A method and arrangement are disclosed for measuring a flow rate of optically non-homogeneous material in a process pipe. The non-homogeneous material can be illuminated through a window. Images are taken with a camera, through a window, of illuminated non-homogeneous material. Correlation between temporally successive images determines travel performed by the non-homogeneous material in the process pipe between capture of temporally successive images. Velocity of the non-homogeneous material is determined by the time difference between the successive images and the travel.

A method and arrangement are disclosed for measuring a flow rate of optically non-homogeneous material in a process pipe. The non-homogeneous material can be illuminated through a window. Images are taken with a camera, through a window, of illuminated non-homogeneous material. Correlation between temporally successive images determines travel performed by the non-homogeneous material in the process pipe between capture of temporally successive images. Velocity of the non-homogeneous material is determined by the time difference between the successive images and the travel.

A fluid conductivity sensor (FCS) system for determining a water void fraction in a fluid mixture flows comprises a duct containing the fluid mixture flows; a dielectric window system operatively connected to the duct, wherein the dielectric window system comprises a first dielectric window built-into a first surface of a wall of the duct and a second dielectric window built-into a second surface of the wall aligned and opposite to the first surface; a split-toroidal loop-gap resonator (split-TLGR) system operatively connected to the dielectric window system and the duct, wherein the split-TLGR system comprises a first split-TLGR built-into the first dielectric window and a second split-TLGR built-into the second dielectric window; and a vector network analyzer (VNA) operatively connected to the split-TLGR system and configured to measure the fluid conductivity, wherein the water void fraction is derived from the fluid conductivity.

A fluid conductivity sensor (FCS) system for determining a water void fraction in a fluid mixture flows comprises a duct containing the fluid mixture flows; a dielectric window system operatively connected to the duct, wherein the dielectric window system comprises a first dielectric window built-into a first surface of a wall of the duct and a second dielectric window built-into a second surface of the wall aligned and opposite to the first surface; a split-toroidal loop-gap resonator (split-TLGR) system operatively connected to the dielectric window system and the duct, wherein the split-TLGR system comprises a first split-TLGR built-into the first dielectric window and a second split-TLGR built-into the second dielectric window; and a vector network analyzer (VNA) operatively connected to the split-TLGR system and configured to measure the fluid conductivity, wherein the water void fraction is derived from the fluid conductivity.

A sensor system for an aircraft for determining the air velocity of air flowing past the aircraft includes a first sensor and an evaluation device. The first sensor is configured for being arranged at the structure of the aircraft and determines a first response of the structure to a first local pressure fluctuation of a boundary layer of the air flowing past the aircraft. Furthermore, the first sensor generates a first signal on the basis of the determined first response of the structure. The evaluation device is configured for processing said first signal and for determining the actual air velocity on the basis of the first signal.

Systems and methods for determining gas velocity based on phase differences of signals from two or more interaction paths in a gas analyzer system. A laser source, which can provide access to an absorption gas line, is expanded, or is split into two or more beams. These beams can be used to create two (or more) parallel sampling paths separated by a known distance. Gas travelling in the plane of the two beams of light will pass through the optical paths at two (or more) different times creating very similar signals that will be out of phase with each other. The amount of phase difference will be inversely proportional to the velocity of the gas.

A method for determining a characteristic of a flowing fluid having particles in a sample space by Fourier domain optical coherence tomography includes estimating a velocity of the fluid in the sample space; controlling an optical scanner to radiate a beam of light along an optical path to the fluid in the sample space and to sense a signal of interference of measurement light scattered back along the optical path mixed with reference reflected light, while moving the optical scanner, where the beam of light is moved with a scanner velocity being aligned with a velocity component of the velocity of the fluid perpendicular to the optical axis of the beam of light, processing the signal into a corresponding complex-valued optical path length resolved OCT signal, where the OCT signal represents the fluid in the sample space; determining the characteristic of the fluid based on the OCT signal.

A method for determining a characteristic of a flowing fluid having particles in a sample space by Fourier domain optical coherence tomography includes estimating a velocity of the fluid in the sample space; controlling an optical scanner to radiate a beam of light along an optical path to the fluid in the sample space and to sense a signal of interference of measurement light scattered back along the optical path mixed with reference reflected light, while moving the optical scanner, where the beam of light is moved with a scanner velocity being aligned with a velocity component of the velocity of the fluid perpendicular to the optical axis of the beam of light, processing the signal into a corresponding complex-valued optical path length resolved OCT signal, where the OCT signal represents the fluid in the sample space; determining the characteristic of the fluid based on the OCT signal.

The present application provides a method and apparatus for simultaneous measurement of flow-field velocity and temperature, and a storage medium. The method includes: determining a motion trajectory and a gray-level change of a target temperature-sensitive phosphorescent particle in particle timing frame images; determining a velocity of the target temperature-sensitive phosphorescent particle based on the motion trajectory of the target temperature-sensitive phosphorescent particle in the particle timing frame images; determining a decay-slope constant of the target temperature-sensitive phosphorescent particle based on the gray-level change of the target temperature-sensitive phosphorescent particle in the particle timing frame images; determining a temperature of the target temperature-sensitive phosphorescent particle based on the decay-slope constant of the target temperature-sensitive phosphorescent particle and a preset correspondence; and determining a velocity and a temperature of a flow field to be measured based on the velocity and the temperature of the target temperature-sensitive phosphorescent particle.

The present application provides a method and apparatus for simultaneous measurement of flow-field velocity and temperature, and a storage medium. The method includes: determining a motion trajectory and a gray-level change of a target temperature-sensitive phosphorescent particle in particle timing frame images; determining a velocity of the target temperature-sensitive phosphorescent particle based on the motion trajectory of the target temperature-sensitive phosphorescent particle in the particle timing frame images; determining a decay-slope constant of the target temperature-sensitive phosphorescent particle based on the gray-level change of the target temperature-sensitive phosphorescent particle in the particle timing frame images; determining a temperature of the target temperature-sensitive phosphorescent particle based on the decay-slope constant of the target temperature-sensitive phosphorescent particle and a preset correspondence; and determining a velocity and a temperature of a flow field to be measured based on the velocity and the temperature of the target temperature-sensitive phosphorescent particle.