70results about How to "Improve flow field quality" patented technology

The invention relates to a throat structure capable of improving the Reynolds number of a tube wind tunnel test. An upstream section, a transition section and a downstream section constitute the throat structure from left to right; the upstream section, the transition section and the downstream section are fixed together by flanges; the throat structure is arranged between the tube wind tunnel driving section and test section of a wind tunnel test; the throat structure at the upstream section is a subsonic speed expansion section in a conical structure form; the middle of the transition section comprises a multi-throat parallel spray tube structure; the middle of the downstream section is a contracted downstream spray tube; and the right end of the downstream section is a supersonic expansion section. According to the throat structure of the present invention, it only requires to make local modification on a tube wind tunnel, and requirements can be met by means of an aerodynamic principle; and a rectifying device is additionally arranged in the transition section, so that the startup time of the wind tunnel can be shortened, and the quality of the flow field of the test section can be improved.

The invention provides a supersonic free vortex mixing layer wind tunnel. The wind tunnel comprises a transition section (1), a stabilizing section (2) and a spray pipe experimental section (3), wherein the transition section (1) is used for introducing air flow; the stabilizing section (2) is connected to the downstream side of the transition section (1) and is provided with a first separation plate (21) for separating the introduced air flow into two strands of air flow; the spray pipe experimental section (3) is connected to the downstream side of the stabilizing section (2) and comprises a spray pipe part (31) and a mixing experimental part (32); a transparent window is formed on the peripheral wall of the spray pipe experimental section (3); the spray pipe part (31) has a double free vortex spray pipe structure and is used for accelerating the two strands of air flow to form a free vortex state respectively; the mixing experimental part (32) is positioned on the downstream side of the spray pipe part (31) and is used for mixing the two strands of air flow in the free vortex state to form a free vortex mixing layer, so that velocity fields of the two strands of air flow at an inlet of the experimental part of the wind tunnel meet the requirement of supersonic free vortex distribution; therefore, an ideal supersonic free vortex mixing layer can be obtained in the wind tunnel.

The invention provides an annular supersonic velocity spray pipe and a design method thereof. The design method for the annular supersonic velocity spray pipe comprises the following steps of: predicting a flow field parameter in a transonic velocity segment area, and extracting an initial characteristic line from the flow field parameter; determining the mach number distribution of a supersonic velocity upright wall of the spray pipe according to design requirements; and determining a supersonic velocity curved wall molded surface of the spray pipe by a characteristic line method according to the initial characteristic line and the mach number distribution of the supersonic velocity upright wall. According to the design method for the annular supersonic velocity spray pipe, compression waves are not concentrated in a flow field of the designed annular supersonic velocity spray pipe, the distribution of the flow field parameter can be optimized according to actual application, and thequality of the flow field of the annular supersonic velocity spray pipe can be greatly improved. According to the annular supersonic velocity spray pipe, the design method for the annular supersonic velocity spray pipe is utilized.

The invention discloses an automatic adjustable automobile wind tunnel testing platform with the function of interference elimination. The testing platform comprises a testing bench, an automatic wheel base adjusting part, and a tread adjusting part. The testing bench is installed on a wind tunnel testing segment floor and covers a balance support. The automatic wheel base adjusting part is installed at the lower part of the balance support; and the tread adjusting part is installed in the balance support. The automatic wheel base adjusting part consists of a wheel base displacement sensor, a gear rack driving device, a drive motor, a wheel base adjustment support and a guide rod; the wheel base adjustment support is fixed at the bottom of the balance support; the guide rod passes through the wheel base adjustment support and the is connected with a balance floating frame; the wheel base adjustment support can move axially along the guide rod; the wheel base displacement sensor is arranged on the wheel base adjustment support; and the wheel base adjustment support is connected with the drive motor by the gear rack driving device. According to the invention, the interference on the process quality by the support exposed in the flow field in wind tunnel testing can be eliminated; and supports of vehicles with different wheel bases and threads can be realized.

The invention relates to an intelligent wind tunnel with a variable section of a test section, wherein the inlet of the test section of the wind tunnel is connected to a contraction compressed gas retaining structure of a contraction section, and the outlet of the test section is connected to a steady flow section front end structure of a steady flow section; the test section is integrally in a rectangular structure and is composed of upper and lower two parts which are nested with each other, the upper part can move up and down in the lower part under the action of the telescopic structure, and the height of the lower end surface of the upper part is not greater than the distance from the upper ends of the outlet and the inlet to the top when the test section dose not stretch out and drawback; a rubber airbag plate is arranged on the inner wall side of the cavity of the test section, a plurality of rubber airbags are arranged on the rubber airbag plate, the inflation and deflation states of each rubber airbag are controlled by an air pump and a corresponding control valve; the above-mentioned telescopic structure, the air pump and the control valve are all connected to a controlsystem in a wind tunnel control room. The wind tunnel can automatically change the cross-sectional area and volume according to various data of the real scene as needed, which realizes intelligent useof the wind tunnel, and completes various pneumatic tests efficiently and reliably.

The invention discloses a supersonic velocity integrated spray pipe design method and relates to the field of wind tunnel tests. The method includes the following steps of 1, creating a spray pipe model, wherein the model includes a retraction segment, an expansion segment, a testing segment and a boundary layer; 2, figuring out a TG segment curve according to a characteristic line equation of theTG segment curve, figuring out an AD segment curve according to a characteristic line equation of the AD segment curve, and correspondingly obtaining a complete curve of the outer wall of the expansion segment; 3, calculating the displacement thickness of the boundary layer to obtain a boundary layer curve; 4, obtaining a complete curve of the retraction segment; 5, obtaining a complete curve ofthe testing segment. By means of the method, a testing area is enlarged, and the parameters such as a Mach number root-mean-square deviation, an axial Mach number gradient and an airflow-deviation angle of the testing segment are all in line with national military-standard advanced indexes.

The invention discloses a large wind tunnel nozzle test section integrated device, and relates to the technical field of aerospace testing. The large wind tunnel nozzle test section integrated devicecomprises an nozzle test integrated section, an outlet flange section, a support frame car, a thread pin and wind tunnel devices; the support frame car is horizontally placed on the ground; the nozzletest integrated section is placed horizontally on the upper surface of the support frame car, and the axial direction of the nozzle test integrated section is identical to the longitudinal directionof the support frame car; the outlet flange section is coaxially fixed and installed in an axial outlet end of the nozzle test integrated section; the outlet flange section and the nozzle test integrated section are fixedly connected through the threaded pin; the wind tunnel devices are coaxially and fixedly mounted on the axial inlet end of the nozzle test integrated section and the axial outer end of the outlet flange section. The large wind tunnel nozzle test section integrated device adopts the modular design, is low in processing and manufacturing cost, is high in economy; driving is achieved by a wheel set, guiding and positioning is achieved by a guide rail; the operation is simple, and the safety is high; and the precise positioning design reduces the labor cost, and the disassembly and assembly is convenient. .

The invention discloses a Ludwieg tube wind tunnel and a high Mach number expansion method thereof, and belongs to the technical field of hypersonic speed wind tunnels. According to the invention, a stable section is added on the basis of a traditional Ludwieg tube wind tunnel; an inlet of the stable section is matched with an outlet of a quick-opening valve; an outlet of the stable section is matched with an inlet of a spray pipe; a stable subsonic flow field is formed between the wind tunnel quick-opening valve and a spray pipe section; meanwhile, a throat specification replaceable spray pipe matched with the stable section is designed, and due to the addition of the stable section, the operation mach number of the wind tunnel can be expanded to a high mach number only by replacing spraypipes with different throat specifications on the premise of not changing other parts of the wind tunnel. Through the technical scheme of the invention, the high mach number expansion of the Ludwiegtube wind tunnel can be realized. The method for expanding the high Mach number wind tunnel is simple and economical, a good test flow field is easy to obtain, and in addition, the method can also beused as a method for improving the quality of the flow field of the Ludwieg tube wind tunnel.

The invention provides a method for designing an ultrasonic-speed turning flow channel. The method comprises the following steps of: determining the inlet boundary of the wall surface curve of the ultrasonic-speed flow channel according to the geometric constraint of the design structure of the ultrasonic-speed flow channel; determining the one-sided wall surface curve of the ultrasonic-speed flow channel according to the geometric constraint of the design structure of the ultrasonic-speed flow channel; determining the opposite-side wall surface curve which corresponds to the one-sided wall surface curve by adopting the method of characteristics; and determining the wall surface curve of the ultrasonic-speed flow channel according to the parameters of an outlet flow field. Due to the adoption of the method, the shock-free ultrasonic-speed flow channel of the whole flow field can be obtained, and a better flow field environment can be provided for the aerodynamic and structural design of an ultrasonic-speed wind tunnel, an ultrasonic-speed ejector and an ultrasonic-speed aircraft.

The invention belongs to the field of design of a core drive fan and a high pressure compressor in a gas turbine type engine, and provides an external culvert structure adapted to a variable incomingflow angle low loss adjustable support plate. A second external culvert inlet is located on a casing between the outlet of a CDFS (5) and the inlet of a high pressure compressor rotor (7), and an external culvert support plate of a second external culvert adopts a segmented adjustable structure. According to the external culvert structure adapted to the variable incoming flow angle low loss adjustable support plate, the second external culvert between the CDFS and the high pressure compressor is redesigned, and the inlet position of the second external culvert, an upper flow passage of the second external culvert, a lower flow passage of the second external culvert and a support plate structure of the second external culvert are specially designed, so that the air entraining content requirement under different bypass ratios can be realized under the condition that the high pressure compressor has better quality of an inlet flow field; and the flow losses in the second external culvertcan be well controlled under different incoming flow angles to ensure the better quality of an outlet flow field of the second external culvert.

The invention discloses a current stabilizer, which comprises a shell, a first plate body, a deformable container, an air source and a controller, wherein the first plate body is arranged in the shellto divide a closed cavity into a first cavity and a second cavity which are mutually communicated, the deformable container is disposed within the first cavity and defines a gas chamber within the deformable container for containing gas, the gas chamber has a gas preload, the deformable container is configured to contract when the gas preload is less than a circulating liquid pressure within theshell, and to expand when the gas preload is greater than the circulating liquid pressure within the shell, the gas source is communicated with the gas chamber through a gas chamber connecting pipe, the controller is respectively connected with the gas source and the gas chamber, and the controller controls the gas source to provide gas to the gas chamber according to the pressure in a circulatingfluid loop so as to form gas prepressing. According to the current stabilizer provided by the embodiment of the invention, the flow and pressure fluctuation in the circulating fluid loop can be effectively absorbed, so that the stable flow of the circulating fluid in the circulating fluid loop is ensured, and the quality of a flow field is improved.

The invention discloses a single-pair supersonic flow direction vortex generation device. The device comprises a laval nozzle, a transition section, a vortex generation section and a test window whichare sequentially connected. A uniform supersonic flow is formed through the laval nozzle and the transition section and enters the vortex generation section, the side wall boundary layer is induced to form transverse flow by means of radial pressure gradient, a pair of large-scale flow direction vortices are generated on one side of a pipeline, and through the design of wave elimination, a uniform and background-free supersonic core flow and a fully-developed single-pair supersonic flow vortex can be generated in the test window. The vortex generation device has the advantages of being simplein structure, convenient to integrate with an existing test bed and display a flow field, and effectively avoiding the pollution of a background wave system to the flow field. In addition, the flow channel area of a test device is gradually increased, and an additional vortex generation device is not needed, so that the requirement of a direct-connected test bed on the plugging degree of a modelis more easily met, a feasible test device is provided for researching the interference mechanism of a shock wave string and the supersonic flow direction vortices in a scramjet engine.

The invention relates to a pressurization flow control device-containing SERN structure for a TBCC. The SERN structure comprises a lower wall surface of a single expansion ramp nozzle, a contraction section of the single expansion ramp nozzle and a single expansion ramp nozzle single-side expansion section, and further comprises the pressurization flow control device arranged on the single expansion ramp nozzle single-side expansion section, wherein the pressurization flow control device comprises a U-shaped communicating pipeline and a supercharger arranged on the U-shaped communicating pipeline; besides, a front port of the U-shaped communicating pipeline is positioned in front of an intersection point of an oblique shock wave and the single expansion ramp nozzle single-side expansion section; and a back port of the U-shaped communicating pipeline is arranged at the back of the intersection point of the oblique shock wave and the single expansion ramp nozzle single-side expansion section. According to the SERN structure, airflow flowing through the communicating pipeline is pressurized, extra airflow in a diverging zone is extracted and then is ejected from the front port at a relatively high speed, so that the separation zone range is greatly decreased and even eliminated, the shock wave is moved forwards, the static pressure distribution of a main flow is changed, and the working condition of overexpansion operation is improved.

The invention discloses a multiphase flow vertical-type water hole with a bi-directional flowing function. The multiphase flow vertical-type water hole comprises a power section, a backflow section, alower rectifying section, a lower diameter-variable section, a work section, an upper diameter-variable section, an upper rectifying section and an upper tank. In work, a second water pump is closed,a first water pump is started, a fluid in the water hole flows to the lower rectifying section, the lower diameter-variable section, the work section, the upper diameter-variable section and the upper rectifying sectionsequentially along the backflow section and then enters the upper tank for closed circulation; or the first water pump is closed, the second water is started, the fluid in the water hole flows to the upper rectifying section, the upper diameter-variable section, the work section, the lower diameter-variable section and the lower rectifying section sequentially along the upper tank and then enters the backflow section for closed circulation. According to the multiphase flow vertical-type water hole, the mode that the first water pump and the second water pump are arranged inparallel is adopted, the movement direction of the fluid is conveniently and rapidly converted; and water replenishing connecting pipes and particle solution connecting pipes are evenly distributed on the lower diameter-variable section and the upper diameter-variable section, the influences of flowing separation on the experimental result are prevented from water replenishment, and through adding of bubbles and particles, multiphase flowing is achieved.

The invention relates to a dynamic response characteristic test method for an air propeller electric propulsion system. The method comprises: a ground test system of an electric aircraft propeller is constructed; a trailer is accelerated to be at a steady-state speed at different accelerated speeds, the acceleration state is kept for a period of time, and a tensile force and a torque of the propeller and a rotating speed of the motor are measured; the speed of the trailer is kept to be constant, the rotating speed of a motor is adjusted, and a tensile force and a torque of the propeller are measured; and the influence on the rotating speed of the motor by a trailer speed change as well as influences on the tensile force and torque of the propeller by the trailer speed change or motor rotating speed change is analyzed. The test method has the following advantages: the trailer speed can be controlled precisely; the trailer system has the large accelerated speed; the marching speed of the propeller can be changed; and the dynamic response characteristic of the propulsion system can be simulated when gust happens. The speed regulation characteristic of the electric propulsion system of the propeller can be measured by changing the rotating speed instruction of the motor. The test method is suitable for a dynamic response characteristic test of a propulsion system of a low-speed electric propeller aircraft.

The invention provides a supersonic-speed axisymmetric mixing layer wind tunnel which is characterized by comprising a transition section (1), a stabilization section (2) and a spray pipe experimental section (3), wherein the transition section is used for introducing an airflow; the stabilization section is provided with a first partition board (21) which divides the introduced airflow into two airflows; the spray pipe experimental section is connected at the downstream part of the stabilization section (2) and forms a fan-shaped axisymmetric structure relative to an axis (O) of revolution; the cross section of the peripheral wall of the spray pipe experimental section (3) is in a sector ring shape; a transparent window is formed on the peripheral wall; a spray pipe part (31) and a mixing experimental section (32) are formed on the spray pipe experimental section (3); and a second partition board (33) is arranged in the spray pipe part and the mixing experimental section is used for forming an axisymmetric mixing layer. By using the supersonic-speed axisymmetric mixing layer wind tunnel, the supersonic-speed axisymmetric mixing layer flow field of a totally-circular flow channel can be simulated and implementing the optical non-contact testing technology becomes convenient.