A method of fluid flow measurement includes a emitting a light beam into a pipe through which a fluid flows, the light beam illuminating the fluid flowing in the pipe, using a light detector array to detect light caused by scattering of the beam with particles found in the fluid, the light beam being outside a field of view of the light detector array, dividing the field of view of the light detector array into layers, and determining an instantaneous flow velocity in each of the layers as a function of signals transmitted from the light detector array in each of the layers.

A method for determining a kinematic structure of a two-dimensional wind field and a system determining the same are provided. The method comprises receiving a plurality of Doppler velocities and a plurality of distances between a Doppler radar and a gate. Each Doppler velocity of the plurality of Doppler velocities corresponds to a respective distance of the plurality of distances between the Doppler radar and the gate. The method further comprises calculating a plurality of distance Doppler velocity values. The distance Doppler velocity values represent the plurality of measured Doppler velocities and the distance between the Doppler radar and the gate. The method further comprises estimating the kinematic structure of the 2D wind field using the plurality of distance Doppler wind velocity values.

A portable electronic device is operable in a particulate matter concentration mode where the portable electronic device uses a self-mixing interferometry sensor to emit a beam of coherent light from an optical resonant cavity, receive a reflection or backscatter of the beam into the optical resonant cavity, produce a self-mixing signal resulting from a reflection or backscatter of the beam of coherent light, and determine a particle velocity and/or particulate matter concentration using the self-mixing signal. The portable electronic device is also operable in an absolute distance mode where the portable electronic device determines whether or not an absolute distance determined using the self-mixing signal is outside or within a particulate sensing volume associated with the beam of coherent light. If not, the portable electronic device may determine a contamination and/or obstruction is present that may result in inaccurate particle velocity and/or particulate matter concentration determination.

Apparatuses, systems, and methods are provided for measuring the velocity and direction of a fluid flow. In some instances, a measuring system may include a housing capable of holding one or more pressure sensors in a desired location and orientation. The housing may include a cavity for each of the one or more pressure sensors and each cavity may have a connection to an opening at the outside surface of housing. Each opening may be able to face in any desired direction such that the pressure at any desired location on the outside surface of housing, which may be capable of facing in any desired direction, may extend to the cavity inside housing where it can be measured by a pressure sensor. The velocity and the direction of a fluid flow around the housing of the measurement system may be based on pressure readings generated by the pressure sensors.

A wind detection apparatus detects wind vectors across a predetermined area at high resolution from a floating support. The apparatus includes a Doppler-based wind vector detection unit configured to detect wind direction, velocity, and turbulence, at selected intervals over the predetermined area. A stabilizer supports the wind vector detection unit and is configured to hold it level relative to a predetermined two-dimensional plane. A processor is provided for rendering the wind vector data into a combined representation of wind patterns across the predetermined area, and the processor continuously updates the rendered combined representation of wind patterns in tandem with the detection unit.

The present invention provides a system and method for velocity vector field calculation at the voxel level of a multi-phase flow system using Electrical Capacitance Volume Tomography sensors.

For determining a changing spatial distribution of particles at each of multiple points in time, real two-dimensional images of the particles are recorded with different mapping functions. An estimated spatial distribution of the particles is provided. Virtual two-dimensional images of the estimated spatial distribution are calculated applying the different mapping functions. Differences between the virtual and the real two-dimensional images are determined; and the estimated spatial distribution of the particles are varied for reducing the differences to obtain a spatial distribution approximated to the actual spatial distribution of the particles. The estimated spatial distribution of the particles is provided in that the locations of the individual particles in a spatial distribution approximated for one other point in time are shifted dependently on how the locations of the individual particles have changed between at least two spatial distributions approximated for at least two other points in time.

A method is provided to measure a distribution of axial velocities and a flowrate in a pipe or a vessel. The method comprises selecting a single cross-section at a stable-flow segment in a pipe or a vessel, installing a plurality of acoustic wave sensors along a peripheral wall of the pipe or the vessel to form a plurality of effective sound wave paths; measuring sound wave travelling time on each sound wave path; substituting the measured sound wave travelling time data into the model formulas based on a sound path refraction principle for reconstruction calculation to obtain a distribution of axial velocity in the measured cross-section of the pipe or the vessel, u(x,y); and integrating the distribution of the axial velocity u(x,y) along the cross-section to obtain a flow rate. A system is also provided to measure an axial velocity distribution and a flow rate in a pipe.

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.

Systems and methods are provided for determining a velocity or an inflation rate of a droplet in a microfluidic channel. The droplet is exposed to two or more temporally separated flashes of light, each flash including light of one wavelength band, and imaged using a detector configured to distinguish light in the wavelength bands. Two or more images of the droplet are acquired, each corresponding to one of the flashes, and all within a single video frame or photographic exposure. The images can be processed separately and the position or size of the droplet in each image is calculated. A velocity or inflation rate is then determined by dividing the change in position or size by the amount of time allowed to pass between the flashes.