VORTEX GENERATING FLOW PASSAGE DESIGN FOR It is an object of the invention to provide a film cooling apparatus of increased effectiveness and efficiency. In accordance with the invention, a cooling fluid is injected into a hot flowing gas through a passageway in a wall which contains and is subject to the hot gas. The passageway is slanted in a downstream direction at an acute angle to the wall. A cusp shape is provided in the passageway to generate vortices in the injected cooling fluid thereby reducing the energy extracted from the hot gas for that purpose. The cusp shape increases both film cooling effectiveness and wall area coverage. The cusp may be at either the downstream or upstream side of the passageway, the former substantially eliminating flow separation of the cooling fluid from the wall immediately downstream of the passageway. Vibration and stability of a primary seal ring is controlled by a secondary seal system. An inflatable bladder which forms a portion of secondary seal varies the damping applied to this seal ring. The amplitude of vibration of the primary seal ring is sensed with a proximity probe that is connected to a microprocessor in a control system. The bladder pressure is changed by the control system to mitigate any sensed instability or vibration. METHOD OF FLUXLESS BRAZING AND DIFFUSION BONDING OF ALUMINUM CONTAINING COMPONENTS NASA Case No. MSC-14435-1 Address inquiries to: Inventor: Aleck B. Featherson, et al. Johnson Space Center Canada, Japan Attn: Patent Counsel Corresponding to U.S. Patent No. 3,937,387 Filed 8-12-74 Issued 2-10-76 Aluminum and its alloys are extremely attractive for fabrication into certain components. Among these is the fabrication of radiator panels for use in orbiting satellites. This invention discloses a new welding technique for aluminum alloys namely diffusion bonding or brazing. The salient step of the invention is the use of a polymeric sealer which is applied to clean the surface and which leaves no residue when thermally removed. A method and apparatus for use as a linear frequency chirp in a transmitter/receiver having a correlator to synthesize a narrow beamwidth pattern from otherwise broadbeam transducers when there is relative velocity between the transmitter/receiver and the target. The chirp is produced in a generator in bandwidth, B, and time, T, to produce a time-bandwidth product, TB, that is increased for a narrower angle. A replica of the chirp is time delayed and Doppler shifted for use as a reference in a receiver for correlation of received chirps from targets. This reference is Doppler shifted to select targets preferentially to not only synthesize a narrow beam but also aim the beam in azimuth and elevation. An unsaturated polyester, such as propylene glycolmaleic acid-phthalic acid prepolymer dissolved in styrene interpolymerized with an ultraviolet absorber of the formula: where R and R2 are selected from H or lower alkyl such as mythyl and R1 is tertiary alkyl such as tertiary butyl to form a polymer stable to exposure to the outdoors without degradation by ultraviolet radiation, thermal and/or photooxidation. |