Gas Turbine Engine Cooled Turbine Vane Feather Seal Leakage Reduction

Feather seals are used to seal the gaps between the stator vanes in the turbine section of the engine. Currently, there is no way to evaluate leakage through these seals on an operating jet engine, nor does the sponsor have a static test rig that can quantify this air mass leakage. A static test rig was designed that uses sonic nozzles in the choked flow condition. The rig measures ambient pressure and pressure differentials upstream and downstream of these nozzles, and the temperature inside the pressure vessel. The test rig takes in compressed shop air, which flows through sonic nozzles maintained in the choked flow condition by pressure differentials. The pressurized air enters a pressure vessel that houses six feather seals. The small amount of air that flows past the feather seals and into the atmosphere can be quantified using pressure and temperature data. This data can then be used to calculate air mass flow through the feather seals. The rig can test six seals of the same design at once, allowing average leakage to be calculated for any given design. A variety of seal designs can be installed and tested in the rig to determine which design creates the best seal.