Abstract: A boom for a sailboat is controllably flexible to assume a predetermined specific airfoil-derived contour and to impose an aerodynamically efficient shape on the large lower portion of the sail. The boom is formed of five segments connected by four flex joints. The lengths of the segments and the hinge angles assumed by the flex joints are determined by piecewise approximation of a shape producing a pressure distribution corresponding to the pressure distribution of specific proven airfoil contours, for instance the Joukovsky airfoil profile. Flexure of the boom is achieved by tensioning cables extending along the sides of the airfoil boom. Controlled boom flexure can also be achieved by continuously varying the cross-sectional moment of inertia of the boom to match the radius of curvature of the boom with a specific airfoil profile or by inserting a controllably bendable flexible plate in a pocket along the sail foot.

Abstract: A hollow cylindrical amplifier driven actuator spool has first and second vortex chambers divided by an internal piston. A shaft is attached to the pistion and extends out the cylinder. Fluid logic controls the fluid flow in the vortex chambers so that the resulting chamber pressure causes the piston to accelerate. The use of beam deflection amplifiers for fluid control in connection with a push-pull vortex amplifier arrangement results in a device with low fluid flow leakage.

Abstract: A null balanced fluidic sensing system that is less susceptible to pressure upply disturbances includes sensing and amplifying elements in a closed loop arrangement. The differential output of the sensor, developed as a result of an input stimulus, is fed into the inputs of a single sided amplifier. The output of the amplifier is used as a source of supply for the sensor. This closed loop arrangement uses the null offset characteristics of the elements to create a null balanced fluidic sensing system.

Abstract: A fluidic system for stabilizing movement of a body subject to oscillation at its natural frequency, such as a tank-mounted gun, with appropriate circuitry and controls for notch filtering control output signals at the natural frequency.

Abstract: A trim circuit for compensating for null offset of the jet stream in a flic transducer, such as an amplifier or jet deflection sensor, includes a flow bias control circuit and a supply sensitive difference flow control circuit. The flow bias control circuit supplies fluid pressure to a pair of symetrically disposed control channels at the input end of the transducer. This fluid pressure tends to decrease the amount of null offset of the jet stream from a central axis of the transducer which intersects a pair of symetrically disposed output channels. The supply sensitive difference flow control circuit removes the null offset remaining after correction by the flow bias control circuit. The supply sensitive difference flow control circuit may be disposed in one of the later stages of a cascaded fluidic amplifier chain or at the control inputs of a single stage transducer or amplifier.

Abstract: A fluidic driver amplifier for a servovalve has its controllably directed fluid jet differentially divided by a divider element which moves with a main valve piston in a manner to equalize the differential pressure received from the jet when the piston reaches the commanded position. In order to permit use of a small, low-leakage, fluidic driven amplifier, without the disadvantage of reduced speed of response, a derivative piston is linked to move with the main piston and displace fluid in a chamber containing a spring-centered secondary valve piston. When displaced, the secondary piston admits pressurized fluid into the main valve chamber in a positive feedback sense to aid the fluidic driver in positioning the main piston. The secondary piston is displaced only when the main piston is in motion and therefore has no effect once the main piston reaches the commanded position.

Abstract: A fluidic system for stabilizing movement of a body subject to oscillation at its natural frequency, such as a tank-mounted gun, with appropriate circuitry and controls for notch filtering control output signals at the natural frequency.

Abstract: The temperature sensors shown utilize a constant frequency fluidic oscillr to excite resonance tubes, whose frequency response is a function of temperature. The outputs of these sensors control a fluidic amplifier, whose output is rectified and filtered to produce a D.C. fluid signal which is a function of the sensed temperature. Different embodiments utilize resonance tubes excited in phase or 180.degree. out of phase to sense the difference between two temperatures or to provide increased sensitivity.

Abstract: A fluidic flow or pressure regulator which utilizes a linear and a non-lir resistance arranged in parallel supplying control passages to change the direction of a jet as a function of the pressure of an unregulated fluid source. An output means is provided which can supply fluid having pressure which is a desired function of the unregulated pressure, including a constant pressure. One embodiment forms the variable direction jet solely from the two control passages while another embodiment uses the control passages to change the direction of a power jet.

Abstract: A fluidic throttling flow controller for controlling core cooling flow in a uclear reactor. Increased temperature of cooling flow adajcent the core increases the flow adjacent the core and is used to control a focused jet amplifier which in turn controls a vortex valve to reduce flow and shut down the reactor when overheating occurs.

Abstract: Described herein is a flueric laminar bi-stable amplifier. The device comses essentially a flueric amplifier having a supply nozzle, a pair of outlet nozzles, a pair of control nozzles, vent means located along the axial path of fluid flow and means for providing a supply of pressure to the vent means so as to maintain the vent pressure above ambient pressure. Means are also provided for grounding the control ports and for providing back pressure to the control ports. Essentially, the device is a flueric laminar flip-flop that does not use the Coanda effect, but rather it relies upon the instability of jet position due to vent pressurization. If vent flow is allowed to enter the control region in excess of that demanded by entrainment and the control port is vented to ambient, then any small perturbation will cause more flow to enter one side and less on the other, thereby increasing the pressure differential and causing the jet to deflect more until it reaches a stable position on one side or the other.

Abstract: A laminar fluidic device for sensing fluid properties that affect viscosity s disclosed, the device comprising a source of supply for directing a jet of fluid outwardly from a nozzle, a pair of control channels disposed on opposite sides of the jet of fluid for deflecting the jet in response to a difference in the resistence of one control channel with respect to the other control channel, such resistence difference effecting a pressure differential across the jet, a pair of output channels for receiving the jet of fluid in accordance with the deflection thereof, and vent means disposed between the nozzle and the output channels. Each of the control channels normally exhibits channel resistence equal to the jet edge resistence and this normal channel resistence is brought about through a preselection of the control channel length, which length is contemplated to be approximately 70 times the width of the nozzle.