Numerical analysis on the film cooling of leading edge with laid back holes to determine the optimal angle for the holes

ABSTRACT

In the present paper, investigation of the optimal angle for the holes on the leading edge of a gas turbine blade was carried out considering different blowing ratios in order to assess the local film cooling effectiveness. First, the suitability of different eddy viscosity models compared to experimental results was validated to predict local and average film cooling effectiveness. Computations were performed employing the self-developed object-oriented C++ programming in OpenFOAM CFD package. The realisable k–ε model predicted more accurate results compared to RNG k–ε and standard k–ε models for the average film cooling effectiveness since this model has a variable C_μ which causes sensitivity of this model to the mean flow and turbulence. The results obtained for the average film cooling effectiveness versus the different blowing ratios in the realisable k–ε model for holes oriented 20°, 25°, 30° and 35° showed that the holes at an angle of 25° have better performance in comparison to the other angles.

KEYWORDS:

• Computational fluid dynamic (CFD)
• gas turbine blade
• film cooling effectiveness
• optimum blowing angle

Nomenclature

Table

Subscript

inilnetaveaverage tturbulentxstram-wise direction yvertical direction zlateral direction ∞cross-flowccoolant

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Akbar Mohammadi-Ahmar

Akbar Mohammadi-Ahmar is a PhD candidate in Mechanical Engineering at the University of Tehran. His research interests are numerical modeling, CFD analysis, renewable energy and turbulence modeling.Ali Solati is a PhD candidate in Mechanical Engineering at the University of Tehran. His research interests are numerical modeling, laser material processing, renewable energy and CFD analysis. Jalal Ghasemi is an assistant professor in Mechanical Engineering at the University of Zanjan.  His research interests are numerical modeling, CFD analysis and heat transfer.