Gas Turbine seeks to produce eco-friendly energy, a device that can convert
chemical energy from natural gas or several fuels into mechanical energy. The increasing
turbine inlet temperature is required to increase the efficiency of the gas turbine, which
has exceeded the melting point limit of the current material. As a result, the
development and cooling technologies of materials that require tolerable durability in
high temperature and high-pressure environments have been studied and applied for
many years.
In this work, the film-cooling technique applied to the first-stage vanes, a
component of turbines, is studied by giving changes in the compound angle and delta
wing geometry of the film cooling hole. The film-cooling technique is the protection of
hot gas in the main flow by forming a film with cooling gas from a small hole in the
part. This may delay or prevent the deterioration of parts.
We first conduct a laser-based flow visualization experiment on the compound
angle of cylindrical holes for 0 ?, 90 ?, and 180 ?. Through the side view and top view, we
analyzed the flow and flow of gas from the hole. Next, we conduct flow visualization
experiments on two cylindrical hole features and delta wing features. The Delta shape is
attached to a cylindrical hole shape with an isostatic triangular structure, referred to in
this study as the delta wing tip, delta wing flop. The Delta shape was also analyzed with
a focus on the flow and flow deviations as shown in the first.
Following the flow visualization, the surface around each hole was photographed
using an IR camera to determine the efficiency of film cooling, which was shown by
converting it into film cooling efficiency. Using this obtained image, a quantitative
graph of the center line and spanwise of each hole was created and displayed.
In conclusion, the application of the delta wing features presented in this paper
made film flow ideal, of which the delta wing flop features showed the best flow and
film cooling efficiency for all blowing ratios.