17 results about "Thrust efficiency" patented technology

The invention discloses a surface coating method for realizing thrust amplification of a sail, which is characterized in that a sail blade which takes a glass fiber composite material as a basic material comprises a step of anti-drag coating of a convex surface part of the sail blade, a step of anti-drag coating of a concave surface of the sail blade, a step of special coating of a sail blade end plate and a step of special coating of a sail blade guide device. A low-friction and high-wear-resistance coating which takes modified PTFE resin as a base material and contains nano aluminum oxide and graphite micro powder is adopted for the convex surface; and the concave surface adopts a vortex breaking-strong adhesion type coating which takes fluorocarbon resin (PVDF) as a base material and contains nano silicon dioxide and hollow glass beads. According to the invention, the thrust efficiency is improved by 60-80%; the thrust stability under the wide wind speed is improved by more than 60%, the service life of the sail blades can be prolonged, the operation and maintenance cost is reduced, an existing sail can be directly transformed, and the sail has the advantages of being low in cost and high in efficiency and has economic and environment-friendly values.

The utility model discloses a low-altitude aircraft which comprises an aircraft body, four fixed machine arm rods are arranged in the cross direction of the aircraft body, the surfaces of the fixed machine arm rods are movably connected with movable machine arm rods, one sides of the movable machine arm rods are provided with locking pieces, and the other sides of the movable machine arm rods are connected with the locking pieces. The locking piece comprises fixing frames fixed to the top and the bottom of one end of the movable machine arm rod, a connecting plate is arranged on one side of each fixing frame, and a clamping column is fixedly connected to the inner side of each connecting plate. The fixed machine arm rod can move in the inner cavity of the movable machine arm rod, so that the total length of the fixed machine arm rod and the movable machine arm rod can be changed, the length of the machine arm can be adjusted, the two clamping columns enter the through holes, the adjusted length can be locked, the length of the machine arm can be adjusted according to task requirements, and the machine arm is convenient to use. The aircraft arm is suitable for different terrains and weather conditions, dynamic adjustment of the arm of force of the propeller is achieved, lift and thrust efficiency is optimized, and the fixed aircraft arm rod and the movable aircraft arm rod can be rapidly detached and replaced.

The utility model provides a contra-rotating ducted fan power device which comprises a ducted shell, a center body, a rotating mechanism, a supporting mechanism and a driving mechanism, the center body, the rotating mechanism, the supporting mechanism and the driving mechanism are arranged in the ducted shell, a ducted inner space is formed in the ducted shell, and the center body is arranged in the center of the ducted inner space. The rotating mechanism, the supporting mechanism and the driving mechanism are all connected to the center body, the supporting mechanism is connected to the middle position of the center body, the driving mechanism is in transmission connection with the rotating mechanism, and the rotating mechanism comprises a first rotating mechanism body and a second rotating mechanism body; according to the contra-rotating ducted fan power device, the rotating directions of the two rotating mechanisms are opposite, the contra-rotating rotating mode can balance torque generated by rotating blades, vibration is reduced, the stability of a system is improved, the service life of the system is prolonged, meanwhile, the contra-rotating blades neutralize the eddy current effect, tail flow kinetic energy loss is reduced, and the service life of the system is prolonged. Therefore, higher thrust efficiency is realized.

This invention discloses a pneumatic concave cavity flame stabilization device for an afterburner, comprising a central cylinder, an annular combustion chamber shell, a diffuser, an afterburner shell, a pneumatic concave cavity pipe, and a central cylinder connecting rod. The diffuser fixes the annular combustion chamber shell and the afterburner shell together. The central cylinder is fixed to the center of the annular combustion chamber shell via the central cylinder connecting rod. The pneumatic concave cavity pipe extends through the central cylinder into the afterburner shell. The vertical jet from the pneumatic concave cavity exhaust port of this invention can enhance the recirculation zone and stably maintain a low-speed recirculation vortex under different operating conditions, stabilizing the combustion operating range and reducing the risk of flameout. The vertical jet from the pneumatic concave cavity exhaust port of this invention can entrain fuel and air into the cavity, prolonging the fuel residence time and fundamentally improving combustion efficiency. The vertical jet from the pneumatic concave cavity exhaust port of this invention can fill the low-pressure zone at the rear edge of the cavity, reducing resistance, significantly reducing total pressure loss, and improving engine thrust efficiency.

The present application belongs to the technical field of cross-medium unmanned vehicles, and particularly relates to a water-air cross-medium running unmanned vehicle, which forms a smooth transition fluid channel through a hemispherical cover, a cylindrical cabin, an annular duct and a conical bottom cylinder, and solves the problems of low power efficiency, large flow resistance, attitude instability and poor reliability in the prior art. The head part is integrated with a detection and rudder control system, and the open rudder cabin can dynamically adjust the water volume to optimize the center of gravity; the middle part adopts an annular duct integrated constraint propeller flow field to improve water-air thrust efficiency, and the center cabin body is integrated with a core control module; the tail part is convergent design to optimize the fluid trajectory. The modules are quickly and reliably connected through piston sealing and rotary buckles. The present application significantly reduces the cross-medium resistance and water outlet time, ensures the smooth attitude conversion, and greatly improves the maintenance convenience and system reliability due to the modularization and high sealing design, and is suitable for various cross-domain operation scenes such as ocean exploration, emergency search and rescue, etc.

The invention provides a marine annular blade adjustable pitch propeller, and belongs to the technical field of ship propulsion and energy-saving equipment.The marine annular blade adjustable pitch propeller comprises a propeller hub, a pitch adjusting mechanism and an annular propeller mechanism, the annular propeller mechanism is connected with the pitch adjusting mechanism, and the pitch adjusting mechanism is installed on the propeller hub; the screw pitch adjusting mechanism comprises a screw pitch adjusting assembly, a limiting sliding block and an outer adjusting gear, the screw pitch adjusting assembly comprises a cylindrical limiting body, an inner adjusting gear and a screw hole, the cylindrical limiting body is mounted in the mounting hole, the outer adjusting gear is mounted on the adjusting hole, and the outer adjusting gear and the inner adjusting gear are meshed to drive the screw pitch adjusting assembly to rotate; the limiting sliding block moves in the axial direction of the fixed-pitch groove, the limiting sliding block is provided with teeth, and the limiting sliding block is meshed with the inner adjusting gear to achieve fixed pitch. Fine adjustment and limiting of the screw pitch of the propeller are achieved through axial movement of the limiting sliding blocks, the annular propeller mechanism is of a novel annular blade structure, and the thrust performance and the thrust efficiency of the propeller can be greatly improved.

This invention provides a compact linear motor that maintains a sufficient stroke while suppressing performance changes and preventing a decrease in thrust efficiency during operation. [Solution] The linear motor according to the present invention has a first coil and a second coil, and a magnet arranged opposite the first coil and the second coil, the poles of the magnet change periodically along the driving direction, the first coil and the second coil are arranged such that in the driving direction their phases are shifted by 90° in electrical angle, and a portion of the surfaces of the first coil and the second coil that face the magnet overlap.

The application discloses a surface coating method for realizing sail thrust amplification, and a sail leaf based on a glass fiber composite material, which comprises a drag reduction coating step of a convex surface part of the sail leaf, a drag reduction coating step of a concave surface part of the sail leaf, a special coating step of an end plate of the sail leaf, and a special coating step of a flow guide device of the sail leaf. The convex surface part adopts a "low-friction and high-wear-resistance type" coating layer with modified PTFE resin as a base material and containing nano-aluminum oxide and graphite powder. The concave surface part adopts a "vortex breaking and strong adhesion type" coating layer with fluorocarbon resin (PVDF) as a base material and containing nano-silicon dioxide and hollow glass microbeads. The thrust efficiency is improved by 60-80%, the thrust stability under wide wind speed is improved by more than 60%, the service life of the sail leaf is prolonged, the operation and maintenance cost is reduced, the existing sail can be directly transformed, the application has the characteristics of low cost and high efficiency, and has economic and environmental values.

This invention discloses an automatic throttle speed control method and system for aircraft based on dynamic inverse, belonging to the field of design technology. The method includes: multiplying the difference between the ground speed command and the ground speed feedback by an acceleration gain proportional term to obtain the desired ground speed acceleration increment; solving for the ground speed acceleration increment using climb angle, angle of attack, sideslip angle, axial overload, lateral overload, and normal overload; multiplying the difference between the desired ground speed acceleration increment and the ground speed acceleration increment by a state function related to the aircraft's mass to obtain the desired thrust acceleration increment; obtaining the engine thrust efficiency matrix by taking the partial derivative of the engine thrust with respect to the throttle opening; multiplying the calculated desired thrust acceleration increment by the inverse of the thrust efficiency matrix, and then adding the throttle state variable from the previous cycle to obtain the final throttle control command. The automatic throttle control law of this invention is derived from pure equations of motion, with clear physical meaning. The control law structure does not contain integrators, feedforward compensation, or other terms, reducing the "trial and error" work of gain preset while achieving consistent control performance. It exhibits high robustness and has broad engineering application prospects.

The invention discloses an online water electrolysis working medium supply system for a microwave electric thruster and a temperature control method. The problems that an existing water working medium thruster is low in specific impulse, storage safety of a traditional gas working medium is poor, reaction products are prone to condensation, and thrust stability is affected are solved. The system comprises a water storage unit, a trace conveying unit, an electrolytic reaction unit, a gas-liquid treatment unit, a flow regulation and control unit and a temperature control unit, the water storage unit is connected with the electrolytic reaction unit through the trace conveying unit, and liquid water is conveyed to the electrolytic pile in real time for electrolysis; a hydrogen-oxygen mixed product generated by electrolysis is subjected to drying and gas-liquid separation through the gas-liquid treatment unit and then enters the flow regulation and control unit for pressure stabilization; and finally, the gaseous working medium is injected into the microwave resonant cavity through the microwave thruster interface. The temperature control unit is thermally coupled with the resonant cavity, and the temperature of the cavity is maintained by circularly heating a medium, so that water vapor generated by hydrogen-oxygen reaction is prevented from being condensed at the spray pipe. According to the microwave electric thruster, safe and easy-to-store liquid water can be converted into a high-specific-impulse hydrogen-oxygen gaseous working medium on line, the single-phase stability of working medium discharge is ensured, the thrust efficiency and specific impulse performance of the microwave electric thruster are remarkably improved, and the structure is modularized and easy to integrate.

The invention relates to the technical field of ship propulsion, and discloses a ship folding fan type sail independent control method based on a wind regime, and the method specifically comprises the steps: data collection, data analysis and fault early warning, wind direction compliance determination, safety evaluation, target angle execution, and angle error determination and compensation. By means of multi-sensor fusion and an intelligent algorithm, high-precision and high-safety autonomous control over the folding fan type sail of the ship is achieved, mechanical faults such as a bearing can be early warned in real time, the sail unfolding angle is dynamically optimized to maximize thrust efficiency, meanwhile, the wind direction effectiveness and structural stress safety are strictly verified, and operation under the dead wind or overload working condition is avoided; and the feedback of the incremental encoder and a grading error compensation mechanism are combined, so that the angle control precision is within + / -1 degree, the wind energy utilization efficiency is remarkably improved, the fuel consumption and carbon emission are reduced, and the safety of the sail and the ship body structure is effectively guaranteed.

This invention relates to the field of aero-engine technology and discloses a variable-camber ducted fan and its adjustment method. The fan comprises two rows of rotor blades: a first row and a second row, mounted on a hub. The first row of rotor blades is angled relative to the fixed second row. By adjusting the inlet angle of the first row of rotor blades, the bypass ratio is dynamically changed according to flight conditions. This invention, through variable-camber ducted fan technology, employs a high bypass ratio during vertical takeoff and landing (VTOL) to improve lift efficiency and reduce fuel consumption; while switching to a low bypass ratio during high-speed level flight ensures high thrust efficiency. Furthermore, the variable-camber ducted fan can dynamically adjust the bypass ratio according to flight conditions to adapt to different mission requirements, such as VTOL, hovering, and level flight, ensuring high efficiency and low energy consumption in various flight modes.

The invention discloses a trapezoidal-configuration flying wing layout tilting rotor aircraft, which belongs to the technical field of aviation and comprises a fuselage, flying wing type wings, tilting mechanisms, driving parts and four rotors. The tilting mechanism comprises an arm assembly and a tilting driving assembly, a first pipe and a second pipe of the arm assembly are fixed to the wing tip and the wing root of the wing respectively, and the tilting driving assembly drives the rotor wings to tilt synchronously. In an initial state, a rotor rotating shaft is perpendicular to the horizontal plane, and a rotating sweeping surface is not overlapped with the fuselage and the wings, so that interference of lower washing flow of the rotors on the wings is reduced; in the level flight state, rotating shafts of the rotors are parallel to the horizontal plane, the four rotors are distributed in a trapezoid shape with the front portion wide and the rear portion narrow in the overlook direction, the rotary sweeping face of the front side rotor completely covers the wingtip, and the rotary sweeping face of the rear side rotor is mainly located on the upper surface of the wing. The aerodynamic interference between the front rotor wing and the rear rotor wing is reduced from the layout level, the thrust efficiency of the rear rotor wing is improved, and the lift-drag ratio and the cruising ability of the whole machine are improved.

The invention provides a front-back linkage type multi-mode variable-configuration spraying pipe which comprises a multi-blade type air inlet quantity adjusting rotary control plate module, an integrated bin pressure driving nozzle mode switching module and a spraying pipe air inlet and outlet flow channel molded surface assembly. The front end controls an air inlet flow guide adjusting rotary plate to rotate through an electric rotary driving motor, so that the air inlet amount is accurately adjusted; the rear end regulates and controls the air pressure in the closed bin cavity through four groups of tubular air path on-off interfaces, the pneumatic differential pressure type air outlet mode regulating valve is driven to move axially, and the regulating valve integrates an air pressure detection device and an infrared distance measurement device to construct closed-loop control; coupling linkage is formed by front-end air inlet adjustment and rear-end nozzle driving, and multi-mode efficient switching is achieved. The integrated cylindrical shape is adopted, airflow disturbance is resisted, the aircraft and industrial scenes are adapted, the multi-performance requirements of thrust efficiency, noise control and the like are met, switching precision is high, reliability is high, and the wide application value is achieved.

The invention belongs to the technical field of cross-medium unmanned aerial vehicles, and particularly relates to a water-air cross-medium operation unmanned aerial vehicle which solves the problems of low power efficiency, large flow resistance, attitude instability and poor reliability in the prior art by forming a fluid channel in smooth transition along a hemispherical cover, a cylindrical cabin, an annular duct and a conical bottom cylinder. The head is integrated with a detection and rudder control system, and an open steering engine room can dynamically adjust the water volume to optimize the gravity center; the middle part adopts an annular duct to integrally restrain a propeller flow field, the water-air thrust efficiency is improved, and a central cabin body is integrated with a core control module; and the tail convergence design optimizes the fluid trajectory. All the modules are quickly and reliably connected through piston seals and rotary buckles. According to the invention, the cross-medium resistance is obviously reduced, the water outlet time is obviously shortened, the stable attitude conversion is ensured, the maintenance convenience and the system reliability are greatly improved due to the modular and high-sealing design, and the system is suitable for various cross-domain operation scenes such as ocean exploration, emergency search and rescue and the like.

The invention discloses a tailstock type unmanned aerial vehicle hovering stability control method based on PID and thrust compensation, and the method comprises the following steps: S1, system parameters and fixed PID parameters are initialized in a Simulink simulation environment, the system parameters comprise core parameters such as a motor arm of force, control surface efficiency and maximum thrust, and the PID parameters employ a pre-debugged height loop optimal value; s2, acquiring real-time pitch angle, roll angle and height data of the unmanned aerial vehicle in the Simulink simulation model, and forming eight-dimensional state variables including height, attitude angle and corresponding rate; s3, calculating the vertical thrust efficiency based on the attitude angle obtained through simulation, dynamically correcting the basic thrust output by the fixed PID according to an efficiency threshold value, obtaining the compensated total thrust, and limiting the compensated total thrust in a safe range; s4, distributing the compensated total thrust to a left motor and a right motor, distributing a control surface deflection angle by combining attitude control torque, and synchronously performing amplitude limiting protection on the motor thrust and the control surface deflection angle; s5, state differential is calculated through a simplified dynamic model built in the Simulink; and S6, updating the state variable, and feeding back to the fixed PID to form closed-loop control to realize hovering stable control. According to the method, direct verification can be carried out in a Simulink simulation environment, the problem that the height is out of control when the attitude angle is not zero can be solved without modifying an existing control framework, the stability of the hovering height is guaranteed, and the method meets the low-cost engineering development requirement of small and medium-sized tailstock type unmanned aerial vehicles.

The invention discloses a small valveless pulsating jet engine which comprises a combustion chamber, an air inlet, a resonance tube, an exhaust nozzle and a rectifying ring. The rear end face of the combustion chamber is connected with air inlets and resonant tubes; the outlet direction of the air inlet faces behind the engine; the front end of the resonance tube is connected with the combustion chamber; and the rectifying ring is mounted at a nozzle of the exhaust nozzle. The pulsating jet engine is simple in structure, free of movable parts, stable in work in the flying process and high in thrust efficiency.