1356 results about "Angle of attack" patented technology

A method, apparatus, and computer program product for identifying air data for an aircraft. The lift for the aircraft is identified. The number of surface positions for the aircraft is identified. The angle of attack during flight of the aircraft is identified. A synthetic dynamic pressure is computed from the lift, the number of surface positions, and the angle of attack.

Smooth, preferably variable-sweep fluid collection device surfaces disposed into opposition with wind, river, surf, ocean or tidal currents generate enhanced velocity fluid flows at length driven into onboard work-extracting disc turbines at advantageous angles of attack. Keyed to shafts turning freely through optionally extendable volutes, disc turbines comprising a dense population of smooth, axially fixed or adjustably spaced discs conducting preferably laminar flow between adjacent elements develop significant torque through boundary layer adhesion and viscous shear-stress between fluid layers. Exhaust of disc turbine throughput into divergent channels drafting into external currents of initially higher than ambient velocity and lower pressure may reduce turbine discharge backpressure, rapidly clear system throughput, and allow normally disadvantageous drag to be utilized to develop greater work generation. Gainfully turning with, instead of at odds to natural or anthropogenic currents provided, disc turbines utilized as disclosed may provide unprecedented renewable energy from fluids in motion.

A screeding apparatus for screeding and smoothing an uncured concrete surface includes a vibrating member and a grade setting device adjustably mounted to said vibrating member. The screeding apparatus may include a wheeled support which at least partially supports the vibrating member and/or the grade setting device. The grade setting device is vertically adjustable, such as via a laser plane responsive control system, to set or indicate the desired grade of the concrete surface as the screeding apparatus is moved over and through the uncured concrete. The level of the screeding apparatus may be automatically adjustable to maintain a desired level and angle of attack of the vibrating member. The vibrating member may be activated only when the screeding apparatus is moved in a screeding direction so as to reduce depressions that otherwise may occur if the vibrating member vibrates on the uncured concrete when not moving.

The composite rotating fixed-wing aircraft consists of the coaxial counter-paddle, reverse gear, engine output shaft, engine with a starter-generator, wings, tail blades, landing device, culvert, steering gear, fairing, fuselage, motor, motor drive shaft, wing control unit of small angle of attack, aileron rudder surface, and tailplane rudder surface. Co-axial counter-blade is located in the upper part of the aircraft, which connects with the engine output shaft; the reverse gear is installed between the co-axial counter-propellers; the motor connects with motor drive shaft powered by the starter-generator of the engine; the wings are located on both sides of aircraft and connect with the fuselage; the tail blades are located at the aircraft tail, which are installed behinde motor drive shaft; the landing device is located under the lower part of the fuselage and fixed with it; the culvert connects with the landing device; the fairing is installed in the culvert and connects with the steering gear; the wing control unit of small angle of attack is installed on the wing. The aircraft design method has six steps with strict scientific idea; this invention has a wide range of practical value and application prospect.

An avionics system for a mechanically-controlled aircraft configured to provide envelope protection for deterring a pilot from flying outside of acceptable flight parameter limits for flight parameters such as banking angle, pitch attitude, g loading, proximity to terrain and/or obstacles, angle of attack, and/or airspeed. The avionics system may comprise at least one servo actuator and a computing device. The computing device may engage envelope protection by engaging the at least one servo actuator if the aircraft reaches a maximum or minimum limit for any of the flight parameters, such that the at least one servo actuator provides a force to urge a flight control device in a direction to bring the aircraft back within the acceptable flight parameter limits. The servo actuator may be disengaged when the aircraft flight parameters reach an end value corresponding to the start value that triggered envelope protection to engage.

The invention provides a scale measuring device for a pitching dynamic derivative experiment. An electric motor is arranged in a motor support rod; a motor output shaft is connected with a transmission shaft via a speed reducer and a shaft coupling; the transmission shaft is rotationally connected with a scale support rod; the rear end of the scale support rod is fixedly connected with the front end of the motor support rod; the front end of the transmission shaft is provided with an eccentric wheel which is provided with a lug; the lug is inserted into a sliding chute of a slide block; upper and lower cross springs of a cross spring scale have a crisscross structure respectively, and the front and rear ends thereof are fixedly connected with a scale frame via a front seat; and central positions of the upper and lower cross springs are provided with supporting cylinders. The scale measuring device for the pitching dynamic derivative experiment is a novel pitching dynamic derivative scale device. A pitching direct derivative of an aerial craft and a rolling crossover derivative induced by yaw oscillation can be measured under a big attack angle by designing a special vibrating mechanism, the cross spring scale and a pitching five-component scale structure. The scale measuring device for the pitching dynamic derivative experiment can meet the requirement of a wind tunnel trial.

The invention relates to a network defense strategy selection method and apparatus based on Markov evolutionary game. The method comprises the following steps: constructing a multi-stage Markov attack and defense evolutionary game model according to dynamic attack and defense game in a network attack and defense process, wherein the model contains a plurality of sub game stages; solving and outputting optimal defense strategies of the stages of the attack and defense game by using an optimal defense strategy selection algorithm for the multi-stage Markov attack and defense evolutionary game model. According to the network defense strategy selection method and apparatus provided by the invention, a dynamic evolution process of network attack and defense in view of the multi-stage Markov attack and defense evolutionary game model, the state skip of the evolutionary stages is described as a random process from the angle of attack and defense confrontation, and the multi-stage Markov evolutionary game is constructed on the basis of the Markov process; the total discount gain of the game is used as a target function, a discount factor eta is imported to perform discount processing on the game gains of different stages, a network security analysis method and a defense technology system are researched and searched, and thus the network defense strategy selection method and apparatus have important practical significance.

A method for operating a wind turbine with at least one blade includes providing at least one blade with an active flow control actuator configured to increase an angle of attack range in which the blade or blades can generate torque without flow separation, and using the flow control actuator to adjust this angle of attack range in accordance with load.

A subpart (430) of a drill string (211) is described having an outer circumferential surface which is contoured and adapted to engage the wall of the borehole with a small angle of attack while exerting during rotary drilling operations an compacting pressure on mud cake and/or cuttings present in the annulus between the drill string and the borehole.

A loop is formed by a bow having across one side a strip or blade. The bow has flexure and memory. The flexure and memory of the bow are imparted to the strip, enabling the strip to be either taut or loose, depending on the pressure exerted by the operator upon the bow. The bow is held and manipulated by the operator with the thumb and finger. The strip is positioned under tension. A holder for the device allows additional variability in the angle of attack of the strip, and facilitates quick and easy interchange of the strips. A holder avoids insertion of fingers far back in the mouth, where working space is limited.

The United States of America consumes nearly 20 million barrels of oil a day, 6.6 billion per year. This depleting chemical composition, in part, ends up in our air, on our trees, on our clothing, in our lungs, in our blood streams. A large portion of this oil is imported causing a dependency on foreign countries and a significant economic burden to this country. Clean, renewable, domestic energy is a necessity, not a luxury. The Z-333 Energy Management System is an answer to this challenge. There have been many Vertical Axis Wind Turbine patents issued since Mr. Elhanan L. Stoners' patent in 1891. However it appears that none has yet manifested itself into a large scale economic reality. The Z-333 Energy Management System is the latest of a series of improved Vertical Axis Wind Turbine designs which will make that reality come to pass. The Z-333 Energy Management System includes several novel changes to previously patented designs, plus incorporates totally new accessories to make man's continuing conquest of wind an actuality. These innovations include; Aerodynamic “balanced” wings. Tightly stretched fabric-only wings strengthening the overall structure, and at the same time, drastically lower the cost of construction. Flexible photovoltaic cells cover the aforementioned fabric-only-wings. A rotating tower that is flexible and safer. A unique high winds shut off switch. A multi-generator braking system maintains the shaft at a constant RPM. Generators and gears mounted to removable panels. Rubber-like covered shaft and large ring transmission. A low cost switch that controls the angle of attack of the wing with less problems and cost. A tower made of prefabricated interchangeable modules that can be used as a home, water tank, storage room, shop, and/or a shed. A base which is also a large battery and/or a control box shell. A programmable intelligent control box, which notifies the owner by cell phone, of battery fast charge/discharge, vandalism, key energy indicators, integrates a multi-circuit station timer, plus provides an electric-fence-like shock protection from animals and vandals. Low cost, multi-pancake generator that is highly efficient. A shaft centered flywheel. A shaft centered centrifugal pump. A sea base with ballast for low cost erection. A sea base with desalinization equipment built inside. A sea base with integrated hydrogen and oxygen producing equipment.

A zero transition vertical take-off and landing (VTOL) aircraft, which is stable in all levels of flight, especially the transition phase from vertical to horizontal flight. The zero transition VTOL aircraft is capable of achieving both vertical and horizontal flight without changing the positioning of thrusters, such as through the use of tiltable or rotatable nacelles or wings. Rather a front thruster assembly and a rear thruster assembly are positioned at specific angles in relation to each other along at least one fuselage in order to generate the desired ratio of vertical to horizontal thrust. At least one wing is also positioned at a specific wing angle in order to achieve a desired angle of attack when in horizontal flight. The attitude of the zero transition VTOL aircraft can be controlled through the use of differential thrust alone, or in conjunction with control surfaces.

The present invention is directed to a turbine comprising a plurality of blades that rotate in a single direction when exposed to fluid flow, wherein the plurality of blades are joined to the central shaft by a plurality of radial spokes disposed substantially perpendicular to the central shaft such that the rotating plurality of blades causes the shaft to rotate. The plurality of blades has a uniform airfoil-shaped cross section, where the airfoil cross section presents a non-zero angle of attack to the current. The plurality of blades wind in a spiral trajectory, rotating around the central shaft and having a variable radius along the length of the central shaft such that a distance measured from the plurality of blades to the center shaft is greater near the center of the turbine than at either end.

The invention provides a method for correcting the influence of high-speed wind tunnel model afterbody distortion on lateral-directional aerodynamic characteristics. A test model contains a freely-replaceable real afterbody and a distortion afterbody model; the test model pre-deviates to a given sideslip angle through a sideslip angle-varying blade belly supporting device; a wind tunnel test is performed on the real afterbody model and the distortion afterbody model according to the same test conditions; interpolation is performed on lateral-directional aerodynamic coefficients according to the same angle of attack sequence; subtraction is performed on two kinds of interpolated lateral-directional aerodynamic coefficients, so that an obtained difference value of the two kinds of interpolated lateral-directional aerodynamic coefficients is the influence of the afterbody distortion on the aerodynamic characteristics of the test model. The method can be used for correcting the influence of the afterbody distortion on the lateral-directional aerodynamic characteristics of the model test under the given sideslip angle.