Abstract: In a heat exchanger of the plate-fin type through which two fluid streams of different temperatures are passed through alternate layers in a cross-flow arrangement whereby heat transfer occurs between the two fluid streams, solid closure bars attached to the heat exchanger core are shaped and arranged in a manner such that the closure bars form a continuous protruding flange at the corners or along the length of the heat exchanger core. The headers, which previously were welded directly to the heat exchanger core, are now welded to the flange, thereby preventing damage to the brazed heat exchanger core components and adding flexibility between core and headers during thermal cycling. In a preferred embodiment the closure bars on one face of the heat exchanger have an "L" shape with the "L" extending away from the core, and the closure bars on the adjacent face are straight and extend beyond the edge of the core the same distance as the extended "L" and in the same plane to form a straight flange.

Abstract: In an air conditioning system for a load, air is used as the refrigerant, and identical components including a turbocompressor and a regenerative heat exchanger are used for both cooling in the refrigeration mode and heating in the heat pump mode. A plurality of valves are arranged so that in the refrigeration mode the refrigerant air operates in a closed dry air loop to avoid problems associated with moisture. In the heat pump mode the valves are arranged to cause the refrigerant air to operate open loop by using ambient air as the input to the cycle, and avoiding icing problems by rejecting the refrigerant air, together with any ice present, back into the ambient. Operation closed loop in the refrigeration mode and open loop in the heat pump mode results in maximum cycle efficiency with minimum difficulty caused by moisture entrained in the refrigerant air.

Abstract: A turbosupercharging system for internal combustion engines, both otto cycle and diesel cycle, simultaneously varies the geometry of both the compressor discharge diffuser housing and the turbine inlet nozzle housing in a fixed relationship. The geometry variation is preferably accomplished by a single actuator which is positioned for optimum turbomachine geometry by a control responsive to selected engine parameters such as engine output torque demand and/or internal combustion engine volume flow. The variable geometry turbosupercharger effectively changes the size of the machine for varying engine operating conditions resulting in increased efficiency over the entire engine operating range.

Abstract: An air cycle heat pump uses a regenerative heat exchanger to provide warm air to heat a load, while at the same time providing fresh air to the load. The stale air returned from the load is utilized as the refrigerant air in an electrically driven regenerative air cycle heat pump, and no additional heat exchangers are required, thereby significantly reducing the electric power needed for heating the load. A turbine-driven compressor is used to raise the stale load air in pressure and temperature and, after giving up some of its heat to the fresh ambient air used to heat the load, the compressed refrigerant air performs useful work in the expansion turbine before being returned to ambient.

Abstract: In a fluid pumping system in which a fluid is pumped from a fluid supply to a load, two continuously driven fixed displacement pumps are operated in parallel to provide the pumping action. The two pumps are arranged with a common inlet, and with a common outlet, the flow delivered to the load from one of the two pumps passing through a check valve upstream of the common outlet. The fluid flow is regulated to provide a constant pressure by sequentially bypassing fluid around each pump through separate pump bypass ducts. This sequential fluid bypassing or pump unloading is effected by a single control responsive to the flow requirements of the load necessary to maintain that constant pressure. The pump whose delivered flow outlet contains the check valve is the pump whose flow is bypassed initially when less than full pumping capacity is desired. During maximum flow demand operation, both pumps are delivering against full delivery pressure.

Abstract: A large wind turbine rotor blade having a filament wound composite spar securely mounted to a support structure in a manner by which blade loads are transmitted via redundant load paths. Concentric inner and outer metallic adapter sleeves are bonded to the inboard end of the blade spar, and the adapter sleeves and blade spar are joined by a first series of shear bolts and nuts which pass radially through the spar. A second series of radially extending bolts and nuts join the inner and outer sleeves slightly inboard of the end of the spar. The end of the spar is of slightly reduced diameter forming a conical surface which interacts with the inner and outer sleeves to produce a positive lock when the blade is subject to centrifugal loads. The outer sleeve is adapted to be connected to the support structure by conventional techniques such as by a plurality of bolts which extend axially into the butt end of the outer sleeve.

Abstract: In a compressed air powered refrigeration system for aircraft containing a refrigeration turbine and associated heat exchangers for supplying cool air to the aircraft cabin, air is recirculated from the cabin by a recirculation means and combined with the turbine discharge air to simultaneously melt ice present in the turbine discharge and provide cooling to the recirculated air. The lack of ice in the turbine discharge allows the use of an ice-free regenerative heat exchanger, in heat exchange relation with the mixture of the turbine discharge air and recirculated cabin air, to condense moisture from the air entering the turbine. The use of heat from the cabin air to melt ice coupled with maximum utilization of the recirculation means supplying the recirculating cabin air enables the turbine to provide air at a temperature below freezing and results in improved cycle efficiency as well as maximum possible ventilation rate to the load.

Abstract: Two fluid streams of different temperatures flow through two concentric pipes, the flow of each stream being modulated to achieve a desired mixture temperature. An in-line slide valve is interposed in one fluid flow path, and an in-line poppet valve is interposed in the other fluid flow path. A thermally responsive element is positioned downstream to sense the temperature of the mixed fluid stream, the element being connected via a rod to both the slide valve and the poppet. When the mixture temperature varies from a preselected temperature, the thermally responsive element moves the rod to gradually close the slide valve and open the poppet, or gradually close the poppet and open the slide valve, thereby changing the flow of both fluid streams and maintaining the desired mixture temperature.

Abstract: A multi-mode electronic wind turbine control system establishes a reference blade angle for a two-bladed, horizontal axis, variable pitch wind turbine rotor, the blade angle being regulated by a hydraulic pitch change mechanism. The rotor, via appropriate shafts and a gearbox, is coupled to a synchronous generator to produce electrical energy which is fed to a power utility grid. The control system provides closed loop pitch control for rotor acceleration rate during start-up, for rotor deceleration rate during shutdown, for speed control when the synchronous generator is off-line, and for power control when the synchronous generator is on-line. A single control integrator is used for all closed loop operating modes, with a rate limiter circuit in front of the control integrator to prevent integrator overtravel. The integrator has maximum and minimum blade angle stops, the minimum stop being variable as a function of rotor speed and wind speed.

Abstract: A power generating system includes a wind turbine driven generator, the wind turbine having a wind turbine driven rotor with a variable pitch angle blade. Stresses on the system during startup and shutdown are minimized by scheduling the blade angle as a function of the rotor speed and wind velocity to provide a minimum blade angle relative to the fully powered blade angle during rotor acceleration, and to provide a minimum blade angle relative to the fully powered blade angle during rotor deceleration.

Abstract: A water separator consisting of a baffle and scupper is inserted inside the outlet header of a regenerative heat exchanger for removing water from the air discharged therefrom. The cooled air which contains water droplets leaving the core of the heat exchanger is passed through a baffle constructed to provide a gradual restriction in area in order to increase flow velocity. Heavy droplets of water are separated by the sudden change in airflow direction through the baffle and header. The flow including the heavier centrifuged water droplets then impinge on the inside surface of the header to which the accumulated particles of water adhere and are accelerated by the airflow and the contour of the header toward a scupper located downstream of the baffle opening. The water is collected in the scupper cavity, collected in a drain well, and drained with the assistance of gravity and the resulting pressure differential across the drain port.

Abstract: A small diameter, highly loaded multiple bladed variable pitch propulsor having swept blades with thin advanced airfoil sections, integrated with a nacelle contoured to retard the airflow through the blades thereby reducing compressibility losses and designed to operate with a turbine engine and using a single stage reduction gear resulting in a high performance, lightweight propulsion system providing a substantial improvement in efficiency over the high bypass ratio turbofan engine.

Abstract: A power generating system includes a wind turbine driven generator, the wind turbine having a wind driven rotor with a plurality of variable pitch angle blades. The blade angle is scheduled during acceleration and deceleration of the wind turbine by open loop controls to minimize stresses, and is scheduled during powered operation by closed loop controls to maintain desired torque or speed. The closed loop controls contain an integrator which produces an integral blade angle control signal. The scheduled blade angle is fed back to the integrators through an integrator tracking network to maintain the integral blade angle control signal at all times within a preselected range relative to the scheduled blade angle.

Abstract: The contaminants in the exhaust gas emissions from a motor vehicle such as carbon monoxide (CO) and hydrocarbons (HC) are analyzed within a nondispersive infrared analyzer which includes means for assuring that the vehicle being tested has achieved a predetermined engine speed and that no blockage has occurred in the gas transport system when the measurements are made.

Abstract: Wind energy is used to drive a wind turbine, which is in turn connected to an electrical generator to produce electrical power. The pitch angle of the wind turbine blades is controlled in a closed loop manner to maintain either a constant generator speed for isolated power generating stations or when the generator is synchronized to the load, or constant generator output power or shaft torque when the generator is connected to an electrical grid. Open loop acceleration and deceleration schedules are provided to minimize blade stress and shaft torque variations during start up and shutdown transients, limiting blade angle excursions as a function of wind velocity and speed. The schedules may be implemented either electronically or by a suitably programmed digital computer. The gains in the speed, torque and power loop controls are scheduled as a function of average wind velocity to optimize stability and response.

Abstract: A capacitive coupled clamp-on voltage probe having three concentric cylindrical capacitive plates each separated by a thin dielectric is adapted to be clamped onto an insulated wire such as the ignition wire in an automobile to measure the potential of the wire. In one embodiment the probe contains a solid dielectric center with a slot along its longitudinal axis which extends radially from the outside to the center of the probe thereby allowing the probe to be easily positioned over and released from an automobile ignition wire by slipping the probe over any insulated portion of the wire. The slot is dimensioned to hold the wire securely at the center of the probe. The probe also includes a releasable clamp having a thumb actuated lever to assist in maintaining the wire securely at the probe center and to permit easy positioning and release of the wire.

Abstract: A nonlinear delay line correlator and convolver is described which comprises a tapped, piezoelectric surface acoustic wave delay line and an array of series or parallel connected forward biased semiconductor diodes. An interdigital signal transducer is connected to each end of the delay line and voltages are applied to each transducer to generate contra-flowing acoustic strain waves which are radiated toward an interaction region comprising a plurality of equi-spaced weakly coupled interdigital transducers, each transducer being connected to one diode. Nonlinear signal mixing in the diode array is utilized to perform serial product convolution or correlation of the signal modulation applied at the two signal input transducers. Because of the large nonlinearity of semiconductor diodes, insertion loss is relatively low.