Bump and trench modifications to film-cooling holes at the vane-endwall junction

N. Sundaram, K. A. Thole

Research output: Contribution to journalArticlepeer-review

53 Scopus citations


The endwall of a first-stage vane experience high heat transfer and low adiabatic effectiveness levels because of high turbine operating temperatures and formation of leading edge vortices. These vortices lift the coolant off endwall and pull the hot mainstream gases toward it. The region of fucos for this study is the vane-endwall junction region near the stagnation location where cooling is very difficult. Two different film-cooling hole modifications, namely, trenches and bumps, were evaluated to improve the cooling in the leading edge region. This study uses a large-scale turbine vane cascade with a single row of axial film-cooling holes at the leading edge of the vane endwall. Individual hole trenches and row trenches were placed along the complete row of film-cooling holes. Two-dimensional semi-elliptically shaped bumps were also evaluated by placing the bumps upstream and downstream of the film-cooling row. Tests were carried out for different trench depths and bump heights under varying blowing ratios. The results indicated that a row trench placed along the row of film-cooling holes showed a greater enhancement in adiabatic effectiveness levels when compared to individual hole trenches and bumps. All ggmetries considered produced an overall improvement to adiabatic effectiveness levels.

Original languageEnglish (US)
Article number041013
JournalJournal of Turbomachinery
Issue number4
StatePublished - Oct 2008

All Science Journal Classification (ASJC) codes

  • Mechanical Engineering


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