Computational predictions of endwall film-cooling for a first stage vane

In gas turbine development, the direction has been higher turbine inlet temperatures to increase the work output and thermal efficiency. This extreme environment can significantly impact component life. One means of preventing component burnout in the turbine is to effectively use film-cooling whereby coolant is extracted from the compressor and injected through component surfaces. One such surface is the endwall of the first stage nozzle guide vane. This paper presents results from a computational study of two endwall film-cooling hole patterns combined with cooling from a flush slot that simulates leakage between the combustor and turbine sections. Results indicate reasonable agreement between predictions and measurements of the turbine endwall cooling for a flush slot alone. Effectiveness predictions showed an increase in film cooling flow was needed for both hole patterns to insure coolant was present near the pressure side of the vane. Results also indicated that superposition overpredicted the effectiveness levels along the endwall for the combined endwall film-cooling and slot cooling configurations.