摘要 |
A fluid-cooled element for partially defining hot gas flow passage extending upstream and downstream of a minimum area throat. A serpentine conduit of fluid communication with a coolant source routes cooling fluid within the downstream portion of the element wall bounding the hot gas passage to an internal pocket upstream of the throat. The coolant is thereafter exhausted upstream of the throat as a film over the wall. The upstream wall portion is cooled by the known impingement and film-cooling technique resulting in an element wherein all of the coolant enters the hot gas passage in a low Mach number region upstream of the throat, thereby minimizing momentum losses due to mixing. In the preferred embodiment, the passage throat is defined by a plurality of turbine nozzle vanes, the fluid-cooled element comprising a nozzle band thereof. Flanges support the nozzle within a gas turbine engine and are located upstream of the nozzle throat so as to provide a barrier which minimizes coolant leakage downstream of the throat.
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