Patent ID: 8408071

Claim:
A vortex-shedding flowmeter comprising: a flow tube having a longitudinal flow axis through which a fluid stream to be metered is conducted from an upstream end of the flow tube to a downstream end thereof when the flowmeter is in operation; an elongated upstream obstacle disposed within the flow tube so that a bluff upstream face of the upstream obstacle is perpendicular to the flow axis, a shape of the upstream obstacle selected so that no surface thereof is parallel to the flow axis; a downstream obstacle comprising two members that are parallel to each other and to the upstream obstacle, the two members spaced apart from the upstream obstacle along the flow axis by a selected distance, both of the two members of the downstream obstacle having a shape selected so that no surface of either member is parallel to the flow axis; and at least one acoustic transducer operable, when the flowmeter is in operation, to project an acoustic signal along a path transverse to the flow axis.