Abstract:
The invention refers to an arrangement for sealing an open cavity against hot gas entrainment. The open cavity is arranged between two axially adjacent stationary components limiting radially a hot gas path of a rotary flow machine, of which at least the downstream component carries at least one airfoil extending radially into said hot gas path. A multitude of air jets is directed into the open cavity such that hot gas flowing over the open cavity is prevented from penetrating into the open cavity completely. The invention has an arrangement of supply conduits for air jets which are directed into the open cavity with a jet momentum such that hot gas is induced not to enter the open cavity and forming at least one hot gas vortex close to the hot gas path within the open cavity and preventing hot gas from penetrating into the open cavity beyond the extension of the hot gas vortex.
Abstract:
A gas turbine is provided having a secondary combustion chamber and a first guide vane row of a low-pressure turbine, the row being arranged directly downstream of the chamber. The radially outer boundary of the secondary combustion chamber is formed by at least one outer wall segment, which is secured on at least one support element arranged radially outwardly. The flow path of the hot gases is bounded radially outwardly, in the region of the guide vane row, by an outer platform which is secured at least indirectly on at least one guide vane support. A substantially radially extending gap-shaped cavity having a width in the range of 1-25 mm in the axial direction in the inlet region is arranged between the wall segment and the outer platform. At least one step element, which reduces the width by at least 10% in at least one step, extending substantially perpendicularly to the direction of flow of the hot gas in the cavity, is arranged in the inlet region.