Abstract: An apparatus for the creation of an impingement jet generating annular swirls includes a fluidic switching element having an inlet branch with an inlet opening via which cooling gas can be supplied to the fluidic switching element, outlet branches provided downstream of the inlet branch and ending each in an outlet opening, a branching point at which the inlet branch splits into the outlet branches, and control means for controlling the cooling gas flowing in the inlet branch such that the cooling gas is routed alternatingly into the one or the other of the outlet branches, with an impingement jet pulsating at a frequency being generated in each outlet branch. The fluidic switching element is designed and provided for emitting cooling gas at the outlet openings with a mean outflow velocity and a frequency such that the impingement jet exiting the outlet openings forms annular swirls.

Abstract: The present invention relates to an apparatus and a method for the creation of an impingement jet (P) generating annular swirls (7). The apparatus includes at least one fluidic switching element (1, 1?) having an inlet branch (2) with an inlet opening (21) via which cooling gas (G) can be supplied to the fluidic switching element (1), at least two outlet branches (31, 32) provided downstream of the inlet branch (2) and ending each in an outlet opening (8), a branching point (4) at which the inlet branch (2) splits into the at least two outlet branches (31, 32), and control means (31, 32, S) for controlling the cooling gas (G) flowing in the inlet branch (2) such that the cooling gas (G) is routed alternatingly into the one or the other of the outlet branches (31, 32), with an impingement jet (P) pulsating at a frequency (f) being generated in each outlet branch (31, 32).

Abstract: In impingement air cooling of gas turbine components, cooling air velocity packs of a certain amplitude and a given frequency are applied to impingement air openings, with intervallic annular swirl structures being formed which penetrate a cross-flow and hit a component to be cooled with high intensity, thus providing for efficient cooling. In order to obtain annular swirl structures with optimum cooling effect, the Strouhal number, which is determined by a ratio of amplitude, frequency of the velocity packs and size of impingement air cooling openings, ranges between 0.2 and 2.0, and preferably between 0.8 and 1.2.

Abstract: In impingement air cooling of gas turbine components, cooling air velocity packs of a certain amplitude and a given frequency are applied to impingement air openings, with intervallic annular swirl structures being formed which penetrate a cross-flow and hit a component to be cooled with high intensity, thus providing for efficient cooling. In order to obtain annular swirl structures with optimum cooling effect, the Strouhal number, which is determined by a ratio of amplitude, frequency of the velocity packs and size of impingement air cooling openings, ranges between 0.2 and 2.0, and preferably between 0.8 and 1.2.