The disclosure herein discloses an imaging method of internal defects in longitudinal sections of trees, and belongs to the field of nondestructive testing of trees. The method includes the following steps: with the propagation time of stress waves in a tree as input data, dividing an imaging plane into a predetermined number of grid cells to establish initial velocity distribution in the imaging plane; then performing multiple iterations using a linear propagation model; following each iteration, adjusting the velocity distribution in the imaging plane using the SIRT algorithm; constraining the velocity of each grid cell using maximum and minimum velocity constraints and fuzzy constraints based on grid cell groups, and ending iteration until the final velocity distribution is in good fit with the measured data; by comparing the velocity value of the grid cell at this moment with the reference value of the tested healthy tree, determining an abnormal grid cell; and then performing secondary smoothing processing on the grid cell imaging to obtain the defect location inside the tree. The method can accurately detect the defective area of the tree, and has less false detection areas and good imaging effect.

This invention provides the following: a diagnostic device that may, with a simple design, diagnose the condition of a wide area of a structure such as a pipe; and the like. The diagnostic device 100 has a determining means for determining the condition of the structure on the basis of the speed of sound therein.

This invention provides the following: a diagnostic device that may, with a simple design, diagnose the condition of a wide area of a structure such as a pipe; and the like. The diagnostic device 100 has a determining means for determining the condition of the structure on the basis of the speed of sound therein.

The present disclosure relates to a novel method to monitor rotor blade vibration using unsteady casing pressure. The novel method applies a non-intrusive blade vibration monitoring technique by using an array of unsteady pressure sensors flush-mounted in the casing of a multistage axial compressor. The novel method comprises using spinning mode theory to obtain frequency and nodal diameter information for all pressure waves that can be identified and determining any of the pressure waves that is associated with blade vibration.

The present disclosure relates to a novel method to monitor rotor blade vibration using unsteady casing pressure. The novel method applies a non-intrusive blade vibration monitoring technique by using an array of unsteady pressure sensors flush-mounted in the casing of a multistage axial compressor. The novel method comprises using spinning mode theory to obtain frequency and nodal diameter information for all pressure waves that can be identified and determining any of the pressure waves that is associated with blade vibration.

An acoustic air data sensing system includes an acoustic transmitter, a plurality of acoustic receivers, and a skin friction sensor. The acoustic transmitter is located to transmit an acoustic signal into airflow about an exterior of a vehicle. Each of the acoustic receivers is located at a respective angle from a wind angle reference line and a respective distance from the acoustic transmitter. The skin fiction sensor is positioned in a boundary layer region of the airflow that interacts with the acoustic receivers and transmitter. Based on time of flight values of the acoustic signal from the transmitter to each of the receivers and a skin friction measurement from the skin friction sensor as inputs to a transformation matrix, the acoustic air data sensing system outputs, from the transformation matrix, the true airspeed, the relative wind angle, and the speed of sound for operational control of the vehicle.

The invention concerns a tank (1) of fluid (4) for a motor vehicle (3), comprising a body (5) arranged to receive the fluid (4) and a system (9) for measuring a parameter of the fluid (4) in the tank (1) from an acoustic wave. According to the invention, the acoustic wave (6) is generated by another system (7), the main function of which is not that of emitting an acoustic wave.

Disclosed and described herein are systems and methods used to analyze ultrasonic waves and nondestructively infer acoustic wave velocities and dynamic elastic properties of materials. Disclosed methods employ the selective rotation of ultrasonic transducers immersed in a liquid (water) adjacent to the sample under study.

Avionic display systems and methods are provided for generating avionic displays, which include symbology and other graphics pertaining to forecast overpressure events, which are forecast to occur during supersonic aircraft flight. In various embodiments, the avionic display system includes a display device on which an avionic display is produced. A controller architecture is operably coupled to the display device. Storage media contains computer-readable code or instructions that, when executed by the controller architecture, cause the avionic display system to determine whether an overpressure event is forecast to occur due to the predicted future occurrence of a sonic boom, which has a magnitude exceeding a boom tolerance threshold. When the controller architecture determines that an overpressure event is forecast to occur, the avionic display system further generates symbology on the avionic display indicative of or visually signifying the forecast overpressure event.

Avionic display systems and methods are provided for generating avionic displays, which include symbology and other graphics pertaining to forecast overpressure events, which are forecast to occur during supersonic aircraft flight. In various embodiments, the avionic display system includes a display device on which an avionic display is produced. A controller architecture is operably coupled to the display device. Storage media contains computer-readable code or instructions that, when executed by the controller architecture, cause the avionic display system to determine whether an overpressure event is forecast to occur due to the predicted future occurrence of a sonic boom, which has a magnitude exceeding a boom tolerance threshold. When the controller architecture determines that an overpressure event is forecast to occur, the avionic display system further generates symbology on the avionic display indicative of or visually signifying the forecast overpressure event.