2281 results about "Fluid field" patented technology

In a method for evaluating one or more components in a data center, inlet and outlet temperatures of one or more heat dissipating devices are detected. In addition, the temperatures of air supplied by one or more computer room air conditioning (CRAC) units are also detected. Indices of air re-circulation for the one or more heat dissipating devices are calculated based upon the detected inlet temperatures, outlet temperatures and supplied air temperatures. The indices of air re-circulation are determined at various flow field settings of air delivered to the one or more heat dissipating devices and the one or more components are evaluated based upon changes in the indices of air re-circulation for the one or more heat dissipating devices at the various flow field settings.

In a method for evaluating one or more components in a data center, inlet and outlet temperatures of one or more heat dissipating devices are detected. In addition, the temperatures of air supplied by one or more computer room air conditioning (CRAC) units are also detected. Indices of air re-circulation for the one or more heat dissipating devices are calculated based upon the detected inlet temperatures, outlet temperatures and supplied air temperatures. The indices of air re-circulation are determined at various flow field settings of air delivered to the one or more heat dissipating devices and the one or more components are evaluated based upon changes in the indices of air re-circulation for the one or more heat dissipating devices at the various flow field settings.

A field effect transistor device includes: a reservoir bifurcated by a membrane of three layers: two electrically insulating layers; and an electrically conductive gate between the two insulating layers. The gate has a surface charge polarity different from at least one of the insulating layers. A nanochannel runs through the membrane, connecting both parts of the reservoir. The device further includes: an ionic solution filling the reservoir and the nanochannel; a drain electrode; a source electrode; and voltages applied to the electrodes (a voltage between the source and drain electrodes and a voltage on the gate) for turning on an ionic current through the ionic channel wherein the voltage on the gate gates the transportation of ions through the ionic channel.

A method and apparatus for extracting centerline representations of vascular structures in medical images is disclosed. A vessel orientation tensor for each of a plurality of voxels associated with the target vessel, such as a coronary artery, in a medical image, such as a coronary tomography angiography (CTA) image, using a trained vessel orientation tensor classifier. A flow field is estimated for the plurality of voxels associated with the target vessel in the medical image based on the vessel orientation tensor estimated for each of the plurality of voxels. A centerline of the target vessel is extracted based on the estimated flow field for the plurality of vessels associated with the target vessel in the medical image by detecting a path that carries maximum flow.

A method of producing a porous flow field material for a bipolar separator plate is provided. The method includes bonding a single layer of wire mesh or bonding together at least two layers of wire mesh to form a porous flow field material, wherein the bonding is achieved by diffusion bonding, continuous resistance welding, continuous sintering, or a combination thereof. Such porous flow filed materials may function as, for example, fluid flow fields, current collectors, gas distribution layers, and / or coolant layers. A method of producing a bipolar separator plate including such porous flow field materials is also provided, wherein the component layers are bonded together by diffusion bonding, continuous resistance welding, continuous sintering, or a combination thereof, thereby forming a bipolar separator plate.

A system for cooling a fuel injector extending into a combustion gas flow field includes a liner that defines a combustion gas flow path within a combustor and a fuel injector that extends through the liner. The fuel injector includes a main body having an annular first portion that extends outward from the liner and a second portion that extends from the first portion inward into the combustion gas flow path. The main body defines a cooling channel that is fully circumscribed within the main body and that extends between the first portion and the second portion. A cooling air inlet is defined within the annular first portion and is in fluid communication with the cooling channel. A cooling air outlet is in fluid communication with the cooling channel and is defined within the second portion downstream from the cooling air inlet.

After an ignition switch is turned off, in order to suppress operation of an air compressor and thereby reduce noise, liquid droplets residing in an oxygen-containing gas flow field as well as liquid droplets residing in a fuel gas flow field are removed during separate time periods, such that the flow rate in the oxygen-containing gas flow field and the flow rate in the fuel gas flow field do not become large at the same time. Then, an electrolyte membrane is dried using an oxygen-containing gas, in order to improve the performance upon starting a next operation.

A method for determining electrophysiology properties of tissue comprising acquiring electrical signal data from a plurality of electrodes (130) of one or more catheters, determining at least one electrode clique from the plurality of adjacent electrodes (136), computing local conduction velocity vectors for the at least one electrode clique (138), determining at least one catheter orientation independent indicator from which to classify an arrhythmia source based on one or more of an angular dependence parameter associated with a flow field of the local velocity conduction vectors, an eccentricity parameter reflecting the uniformity of local conduction velocity, and divergence and curl-like sums or closed path integral parameters associated with the local velocity vectors, and displaying a rhythm classification responsive to catheter movement thereby facilitating identification of types and causes of arrhythmia disorders.

The present invention provides a system and method for actively manipulating and controlling aerodynamic or hydrodynamic flow field vortices within a fluid flow over a surface using micro-jet arrays. The system and method for actively manipulating and controlling the inception point, size and trajectory of flow field vortices within the fluid flow places micro-jet arrays on surfaces bounding the fluid flow. These micro-jet arrays are then actively manipulated to control the flow behavior of the ducted fluid flow, influence the inception point and trajectory of flow field vortices within the fluid flow, and reduce flow separation within the primary fluid flow.

The invention provides a speed change pressure flow field control method applicable to an intermittent transonic speed wind tunnel, and relates to the technical field of aerospace industry wind tunnel tests. The speed change pressure flow field control method applicable to the intermittent transonic speed wind tunnel solves the problem that a traditional flow field control method can not meet the requirements of flutter tests. The technical scheme includes: enabling total pressure and main ejector pressure to rise to first stage set value in a given rate after a wind tunnel starts ramming; controlling a mach number to reach set target value in a flow field regulating procedure; controlling a main pressure regulating valve and a main air discharge valve so as to enable the total pressure of the wind tunnel and the main ejector pressure to reach respective target value in a change total pressure regulating procedure; and controlling the current main ejector pressure to gradually drop to set shutdown main ejector pressure and controlling the current wind tunnel total pressure to gradually drop to set wind tunnel total pressure value when the wind tunnel is shut down. The speed change pressure flow field control method applicable to the intermittent transonic speed wind tunnel can meet the requirements of the flutter tests for intermittent transonic speed wind tunnel flow field control, has rapid, accurate and reliable test effects, and furthermore is high in total pressure control and mach number control accuracy.

The invention discloses a numerical analog method for impact of gas pipeline leakage on an internal flow field, relating to the technical field of gas. The analog method comprises the following stepsof building analog software; modeling gas pipeline leakage and performing simulation analysis; and analyzing gas pipeline leakage numerical results. Before and after gas pipeline leakage, changes of the internal flow field of the pipeline are analyzed; according to computational fluid dynamics (CFD) knowledge, gas pipeline leakage is simulated by using Fluent, and according to fluid dynamics theory, characteristics of the internal flow field of the gas pipeline before and after leakage are obtained through analysis; according to CFD knowledge, gas pipeline leakage under different leakage conditions is simulated, so as to learn that the greater the inlet pressure, the more likely that a leakage accident occures, and the greater the leakage hole diameter, the higher the proportion of a highconcentration area surrounding the leakage hole.

The invention relates to technology for simultaneously measuring multi-phase flow particles online through multi-parameter, and aims to provide a method and a device for simultaneously measuring droplet positions, particle sizes and a complex refractive index. The method comprises the following steps of: (1) dividing a highly coherent continuous laser beam into two beams after spatial filtering and collimating beam expansion, wherein one beam radiates particles in a detected flow field region, and the other beam is used as a reference beam; (2) mixing scattered light of a lateral 30-degree to 90-degree region of particles in the detected flow field region and the attenuated reference beam to perform interference so as to form a hologram, storing the hologram in a computer after being recorded by a digital camera through an imaging device; (3) acquiring a series of reconstructed images of the detected particles along the depth direction by utilizing digital reconstruction technology; and (4) identifying the reflective spot and the refractive spot of the particles from the reconstructed images by utilizing digital image processing technology so as to acquire space coordinates and scattered light intensity ratios. Compared with rainbow measurement technology, the measurement method has the advantages that: a light path system of the measurement device is relatively simple and is easy to implement.

The present invention is whole particle field measuring method and equipment based on laminar laser imaging and features that particles in test flow field are illuminated with orthogonal laminar laser beams and two CCD cameras are used to take the particle motion locus images both in the direction perpendicular to the flow field and in the direction parallel to the flow field separately. The equivalent diameters of particles are determined via particle image distinction and statistical analysis of covered pixels, and the particle motion speeds, including magnitudes and directions, are determined via the distinction and analysis of particle motion locus image, so as to obtain the size spectrum and speed field distribution of particles in the imaging plane. The present invention needs no addition of tracing particle, and may be used widely in the two-phase and multi-phase flow field measurement in various fields.

The invention discloses an ultrasonic ground experimental wind tunnel used for knocking combustion research, and the wind tunnel provided by the invention comprises an ultrasonic premixing heater, an experimental section and a vacuum chamber, wherein the ultrasonic premixing heater comprises an injector 6, a preheating combustion chamber 1, an array nozzle module and a mixing section 3. The preheating combustion chamber adopts three components for combustion, and supplements oxygen or air after combusting hydrogen and air; and the preheating combustion chamber is designed to be in a colliding injection mode. The technique has the advantages that the combustion local high temperature can be effectively reduced, the thermal protection difficulty is reduced, the uniformity of flow field parameters such as gas mixture temperature, components and the like can be ensured, and the content of the oxygen in the gas mixture can be freely adjusted. The vacuum chamber is connected to the back of the experimental section, so that the back pressure of the experimental section can be reduced, and the design range of ultrasonic stream Mach numbers in the experimental wind tunnel is expanded.

The invention relates to an optimized design method for modelling of an end wall of a high load fan / compressor. The method comprises eleven steps. As the stage pneumatic load is improved, internal flow of the fan / compressor is more severe, massive secondary flow is easily generated in an area close to the end wall, and a risk of flow stall exists. The modelling of the end wall has important influence on control over the secondary flow in an end area of the high load compressor, and becomes an important research direction. Firstly, an end wall modelling parameter defining method is researched; secondarily, based on an adaptive genetic algorithm and an artificial neural network response surface model, which are developed by the research group, an orthogonal experimental design, end wall parameter definition and a flow field value simulating technology are combined to realize automatic global optimization of the end wall of the compressor; thirdly, the effectiveness of the optimizing method is verified through different test functions; finally, a blade grid of the compressor is subjected to nonaxisymmetrical optimization based on the method. A result shows that the blade grid after modelling has good pneumatic performance.

A bipolar assembly for use in electrochemical cell stacks, especially stacks operated at low pressure. The bipolar assembly is lightweight and provides a "post-type" flow field that operates with a low pressure drop. The bipolar assembly comprises a gas barrier having an array of electronically conducting posts disposed approximately perpendicular to the gas barrier. Each end of the posts is in electrical communication with the surface of an electrode. Because the bipolar assembly separates a cathode from an anode, the posts contact an anode electrode on one end and a cathode electrode on the other end. The posts provide current conduction through the stack as well as provide the flow fields for the electrochemical reactants. Optionally, the bipolar assembly may contain cooling fluid channels formed by adding additional gas barriers to the bipolar assembly. The space between the gas barriers form a channel through which cooling fluids may be circulated.

A fuel cell stack has a plurality of polymer electrolyte fuel cells (PEFCs) where each PEFC includes a rectangular membrane electrode assembly (MEA) having a fuel flow field along a first axis and an air flow field along a second axis perpendicular to the first axis, where the fuel flow field is long relative to the air flow field. A cathode air flow field in each PEFC has air flow channels for air flow parallel to the second axis and that directly open to atmospheric air for air diffusion within the channels into contact with the MEA.

The invention relates to a method and a device for spreading trace particles in a supersonic PIV (Particle Image Velocimetry) flow field testing experiment. The trace particles are charged by using vacuum suction in a supersonic wind tunnel high-pressure high-temperature large-flow flow field environment, the trace particles are stored in a particle generator before the experiment, after a gas flow is injected, the gas flow and the trace particles are sufficiently mixed, pass through a high-pressure pipeline, are spread by a particle spreader and then enter a wind tunnel pipeline, the trace particles are uniformly spread under the condition of a high-Mach-number flow, and the trace particles are tested through a particle image velocity-measuring system. Compared with the prior art, the method and the device provided by the invention realize that the PIV trace particles are charged and uniformly spread in a high-pressure high-temperature large-flow flow field ambient condition, the probable agglomeration phenomenon of the trace particles in the injection process is effectively avoided, precise sequence control between a PIV system and wind tunnel operation is guaranteed, and the testing scheme corresponding to the spreading concentration satisfying the PIV operation requirement is determined.

The invention provides a light distribution optimization method for two-dimensional reconstruction of a combustion flow field by combining a tunable semiconductor laser absorption spectrum technology and a computed tomography technology. The method comprises the following steps: a light matrix calculation step, a combustion flow field reconstruction step and a light distribution optimization step and particularly comprises the following steps: step 1, discretizing a region to be tested; pre-setting a light space distribution manner and calculating the length of light penetrating through the discretized region to obtain a light distribution matrix; step 2, selecting a suitable absorption spectrum line and calculating a light projection result of an initial gas distribution model; reconstructing temperatures and concentrations of the tested flow field by using an algebra iterative algorithm and calculating a reconstruction error and a standard deviation; and step 3, wholly searching by using a self-adaption simulated annealing method to obtain an optimal light distribution range and partially searching by using a sequential quadratic programming method to obtain optimal light distribution.

The invention relates to a gas diffusion layer with a gradient hole structure for fuel batteries and a preparation method and applications thereof. The gas diffusion layer consists of a macroporous carbon-based support body and a micro-porous layer which are overlapped, wherein the material of the micro-porous layer is embedded in the macroporous carbon-based support body from one side, far from the flow field of a battery, of the macroporous carbon-based support body to form a transitional hole layer; the transitional hole layer is composed of the material of the micro-porous layer and the fiber of the macroporous carbon-based support body and is obtained by embedding the material of the micro-porous layer in the side, far from the flow field of a battery, of the macroporous carbon-based support body; and the curvature of reaction gas transfer from the side next to the flow field to the side next to a catalyst layer in the gas diffusion layer increases gradiently and the air permeability gradually reduces from 4-10s / 100ml to 100-900s / 100ml. By adopting the gas diffusion layer with the structure, the mass transfer curvatures of water and the gas in the gas diffusion layer (GDL) can be effectively increased, the transfer path of the product-water can be prolonged and liquid water in the battery can be maintained; and the gas diffusion layer is particularly suitable for fuel batteries working under low humidity and the cathodes of alkaline fuel batteries.

The invention discloses a fluid simulation method based on the Eulerian-Lagrangian coupling method. According to the aim of achieving efficient fluid simulation and the core idea of solving the N-S equation through the Eulerian method and the Lagrangian method to carry out fluid simulation, research is conducted through the multi-method coupling calculation method on the basis of SPH and LBM fluid simulation. Firstly, large-scale fluid field modeling is carried out through the LBM method based on Eulerian grids to build the main part of fluid simulation; then, simulation is carried out on fluid details such as spindrifts and water drops through the SPH method based on the Lagrangian particle idea, LBM fluid and SPH fluid are integrated by designing a coupling algorithm, and lifelike and rapid large-scale fluid simulation with details involved is achieved.

A planar velocity measurement system (100) is operative to measure all three velocity components of a flowing fluid (106) across an illuminated plane (108) using only a single line of sight. The fluid flow is seeded with small particles which accurately follow the flow field fluctuations. The seeded flow field is illuminated with pulsed laser light source (102) and the positions of the particles in the flow are recorded on CCD cameras (122,124). The in-plane velocities are measured by determining the in-plane particle displacements. The out-of-plane velocity component is determined by measuring the Doppler shift of the light scattered by the particles. Both gas and liquid velocities can be measured, as well as two-phase flows.

A method for analyzing vortex vibration and fatigue of a depth tension-type vertical pipe, which relates to the field of depth vertical pipe design, comprises the following specific steps of: step 1. obtaining flow field data; step 2. substituting the flow field data into vertical pipe vibration equations 6 and 7; step 3. solving the equations 6 and 7 by using a finite element method, and obtaining calculation results including displacement, velocity, accelerated velocity and stress time interval; and step 4. counting stress cycle number n(i) of an amplitude within a certain time by adopting a rain-flow counting method according to the calculation results, and substituting the n(i) into a fatigue damage calculation formula 8 to calculate the fatigue damage. The method for analyzing vortex vibration and fatigue of the depth tension-type vertical pipe improves the accuracy of stress calculation by adopting a practical pipe-in-pipe model and simultaneously considering direct flow vibration and cross flow vibration.

Provided is a blood processing system having a stationary component separation chamber. Individual blood components as well as other particles and contaminates are separated from blood flowing through the separation chamber by optical traps configured to manipulate specific components are projected into the flow field of the chamber. Cells or particles of the selected components that are manipulated by the optical traps then may be directed from the flow field to individual reservoirs to collect quantities of the selected components.

The invention relates to a fully-three-dimensional simulated visualized displacement simulation experiment system of a fractured-vuggy oil reservoir. The fully-three-dimensional simulated visualized displacement simulation experiment system comprises trough, fractured-vuggy model, water injection, air injection, image acquisition and data acquisition simulation unit, a simulation oil groove and a three-phase separator. The trough simulation unit comprises a cubic trough, a glass pipe and a shaft. The fractured-vuggy model simulation unit comprises a cavern model and a crack model. The water injection simulation unit comprises a water injection tank and a water pump. The air injection simulation unit comprises an air compressor, an air storage tank, an emptying valve, a water draining filter and an air dryer. A particle forming test module of the image acquisition simulation unit is arranged on a sliding rod and installed on a support through the sliding rod. A pressure variator of the data acquisition simulation unit is installed at the connecting position of the shaft and the fractured-vuggy model simulation unit. The output end of the three-phase separator is respectively connected with the simulation oil groove and the water injection tank, and the input end of the three-phase separator is connected with the shaft. The fully-three-dimensional simulated visualized displacement simulation experiment system of the fractured-vuggy oil reservoir is simple and reasonable in structural design and capable of timely, intuitively and accurately monitoring a flow field and pressure change in a stratum.

The present invention provides a system and method for actively manipulating fluid flow over a surface using synthetic pulsators. Synthetic pulsators produce pulsed jet operable to manipulate the primary fluid flow proximate to the synthetic pulsator. The synthetic pulsator includes a dual diaphragm synthetic jet coupled to high performance dual actuator solenoids, wherein the synthetic jet is operable to produce an oscillatory flow. The oscillatory flow of the synthetic jet(s) produces the pulsed jet operable to manipulate the primary fluid flow. These synthetic pulsators may then be actively manipulated to control the flow behavior of the ducted fluid flow, influence the inception point and trajectory of flow field vortices within the fluid flow, and reduce flow separation within the primary fluid flow.

The invention discloses a device and a method for the use of an impeller of a laser 3D (three dimensional) -printing pump, and belongs to the field of 3D printing technology. The device comprises a laser system, a gas protection system, a preheating system, a powder feeding system, a powder paving system, a powder recycle system and a computer system. The manufacturing method mainly comprises the following steps that 1, a CAD solid model of the pump impeller is drawn, and the model is subjected to hierarchical slicing along the Z direction; 2, the slice in each layer is zoned into a zone I and a zone II according to the performance requirements of the pump impeller; 3, the zone I of each slice layer is subjected to low-speed sintering by using powder A, and the zone II is subjected to low-speed sintering by using powder B. The surface of a workpiece and the powder flow filed are subjected to the inert gas shielding in the process of printing. According to the device and the method for the use of the impeller of the laser 3D-printing pump, different requirements of different positions of the pump impeller on mechanical performance can be met, the printing quality and speed are also improved, and the manufacturing cost is reduced.

A device (10) for use in a fuel cell includes a fuel-cell flow-field channel (18) having a channel-inlet section (42) and a channel-outlet section (44). At least one of the channel-inlet section (42) or the channel-outlet section (44) includes an obstruction member (46) that partially blocks flow through the fuel-cell flow-field channel (18).