Purpose -The present study aims to conduct a numerical investigation of a novel film cooling scheme combining in-hole impingement cooling and flow turbulators with traditional downstream film cooling, and was originally proposed by Pratt & Whitney Canada for high temperature gas turbine applications. Design/methodology/approach -Steady-state simulations were performed and the flow was considered incompressible and turbulent. The CFD package FLUENT 6.1 was used to solve the Navier-Stokes equations numerically, and the preprocessor, Gambit, was used to generate the required grid.Findings -It was determined that the proposed scheme geometry can prevent coolant lift-off much better than standard round holes, since the cooling jet remains attached to the surface at much higher blowing rates, indicating a superior performance for the proposed scheme.Research limitations/implications -The present study was concerned only with the downstream effectiveness aspect of performance. The performance related to the heat transfer coefficient is a prospective topic for future studies. Practical implications -Advanced and innovative cooling techniques are essential in order to improve the efficiency and power output of gas turbines. This scheme combines in-hole impingement cooling and flow turbulators with traditional downstream film cooling for improved cooling capabilities. Originality/value -This new advanced cooling scheme both combines the advantages of traditional film cooling with those of impingement cooling, and provides greater airfoil protection than traditional film cooling. This study is of value for those interested in gas turbine cooling.

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