39results about How to "Reduced shape resistance" patented technology

This application describes garments (2), for example swim suits or other sports or athletic garments, in which a plurality of panels (10-22&30-44) are laminated on the outer surface of a base layer (4) of stretchable elasticated fabric to offer (in the case of a swim suit) improved performance for competitive swimmers through a reduction in surface drag, a reduction in form drag and/or improved stability in the water.

The invention discloses an elliptical tube H-shaped fin heat exchanger for waste heat recovery. The elliptical tube H-shaped fin heat exchanger comprises an elliptical heat exchange tube, a plurality of groups of H-shaped fins and a heat exchanger surface, wherein the H-shaped fins are sleeved on the surface of the heat exchange tube; the heat exchanger surface consists of non-uniform triangular small wings, which are elliptically arranged, on the surfaces of the H-shaped fins around the elliptical heat exchange tube. When dusty flue gas flows through the surfaces of the H-shaped fins, the small wings disturb the fluid to enhance the heat exchange on the tube wall and the downstream side, and meanwhile, the deposition of particles on the tube wall is reduced; the pressure drop can be reduced by the elliptical tube while the particle adhesion is reduced. A plurality of longitudinal vortexes are arranged in a non-uniform manner; at the front and rear edges of the wing, the size of the small wings and the windward attack angle are larger; on the middle parts of the H-shaped fins, the size of the small wings and the attack angle are smaller; by using the device, the heat exchange surface in different flow states can be enhanced respectively, the heat exchange of the fins are effectively enhanced, the pressure drop is reduced, and the deposition of dust particles in the flue gas on the heat exchange surface is reduced, so that the heat exchanger can operate efficiently for a long time in the dusty flue gas.

The invention relates to a low-resistance hull under a designed waterline, belongs to the field of hull shape design, and mainly relates to the design of hulls under the designed waterline. A propeller is arranged on a ship bow, a shell bossing is designed to be in a spindly shape similar to a cone, the two sides of a transition position between the shell bossing and the hull above the shell bossing are respectively provided with an arc flow guide water groove, the bow waterline above the shell bossing is designed to be in a V shape with the big end up, and the V-shaped bow waterline has a flow guide effect. An area which has a small included angle between the surface normal of the bow and the navigation direction is designed to be close to one fourth to three fourths of ship width, two inclined flow guide water grooves are formed in the two sides of a main engine space located on the lower portion of the ship bow, a symmetric ship bow or an asymmetric ship bow is used, and the stern of the hull is designed to be a streamline reducing body. The bow and the stern are respectively provided with a flow channel which penetrates through the larboard and the starboard, and a spraying propelling unit is arranged in the hull to meet the steering requirement of the hull. Through linear bow and stern design and the propeller arranged on the bow, the head and wake flow fields of the hull are improved, adverse effects of water on ship navigation are weakened, and ship resistance is reduced.

The invention discloses a pre-rotation triangular conduit for a right-handed rotation single screw vessel. The pre-rotation triangular conduit has a fan-shaped structure; seen from the rear side of a screw propeller, a second blade and a first blade are arranged from top to bottom on the left side of a longitudinal central line of a propeller hub of the screw propeller, and a third blade is arranged on the right side; a blade back of a guide plate is fixedly connected with a blade tip of the first blade, a blade tip of the second blade and a blade tip of the third blade respectively; the included angle range of the first blade and the longitudinal central line of the propeller hub of the screw propeller is 70-75 degrees; the included angle range of the second blade and the longitudinal central line of the propeller hub of the screw propeller is 25-30 degrees; and the included angle range of the third blade and the longitudinal central line of the propeller hub of the screw propeller is 70-75 degrees. By using the principle of pre-rotation before the propeller and screw propeller upper inlet flow acceleration, the pre-rotation triangular conduit is a piece of body energy saving equipment with more uniform inlet flow of the screw propeller disk; and importantly, the energy lost due to rotation of a wake flow field of the screw propeller is reduced, the screw propeller propulsive efficiency is improved and the additional form resistance due to tail flow separation is reduced.

The invention provides a bullet-shaped non-spherical micro-particle and microcapsule. A matrix of the micro-particle and micro-capsule is a polymerized photopolymerizable macromolecule, and the micro-particle and microcapsule is of an integrated bullet shape and consists of a similarly cone-shaped head portion and a cylindrical tail portion which are smoothly connected with each other; the microcapsule has at least one mutually independent chamber; and an oil phase solution is contained in the chamber. The invention further provides a method for continuously preparing the above bullet-shaped non-spherical micro-particle and microcapsule by using a microfluidic technique. The technical scheme provided by the invention can improve the flow characteristics and the movement rate of the microparticle and microcapsule in a channel, and improve the embedding effect of the microparticle and microcapsule. The microcapsule provided by the invention can realize entrapment and transport of activeingredients such as a drug.

The invention discloses a novel vortex generator for a wind turbine blade. The vortex generator comprises a fin body, wherein the fin body is of a back fin structure and is symmetrical relative to thelongitudinal cross section of the fin body; the middle longitudinal section is parallel to the flow direction from the leading edge to the trailing edge of the airfoil section of the wind turbine blade, so that the projection area of the fin body in the direction perpendicular to the flowing direction is reduced, and then the shape resistance is reduced. According to the vortex generator, the bionic design is adopted, and the back fin-shaped fin body has relatively small flow resistance. The middle longitudinal section of the back fin is parallel to the flow direction from the leading edge tothe trailing edge of the airfoil section of the wind turbine blade, compared with the prior art, the fin body has the advantages that the projection area is small in the direction perpendicular to the flow direction of the airflow, and the shape resistance is small. When the airflow flows through a groove, a high-energy flow direction vortex can be induced at the groove and at the edge of the groove, so that the energy in the boundary layer can be increased, and the flow separation is inhibited.

The invention discloses a method for improving the heat exchange reinforcement effect of a vortex generator by use of punching jet flow, belonging to the field of heat exchange reinforcing technology. A hole is formed in a proper position on the windward surface of a wing-type or column-type vortex generator, thus the fluid at the front part of the vortex generator passes through the hole and scours the flow dead area or weak heat transfer area of the leeward surface of the vortex generator, thus the average flow rate and kinetic energy of the area are improved, the weak heat transfer area is eliminated, and the effects of heat exchange reinforcement and flowing resistance reduction of the vortex generator as well as the efficiency of the heat exchanger are further improved; and meanwhile, since the area of the windward surface of the vortex generator and the range of the flowing separation area are reduced by punching, the form resistance of the vortex generator is reduced, thus the flowing loss is reduced. The method has the characteristics of convenience in processing, simple manufacturing and obvious effect, and has wide application prospects and popularization values in the aspect of reinforcement gas-side heat exchange of a gas-liquid or gas-gas heat exchanger.

The invention discloses a prerotation fan-shaped conduit for a right-handed single-screw ship. The prerotation fan-shaped conduit comprises a first vane, a second vane, a third vane, a fourth vane and an arc guide plate; from the rear side of a screw propeller, the left side of a longitudinal central line of a screw impeller hub is sequentially provided with the second vane and the first vane from top to bottom, the right side is sequentially provided with the third vane and the fourth vane from top to bottom, an angle formed between the first vane and the longitudinal central line of the screw impeller hub is 70 to 80 degrees, an angle formed between the second vane and the longitudinal central line of the screw impeller hub is 25 to 30 degrees, an angle formed between the third vane and the longitudinal central line of the screw impeller hub is 35 to 45 degrees, and an angle formed between the fourth vane and the longitudinal central line of the screw impeller hub is 70 to 80 degrees. Compared with the three-vane prerotation triangular conduit, the third vane plays a role in supporting and reinforcing the prerotation and is also arranged outside an air bubble sensitive area, and the adverse impact on the air bubble performance can be avoided.

The invention provides a control plane cavitation effect suppression device, including an air pump and a breather pipe. The air pump is arranged in a ship body and the breather pipe is located in thegap between a rudder horn and a rudder blade. The upper end of the breather pipe is fixed on a transom plate and communicates with the air pump. The lower end of the breather pipe is closed, and air holes for blowing air to the surface of a rudder blade are formed in the breather pipe. Through blowing to the control plane from the gap, control plane pressure increases and a cavitation effect is not prone to being produced. Kinetic energy of fluid near a boundary layer separation point can be increased to move the separation point back and decrease a separation area to achieve the effect of reducing form resistance. A laminar region can be extended, a critical Reynolds number can be increased and viscous resistance can be dramatically reduced under the critical Reynolds number.

The invention discloses a cross-flow fan blade based on bionics. The blade is formed by arranging a plurality of blade units in the axial direction of an impeller, the front edges of the blade units protrude, the rear edges of the blade units are concave inwards, the middle portions of the sides, close to the front edges, of the upper surfaces of the blade units are higher than the two sides, themiddle portions of the sides, close to the rear edges, of the upper surfaces of the blade units are lower than the two sides, and the middle portions of the sides, close to the front edges, of the upper surfaces of the blade units are higher than the middle portions of the sides, close to the rear edges, of the upper surfaces of the blade units. By the adoption of the cross-flow fan blade based onbionics, airflow flowing of the front edge and rear edge of the blade can be improved, an eccentric vortex moves downwards, the efficiency of a cross-flow fan is improved, and energy consumption is reduced.

A method for reducing form drag on a tailsitter aircraft during at least one of takeoff or landing includes vertically taking off from the ground in a tailsitter orientation. The method also includes determining an actual pitch of the tail sitter aircraft in the tailsitter orientation. The method also includes determining a difference between the actual pitch and a predetermined pitch. The method also includes adjusting a heading of the tailsitter aircraft based on the difference to minimize a pitch angle to reduce the form drag on the tailsitter aircraft.

A double-ellipsoidal streamlined rotator irrigation emitter plug comprises a plug back taper. A plug water inlet is formed in the upper end face of the plug back taper, the lower surface of the plug back taper is sequentially communicated with a plug taper neck, a dropper cavity and a dropper water outlet pipe from top to bottom, the contour line of the cross section of the plug back taper is a double-ellipsoidal streamlined curve, the contour line of the cross section of the plug taper neck is a double-ellipsoidal streamlined curve, and the area of the double-ellipsoidal streamlined curve ofthe upper end face is as same as that of the double-ellipsoidal streamlined curve of the lower end face. According to the double-ellipsoidal streamlined rotator irrigation emitter plug and a mountingmethod thereof, the problem of great local head loss can be solved, and the plug form resistance of an irrigation emitter is maximally reduced.

The invention discloses a technique to decrease resistance of straight-flow type water pump controlled valve, which comprises the following steps: setting the intake valve clap as circular arc; setting cone lid as cone; forming a flow guiding body with the intake valve clap and the cone lid. This invention possesses reasonable craft and good idea, which can be spreaded widely.

The invention discloses an electric passenger vehicle for reducing lift force and resistance and extending the range through fluid equipment. The electric passenger vehicle comprises a new vehicle body, air flow channels and fluid machines, wherein the air flow channels and the fluid machines are arranged on the two sides of a front compartment, a passenger compartment, a vehicle tail luggage compartment, a vehicle tail, a vehicle roof, a vehicle bottom and a vehicle body of the electric passenger vehicle. Form resistance, inner circulation resistance, interference resistance, induced resistance and lift force are reduced through the air flow channels and the fluid machines, and the effects that the electric passenger vehicle uses the air flow channels and the fluid machines for reducing air resistance and lift force and increasing the traveling mileage of the electric passenger vehicle are achieved.