Abstract: Aircraft engine cooling apparatus having a plurality of cooling gas inlet nozzles, producing first streams of cooling gas moving in a forward direction, a plurality of first direction reversal members for splitting the first streams into second and third streams straddling the nozzles, and substantially reversed in direction relative to the direction of the first streams, a plurality of second direction reversal members, positioned between pairs of adjacent nozzles, for again substantially reversing the directions of the second and third streams, while combining the second and third streams to form a fourth stream of laminar flow cooling film, and wherein adjacent pairs of the first direction reversal members have wall portions configured to form gradually diverging channels through which the fourth stream cooling film moves.

Abstract: A blade vibration damper for a rotor assembly of an axial flow machine seats simultaneously on a radially inwardly facing surface of a blade platform and the radially inwardly facing surface of an adjacent element, such as the platform of a circumferentially adjacent blade. The damper has its mass center of gravity nearer one contact area than the other so as to reduce the normal load on the blade platform generated by centrifugal force. By properly locating the center of gravity of the damper, the size of the normal force can be optimized to maximize damping.