A system and method of non-intrusive thrust measurement of a gas turbine engine. The system comprises a transmitter disposed at a boundary of fluid flow and at least one receiver adapted to receive transmissions from the transmitter. A processor is coupled to the receivers to determine a parameter from a characteristic of the transmission at the receiver suite and adapted to determine a thrust parameter from the parameter. A method for non-intrusively measuring engine thrust includes transmitting a wave across the exhaust plume, receiving the transmitted wave and determining a measurement parameter of the exhaust plume based on a characteristic of the received wave, and comparing the measurement parameter to a reference parameter and determining the thrust based on the comparison.

A method, apparatus, and system according to which first and second waveguides are adapted to be connected to a pipe and first and second transducers are adapted to be connected to the first and second waveguides, respectively, and to exchange ultrasonic wave signals through the first and second waveguides, the pipe, and a fluid flowing in the pipe. A temperature of the fluid flowing in the pipe exceeds 600° C. The first and second waveguides are configured to, and each have a shape to: (i) insulate the first and second transducers from the pipe, and (ii) permit propagation of the ultrasonic wave signals between the pipe and the first and second transducers, respectively, while maintaining an acoustic attenuation through the first and second waveguides at an acceptable level.

A measuring device, in particular a flow meter, has a measurement tube for receiving or conveying a fluid, first and second oscillation transducers on a side wall of the measurement tube, and a control device. An operating method has the control device drive the first oscillation transducer chronologically in succession for respective mode-selective excitation of a first and a second oscillation mode of a wave conducted in the side wall of the measurement tube. The second oscillation transducer is driven similarly for a second measurement direction. The excited waves are conducted directly in the side wall or indirectly through the fluid and recorded in the other oscillation transducer, resulting in measurement data for each measurement direction and oscillation mode. Result information relates to a property of the fluid or a state of the measuring device determined from the measurement data for both measurement directions and both respective oscillation modes.

An electroacoustic transducer comprising an electromechanical transducer and a vibratory component. The latter has a generally cylindrical side wall, an outwardly directed portion at the base of the side wall, and a generally planar vibratory top wall extending inwardly from the rim of the side wall further from its base to close the upper end of the cylindrical side wall. The said outwardly directed portion is mounted on the electromechanical transducer.

The invention relates to a method and an arrangement for an ultrasound clamp-on flow measurement according to the transit-time method. The problem addressed by the invention is to provide a measurement arrangement for clamp-on flow measurement, which enables measurement using only two pairs of acoustic transducers in both reflection configuration and in X configuration, without requiring the acoustic transducer position to be changed when switching between configurations. For the method according to the invention, at least four acoustic transducers are arranged on a measurement pipe, which are controlled in such a way that the flow measurement is performed consecutively in an alternating manner in the X configuration and in the reflection configuration. For this purpose, two acoustic transducers are connected for each transmission-receiving pair for a flow measurement in X configuration, and/or two acoustic transducers are connected for each transmission-receiving pair for two reflection configurations.

What is described is a method for charactering an airflow, having the following steps: receiving acoustic signals generated by the airflow by means of a microphone array; extracting a characteristic information from the acoustic signals; determining an information on the airflow based on the characteristic information.

A wind velocity sensor comprises a lower platform and an upper platform. Pillars are positioned or connected between the upper platform and the lower platform. Ultrasonic sensors are secured to corresponding ones of the pillars. A lower guard member extends outwardly from a reference ultrasonic sensor by a radial distance greater than a radial separation between any pair of the ultrasonic sensors.

An ultrasonic flow probe (100) comprising a mounting member (101) for mounting on a surface of a conduit and thereby defining a mounting axis (B) perpendicular to the surface, a frame (103) mounted on the mounting member (101), and a plurality of ultrasonic transducers (105) mounted on the frame (103) and aligned along a primary axis (A); wherein the frame (103) and mounting member (101) are configurable such that the primary axis (A) is at an angle to the mounting axis (B) so that, in use, ultrasound passing between the transducers (105) travels at an angle to fluid flowing in the conduit.

The invention relates to a method of operating an ultrasonic flow meter by digitally sampling received signals. Acoustic wave packets are transmitted through a measuring distance in opposite directions, and the received signals are digitized at a sampling frequency being below the Nyquist-limit of two times the signal frequency of the wave packet to generate digitized under-sampled signals 31. From the digitized under-sampled signals, the difference in propagation time along the measuring distance is determined.

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.