Abstract: In an aero-optical interface for an aircraft optical aperture, the separation of the upstream boundary layer from the edge of the aperture creates a region of turbulance which persists downstream over the full area of the aperture. This invention promotes an early develpment of a steady velocity profile at the upstream aperture edge which is approximately the same as a stable, self-similar shear flow velocity profile over the entire aperture. This is accomplished by thickening the boundary layer upstream of the aperture, and blowing a curtain of air across the aperture from its upstream edge at the point of separation of the boundary flow. This produces a shear flow region foot that causes the overall velocity profile to be equal to a stable self-similar free shear layer.

Abstract: A method and apparatus for providing an aero-optical interface by stabilizing a shear layer in a fluid flowing over an aperture. The apparatus extracts fluid from a remote part of the flowing fluid and conveys it to the underside of the shear layer where it feeds the shear layer and prevents the shear layer from deflecting into the cavity underlying the aperture. A preferred embodiment also includes a ramp downstream of the aperture. Stability of the shear layer is optimized by placing the aperture where the pressure distribution absent the aperture would have been constant. The resulting thin, self-similar shear layer is an optimized viscid flowfield interface for uniform transmission of optical radiation.

Abstract: An apparatus for controlling flow over a surface, especially transonic flow, including means for embedding within the surface small vortices with their axes parallel to said surface and transverse to said fluid flow, and means for driving said vortices.

Abstract: A vacuum deposit device for use in producing thin film depositions. A metallic mass is accelerated along a pair of rail-type electrodes. The discharge current passing through the mass during acceleration is controlled as to magnitude and time duration to insure that the magnetic pinch pressure produced by the current exceeds the thermal expansion pressure of the mass thereby maintaining the mass in a solid, non-vapor state during acceleration. The device permits control over mass exit velocities and permits deposition areas of well defined shoulders.

Abstract: The nozzle and laser channel walls for a supersonic electrical discharge gas laser are formed from fully contoured single pieces of dielectric material. The axially symmetric, two-dimensional wall contours of the combined nozzle and laser channel describe a continuous extension of the subsonic flow plenum, into which the gas is initially introduced, and which is located upstream of the combined nozzle-laser channel. A high precision portion of the contour of the combined nozzle-laser channel extends from a beginning point in the nozzle inlet region near the throat to a termination point which is beyond the nozzle exit plane a distance equal to approximately one-half of the nozzle exit height. The high precision portion is a region of continuous curvature supersonic expansion.