 2021 Oct

Keywords

  • Compound angle
  • Gas turbine
  • Laidback fan-shaped hole
  • Large eddy simulation

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanical Engineering
  • Fluid Flow and Transfer Processes

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