7results about How to "Reduced flow separation" patented technology

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 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 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.