A Doppler shift frequency measuring device is provided, which includes a plurality of transmitters respectively configured to transmit a transmission wave, a plurality of receivers provided corresponding to the transmitters, respectively, and configured to receive reception waves that are reflection waves caused by the transmission waves from the transmitters, respectively, and a reception signal processor configured to calculate Doppler shift frequencies of the reception waves by processing reception signals obtained based on the reception waves received by the receivers. The reception signal processor includes a reception circuit configured to generate a synthesized signal by synthesizing processing target signals of which center frequencies of main lobes of power spectra are different from each other, the processing target signals generated based on the reception waves, and a Doppler shift frequency calculating module configured to calculate the Doppler shift frequencies of the reception waves based on the synthesized signal.

An embodiment provides a device for measuring a fluid parameter of fluid flow in a channel, including: a transmitter; at least one receiver; a processor operatively coupled to the at least one transmitter and the at least one receiver; a memory device that stores instructions executable by the processor to: transmit, using the transmitter, directed energy carrying a signal toward a surface of a fluid in a fluid channel, so as to produce one or more reflections from the fluid surface; detect, by the at least one receiver, one or more received signals associated with the one or more reflections so produced; determine, based upon a measurement beam comprising characteristics of the transmitted and received signals, one or more fluid parameters to be measured using a processor of the device; and associate, using a processor of the device, the one or more fluid parameters with a channel segment. Other embodiments are described and claimed.

Disclosed is a method for optimization design of an artificial reef structure. The method includes: arranging an artificial reef model to be tested on a test platform, testing a flow field to obtain flow field data and a pull force of an artificial reef, analyzing the flow field data to obtain a flow velocity reference point, and carrying out optimization analysis in combination with the flow field data and the pull force.

A housing 6 is provided for a wind sensor 2. A sensing element 4 is mounted in the housing 6 to measure the speed of the passing fluid flow, and the housing 6 comprises at least one surface 40, 42 having shaped surface elements 38, such as protrusions from and/or indentations in the surface 40, 42, for inducing turbulence in fluid flowing across the surface 40, 42. The turbulence caused by the shaped surface elements 38 results in the speed measured by the wind sensor 2 being less affected by uncontrolled transitions between laminar and turbulent airflow, and thus enables more accurate calibration of the wind sensor 2.

An Ultrasonic flowmeter for measuring the flow of a medium through a measuring tube (3) with at least two ultrasonic transducers (4,5) and at least one control and evaluation unit (6). The measuring tube (3) has an inner wall, the ultrasonic transducers (4, 5) are transmitters (4,5) for transmitting an ultrasonic signal (7) and/or are receivers (4, 5) for receiving the ultrasonic signal, and are arranged offset in the direction of flow such that the respective transmitter (4, 5) transmits an ultrasonic signal (7) in the direction of flow or against the direction of flow during operation. The receiver (4, 5) receives the ultrasonic signal (7) transmitted by the transmitter (4, 5) after at least one reflection on the inner wall of the measuring tube (3), the ultrasonic signal (7) having a first signal component (8) and at least a second signal component (9).

Externally generated noise can be coupled into a fluid carrying structure such as a pipe, well, or borehole so as to artificially acoustically illuminate the pipe, well, or borehole, and allow fluid flow in the structure or structural integrity to be determined. In the disclosed system, externally generated noise is coupled into the structure being monitored at the same time as data logging required to undertake the monitoring is performed. This has three effects. First, the externally generated sound is coupled into the structure so as to illuminate acoustically the structure to allow data to be collected from which fluid flow may be determined, and secondly the amount of data that need be collected is reduced, as there is no need to log data when the structure is not being illuminated. Thirdly, there are signal processing advantages in having the data logging being undertaken only when the acoustic illumination occurs.

Methods, systems, and apparatuses are provided for detecting and determining conditions of and conditions within a fluid conduit.

Disclosed is a tidal current meter that measures the velocity of a tidal current. The tidal current meter includes an oscillator, a calculation section, a depression angle setup section, and a drive section. The oscillator is capable of transmitting an ultrasonic wave into water and receiving the reflection of the transmitted ultrasonic wave. The calculation section calculates the velocity in accordance with the Doppler shift frequency of the reflection received by the oscillator. The depression angle setup section sets a depression angle, that is, the angle formed by the transmission direction of the ultrasonic wave and a horizontal plane. The drive section drives the oscillator in such a manner as to transmit the ultrasonic wave and receive the reflection of the transmitted ultrasonic wave at the depression angle set by the depression angle setup section.

A method for determining a flow speed of a liquid in a fluid conduit is provided. During a signal-generating phase, an impulse signal is applied to a first ultrasonic transducer. A response signal is then received at a second ultrasonic transducer. A measuring signal is later derived from the response signal, wherein the derivation comprises reversing a signal portion with respect to time. During a measurement phase, a liquid moves with respect to the fluid conduit. The measuring signal is then applied to one of the two transducers and a response signal of the measuring signal is measured at the other transducer. A flow speed is derived from the response signal of the measuring signal.

Externally generated noise can be coupled into a fluid carrying structure such as a pipe, well, or borehole so as to artificially acoustically illuminate the pipe, well, or borehole, and allow fluid flow in the structure or structural integrity to be determined. In the disclosed system, externally generated noise is coupled into the structure being monitored at the same time as data logging required to undertake the monitoring is performed. This has three effects. First, the externally generated sound is coupled into the structure so as to illuminate acoustically the structure to allow data to be collected from which fluid flow may be determined, and secondly the amount of data that need be collected is reduced, as there is no need to log data when the structure is not being illuminated. Thirdly, there are signal processing advantages in having the data logging being undertaken only when the acoustic illumination occurs.