313results about "Full-field flow measurement" patented technology

Generally, and in one form of the present invention, is a polarization-maintaining fiber-based polarization sensitive optical low coherence reflectometer for depth resolved birefringence measurement. With the present invention, linear birefringence of a sample may be measured from data recorded in a single A-Scan. In addition, the present invention provides for the simultaneous measurement of retardation and orientation of birefringent axes, wherein measured retardation is insensitive to sample rotation in the plane perpendicular to ranging.

A photoactive moiety exhibiting an anisotropic transition dipole. The moiety exhibits emission of polarized light in response to energy absorption. In a preferred embodiment, the moiety comprises a particle from the group consisting of a crystalline arrangement of photoactive molecules and a photoactive nanocrystal. The moiety may include a matrix in which photoactive objects exhibiting an anisotropic emission dipole are embedded. The moiety may be photobleached to product the anisotropy and the photoactive objects may have a one dimensional transition dipole in their natural state.

Nozzles and nebulizers that can be adjusted to produce an aerosol with optimum and reproducible quality based on the feedback information obtained using laser imaging techniques are provides. Two laser-based imaging techniques based on particle image velocimetry (PIV) and optical patternation are provided to map and contrast the size and velocity distributions for indirect and direct pneumatic nebulizations in plasma spectrometry. The flow field of droplets is illuminated by two pulses from a thin laser sheet with a known time difference. The scattering of the laser light from droplets is captured by a charge coupled device (CCD), providing two instantaneous images of the particles. Pointwise cross-correlation of the corresponding images yields a two-dimensional (2-D) velocity map of the aerosol velocity field. For droplet size distribution studies, the solution is doped with a fluorescent dye and both laser induced florescence (LIF) and Mie scattering images are captured simultaneously by two CCDs with the same field of view. The ratio of the LIF/Mie images provides relative droplet size information, which is then scaled by a point calibration method via a phase Doppler particle analyzer (PDPA). Two major outcomes are realized for three nebulization systems: 1) a direct injection high efficiency nebulizer (DIHEN); 2) a large-bore DIHEN (LB-DIHEN); and 3) a PFA microflow nebulizer with a PFA Scott-type spray chamber. First, the central region of the aerosol cone from the direct injection nebulizers and the nebulizer-spray chamber arrangement comprise fast (>13 m/s and >8 m/s, respectively) and fine (<10 μm and <5 μm, respectively) droplets as compared to slow (<4 m/s) and large (>25 μm) droplets in the fringes. Second, the spray chamber acts as a momentum separator, rather than a droplet size selector, as it removes droplets having larger sizes or velocities. Smart-tunable nebulizers may utilize the measured momentum as a feedback control for adjusting certain operation properties of the nebulizer, such as operating conditions and/or critical dimensions.

Three-Dimensional Defocusing Particle Image Velocimetry (3DDPIV) allows for measurement of three-dimensional velocities within a volume. In the disclosed embodiment, a mask with a plurality of apertures is disposed with a lens between the test section and a color camera. The field-of-view is backlit and the test section is seeded with black particles. This configuration allows for a lower power light source as compared to conventional 3DDPIV. Color-coded particle images are formed on a white background, wherein each of the color images is generated from light that travels through the filters not blocked by the imaged particle, thereby producing a color image that is of a color different from the color of any of the filters. A color space linear transformation is used to allow for accurate identification of each pinhole exposure when the color filters' spectrum does not match those of the 3-CCD color camera.

Provided is an optical image measuring apparatus capable of speedily measuring a velocity distribution image of a moving matter. Including a broad-band light source, means for increasing a beam diameter, a polarizing plate converting the light beam to linearly polarized light, and a half mirror, a wavelength plate converting the reference light to circularly polarized light, the half mirror superimposing the signal light whose frequency is partially shifted by the moving matter in the object and the reference light is circularly polarized light to produce superimposed light including interference light, CCDs for receiving different polarized light components of the interference light, and outputting detection signals including interference frequency components corresponding to beat frequencies of the interference light, and a signal processing portion for forming the velocity distribution image based on interference frequency component corresponding to a beat frequency equal to an intensity modulation frequency of the light beam.

In-line holography to create images of a specimen, such as one or more particles dispersed in a transparent medium. Analyzing these images with results from light scattering theory yields the particles' sizes with nanometer resolution, their refractive indexes to within one part in a thousand, and their three dimensional positions with nanometer resolution. This procedure can rapidly and directly characterize mechanical, optical and chemical properties of the specimen and its medium.

A system and method for detecting turbulence includes several mobile platforms, a mobile platform velocity sensor, and several electromagnetic energy transmitters and receivers. The receivers receive the energy transmitted by the transmitter(s) after it has traveled along a path subject to the turbulence. The receivers detect alterations of the energy caused by the turbulence and filter the alterations for effects of the mobile platform velocity (on which either a transmitter or receiver is located). Additionally, the system may create a three-dimensional model of the. In another preferred embodiment, the present invention provides a method of detecting turbulence using a mobile platform. The method includes receiving electromagnetic energy that has traveled along a path subject to the turbulence and determining the alteration to the energy caused by the turbulence. The alterations are filtered of the effects of the velocity of the mobile platform on which the receivers are preferably located.

A method of measuring fluid flow including the steps of providing a light source including at least one LED, providing an image detecting element and defining an illuminated measurement space with an optical element located between the measurement space and the image detecting element. The measurement space is located optically in-line between the light source and the image detecting element. The method further includes the steps of providing a fluid flow through the measurement space, the fluid flow including particles, and illuminating the measurement space with the light source to induce light extinction from the particles comprising shadow markers of the position of the particles within the fluid flow. The image detecting element is used to detect the shadow markers produced by the particles to record displacement of the particles as a function of time corresponding to movement of the fluid flow. In a further aspect, the light source includes plural LEDs emitting different colors.

Methods and apparatus for fast computation of fluid velocity fields in the presence of objects causing flow discontinuity are disclosed. Rigorous evaluation of perturbed velocity fields, each resulting from placing an object in a bounded space sustaining a reference velocity field, are determined for different orientations of the object with respect to a reference velocity field and different values of the magnitude of the velocity field. A velocity field is determined at selected sampling points within an enclosure surrounding the object. Pre-computed perturbed velocity fields determined for each object of a set of reference objects are stored in a computer memory. Fast real-time computation of velocity-field perturbations caused by presence of objects at arbitrary positions in a space sustaining velocity fields of different magnitudes and directions are realized using the stored pre-computed data.

A synthetic aperture three-dimensional fluid flow imaging apparatus is provided. The apparatus includes a plurality of cameras. At least two of the cameras are oriented to view a volume along mutually non-parallel directions. The cameras are connected to a programmable computer. The computer captures images from the cameras to generate three dimensional intensity fields. The computer can refocus the images on at least one refocus plane to generate reconstructed three dimensional intensity fields on a plane within the volume. Intensity field cross-correlation is performed on the reconstructed three dimensional intensity fields to extract velocity fields within the volume. The velocity fields represent velocities of objects or fluid phases within the volume. These velocity fields can be recorded for later use.

An imaging method and corresponding apparatus according to an embodiment of the present invention enables measurement and visualization of fluid flow. An embodiment method includes obtaining video captured by a video camera with an imaging plane. Representations of motions in the video are correlated. A textured background of the scene can be modeled as stationary, with a refractive field translating between background and video camera. This approach offers multiple advantages over conventional fluid flow visualization, including an ability to use ordinary video equipment outside a laboratory without particle injection. Even natural backgrounds can be used, and fluid motion can be distinguished from refraction changes. Depth and three-dimensional information can be recovered using stereo video, and uncertainty methods can enhance measurement robustness where backgrounds are less textured. Example applications can include avionics and hydrocarbon leak detection.

Apparatus and methods for estimating the optical flow velocity components using an upwind discretization are presented. In prior art, the knowledge of the signs of the optical flow velocity components is needed for using upwind discretization. But in optical flow computations the velocity components are precisely the unknowns and thus their sign information is not available. This invention discloses apparatus and methods in which upwinding is done based on the sign of the local time derivative instead of the signs of the optical flow velocity components.

Provided is a blood flow rate imaging device that can automatically distinguish an artery and a vein from a blood flow rate obtained on a time series blood flow map. A blood flow rate imaging device of the present invention includes a laser beam irradiation system (1) that irradiates a laser beam to a biological tissue that has a blood cell, a light receiving system (2) that has a light receiver (5) including many pixels that detect reflected light from the biological tissue, an image capture section (12) that continuously captures a plurality of images for a predetermined time of one or more cardiac beats on the basis of signal from the light receiver (5), an image storage section (15) that stores a plurality of images, and an arithmetic section (16) that calculates a blood flow rate within a biological tissue from the time variation of the output signal of each pixel corresponding to a plurality of stored images, wherein the above arithmetic section has a detecting section that detects an artery and a vein from a plurality of images of the above one or more cardiac beats and displays an arterial pulse part and a venous pulse part on the blood flow map.

Techniques, devices and systems are disclosed for characterizing particles in a fluid sample by optical space-time coding. In one aspect, a microfluidic device for optical detection of particles includes a substrate, a microfluidic channel formed on the substrate and structured to carry a fluid sample containing particles, in which the microfluidic channel is structured to transmit a probe light, and a mask formed on one side of the microfluidic channel and structured to include a pattern of openings along the microfluidic channel, in which at least two of the openings have varying dimensions across the microfluidic channel, and in which the pattern of openings encodes a waveform on the probe light that transmits through the microfluidic channel to allow optical detection of a position of a particle in the microfluidic channel.

A method of and system for analyzing image data representative of a sequential set of images of a spray plume, each of the images being representative of a density characteristic of the spray plume (i) along a geometric plane that intersects the spray plume, and (ii) at a predetermined instant in time, that in one aspect comprises sequentially displaying the set of images so as to exhibit a time evolution of the spray plume along the geometric plane. The invention may further integrate the set of images so as to exhibit a time-average representation of the images. In one embodiment, the invention comprises a general purpose computer executing software that receives and sequentially displays the set of images so as to exhibit a time evolution of the spray plume along the geometric plane, and provides a user interface for measuring one or more spray plume parameters associated with the spray plume within one or more of the images.

A method for generating hydrologically correct flow vectors based on elevation data in a watershed which includes any one or more of depressions, flat areas and peaks. The watershed is typically divided into a plurality of major cells each of which encompasses a plurality of minor cells, and a user selects one or more major cells for which flow vectors are desired. Flow vectors are then calculated pursuant to the D8 method and assigned to those minor cells in the selected major cell and in surrounding major cells for which an optimal D8 solution is possible. The remaining minor cells are designated as zero vector cells and include those cells located in the problem areas. The method then generates flow vectors for minor cells in all depressions, flat areas and peaks, in that order, which exist in the selected major cells.

The present invention provides an apparatus and method for obtaining data to determine one or more characteristics of a wind flow field using one or more radars. Data is collected from the one or more radars, and analyzed to determine the one or more characteristics of the wind flow field. The one or more radars are positioned to have a portion of the wind flow field within a scanning sector of the one or more radars.

The invention discloses a three-dimensional flow field testing method based on a single light field camera, A1, using a single light field camera to obtain a time series particle light field image of tracer particles in the flow field to be tested; A2, preprocessing the time series particle light field image , to remove background noise; A3, use CPU and/or GPU parallel processing methods to reconstruct time-series particle light field images to obtain time-series 3D particle images; A4, perform cross-correlation calculations on time-series 3D particle images to obtain 3D flow field velocity Field distribution; A5, post-processing the velocity field of the three-dimensional flow field, eliminating the wrong velocity vector, and replacing the eliminated wrong vector with interpolation based on the adjacent correct vector. The present invention can obtain the three-dimensional velocity distribution of the flow field to be tested through the sequential image acquisition of a single light field camera. Compared with the existing multi-view three-dimensional flow field test method, the hardware system configuration is greatly reduced and the hardware system adjustment is simplified. Steps, especially suitable for three-dimensional flow field measurement in confined space.