27 results about "Compressibility" patented technology

The invention provides a three-dimensional numerical simulation method and system for supercavitation projectile high-speed inclined water discharge, and the method comprises the steps: building a three-dimensional geometric model of a projectile and a flow field computational domain, and outputting projectile body attribute parameters; estimating the size of a projectile body motion area, performing grid division on the projectile body and a flow field calculation domain, importing fluid solving software, establishing an overlapping calculation domain, and setting projectile attribute parameters and fluid solver boundary conditions; the influence of compressibility of water on the high-speed projectile is considered, a user-defined function is adopted, and the nonlinear relation between the density and the pressure of the compressible liquid under the isothermal condition is established; initial motion parameters of the projectile are defined, numerical solution is carried out, and cavitation evolution, flow field distribution, stress and motion characteristics in the water outlet process of the high-speed inclined projectile are obtained. According to the invention, the high-speed inclined water outlet process of the projectile under different working conditions can be simulated, the cost can be effectively reduced, and a technical basis is provided for a submarine launching test.

The invention discloses a non-overload centrifugal impeller with the characteristic of reducing pressure pulsation, which belongs to the technical field of non-overload centrifugal pumps and comprises a wheel disc, and a plurality of blades are fixedly connected to the circumference of the wheel disc; the part from the tail edge of the blade to the front edge of the blade is hollowed out to form a pulse pressure buffer area, the pulse pressure buffer area is located between the pressure face and the suction face of the blade, and the pulse pressure buffer area penetrates through the tail edge of the blade but does not penetrate through the front edge of the blade. The pulse pressure buffer area is arranged, so that instantaneous pressure change caused by local flow channel contraction can be absorbed and dispersed, and the peak value of pressure waves is effectively stabilized through compressibility, viscosity and inertia of fluid; therefore, the phenomenon of periodic pressure change caused by contraction of a local flow channel between the blade and the baffle tongue is relieved.

A method can include determining carbon dioxide acoustic properties for at least supercritical carbon dioxide using thermodynamics that relate isothermal compressibility and adiabatic compressibility: determining fluid-saturated rock acoustic properties using the carbon dioxide acoustic properties; and performing a seismic workflow using the fluid-saturated rock acoustic properties.

The invention discloses a hypersonic aircraft rough wall aerodynamic characteristic prediction method and device and a medium, and relates to the field of aircraft aerodynamic characteristic prediction.The method comprises the steps that the roughness height used for describing the roughness shape and the corrected surface infiltration area ratio are obtained; based on the wall temperature ratio, the compressible correction factor and the zoom coefficient, establishing a hypersonic rough wall RANS model; based on the hypersonic flight vehicle model with the smooth surface, the rough height and the corrected surface infiltration area ratio, in combination with the hypersonic rough wall RANS model, by means of a computational fluid dynamics method, streaming flow field simulation of the hypersonic flight vehicle to be predicted with the rough surface is carried out, and simulation data is obtained; and performing data post-processing on the simulation data to obtain the resistance and the heat flow of the to-be-predicted hypersonic aircraft with the rough surface. According to the method, the rough wall resistance and the heat flow of the hypersonic aircraft can be accurately predicted.

This invention discloses a passive buoyancy compensation method using gas-liquid mixing for profiling buoys, belonging to the field of buoyancy adjustment technology for marine observation buoys. This method constructs a passive buoyancy compensation system containing gas and liquid chambers, and adjusts the gas-liquid volume ratio to achieve linear and continuous adjustment of the system's equivalent compressibility coefficient, dynamically matching the compression characteristics of seawater at different depths. A mathematical model of the overall force on the buoy is established to determine system design parameters. Sensors are deployed to collect buoy depth and axial acceleration data, calculate motion parameters, predict and estimate the depth, and compare it with the target depth. When the deviation threshold is exceeded, an active fine-tuning judgment process is initiated. Active adjustment is disabled during the inertial-dominated phase, and during the non-inertial phase, the controller sends a fine-tuning command to the active buoyancy system to execute reverse buoyancy adjustment. The passive buoyancy compensation method using gas-liquid mixing provided by this invention can achieve low-power buoyancy control with passive adjustment as the primary method and active adjustment as a secondary method, effectively extending the underwater operational life of the buoy.

A method can include determining carbon dioxide acoustic properties for at least supercritical carbon dioxide using thermodynamics that relate isothermal compressibility and adiabatic compressibility; determining fluid-saturated rock acoustic properties using the carbon dioxide acoustic properties; and performing a seismic workflow using the fluid-saturated rock acoustic properties.

The invention relates to the technical field of thin interbed compressibility evaluation, in particular to a comprehensive compressibility evaluation method for a thin interbed tight reservoir, which comprises the following steps: acquiring original geological parameters and original engineering parameters of a target thin interbed reservoir, and sequentially executing two different types of preset micro-dynamic excitation operations on the target thin interbed reservoir, synchronously acquiring a multi-dimensional response signal generated by the stratum under each excitation operation; for each type of excitation operation, based on the corresponding multi-dimensional response signal, determining a conduction mode sequence of the event signal under the type of excitation in the longitudinal direction; conducting mode sequences determined by all types of excitation operations are fused and analyzed, and a dynamic coupling strength index and a stress interference mode between thin interlayers are determined; by analyzing conduction behaviors of the dynamic response signals, real controlled factors of stress wave propagation and fluid pressure transmission in the fracturing process can be directly reflected, and the pertinence and accuracy of evaluation are improved.

This invention discloses a method and system for calculating high-frequency noise of underwater vehicles based on fluid compressibility. The method includes: obtaining the local static pressure of the flow field; calculating the density distribution of the compressible water flow based on the local static pressure and the compressibility characteristics of the water; constructing a flow control equation considering fluid compressibility based on the density distribution of the compressible water flow, and solving the velocity distribution, pressure distribution, and density fluctuation distribution of the flow field through numerical iteration; constructing the FW-H equation based on the density distribution, velocity distribution, pressure distribution, and density fluctuation distribution of the compressible water flow; and embedding the flow control equation and the FW-H equation considering fluid compressibility into a computational fluid dynamics solver for solving, thereby obtaining the high-frequency noise calculation results of the underwater vehicle. This invention can effectively control the high-frequency noise rise phenomenon and improve the accuracy of high-frequency noise prediction for underwater vehicles.

The utility model relates to the technical field of engineering blasting, and specifically discloses an engineering blasting water hole blasting charge structure, which comprises a baffle, the baffle is a cylindrical structure with open ends, a supporting plate is fixedly connected to the lower part of the inside of the baffle, a buffer plate is arranged directly above the supporting plate, a plurality of springs that are uniformly distributed in a circular shape are fixedly connected between the supporting plate and the buffer plate, a base is arranged on one side of the baffle, the gas compressibility and the elastic support mechanism are combined, the technical bottleneck of pressure balance and the stability of the propellant column in deep water blasting is broken through, the modular sealing connection design greatly reduces the construction difficulty of complex working conditions, the baffle is infinitely expanded through a standardized threaded interface, the hole depth limit is broken through, the positioning accuracy of the device in the inclined blast hole is significantly improved through self-adaptive counterweight, and the safety and the economy are both improved as a whole.

Device and method for determining a property, in particular a viscosity or compressibility, of a fluid, in particular a functional fluid, of a component (102), in particular a viscosity or compressibility, wherein measurement data characterizing an operating characteristic of the component (102), in particular a power and / or a rotational speed of a pump with which the fluid is pumped, and / or a displacement of a hydraulic cylinder driven by the fluid, are acquired (206), wherein, depending on the acquired measurement data, a characteristic parameter for the function of the component (102), in particular a power signal and / or a force-displacement characteristic curve, is determined (208), wherein the property is determined depending on a result of a comparison between the determined characteristic parameter and a predetermined characteristic parameter for the function of the component (102).in particular a given power signal and / or a given force-displacement characteristic, is determined (210).

This invention provides a three-dimensional numerical simulation method and system for high-speed inclined water ejection of a supercavitating projectile. The method includes: establishing a three-dimensional geometric model of the projectile and the flow field computational domain, and outputting the projectile's property parameters; estimating the size of the projectile's motion region, meshing the projectile and flow field computational domains, importing the meshes into fluid dynamics software, establishing an overlapping computational domain, and setting the projectile's property parameters and the fluid dynamics solver's boundary conditions; considering the influence of water compressibility on the high-speed projectile, using a user-defined function to establish the nonlinear relationship between density and pressure of a compressible liquid under isothermal conditions; defining the initial motion parameters of the projectile, performing numerical solutions, and obtaining the cavitation evolution, flow field distribution, force and motion characteristics of the high-speed inclined projectile during water ejection. This invention can simulate the high-speed inclined water ejection process of a projectile under different operating conditions, effectively reducing costs and providing a technical basis for submarine-launched tests.

The invention provides a fan blade aerodynamic load calculation method considering air compressibility. The fan blade aerodynamic load calculation method comprises the steps that a thrust equation for updating an axial induction factor is constructed; updating the axial induction factor by using a thrust equation, and synchronously updating the tangential induction factor; obtaining a corresponding local inflow angle, a lift coefficient and a resistance coefficient according to the updated axial induction factor and tangential induction factor; calculating the aerodynamic load of the fan blade; wherein the thrust equation comprises a first thrust equation constructed according to a compressible air density expression, an Euler equation and a blade element theory and a second thrust equation constructed according to an empirical relational expression between a Glauert high thrust coefficient and an induction factor and the blade element theory. According to the method, the first thrust equation considering the air compressibility is constructed, and more accurate induction factors and lift-drag coefficients are iterated in combination with the existing second thrust equation, so that the aerodynamic load calculation precision of a large fan is higher, and the requirement of large-scale development of a wind turbine generator is better met.

The invention provides a pressure measuring device and method applied to fluid. The pressure measuring device comprises a pressure conversion module which is used for receiving fluid through a pipeline area and converting the pressure of the fluid into the pressure of an isolation medium; the pressure detection module is arranged at the end, away from the fluid, of the pressure conversion module and used for detecting pressure data borne by the isolation medium in real time; and the pressure analysis module is used for receiving the pressure data of the isolation medium and analyzing the fluid pressure according to a preset algorithm. According to the invention, the pressure transmission module with volume difference is designed, the compressibility of the isolation medium is utilized, the pressure signal is transmitted through the isolation medium to realize indirect measurement of the fluid pressure, and meanwhile, the device can better adapt to the application scene of intermittent or continuous detection.

The invention discloses a front body / air inlet channel integrated design method based on longitudinal segmentation multi-stage compression, and relates to the field of high-speed aircraft front body / air inlet channel design. The method comprises the steps that at least two-stage compressed cone-guided waverider front bodies are designed, and the incoming flow Mach number of an air inlet channel is determined; constructing an inner cone type axisymmetric reference flow field by adopting a characteristic line design method, and performing matching design on the axisymmetric reference flow field and a cone-guided waverider precursor shock wave to form an air inlet capture molded line; adopting a forward and reverse tracking design fusion mode to obtain an inward rotation type air inlet channel; and the inward rotation type air inlet channel and the cone-guided waverider precursor are fused, and the precursor and air inlet channel integrated configuration is obtained. After the forward and reverse fusion design is adopted for the air inlet channel, the air inlet channel is further fused with the front body, and compared with the existing independent design of the front body and the air inlet channel, the air inlet channel has the advantages that the pre-compression performance of the air inlet channel is improved, the length of the front body of the aircraft is shortened, the total pressure recovery and supercharge ratio of the air inlet channel is increased, and the starting performance of the air inlet channel is widened.

The invention belongs to a theoretical calculation method for structural dynamic response under the action of shock waves, particularly relates to a calculation method for motion response of an air back flat plate structure under the action of fluid shock waves, and belongs to the technical field of structural impact dynamic response test and evaluation. Comprising the following steps: S1, calculating a post-wave state of an incident shock wave in a fluid medium; s2, calculating the post-wave state of the reflected shock wave in the fluid medium; s3, calculating the sparse wave pressure p3 in the fluid medium caused by the movement of the flat plate structure; s4, calculating the motion response of the flat plate structure; according to the method, the basic principle of fluid dynamics is combined, the acoustic linear hypothesis that fluid cannot be compressed in the Taylor plate theory is replaced with a compressible state equation of substances, the compressibility of the fluid and the plate structure is considered, and meanwhile the influence of sparse wave propagation in a flow field on movement of the plate structure is also considered; according to the method, a quantitative result can be calculated more efficiently and more accurately, and the method is used for guiding underwater explosion test and damage evaluation.

The invention discloses a cross-medium aircraft high-speed water outlet flexible load reduction rectifying device, and relates to the technical field of cross-medium aircraft structure protection. The device conformally wraps the head of the aircraft and sequentially comprises an inner side bonding layer, an anti-static pressure air bag layer, an energy absorption foam layer and an outer side protection layer from inside to outside, underwater collapse is prevented through the internal pressure of preset gas of the anti-static pressure air bag layer, and low-frequency large-displacement buffering is provided through the compressibility of the gas at the water outlet moment; high-frequency impact is absorbed through deformation of the energy-absorbing foam layer, and transition from a blunt-end inner shape to a pointed-end outer shape is achieved. And supercavitation is formed through the streamline shape, so that the water outlet resistance is reduced. Through the material, shape and thickness design of each layer, water outlet resistance reduction and pressure resistance keeping in a deep water environment and efficient buffering at the water outlet moment are achieved, the underwater launching success rate is effectively increased, and precise instruments at the head of an aircraft are protected.

The invention belongs to the technical field of metal component detection, and discloses a high-strength anti-seismic bracket performance testing device, which comprises a hydraulic tension testing machine, and an upper driver and a lower driving system which are arranged on the hydraulic tension testing machine. Through cooperation of structures such as the buffer mechanism, fracture stress pushes the first oil tank and the fixing device to ascend and suddenly extrude hydraulic oil into the second oil tank, the fixing device enters the first oil tank, the stress acts on the hydraulic oil in the fixing device, and the flow characteristic of the hydraulic oil can effectively weaken generation of instantaneous stress; the compressibility and the fluidity can disperse the propagation velocity of pressure waves and prolong the stress release time, through flow limitation of the steel pipe and downward thrust of the spring telescopic rod, the flow velocity is reduced, the effect of weakening impact force is enhanced, the stress borne by the spring telescopic rod is weakened by the damper, the stress generated by component breakage is further absorbed, and the service life of the spring telescopic rod is prolonged. And the damage probability of internal electronic elements and structures of the hydraulic tension testing machine is greatly reduced.

A method can include determining carbon dioxide acoustic properties for at least supercritical carbon dioxide using thermodynamics that relate isothermal compressibility and adiabatic compressibility; determining fluid-saturated rock acoustic properties using the carbon dioxide acoustic properties; and performing a seismic workflow using the fluid-saturated rock acoustic properties.

The invention relates to the technical field of air permeability of parachute canopies, in particular to a method for calculating air permeability of a parachute canopy under a high pressure difference condition, which comprehensively considers weaving structure characteristics of a canopy fabric, gas compressibility under the high pressure difference condition and conditions and working conditions during supersonic flight of a parachute. The method for rapidly calculating the air permeability of the parachute canopy under the specified high pressure difference condition is established. According to the method, a more accurate mathematical model can be provided for air permeability numerical simulation calculation, canopy engineering design and the like of the parachute under the supersonic speed and high pressure difference conditions, and guidance is provided for research and design of the parachute.

The invention discloses a compressibility evaluation method based on a post-compression coring nondestructive mechanical experiment, and relates to the technical field of coring and testing. The method comprises the following specific steps: carrying out pressure-maintaining coring on a core layer position of a fractured well according to specific layer position requirements of a development block to obtain a high-quality fractured rock core sample; and performing high-energy CT ring scanning on the collected post-fracturing coring sample, and distinguishing by adopting a gray scale method to obtain a specific fracture three-dimensional distribution form of a rock core in a fracture development area, so as to realize quantitative evaluation of the development degree of the natural fracture before and after fracturing. According to the compressibility evaluation method based on the after-fracturing coring nondestructive mechanics experiment, natural fracture distribution, rock mechanics and ground stress characteristics after volume fracturing are evaluated are tested, key compressibility evaluation parameters can be obtained on the basis that rock cores are not damaged, and the compressibility effect is evaluated; and the method has important significance in guiding subsequent volume fracturing to carry out targeted fracturing parameter design.

The invention discloses a volume fracturing compressibility characterization method which comprises the following steps: measuring the horizontal ground stress of each well, calculating a stress difference coefficient D, observing the natural fracture development degree K of a well position reservoir, obtaining the elastic modulus and Poisson's ratio distribution of a reservoir section, and calculating the brittleness index B of reservoir rock according to the elastic modulus and Poisson's ratio distribution. And finally, calculating a compressibility index F according to the three parameters, and selecting a regional reservoir with the highest F value as a target dessert region for volume fracturing transformation. According to the method, the problem that the compressibility of the reservoir cannot be accurately described only by using the brittleness index in an existing reservoir compressibility characterization method is solved.

The application relates to the technical field of temperature-pressure phase diagram modeling, and discloses a temperature-pressure phase diagram modeling method based on a Grover model, which comprises the following steps: S1: obtaining the thermal expansion coefficient, volume and isothermal bulk modulus thermodynamic data of a rare earth tantalate system under different temperature and pressure conditions; S2: respectively correcting the molar volume and the isothermal compressibility under standard atmospheric pressure, reducing the influence of excessive sensitivity of the heat capacity on the coupling relationship between the temperature and the pressure, so as to realize the correction of the Grover model; and S3: obtaining the Gibbs free energy change through the corrected Grover model state equation, and linearly superimposing the Gibbs free energy change and the Gibbs free energy under standard atmospheric pressure given by a thermodynamic database to obtain a temperature-pressure phase diagram model. The application can ensure the accuracy of the obtained Gibbs free energy, thereby ensuring stable modeling and ensuring the reliability of the phase diagram.

The application discloses a kind of low temperature high pressure reciprocating pump liquid force end vaporization loss rate measurement method based on indicator diagram;The method comprises: establishing the relationship between the closing lag angle of inlet valve and the measurement error, combined with the estimated error level, to determine whether the closing lag angle needs to be measured;Measure the load of piston rod and real-time phase or position, draw indicator diagram after preprocessing;According to the estimated or measured closing lag angle, and the internal relationship between the actual indicator diagram slope when the cylinder pressure of discharge stroke is equal to the critical pressure and the isothermal and adiabatic compression slope, determine the starting point of compression stage;Use low-temperature fluid saturated thermophysical property to calculate gas-liquid density;Based on mass conservation, build the vaporization loss rate calculation formula.The application solves the problem that conventional technology cannot be used for such pumps due to the significant difference in compressibility and thermophysical properties of low-temperature fluids, and has the advantages of high measurement accuracy, good engineering applicability, etc.

The present invention relates to the technical field of oil and gas field development, and specifically relates to a method for calculating the production splitting coefficient based on the isothermal compressibility coefficient. The production splitting coefficients of each producing layer are calculated using the formula. The present invention clarifies the determining factors of the production splitting coefficient, proposes a simple calculation procedure, enriches the calculation methods of the production splitting coefficient, and has guiding significance for gas reservoir development.

A tight reservoir compressibility evaluation method at logging scale belongs to the technical field of fracturing in downhole operation in the petroleum industry, and comprises the following steps: S1, gamma, density, acoustic data are introduced into the ground stress profile software to obtain the ground stress, Young's modulus and Poisson's ratio parameters, and the horizontal stress difference coefficient, stress quality coefficient and brittleness index factor are respectively calculated according to the formula; S2, the minimum horizontal principal stress is taken as the main control factor of compressibility, and the partial correlation coefficients of the horizontal stress difference coefficient, stress quality coefficient, brittleness index, macroscopic crack factor and the main control factor are measured under the condition of controlling other factors; S3, the compressibility coefficient is obtained by multiplying the values of each influencing factor and the corresponding weight. Through post-pressure test analysis, it is verified that the tight reservoir compressibility evaluation method at logging scale is reliable and simple, and can effectively guide the single well fracturing design.

The invention relates to the technical field of aerospace vehicle aerodynamics ground tests, in particular to a wing body assembly large attack angle asymmetric separation flow experiment method and system. The method comprises the following steps: presetting train number parameters of a wind tunnel test model, a multi-color continuous oil supply module, a pressure image acquisition module, a flow display module, a pressure measurement module and a wind tunnel; image data and pressure data are synchronously acquired, the image data are pixel-level resolution time sequence oil flow image data formed on the basis of the surface of the wind tunnel test model, and the pressure data are acquired high-precision pressure distribution data on the surface of the wind tunnel test model; based on the acquired image data and the pressure data, acquiring an asymmetry degree, a bistable depth, a fitting coefficient and a compressibility suppression ratio; if the bistable depth is gt; 0.05 and the fitting coefficient is gt; when 0.9 is reached, judging that the state is an obvious bistable state; and otherwise, determining the state as weak bistable state / no bistable state.

The invention provides a gas reservoir flowing substance equilibrium reserve calculation method, and relates to the technical field of gas reservoir reserve calculation. The method comprises the steps that basic parameters of a constant-volume gas drive gas reservoir and dynamic data of well bottom flowing pressure actually measured in the stable production stage of a gas well are sorted and smoothed; secondly, initial flowing bottomhole pressure and a pressure square difference initial value are determined, and it is assumed that the pressure square difference is constant; then, the average formation pressure, the gas deviation coefficient and the gas isothermal compression coefficient in the gas well stable production process are circularly calculated; then constructing a gas reservoir flowing substance balance equation considering the non-Darcy effect, and calculating dynamic data of variables X and Y; adjusting a pressure square difference value through iteration, and performing linear fitting on the X and Y scatter points until the longitudinal axis intercept of a linear function approaches zero, so as to determine a straight slope; and finally calculating the single well control reserves according to the slope and the basic parameters. According to the method, the limitation of Darcy seepage hypothesis is overcome, and accurate reserve evaluation based on whole-process data is realized.