Method for testing variable cooling geometries in a turbine vane

1. A method for designing an air cooled turbine airfoil used in a gas turbine engine comprising the steps of:

selecting a number of different internal cooling air circuits for an airfoil;

forming a ceramic core for each of the number of internal cooling air circuits;

forming an airfoil surface over each of the ceramic cores using a metal additive manufacture process;

removing each of the ceramic cores from the airfoils;

placing the airfoils in an engine or a test rig all in one stage;

passing a hot gas stream through the stage of airfoils under similar conditions to a real engine operation;

passing cooling air through each of the internal cooling air circuits of the airfoils;

measuring a pressure and temperature difference for each of the different cooling air circuits; and,

from the measurements, determining which internal cooling air circuit has the best performance.

2. The method for designing an air cooled turbine airfoil of claim 1 , and further comprising the step of:

the metal additive manufacture process includes an electron beam melting, or an electron beam welding, or a digital direct manufacture, or a metal printing process.

3. The method for designing an air cooled turbine airfoil of claim 1 , and further comprising the step of:

the number of different internal cooling air circuits is equal to a number of airfoils in a stage of the turbine.