Sensor apparatus and method for measuring flow

摘要

A sensor apparatus (180) is provided for measuring within a region (260) of a conduit (100) for guiding a flow (110). The apparatus (180) includes a transducer arrangement (200, 300, 510, 540) disposed at least partially around an external surface of a wall of the conduit (100). The transducer arrangement (200, 300, 510, 540) includes one or more driver elements (220) for exciting in operation a helical acoustic wave propagation within the wall of the conduit (100) for leaking acoustical energy from the helical acoustic wave propagation over an extensive area of the wall of the conduit (100) for stimulating waves in chordal paths within the flow (110), wherein the waves in the choral paths within the flow (110) re-enter the wall of the conduit (100) to propagate further as a guided helical wave. The transducer arrangement (200, 300, 510, 540) includes one or more sensors for receiving a reentered portion of the acoustic wave propagation along the chordal paths within the flow (110) which interacts with the flow (110) and which includes information which characterize properties of the flow (110). The transducer arrangement (200, 300, 510, 540) is operable to perform at least one of: switching between selected acoustic wave modes present in the acoustic wave propagation, steering an acoustic propagation direction of the acoustic wave propagation.