Computational Analysis of a Novel Cooling Scheme for Ultra Compact Combustor Turbine Vanes

Abstract

The Ultra Compact Combustor (UCC) has the potential to improve overall engine efficiency at a reduced size, while offering a unique component configuration that can allow for novel cooling of turbine vanes located below the circumferential cavity. In this configuration the leading edge of the turbine vane is located upstream of the combustor, with hot gases impinging near 1/5-chord and aft to the trailing edge. Therefore the leading edge remains in a cold region of the flow allowing openings in the stagnation region of the vane to ingest cool core flow. A computational fluid dynamics (CFD) analysis is presented that analyzed stagnation fed cooling variations for the current UCC turbine vane. The variants included several internal only cooling schemes and one external film cooling scheme. The internal only variants showed that with proper component geometry the internal pressure could exceed the external pressure downstream from the leading edge. The film cooling hole variant showed that coolant did in fact exit the vane through 3 of the 8 cooling holes in a similar fashion as a compressor fed scheme. The determination if coolant would exit the holes was highly dependent on the external pressure gradient on the vane.