75results about How to "Reduce differential pressure resistance" patented technology

The invention discloses a centrifugal fan blade, a centrifugal fan and an air conditioning device, and relates to the technical field of air conditioners. The mainly adopted technical scheme lies in that the centrifugal fan blade comprises a front disc, a back disc and a plurality of fan blades, wherein an air inlet is formed in the front disc; an air outlet is formed between the back disc and the front disc; the plurality of blades are uniformly distributed between the front disc and the back disc; the shape of the front edges of the blades imitates the shape of the outer edges of bird wings; an air current enters the centrifugal fan blade through the air inlet, enters a runner through the front edges of the blades, and flows out of the air outlet through the back edges of the blades; the centrifugal fan comprises the centrifugal fan blade; and the air conditioning device comprises the centrifugal fan. The invention mainly aims to improve the working efficiency of the centrifugal fan blade, the centrifugal fan and the air conditioning device and reduce the noise and power consumption of the centrifugal fan blade, the centrifugal fan and the air conditioning device.

The invention provides an air guiding device applied to a van trailer. The air guiding device comprises a tail door guiding device installed on a rear compartment door of the van trailer. The tail door guiding device comprises a guiding device body I and a guiding device body II. An included angle is formed between the upper end face of the guiding device body I and the top face of the van trailer. An included angle is formed between the outer side face of the guiding device body II and the side face of the van trailer. The air guiding device further comprises rear lower side guiding devices,side face guiding devices and front lower portion guiding devices, all of which are installed on the lower side of a compartment of the van trailer. The rear lower side guiding devices are symmetrically arranged on the left side and the right side of the rear portion of a trailer frame of the van trailer, the side face guiding devices are symmetrically arranged on the left side and the right sideof the middle portion of the trailer frame of the van trailer, and the front lower portion guiding devices are symmetrically arranged on the left side and the right side of the front portion of the trailer frame of the van trailer. The air guiding device is reasonable in design, surrounding air flows of the van trailer can be orientated and guided in sequence, the possibility that turbulence cyclones and flow separation are generated around the van trailer through the air flows is reduced, air resistance is reduced, and the air guiding device is low in carbon, environment-friendly and worthy of popularization.

The invention discloses a micro-blowing structure and method for resistance reducing and lift increasing of a supercritical airfoil and belongs to the technical field of aircraft design. Skins with micro holes are arranged near the rear edge of the lower airfoil surface of the airfoil, micro-blowing is started under the cruising state, the wall face friction resistance in the micro-blowing actingarea is reduced remarkably, and the pressure difference resistance of the airfoil is further reduced through increasing of the pressure intensity in a micro-blowing upstream part, so that the total resistance of the airfoil is reduced; meanwhile, the lift of the airfoil can be increased through pressure intensity increasing caused by micro-blowing of the lower airfoil surface; and finally, the resistance reducing and lift increasing effects can be achieved simultaneously. The micro-blowing technique can be used in wide flowing fields including low-speed airliners, high subsonic speed airlinersand even supersonic aircrafts, and rapid development of manufacturing techniques in recent years provides a guarantee for application of the micro-blowing technique.

The invention provides a grid rudder and an aircraft. The grid rudder comprises a plurality of partition plates which are connected with each other and form a grid structure; wherein each partition plate is oppositely provided with a windward side and a leeward side along the two ends of the intersection line of the partition plates, at least one part of the windward side is provided with a notch,and the absolute value of the tangent slope of the outer surface where the notch is located is continuously reduced along the direction from the windward side to the leeward side, a flow guide curvedsurface is formed at the windward side, square arrangement at the windward side is avoided, and under hypersonic speed environment, on one hand, differential pressure resistance and friction resistance are reduced, power efficiency is improved, the total heat generated by heating of the windward side is reduced, and the structural strength of materials of the grid structure is guaranteed; on theother hand, the condition of local high heat generated by protruding parts such as edges and corners under the condition of airflow friction is improved, the aerodynamic heat of the grid structure isreduced, the thermal environment distribution of the grid structure is improved, and the temperature distribution uniformity is improved, so that the structural thermal stress is reduced, and the strength performance is optimized.

The invention provides an adjustable dry hanging structure for a large-size vitrified tile on he wall surface. The adjustable dry hanging structure comprises a torque adjusting mechanism, a connectingpiece and a dry hanging piece; the torque adjusting mechanism comprises an installation base, a spiral torque adjusting rod and a sliding base, the installation base is fixedly installed on the baselayer wall surface, the spiral torque adjusting rod is rotatably installed on the installation base, and the spiral torque adjusting rod is perpendicular to the base layer wall surface; the sliding base is arranged on the spiral torque adjusting rod in a sleeving mode, the connecting piece is fixedly installed on the sliding base, the dry hanging piece is fixedly installed on the vitrified tile through an expansion bolt, and the dry hanging piece is buckled on the connecting piece. The invention further provides an installation method of the adjustable dry hanging structure for the large-sizevitrified tile on the wall surface. Compared with the prior art, the installation position of the vitrified tile can be adjusted, field installation is convenient and fast, the construction difficultyis reduced, and the construction period is shortened.

The invention relates to the technical field of a piezoelectric pump, and discloses a valveless piezoelectric pump. The valveless piezoelectric pump comprises a pump body, a piezoelectric vibrator anda flow pipe, wherein a chamber is formed in the pump body, and the piezoelectric vibrator is arranged in the chamber to form a pump chamber; the flow pipe is arranged on the pump body, and a flow channel communicating with the pump chamber is formed in the flow pipe; the flow channel is a rotating body cavity formed by using a curve as a bus, and the curve comprises a hyperbolic segment and a circular arc segment which are in the form of smooth transition; the center of the circular arc segment is positioned outside the flow channel, and the curvature of the hyperbolic segment is less than that of the circular arc segment; and the diameter of the flow channel decreases first and then increases. When a fluid flows through the flow channel, the speed can always increase first and then decrease, so that the pressure differential resistance of the fluid is reduced, and the flow speed is increased and the generation of vortex is minimized at the same time. Thus, the internal flow field ofthe valveless piezoelectric pump reaches a critical state, which is compatible with the two performances of large flow and low vortex. In addition, the structural stability of hyperbola is better.

The invention relates to a bionic double-turbine hydraulic torque converter which comprises a pump wheel, a pump wheel outer ring, a pump wheel inner ring, a first turbine, a guide wheel and a second turbine. Blades of the guide wheel are bionic blades; a momentum distribution function polynomial of the blades is y=ax<3>+bx<2>+cx+d, the x is horizontal coordinates of equal division points on a mean camber line, and the y is a corresponding momentum distribution value; and the a is larger than or equal to 0.6044 and smaller than or equal to 1.4151, the b is larger than or equal to -0.5792 and smaller than or equal to -0.1698, the c is larger than or equal to -0.1989 and smaller than or equal to 0.581, and the d is larger than or equal to -0.4221 and smaller than or equal to 0.3746. Due to the fact that the blades of the guide wheel are bionic blades, the starting torque ratio and the efficiency of the bionic double-turbine hydraulic torque converter are improved compared with an original double-turbine hydraulic torque converter. Furthermore, the capacity coefficient of the pump wheel is larger than that of a hydraulic torque converter using general blades.

The invention discloses a hollow-out SUV rear spoiler that can reduce drag and lift. A rectangular hole is opened in the middle of the rear spoiler to allow airflow to flow directly through the rectangular hole, thereby reducing the low pressure behind the rear window of the vehicle. zone, reducing the pressure differential resistance encountered by the vehicle during driving. At the same time, the cross-section of the spoiler behind the rectangular hole is designed as an inverted airfoil to compensate for the downforce loss caused by the opening, so as to ensure that the pressure difference resistance is reduced while not affecting the rise of the rear spoiler on the vehicle. The counteracting effect that the force should have.

The bionic dynamic variable-structure skin comprises a front section and a rear section, each of the front section and the rear section is formed by compositing a top layer, a middle layer and a bottom layer, the top layers of the front section and the rear section are flexible organic polymer films, the bottom layers of the front section and the rear section are ceramic heating pieces, and the ceramic heating pieces are arranged in the middle of the front section and the rear section. The middle layer of the front section is made of a temperature-control phase-change material, the middle layer of the rear section is a metal flat plate, a plurality of rhombic holes are formed in the metal flat plate, and the rhombic holes are filled with the temperature-control phase-change material. The heat production amount can be controlled by adjusting the bottom layer ceramic heating sheet, so that the temperature control phase change material deforms to a corresponding degree, the process that wrinkles of the dolphin skin and body thorns of the dolphin skin change along with the change of the speed of external water flow is simulated, the viscosity of water flow on the surface of the skin can be reduced through redundant heat, and the skin quality is improved. And finally, the skin has a self-adaptive resistance reduction function.

The invention discloses a micro-blowing structure and method for resistance reducing and lift increasing of a supercritical airfoil and belongs to the technical field of aircraft design. Skins with micro holes are arranged near the rear edge of the lower airfoil surface of the airfoil, micro-blowing is started under the cruising state, the wall face friction resistance in the micro-blowing actingarea is reduced remarkably, and the pressure difference resistance of the airfoil is further reduced through increasing of the pressure intensity in a micro-blowing upstream part, so that the total resistance of the airfoil is reduced; meanwhile, the lift of the airfoil can be increased through pressure intensity increasing caused by micro-blowing of the lower airfoil surface; and finally, the resistance reducing and lift increasing effects can be achieved simultaneously. The micro-blowing technique can be used in wide flowing fields including low-speed airliners, high subsonic speed airlinersand even supersonic aircrafts, and rapid development of manufacturing techniques in recent years provides a guarantee for application of the micro-blowing technique.