Abstract: A fluid impingement arrangement comprising a supply manifold and at least one nozzle exit coupled to the supply manifold. The nozzle exit is arranged as a Coanda surface having a restriction and has at least one static pressure tapping that cross-connects two regions of the restriction to induce passive oscillation in a fluid jet passing through the nozzle exit.

Abstract: A gas turbine engine having a rotational axis, an intake and a compressed gas source; the intake includes a lining having a facing which defines an inlet surface and an array of holes; the array of holes includes at least a first set of holes and a second set of holes, the holes of the first set of holes are angled a relative to a radial line and the holes of the second set of holes are angled ? relative to the radial line; the angles ? and ? are different. An active flow control arrangement including a compressed gas supply pipe, a valve arrangement, a controller, a compressed gas distribution pipe may be provided. Compressed gas may be provided to prevent the formation of separation of a main gas flow through the intake and prevent or remove ice accretion.

Abstract: A fluid impingement arrangement comprising a supply manifold and at least one nozzle exit coupled to the supply manifold. The nozzle exit is arranged as a Coanda surface having a restriction and has at least one static pressure tapping that cross-connects two regions of the restriction to induce passive oscillation in a fluid jet passing through the nozzle exit.

Abstract: An arrangement for reducing vorticity downstream of a turbine nozzle guide vane 34 in a gas turbine engine. The arrangement including directing cooling air through the guide vane 34 and out through outlets 40 in directions to counteract the wave vorticity produced downstream of the guide vane 34.

Abstract: In turbine blades used as nozzle guide vanes 2, 12, 22, 31 for turbine stages of an engine there is a problem with respect to high lift vanes in that there may be significant stagnation point migration about the pressure surface 13, 21, 32 of that vane. In such circumstances, appropriate positioning of coolant flow apertures 11, 24, 34 for coolant film cooling of the vane is difficult. The present invention provides on the leading edge a bulge ridge 37 which limits the range of potential movement for the stagnation point 30 whilst retaining improved lift for higher engine performance. The present invention has particular applicability with flows directed to the turbine NGV which have a significantly variable swirl angle and therefore presentation to the vane 31.