17results about How to "Reduced flow separation" patented technology

The invention relates to a turbine blade profile optimization method, a blade, computer equipment and a storage medium. The method comprises the following steps: determining a mean camber line coordinate of an initial blade profile; determining a tangent angle of each point of an arc coordinate in the initial blade profile and a corresponding coordinate, and performing nondimensionalization on the tangent angle and the corresponding coordinate; deriving the dimensionless coordinates and the angle to obtain a mean camber line dimensionless angle slope; applying the calculated mean camber line dimensionless angle slope to a disturbance function to obtain a disturbed dimensionless angle slope; carrying out integration on the calculated post-disturbance dimensionless angle slope to obtain post-disturbance dimensionless angle distribution, and carrying out normalization by using a trailing edge dimensionless angle to enable the trailing edge dimensionless angle theta 'to be equal to 1; carrying out inverse operation on the disturbed dimensionless angle and the coordinates to obtain actual mean camber line angle distribution, and carrying out integration to obtain disturbed mean camber line coordinates; and determining a newly constructed mean camber line, and generating a reconstructed blade profile according to original blade parameters and a modeling method.

The invention discloses a particle trap based on a shark skin structure, and relates to particle traps. A plurality of air inlet ducts and air outlet ducts are formed in the carrier, porous medium wall surfaces are arranged between the adjacent air inlet ducts and air outlet ducts, and a plurality of shark skin odontoid imitating placoid scale structures are arranged on the hole walls of the air inlet ducts. By simulating a streamline structure of shark skin, a shark skin odontoid imitating placoid scale structure is designed in the air inlet duct, and the placoid scale structure can destroy a boundary layer and delay flow separation, so that differential pressure resistance is reduced, the effect of optimizing a flow path of airflow is achieved, and exhaust back pressure is effectively reduced.

A double-incident shock wave / boundary layer interference model is designed, incoming flow is 4-7 Mach laminar flow, and an artificial transition tape is installed on the upstream of a separation area; multiple pairs of cylindrical stepped holes are evenly formed in the middle of the surface of the flat plate in the spanwise direction and used for assembling electrodes and high-voltage wires. The invention also provides a hypersonic velocity dual-incident shock wave / boundary layer interference model which comprises the shock wave generator and a dual-incident shock wave / boundary layer interference model below the shock wave generator. In addition, the invention provides a method for regulating and controlling the hypersonic fusion separation bubble through flow direction plasma excitation, high-energy plasma excitation is applied in front of a separation line through a plasma exciter, an intermittent high-energy disturbance effect is generated on a wave system structure through the strong impact effect of high-energy plasmas, the influence of the shock wave reverse pressure gradient on a boundary layer is reduced, and the separation effect of the hypersonic fusion separation bubble is improved. The size scale of separation bubble fusion is reduced, and flow separation induced by shock wave / wall surface boundary layer interference is relieved.

The invention relates to the technical field of aero-engines, and discloses a small-windward-area compressor stator multi-parameter pneumatic construction method and system.The front edge line blade tip point of the meridian projection of a small-windward-area compressor stator is moved forwards, the rear edge line blade tip point is moved backwards, the consistency of the stator tip part can be increased, and the consistency of the stator tip part is improved; flow separation at the tip of the stator is reduced, so that the efficiency and the stability margin of the small-windward-area compressor are improved. Besides, under the condition of the same hub ratio, the consistency of the stator root of the small-windward-area gas compressor can be reduced by further reducing the number of the stator blades, so that the flow capacity of the stator root is improved, and the efficiency and the stability margin of the small-windward-area gas compressor are further improved. According to the method, the design efficiency can be improved, the design period can be shortened, and the working envelope of the engine can be improved; particularly, the stator can be directly used for designing a small-windward-area compressor stator, and the windward area of an engine inlet can be effectively reduced, so that the purpose of reducing weight is achieved.

The invention discloses a low-noise cooling fan and an automobile, and relates to the technical field of cooling fans, and the low-noise cooling fan comprises a center hub used for being connected with a motor shaft; the blades are annularly and unevenly distributed around the central hub, and the distribution angles between the blades are different; the blade roots of the plurality of blades are respectively connected with the central hub; the flow guide ring is connected with the blade tops of the multiple blades; the turbulent flow assemblies are arranged on the suction surfaces of the blades, the turbulent flow assemblies can extend out step by step according to the rotating speed of the fan, when airflow passes through the turbulent flow assemblies, high-strength induced vortexes can be generated, high-energy fluid outside a boundary layer and fluid in the boundary layer are mixed, flow separation of the boundary layer of the suction surfaces is delayed, and the flow separation efficiency is improved. Local reflux and boundary layer thickening of the blade surface are controlled, the airfoil lift force is improved, and meanwhile generation of fan noise is restrained.

The invention particularly relates to a novel structure for reducing pressure pulsation and noise of a mixed-flow pump, which is applied to the mixed-flow pump, the mixed-flow pump comprises a pump cavity, the pump cavity is provided with a first inlet, an impeller is arranged in the pump cavity, an impeller runner is formed in the impeller, and an inlet of the impeller runner faces the first inlet and surrounds the circumferential direction of the first inlet. A protruding block structure is arranged on the inner wall face of the first inlet, the cross section of the side, away from the inner wall face of the first inlet, of the protruding block structure is in a parabola shape, so that the thickness of the two sides of the protruding block structure is smaller than that of the middle of the protruding block structure in the axial direction of the first inlet, and one side of the protruding block structure is inserted into an inlet of the impeller channel. The bump structure is arranged at the first inlet, so that the flow velocity of a medium at the pump inlet is increased, the increased inlet flow velocity can improve the kinetic energy of fluid, the attachment of the fluid on the surfaces of pump blades is facilitated, the flow separation is reduced, the backflow vortex at the pump inlet is inhibited, and the pressure pulsation value of the pump is improved.

The invention provides a high-pressure common-rail oil injector control valve and a cavitation suppression design method thereof. The high-pressure common-rail oil injector control valve comprises a control valve shell and a valve rod. A control cavity and a mounting cavity are formed in the control valve shell; the control cavity is communicated with the rail pipe through the oil inlet hole; a first pore plate and a second pore plate which are in close contact with each other are sequentially and coaxially arranged in the mounting cavity from top to bottom; the peripheral edges of the first pore plate and the second pore plate are in close contact with the inner wall of the mounting cavity; a discharge hole is formed in the first pore plate; a ball valve cavity, a flow guide hole, an oil outlet hole and a middle cavity which are communicated with one another are sequentially formed in the second pore plate from top to bottom; the middle cavity is communicated with the control cavity; the discharge hole is communicated with the ball valve cavity; a sealing steel ball is fixedly arranged at the bottom end of the valve rod; the valve rod penetrates through the first hole plate to enter the ball valve cavity, and the sealing steel ball is located above the flow guide hole and matched with the conical wall face of the ball valve cavity. The cavitation strength of the sealing surface of the ball valve is reduced, and the service life of the oil injector control valve is prolonged.

The invention discloses a downwind type small wind driven generator turbine which comprises a rotor blade body axially swept back from a blade root to a blade tip, the front edge of the blade is provided with a bionic nodule structure changing in a sine rule, and the rear edge of the blade is provided with a sawtooth-shaped corrugated structure; the blades and the hub are connected to form a wind turbine rotor, the rotor is located on the downwind side of the tower, wind flow firstly passes through the tower and then acts on the rotor blades, the downwind layout enables the blades to be capable of natural feathering under the action of wind loads, therefore, dynamic load impact on the tower is reduced, and the yaw system structure is simplified. The tower shadow effect can be remarkably relieved through the whole sweepback type blades, and aerodynamic noise is reduced; the front edge nodules of the blades are bionic to fin limbs of the seat head whale, so that the lift-drag ratio can be effectively increased, broadband noise is reduced, and violent fluctuation of power and load is inhibited; sawtooth ripples on the rear edge of the blade imitate a comb-shaped structure on the rear edge of the flying feather of the owl, so that vortex shedding frequency concentration can be inhibited, and high-frequency noise can be remarkably reduced.

The application discloses a kind of parameterized modeling-based optimization design method and system of centrifugal fan volute profile, belong to industrial centrifugal fan design field.The method includes: firstly, volute profile away from volute tongue side is constructed, determine the width of two circular arcs away from volute tongue side of volute;Second volute tongue profile parameterization constraint, define volute tongue opening degree β, volute tongue radius R, volute tongue center and impeller center distance D key parameter, volute tongue geometry is controlled by three parameters independently;Finally, profile fusion and optimization, adopt single circular arc to connect volute profile away from volute tongue side and volute tongue profile tangentially, avoid geometric over definition problem, complete overall modeling.By improving the degree of freedom of volute tongue area, effectively reduce the flow separation and impeller interference at volute tongue, optimize the uniformity of volute internal flow field.

The plasma combined trailing edge suction flow control device for the rotor blades comprises a plurality of blades (1), and nanosecond pulse dielectric barrier discharge plasma exciters (2) are installed at the front edges of the blades and cover the extension length of the whole blades; the tail end of the paddle is provided with an air suction device (3), and the center of an air suction port is A% c away from the front edge. The tail end air suction device (3) comprises a tail end air suction port (3-1), a low-pressure air chamber (3-2) and a connecting pipeline (3-3). When rotor wing type dynamic stall is controlled, the high-frequency nanosecond pulse power supply (4) is used for powering up the nanosecond pulse dielectric barrier discharge plasma exciter (2). The invention further provides a plasma combined trailing edge suction flow control method for the rotor blade. Through combination of plasma excitation and trailing edge air suction, the airfoil upper surface flow field structure can be effectively interfered, the flow separation degree is reduced, the average lift force of the rotor blade is improved, and therefore the performance of the rotor blade is improved.

The embodiment of the present application provides a centrifugal compressor, a turbocharger and a vehicle, wherein the centrifugal compressor comprises an impeller, a shell and a guide vane assembly, the impeller comprises a disc and a plurality of blades, the blades are arranged on a side of the disc along a radial direction and extend along the radial direction; the shell is provided with an airflow channel, the impeller is rotatably arranged in the airflow channel, the shell is provided with an air inlet along a circumferential direction of the impeller, the shell is provided with an air outlet along a radial direction of the impeller, the air outlet is located on a side of the impeller provided with the blades, and the airflow channel is connected with the air inlet and the air outlet; the guide vane assembly is arranged on the shell, the guide vane assembly comprises a guide vane, the airflow channel is provided with a mounting cavity on an inner wall upstream of the impeller along an airflow direction, and the guide vane is telescopically arranged in the mounting cavity; in an extended state of the guide vane, at least part of the guide vane is located in the airflow channel; and in a retracted state of the guide vane, the guide vane is completely located in the mounting cavity. The centrifugal compressor in the embodiment of the present application improves the working efficiency through the telescopic guide vane.

The present invention belongs to the technical field of impeller test and measurement, and discloses a prism five-hole probe for measuring the dynamic full parameters of a subsonic three-dimensional flow field, including a probe support rod, a transition section, a probe head, a pressure sensor cable, a temperature sensor cable, a heat-insulating seal and a temperature sensor, wherein the probe support rod and the probe head are both cylindrical and connected through a transition section, and the pressure measuring lower hole, the pressure measuring left hole, the pressure measuring right hole, the pressure measuring middle hole and the temperature measuring hole are located on the prism protruding from the probe head, and the temperature measuring hole is grooved on the circumference, and the pressure sensor and the temperature sensor cable are led out of the probe tail through the channel in the probe support rod. The present invention can realize the dynamic measurement of the total pressure, static pressure, deflection angle, pitch angle, Mach number, density and three-dimensional velocity as well as the total temperature and static temperature at the same point in the flow field under the premise of reducing the influence of the flow around the probe head, and has a wide total temperature insensitive angle measurement range, and is suitable for measuring the full-parameter dynamic measurement of the three-dimensional flow field between stages of an aeroengine.

Providing a compression corner shock wave / boundary layer interference model, and designing a state Mach number between Mach 1 and Mach 5; installing a manual transition tape at the upstream of the separation area; a U-shaped electrode cover plate is inserted into the insulating material; a groove array with the same size is formed in the upper surface of the insulating material so as to install a U-shaped electrode cover plate; two rows of grooves are formed in the surface of the insulating material in the flow direction; each row of grooves comprises a plurality of grooves which are uniformly distributed along the flow direction, and the adjacent grooves are kept at the same distance; cylindrical stepped holes are formed in the outward extending positions of the two ends of each row of grooves. The invention also provides a method for regulating and controlling the interference of the shock wave boundary layer by the multi-path plasmas. A plurality of plasma arrays are arranged in front of a separation area, a continuous impact disturbance effect is generated on a wave system structure by utilizing a strong impact effect and a heat effect of high-energy plasmas, and a hot gas mass is formed to regulate and control near-wall shock waves, so that the influence of a reverse pressure gradient on a boundary layer is reduced, and the low-frequency instability of the shock waves is improved; and flow separation induced by shock wave / boundary layer interference is slowed down.

The application provides a register, an indoor unit and a control method, wherein the register is provided with a gap extending along a first direction, the gap separates the register into a front edge part and a main body part in a register direction, and the first direction is perpendicular to the register direction; in a cross section perpendicular to the first direction, the cross section profile of the main body part is a first airfoil profile, the head of the first airfoil profile is located at a side of the main body part close to the front edge part, the cross section profile of the front edge part outside the gap is a head profile of a second airfoil profile, the included angle of the chord line of the front edge part and the chord line of the main body part is β, the chord length of the front edge part is L1, the width of the narrowest part of the gap is L2, and the chord length of the main body part is L3; β = 10-30°, and L3 = 6L1-10L1, L1 = 2L2-5L2. According to the application, the flow blockage of the leeward surface of the register can be reduced, the air volume of the register is almost not attenuated when the register is deflected at a large angle, and the air supply volume of the register is improved; and the unsteady vortex flow can be avoided, and the vortex noise generated by the register is reduced.

This invention provides a plasma device and method for de-icing swept wings, including a plasma power supply and a plasma actuator. The plasma actuator is a surface dielectric barrier discharge plasma actuator, comprising an insulating dielectric layer, exposed electrodes, and buried electrodes. This invention uses a high-voltage AC surface dielectric barrier discharge plasma actuator for de-icing, which has advantages such as small size, light weight, low power consumption, fast response, no mechanical parts, and high heating efficiency. Furthermore, by utilizing the aerodynamic effect of the plasma actuator, energy can be injected into the airfoil boundary layer, delaying surface flow separation and improving the aerodynamic performance of the wing.

The invention discloses an automobile drag reduction control method and system based on a follow-up wave generation device, and relates to the technical field of active flow control, and the method comprises the steps that an exciter array distributed in a master-slave partition mode is arranged based on a key pneumatic area of a target vehicle; acquiring vehicle state data and flow field state data of the target vehicle in real time; acquiring a time delay and a space-time trigger sequence based on the vehicle state data; acquiring an external modulation frequency and a duty ratio of the exciter array based on the flow field state data; a high-voltage electric signal conforming to time delay, a space-time trigger sequence, external modulation frequency and a duty ratio is generated to serve as a control instruction; the exciter array is controlled to generate plasma volume force based on the control instruction, a follow-up wave regulation and control flow field is formed, and the aerodynamic resistance of the target vehicle is reduced. Generation and development of separation vortexes are actively regulated and controlled, flow separation is delayed, and a wake flow area is reduced, so that aerodynamic resistance of an automobile under various running working conditions is remarkably and stably reduced, and the energy efficiency ratio is increased.

The utility model discloses a kind of multi-wing centrifugal fan blade and multi-wing centrifugal fan, it includes: elliptic arc section, the elliptic arc section is located the air inlet end of the blade;Linear section, the linear section is located the air outlet end of the blade;Middle circular arc section, the circular arc section is located the intermediate position of the blade, the circular arc section is connected respectively the linear section and the elliptic arc section.The blade profile is divided into the three-section composite structure of elliptic arc section, middle circular arc section and linear section, different area characteristics of air flow in blade channel are optimized respectively.Elliptic arc section optimizes inlet region air flow angle deviation, reduces inlet impact loss;Middle circular arc section realizes air flow steady turning, reduces flow separation caused by inverse pressure gradient in blade channel;Linear section suppresses outlet cross section vortex area, reduces outlet flow loss.Three-section synergistic effect significantly reduces aerodynamic loss, improves fan system efficiency, solves the defect that single circular arc blade cannot consider inlet impact and passage separation.