Abstract: A horizontal inlet section of a jet engine diffuser extends to a transitional curved section which, in turn, extends to a horizontal outlet section offset from the horizontal inlet section to shield observation of infrared and microwave signals from a downstream jet engine. A vane between the inlet and transitional curved sections further shields the observable signals and deflects inlet airflow against the interior wall of the diffuser for minimizing separation of boundary layer airflow from the wall. A backward facing slot is formed in the wall transversely adjacent the vane for effecting low energy boundary airflow to further minimize boundary layer airflow separation.

Abstract: A visible, or near to mid infra-red, hypersonic gasdynamic laser system incorporated in a hypersonic vehicle which provides high enthalpy ram air for thermodynamic excitation of the laser gases. The hypersonic vehicle defines therein a laser cavity, and ram air directed therethrough supports gasdynamic lasing operations at wavelengths less than 10.6 .mu. meters. An optical train collects the laser radiation from the laser cavity and directs it as a substantially collimated laser beam to an output aperture defined by an opening in the hypersonic aircraft too allow the laser beam to be directed against a target. The present invention is particularly applicable to a hypersonic vehicle powered by a supersonic combustion ramjet engine. Electrical energy is also produced on-board the vehicle, using ram air, or ram air plus fuel combustion, as the power source and an electrical turbogenerator (or another equivalent electrical generator) connected to a supersonic turbine.

Abstract: A diffuser for augmenting a wind turbine having means for energizing the boundary layer at several locations along the diffuser walls is improved by the addition of a short collar extending radially outward from the outlet of the diffuser.

Abstract: A wind powered electrical generating system having a suitable shaped aerodynamic duct or shroud within which a wind turbine having a fixed pitch blade is mounted, as by means of a stator means at the inlet of the duct or shroud with the stator means including mechanism for varying their effective angle of attack with regard to the approaching wind so as to provide the desired swirling approach of the wind to the turbine therebehind in achieving the desired torque and speed of shafting from the turbine to generator driven by the turbine in maintaining constant phase and frequency of the electrical output wherein the duct or shroud is mounted by a tower or shaft that will permit the cocking of the structure into the wind.

Abstract: Pseudo sound created by the interaction of fluid flowing over a discontinuity in a conduit is sensed by a transducer. The transducer signal is reduced to a frequency-amplitude distribution and the amplitude at the characteristic frequency is used to calculate fluid flow rate using a dipole model. The apparatus is non-intrusive and passive. Several transducers may be serviced by a single central, processor remote from the transducer site.Alternative apparatus provides for the determination of change in fluid flow direction and fluid density.