The field of the disclosure relates generally to gas turbine engines and, more particularly, to compressor bleed assemblies and their associated locations in turbomachines and methods of extracting compressor airflow.
At least some known turbomachines, i.e., gas turbine engines, include a compressor that compresses air via a plurality of rotatable compressor blades adjacent to a stationary stator row, and a combustor that ignites a fuel-air mixture to generate combustion gases. The combustion gases are channeled through rotatable turbine blades in a turbine via a hot gas path. Such known turbomachines convert thermal energy of the combustion gas stream to mechanical energy used to generate thrust and/or rotate a turbine shaft to power an aircraft. Output from the turbomachine may also be used to power a machine, for example, an electric generator, a compressor, or a pump.
Many of these known turbomachines include compressor bleed systems that extract compressed air from the compressor for a variety of applications and functions, including, but not limited to, turbine cooling, customer bleed flow applications, and/or engine start/high throttle operating conditions. Generally, the bleed location on a compressor wall is downstream of the stator row and extends around the annulus of the wall. Extracting high pressure compressed air from this compressor wall location may cause flow turbulence within the compressor, thereby reducing engine performance. Additionally, when turbomachines encounter operating conditions with a high level of dust particles, the dust particles may be centrifuged within the compressor thereby increasing the likelihood of entering the bleed system and further reducing engine performance. For example, during compressor bleed for turbine cooling, dust particles can enter the cooling air circuits, accumulating around small features such as rims, film cooling holes, and turbulators, decreasing the effectiveness of cooling the high temperature components, and preventing cooling bleed air from directly contacting heat transfer surfaces of the high temperature components.