Numerical Modeling of Film Cooling from Short Length Stream-Wise Injection Holes

Abstract.

This paper reports a numerical modeling and simulation studies of film cooling from stream-wise injection holes with various small hole length to diameter ratios, using a standard k-ɛ turbulence model with wall function. An anisotropic model was also applied in order to correct the deficit in lateral spreading of the k-ɛ model.

Comparisons of the present predicted results with experimental data and numerical results of previous studies show that using anisotropic turbulence model, multi-block grid techniques and extending the computational domain into the plenum supply of the injection holes tend to improve the prediction of the film cooling effectiveness especially at low blowing rates while for high blowing rates a more detailed description than the wall law approach is needed to describe the lift-off of the jet. Moreover, the film cooling protection is reduced as the hole L/d ratio is decreased.