343 results about "Dynamic pressure" patented technology

The invention belongs to the technical field of aero-engine design, and provides a sliding bearing lubrication gap prediction method based on a PINN neural network, and the method comprises the steps: generating a training data set of the PINN neural network, constructing the PINN neural network, employing a reverse mechanism of the neural network, calculating a partial differential operator through automatic differential, and carrying out the prediction of the lubrication gap of a sliding bearing. Customizing a dynamic pressure lubrication Reynolds equation into a loss function in a deep learning framework; and a prediction data set of the neural network model is generated, the trained PINN model and weight parameters are loaded, construction of a prediction model is completed, and an oil film pressure distribution curved surface is generated. According to the method, the accuracy of oil film pressure distribution calculation is remarkably improved, and meanwhile, the speed of numerical calculation can be remarkably increased.

The utility model discloses a diffusion type exhaust passage structure of double-screw gas conveying equipment, which mainly comprises an air cylinder and an axial exhaust pipe arranged on the air cylinder, and the diffusion type exhaust passage structure of the double-screw gas conveying equipment comprises the specially designed axial exhaust pipe. The direction of the airflow in the pipeline is basically consistent with that of the airflow from the compression cavity, so that mechanical loss caused by rapid turning of the airflow in a traditional structure can be avoided. A guide plate device is specially designed at an inlet of the axial exhaust pipe. Air flow from the compression cavity directly flows into the gaps of the guide plates and moves forwards along the guide plates, and energy loss caused by air turbulence in a traditional structure can be reduced. A plurality of diffusion areas are formed at the inlet of the exhaust pipe by utilizing the guide plate and the inner wall of the pipeline, and the dynamic pressure of high-speed airflow from the compression cavity is converted into static pressure by utilizing the diffusion areas, so that the pressure is increased while the speed is reduced, and the energy loss caused by the high-speed airflow is avoided.

The invention relates to the technical field of automatic control theory application and data center thermal management, and discloses a data center emergency refrigeration control method based on state space model prediction, which comprises the following steps: establishing a thermodynamic cycle state space equation; the refrigeration flow set value change rate and the water return side pressure change amount are obtained, and the dynamic heat exchange sensitivity is determined; monitoring feedback current characteristics of the driving unit, inverting cooling path resistance distribution and updating gain matrix elements; calculating a state prediction information sequence according to the temperature vector prediction deviation, and adjusting a time domain step length; the dynamic heat exchange sensitivity is introduced into prediction logic, controlled variable dynamic pressure retardation is compensated, an emergency refrigeration frequency control instruction is output, fluid fluctuation is converted into sensitivity compensation of a logic level, non-linear dynamic pressure damping of the emergency working condition is effectively impacted, the problems of control overshoot and logic instability caused by physical lag are solved, and the reliability of the system is improved. And the refrigeration response precision at the emergency conversion moment is improved.

The invention discloses a dynamic pressure-based carrier rocket grid rudder control method, which comprises the following steps of: according to a pre-launch binding wind field and the speed of a carrier rocket at the current moment, calculating to obtain the relative airflow speed of the carrier rocket at the current moment; according to the current relative airflow velocity of the carrier rocket, calculating to obtain a current dynamic pressure estimated value; according to the dynamic pressure estimation value at the current moment, solving a control law parameter in the grid rudder online variable gain control law to obtain an optimal control law parameter at the current moment; according to the optimal control law parameters at the current moment, a grid rudder swing angle control instruction at the current moment is obtained through calculation, and real-time control over the grid rudder of the carrier rocket is completed. The method can effectively adapt to the rapid change pneumatic environment of the reentry flight section, remarkably reduces the flight deviation, is suitable for various carrier rocket reentry recovery scenes, and has the advantages of being high in engineering practicability, high in control efficiency and the like.

The invention discloses a CO2 directional fracturing target layer crack propagation simulation control method based on flow regulation and control. The method comprises the steps that a plurality of experimental coal samples are manufactured, and drill holes are formed; the fracturing pump inputs CO2 with set flow into the coal sample through the CO2 injection pipeline; the high-frequency dynamic pressure sensor collects fluid pressure data in the coal sample crack; the acoustic emission sensor monitors and obtains the crack initiation moment and crack initiation pressure of the coal sample; the method comprises the following steps: carrying out cracking and crack width monitoring on a coal sample, calculating a theoretical value of crack initiation pressure and a theoretical value of CO2 injection flow of the coal sample, injecting supercritical CO2 fluid into the coal sample, obtaining a first-stage correction coefficient and a second-stage correction coefficient of the CO2 injection flow, and calculating a corrected CO2 injection flow value. According to the method, under the multi-physical-field coupling environment, the crack initiation pressure of the coal body can be accurately measured and calculated, the correlation between the CO2 injection flow and the crack width of the coal body is established, and the CO2 injection flow better meets the actual requirements of field operation through a CO2 injection flow grading correction mechanism.

The invention discloses a geological disaster hidden danger point rapid identification method based on aerial survey of an unmanned aerial vehicle, and relates to hidden danger point rapid identification. An airborne camera image sequence, the acceleration and angular velocity of an inertial measurement unit, the propeller rotating speed, the flight height, the wind speed and direction and a machine body vibration signal are collected, and image exposure time is used as a unified time axis; the method comprises the following steps: forming a time sequence sample, establishing rotor underwash near-earth boundary layer momentum entrainment prior based on the time sequence sample, calculating underwash dynamic pressure field time sequence estimation, a particle mobilization probability time sequence and an equivalent micro-attitude disturbance spectrum, performing sub-pixel level optical flow and phase accumulation analysis on an image sequence, performing time cross-correlation with the equivalent micro-attitude disturbance spectrum, and obtaining a target object. Coupling evidence is obtained, joint judgment of the triggering intensity and the coupling degree is carried out, a flight parameter self-adaptive fine tuning strategy is triggered, space risk analysis is carried out on the image after compensation reconstruction, a space risk calibration graph is generated, and geological disaster hidden danger points in a critical stable state can be effectively recognized.

The invention relates to the technical field of shale oil exploitation, in particular to a shale oil working fluid displacement device and a reservoir physical property evaluation method. In the shale oil working fluid displacement process, dynamic pressure difference time sequence data corresponding to all moments are obtained, and due to the fact that the viscosity and flow characteristic difference of different fluid media is large, dynamic pressure difference fluctuation is remarkable during displacement; determining the fidelity of the displacement pressure at each moment by analyzing the frequency domain and linear regression characteristics; thirdly, all moments are clustered based on the dynamic pressure difference and the displacement pressure fidelity, and the moments in the same displacement state are clustered into one class; in view of the fact that fixed PID parameters are difficult to adapt to different working fluid medium characteristics and can cause control delay, in a cluster to which the current moment belongs, moment distribution characteristics and dynamic pressure difference time sequence data dynamic estimation characteristics are analyzed, the pressure instability degree and the observation uncertainty are reflected, a preset gain coefficient is adjusted accordingly, more accurate PID control is achieved, and the control precision is improved. And the reliability of subsequent reservoir physical property evaluation is ensured.

This invention relates to the field of research on the operational characteristics of overpressure relief devices, and particularly to an experimental device for measuring the operational characteristics of overpressure relief devices under water hammer conditions. The device includes: a high-pressure air compressor, a frame, a piston accumulator, a quick-opening device, a high-pressure test assembly, and a high-frequency dynamic pressure sensor. This invention enables the measurement of operational characteristics under different pressure rise rate loads caused by water hammer phenomena on a test bench, providing an experimental platform for the research on the operational characteristics of overpressure relief devices under high pressure rise rates. The overall device is simple, quick, and stable. It effectively solves the problem of applying high pressure rise rate loads in current overpressure relief device operational characteristic measurement tests, overcomes the danger of using combustible gas explosions as pressure sources in existing operational characteristic measurement tests, and overcomes the shortcomings of existing test methods, such as long testing times, the need to calculate gas explosion pressure, and the difficulty in accurately controlling the pressure rise rate.

This invention discloses a dynamic pressure-based method for testing and analyzing hammer shock waves in aero-engines, belonging to the field of aero-engine testing and structural strength design. The method first uses a surge-induced pressure method to generate hammer shock waves at the engine inlet. Based on the flow field characteristics of the air intake outlet section (AIP section) during surge, dynamic total pressure and static pressure measuring points are arranged in a combination of circumferential and radial directions. Pressure signals are synchronously recorded using a high-speed data acquisition system, and four characteristic parameters—surge overpressure, overpressure ratio, loading time, and pressure rise rate—are defined to quantitatively analyze the intensity, spatial distribution, and dynamic process of the hammer shock waves. This invention achieves rapid, accurate, and comprehensive characterization of the aerodynamic load of hammer shock waves, providing reliable input loads directly for the strength design of complex structures such as S-curve air intakes, thereby improving aircraft safety.

The invention provides a method for detecting redundancies in an air bearing, which solves the technical problem that the existing dynamic pressure air bearing motor is lack of detection of the redundancies after the air bearing and the motor are assembled, firstly, particles and volatile substances on the surface of the air bearing are removed, and the detection accuracy of the internal redundancies can be improved. A power meter is adopted to measure the power of the motor, the time length is combined, the theoretical motor synchronization time and the minimum starting voltage are determined, the theoretical motor synchronization time and the minimum starting voltage are compared with the actually measured synchronization time and starting voltage, whether redundancy exists or not is determined, and the method is suitable for detecting the redundancy of various types of air bearings; according to the detection method, multiple positions of the bearing can be detected by rotating the output shaft of the motor, and the detection accuracy can be improved; and the method has the advantages of simple operation and wide application range.

The invention relates to the technical field of gas plectrum bearing test appliances, in particular to a technical platform of a gas plectrum bearing test rotor system. The device comprises a basic platform, a balance tire, a turbine shaft, a heat insulation cover, a shaft turbine end positioning accessory, a bearing sleeve set assembly, a shaft pressure end part assembly and an air cylinder. The balance tire is fixedly arranged on the basic platform, and an air inlet is formed below the balance tire; the turbine shaft is installed on the balance tire in an interference fit mode, and the turbine shaft is sequentially sleeved with the heat insulation cover, the shaft turbine end positioning accessory and the bearing sleeve set assembly. The bearing sleeve group is connected with the shaft pressure end part assembly through a pin; an air cylinder is assembled at the rear end of the bearing end part assembly; and a dynamic pressure gas thrust bearing for testing is arranged on the axial pressure end part assembly. According to the technical scheme, the problems of low maximum rotating speed, poor stability and the like of a gas foil bearing technical test platform in the prior art are solved.

To provide a dynamic pressure bearing excellent in bearing rigidity at low cost.SOLUTION: A dynamic pressure generating part P is provided on each of two radial bearings A1, A2 provided at an interval in the axial direction, and a large diameter cylindrical surface 8b having a diameter larger than that of the radial bearings A1, A2 is provided between the radial bearings LA, LA. In the dynamic pressure bearing (bearing member 8) in which the dynamic pressure generating portion P is formed of a concavo-convex surface in which a plurality of dynamic pressure grooves 10 extending in the axial direction and convex hill portions 11 are alternately arranged in the circumferential direction, one radial bearing surface A1 and the large-diameter cylindrical surface 8b are connected via a tapered surface 8c inclined with respect to the axial direction, and the other radial bearing surface A2 and the large-diameter cylindrical surface 8b are connected via a tapered surface 8d having an inclination angle with respect to the axial direction smaller than that of the tapered surface 8b. The dynamic pressure grooves 10 formed in the A2 of the other radial surface are open to the 8d of the tapered surface.SELECTED DRAWING: Figure 4

This invention discloses a hydrodynamic gas thrust bearing with an integrated top and bottom foil, relating to the field of air bearing technology. It can significantly extend bearing life, improve load capacity, and slow down temperature rise. The technical solution of this invention includes several integrated foil sheets fixedly mounted on a thrust back plate. These integrated foil sheets are sequentially connected end-to-end to form a ring, with an overlapping area between adjacent integrated foil sheets. A corrugated foil sheet is provided in the overlapping area, fixedly connected to one of the integrated foil sheets and in contact with the other integrated foil sheet. This invention eliminates the traditional welding connection between the top foil sheet and the bearing back plate, thereby significantly extending the bearing's service life.

The invention relates to the technical field of fans, and aims to solve the problems that a bearing structure of an existing fan is prone to being rubbed with other parts, so that noise of the fan is large, and abrasion is too fast. The invention provides a fan and electronic equipment. The fan comprises a shell, an impeller and a bearing. The housing includes a base plate and a sleeve defining an interior space. The impeller comprises a hub, a shaft rod and a thrust plate. The bearing is arranged in the internal space. The bearing cooperates with the shaft sleeve. The bearing has a first end surface, a second end surface, an inner peripheral surface, and an outer peripheral surface. The fan defines first to fourth oil paths, a first axial dynamic pressure oil path, a second axial dynamic pressure oil path, and a radial dynamic pressure oil path. The first oil way, the second oil way, the third oil way, the fourth oil way and the fourth oil way are sequentially communicated to form a liquid loop, and the first axial dynamic pressure oil way, the second axial dynamic pressure oil way and the radial dynamic pressure oil way generate axial dynamic pressure and radial dynamic pressure to enable the impeller to be kept in a suspension state. The fan has the beneficial effects that the impeller is completely suspended, friction of the fan is reduced, the sound quality is improved, and the service life of the fan is prolonged.

The utility model relates to the technical field of similar simulation experiment equipment, and discloses an experiment device for simulating mine earthquakes induced by movement of a water-containing weakly cemented rock stratum, which comprises a frame body, two movable plate bodies vertically arranged on the frame body and a pressing plate horizontally arranged on the frame body, the two movable plate bodies are in sliding fit with the frame body in the horizontal direction, and the pressing plate is arranged on the frame body. The two movable plate bodies, the pressing plate and a bottom plate of the frame body form a sample chamber for accommodating a rock sample, and the two groups of transverse pressure applying mechanisms are symmetrically arranged on the outer sides of the two movable plate bodies; each group of transverse pressure applying mechanism comprises a horizontal displacement assembly and a pressure applying end part connected to the horizontal displacement assembly, and the horizontal displacement assembly drives the pressure applying end part to move in the direction close to the movable plate body so as to apply pressure in the horizontal direction to the movable plate body. The dynamic pressure change condition of the weakly cemented rock stratum can be truly simulated, and the method has important significance for exploring the law and solving problems.

An aircraft system having a LIDAR system, one or more sensors, and a control unit. The control unit includes processing circuitry configured to calculate during flight a pressure altitude, calibrated airspeed, Mach number, equivalent airspeed, static temperature, static pressure, and dynamic pressure of an aircraft based on a combination of air data measurements from the LIDAR system and the one or more sensors.

The present application provides a capacity control valve with high control accuracy and excellent energy efficiency in normal control. The capacity control valve (V) has a valve housing (10) formed with a discharge port (12) through which a discharge fluid of a discharge pressure (Pd) passes, a suction port (13) through which a suction fluid of a suction pressure (Ps) passes, and a control port (13) through which a control fluid of a control pressure (Pc) passes; a rod (83) driven by a solenoid (80); and a main valve (50) composed of a main valve seat (10a) and a main valve core (51), the communication between the discharge port (12) and the control port (14) being opened and closed by the movement of the rod (83), the capacity control valve being provided with a CS valve (56) between the control port (13) and the suction port (14), the CS valve (56) being controlled by the dynamic pressure of the fluid flowing from the discharge port (12) to the control port (13) through the opening of the main valve (50).

The utility model discloses a shell compression resistance testing device which comprises a base, vertical frames are symmetrically and fixedly connected to the base, second limiting sliding grooves are formed in the vertical frames, a transverse frame is arranged between the two vertical frames, second limiting sliding blocks are fixedly connected to the two ends of the transverse frame, and the second limiting sliding blocks are in sliding fit with the second limiting sliding grooves. A sliding rod is installed in the transverse frame in a sliding mode, a connecting threaded hole is formed in the lower end of the sliding rod, a connecting stud is installed in the connecting threaded hole in a threaded mode, a testing head is fixedly connected to the lower end of the connecting stud, an installation base is fixedly connected to the upper end of the sliding rod, and a limiting screw rod is fixedly connected to the upper face of the installation base. By starting the driving motor, the testing head can be driven to move upwards and then move downwards quickly to hit the equipment shell to carry out dynamic pressure bearing capacity testing, the testing head can also press the equipment shell in a static state directly to carry out static pressure testing on the equipment shell, and the anti-pressure capacity of the equipment shell can be detected more effectively and comprehensively.

The invention discloses the technical field of rice grain grinding production, and discloses a rice huller, main body equipment used for rice hulling and a low-speed roller in the rice huller. The low-speed roller is composed of a plurality of sleeves. The inner walls of the sleeves are fixedly connected with inner gear rings, the sleeves are internally provided with first gears, the first gears are externally connected with sensors, and the sensors are used for detecting the torque of the first gears to the first shafts. An adjusting mechanism, a pressure mechanism and a control mechanism are arranged at each gear; the low-speed roller is composed of the multiple sleeves, the distance between each sleeve and the high-speed roller can be automatically adjusted according to self pressure, then dynamic pressure adjustment is completed, meanwhile, due to the fact that the adjusting processes of the sleeves are mutually independent, the defect that in a traditional scheme, an integrated low-speed roller can only conduct overall pressure adjustment can be effectively overcome, and the overall pressure adjustment efficiency is improved. The pressure adjustment of the low-speed roller on the rice is more refined, so that the hulling rate of the rice is effectively improved, and the broken rice rate of the rice is reduced.

This invention discloses a dynamic pressure air suspension bearing structure, comprising a bearing housing, an air suspension bearing, and a motor shaft. The air suspension bearing is a frustoconical type with an outer end smaller than its inner end, and the inner wall of the inner sleeve hole of its top foil layer is a conical inner wall. The bearing housing has a conical seat hole. The motor shaft has frustoconical sections at both ends for mounting the air suspension bearing, with the smaller end facing outward. These sections have outer conical surfaces adapted to the conical inner walls. The air suspension bearing is installed in the seat hole of the bearing housing, and the frustoconical section of the motor shaft is fitted into the inner sleeve hole of the air suspension bearing. A wedge-shaped gap is formed between the outer conical surface of the motor shaft and the conical inner wall of the air suspension bearing, allowing airflow to pass through. This invention also discloses a motor employing the above-mentioned dynamic pressure air suspension bearing structure.

A new type of oil cavity recess type static and dynamic pressure thrust bearing, with the development of high speed heavy load cutting technology, heavy equipment gradually to high speed heavy load development, we are more and more high performance requirements of static pressure thrust bearing, but with the increase of speed and load, the lubricating oil film because of the action of shear force and extrusion force, shear heat increases, oil film thin, even in local tribology failure phenomenon, and bearing because of local overheating deformation, resulting in lubricating oil leakage, and lubricating oil viscosity decreases, will produce static pressure loss, therefore, the patent puts forward a new type of oil cavity recess type static and dynamic pressure thrust bearing, so that the static pressure thrust bearing work, oil cavity and rotary workbench guide surface between the total wedge gap, under the condition of rotary workbench high speed rotation, meet the conditions of dynamic pressure effect, use dynamic pressure effect, through the dynamic pressure to make up for the lack of static pressure bearing capacity, in order to achieve the purpose of improving the bearing capacity and stability.

The present application relates to the technical fields of experimental fluid mechanics and precision testing instrument, and discloses a kind of fluid resistance precision test system and method in confined space, including thermostatic container component, including coaxial setting inner measuring tube and outer sheath pipe, outer sheath pipe bottom is fixed in positioning hoop.This application uses double-layer coaxial sleeve pipe to match bottom positioning hoop structure, constructs thermostatic cavity with mechanical centering datum as one and coaxial, guarantee the absolute perpendicularity of long-stroke measurement, with the help of dynamic pressure suspension guiding unit and double-line parallel traction mechanism, realize center guiding wire and traction component physical isolation, eliminate cable winding and friction noise, simultaneously through top detachable positioning support and the spiral quick-release hook cooperation of dynamic pressure suspension guiding unit, without cutting heavy binding traction line, can quickly replace test sphere under the premise of reserving system centering datum, so as to greatly improve the efficiency of multi-working condition comparison experiment.

The invention discloses a system and method for detecting the performance of a ventilation accessory of a storage tank, and the system is connected with the ventilation accessory to be detected, and comprises a gas supply module which is used for providing a required gas source and power for testing; the detection module is constructed into a detection loop of an integrated structure, is connected with the gas supply module, and is provided with a first passage for testing the opening pressure and the leakage rate of the first type of ventilation accessories and a second passage for testing the opening pressure and the leakage rate of the second type of ventilation accessories; the data measurement module is arranged between the inlet ends and the outlet ends of the first channel and the second channel and is used for recording the dynamic flow and the dynamic pressure of the gas in each test process; and the data processing module is used for calculating the accessory performance in the corresponding test scene by detecting a pressure sudden change phenomenon according to the dynamic flow and the dynamic pressure. The detection system is safe and reliable, the ventilation accessory does not need to be disassembled, and safe and accurate detection of the performance of the ventilation accessory is achieved.

The invention discloses a mechanical friction spark temperature testing method based on multiple thermocouples and particle size analysis, which comprises the following steps of: 1, preparing a test piece, processing the surface of a friction test piece, and fixing an embedded thermocouple array in the test piece; secondly, dynamic pressure loading is conducted, and friction pressure is adjusted through a high-pressure air bottle and a piston type air cylinder; 3, synchronously monitoring multiple thermocouples, and arranging the thermocouples to synchronously acquire data; step 4, spark particle size capturing: a high-speed camera and a laser particle size analyzer are adopted to acquire particle size distribution and speed track of spark particles in real time; 5, temperature-particle size correlation correction is carried out, and a temperature attenuation model is established based on the specific heat capacity and the heat conductivity coefficient of spark particles; and step 6, data fusion output: fusing and outputting analysis results. A plurality of thermocouple arrays are arranged at the center and the edge of a friction interface and on a spark splashing path, and temperature data in the friction heat and spark cooling process are synchronously collected.

The invention relates to the technical field of bus cylinder disassembly and assembly, and discloses a PLC-based digital disassembly and assembly platform control method and system.The method comprises the steps that real-time bearing data of multiple supporting points of a fault bus cylinder replacement supporting device are obtained, whether the supporting state of the replacement supporting device is safe or not is judged, and if yes, the replacement supporting device is started; carrying out levelness calibration on a digital disassembly and assembly platform, supporting the faulty bus cylinder by the digital disassembly and assembly platform after the levelness calibration reaches the standard, then axially compressing a telescopic joint of the faulty bus cylinder along a first direction to obtain a disassembly and assembly avoidance gap, and obtaining compression displacement of the telescopic joint; and dynamic pressure is calculated according to the compression displacement, and the expansion joint is compressed according to the dynamic pressure until the compression displacement reaches target displacement. Through the method and the corresponding system, the redundant process of dismounting the adjacent units in the process of dismounting the faulty bus cylinder is avoided, and the efficiency and the safety of repairing the faulty bus cylinder are improved.

The invention discloses a self-adjusting overpressure protection overflow valve, and relates to the technical field of valve control, the self-adjusting overpressure protection overflow valve comprises a valve body, the valve body comprises a main valve core and a valve cavity extending axially, the upper part of the main valve core is fixedly sleeved with a valve sleeve, and the side end of the valve sleeve is provided with a valve seat; the first annular damping groove, the second annular damping groove and the third annular damping groove with the through-flow sectional areas changing in a stepped mode are formed in the rear end of the main valve element and form dynamic matching related to displacement with the feedback hole, and the damping self-adjusting function of the overflow valve in different overpressure states is achieved. When the pressure is small, the feedback hole is communicated with the third annular damping groove with the minimum sectional area, strong damping is provided for restraining the valve element from jumping off, the opening process is soft and stable, and pressure impact is effectively eliminated; during moderate and overpressure, the feedback hole is switched to the second annular damping groove, damping is moderate, and dynamic pressure feedback is formed; when overpressure is large, the feedback hole is communicated with the first annular damping groove with the largest sectional area, feedback pressure is established rapidly, and rapid full-open overflow under the emergency working condition is ensured.

This utility model discloses a leak-proof gas engine valve chamber cover, including a cover plate disposed above the gas chamber. One-way valves are evenly distributed on the top of the cover plate. A connecting plate is provided between the cover plate and the gas chamber. A sealing element is provided between the cover plate and the connecting plate. The sealing element includes a metal ring, with a rubber sleeve covering the metal ring. A pre-tightening mechanism is provided above the sealing element, comprising a bolt and a disc spring. In this utility model, by setting up a connecting plate, a liner plate, a cover plate, a sealing element, and a pre-tightening mechanism, and utilizing a disc spring, the vibration of the sealing element is reduced, improving its stability. By setting a one-way valve on the cover plate, a pressure balance channel is formed between the inner and outer sides of the cover plate, thereby achieving dynamic pressure compensation. This avoids uneven pressure at the joint surface between the cover plate and the connecting plate, prevents cover plate deformation, and thus prevents the sealing element from loosening and detaching from the mounting groove, improving the working stability of the sealing element.

The application provides a method of coupling momentum potential theory and pressure wave decomposition and application thereof, and belongs to the field of fluid mechanics and aeroacoustics. The method first acquires flow field data, performs Helmholtz decomposition on the momentum density field based on the momentum potential theory to obtain momentum densities of fluid dynamics, acoustics and entropy components; then, the momentum densities of the components are taken as independent source terms to construct independent Poisson equations for describing fluid dynamics pressure, acoustic pressure and entropy pressure; and finally, the equations are solved to obtain pressure wave fields of the physical components. The application establishes a physical mapping between momentum modes and pressure modes, gets rid of the dependence on filtering threshold or propagation speed criterion in the prior art, realizes automatic and physically consistent separation of acoustic pressure (true sound) and fluid dynamics pressure (pseudo sound) in complex turbulent flow, and is suitable for noise mechanism research, source positioning and noise reduction design.

The invention provides a low-Reynolds-number wing design method based on a cavity pressure pneumatic flexible coupling effect, and relates to the technical field of aircraft design, the method comprises the following steps: detecting the flow separation position of a low-Reynolds-number wing to obtain the mounting position and laying length of an elastic wall plate; the method comprises the following steps: analyzing the airfoil shape of a wing by using the mounting position and laying length of an elastic wallboard, enabling the elastic wallboard to coincide with the shape of the mounting part of the wing in a non-deformation state to obtain the chordwise shape of the elastic wallboard, and testing by using the pressure value of the dynamic pressure in the flight process of the low-Reynolds-number wing. The thickness and material selection of the elastic wall plate are obtained, the cavity pressure value is obtained through calculation according to the lift force of the rigid wing body and the lift force of the wing body provided with the elastic wall plate, the low-Reynolds-number wing provided with the elastic wall plate is adjusted, and the improved low-Reynolds-number wing profile is obtained. The problems of how to improve the lift-drag ratio of the wings and prolong the endurance time of the aircraft are solved.

This invention discloses a hydraulic power module, its application, a hydraulic system, a fire truck, and a method. The hydraulic power module, used in the hydraulic system of a fire truck, is suitable for adjusting various hydraulic components. It includes a pressure signal pipeline for monitoring the pressure values ​​of the hydraulic system and controlling the hydraulic output. The pressure signal pipeline collects dynamic pressure values ​​of the hydraulic system in real time, forming a continuous pressure feedback signal. The pressure feedback signal is compared in real time with a preset target pressure value. If the pressure feedback signal continuously deviates from the target pressure value, a fault signal is issued. This hydraulic power module, by setting multiple hydraulic power sources, allows other hydraulic power sources to provide emergency hydraulic power when one source fails, preventing loss of hydraulic power, improving the stability of the hydraulic system, and providing emergency hydraulic power support. The accumulator absorbs pressure signal peaks, stabilizing the pressure signal.