Abstract: An apparatus 10 is provided that includes a spatial array of at least two unsteady pressure sensors 18–21 placed at predetermined axial locations x1–xN disposed axially along a pipe 14 for measuring at least one parameter of a fluid 12 flowing in the pipe 14. The pressure sensors 18–21 comprise a plurality of pressure sensing elements such as piezoelectric film sensors 23 for measuring unsteady pressures associated with acoustical pressures and/or vortical disturbances. The sensing elements are disposed circumferentially around the pipe and spaced a predetermined distance. The pressure signals P1(t)–PN(t) provided by the pressure sensors 18–21 are processed by a processing unit to provide an output signal indicative of a parameter of the fluid.

Abstract: A sensor head characterizes unsteady pressures in a fluid flowing within a pipe, as may be caused by one or both of acoustic waves propagating through the fluid within the pipe and/or pressure disturbances that convect with the fluid flowing in the pipe. The sensor head comprises a rigid support structure and at least one transducer attached to the rigid support structure. The rigid support structure holds the transducer in contact with an outer surface of the pipe. The at least one transducer senses relative movement between the outer surface of the pipe and the support structure and provides a signal indicative of unsteady pressures within the fluid at a corresponding axial position of the pipe in response to the relative movement. The support structure may be attached to each transducer in an array of transducers, and may include a handle secured thereto for manipulating the sensor head into contact with the pipe.

Abstract: A sensor head characterizes unsteady pressures in a fluid flowing within a pipe, as may be caused by one or both of acoustic waves propagating through the fluid within the pipe and/or pressure disturbances that convect with the fluid flowing in the pipe. The sensor head comprises a rigid support structure and at least one transducer attached to the rigid support structure. The rigid support structure holds the transducer in contact with an outer surface of the pipe. The at least one transducer senses relative movement between the outer surface of the pipe and the support structure and provides a signal indicative of unsteady pressures within the fluid at a corresponding axial position of the pipe in response to the relative movement. The support structure may be attached to each transducer in an array of transducers, and may include a handle secured thereto for manipulating the sensor head into contact with the pipe.

Abstract: A method, apparatus and system are provided to measure the process flow of a fluid or medium traveling in a pipe. The system and apparatus feature a standoff and piezoelectric-based sensor arrangement having a plurality of standoffs arranged on a pipe and a plurality of sensor bands, each arranged on a respective plurality of standoffs, each having at least one sensor made of piezoelectric material arranged thereon to detect unsteady pressure disturbances in the process flow in the pipe which in turn can be converted to the velocity of and/or speed of sound propagating within the pipe, and a cooling tube arranged in relation to the plurality of standoffs for actively cooling the sensor band; and further comprise a processing module for converting one or more sensor signals into a measurement containing information about the flow of the fluid or medium traveling in the pipe, as well as a pump and heat exchanger for processing the cooling fluid flowing through the cooling tube.

Abstract: An apparatus 10 is provided that includes a spatial array of at least two unsteady pressure sensors 18-21 placed at predetermined axial locations x1-xN disposed axially along a pipe 14 for measuring at least one parameter of a fluid 12 flowing in the pipe 14. The pressure sensors 18-21 comprise a plurality of pressure sensing elements such as piezoelectric film sensors 23 for measuring unsteady pressures associated with acoustical pressures and/or vortical disturbances. The sensing elements are disposed circumferentially around the pipe and spaced a predetermined distance. The pressure signals P1(t)-PN(t) provided by the pressure sensors 18-21 are processed by a processing unit to provide an output signal indicative of a parameter of the fluid.