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.