Abstract: A flowmeter of the vortex type in which an obstacle assembly mounted in a flow tube causes vortices to be shed at a frequency that is a function of flow rate. The assembly includes a block fixedly mounted across the flow tube at right angles to the direction of flow, the block having a substantially square cross-section to present a flat face to the incoming fluid. The width of the block has its maximum value at the mid-point thereof and diminishes gradually toward either end where the width assumes its minimum value such that the upper and lower faces of the block are bellied and the front face has a double-convex contour. The maximum width value affords an efficient shedding action, the mean width value of the block being significantly smaller than the maximum value to substantially reduce the pressure drop produced by the meter.

Abstract: A flowmeter of the vortex type in which an obstacle assembly mounted in a flow tube of relatively small diameter causes vortices to be shed at a frequency which is a function of flow rate. The assembly includes a block fixedly mounted across the flow tube at right angles to the direction of flow, the block having a substantially square cross-section to present a flat face to the incoming fluid. The upper and lower rear corners of the block are bevelled to define a flat rear face of reduced area, the resultant block configuration acting to enhance the shedding characteristics of the assembly and to produce substantially linear flow rate measurements at low Reynolds numbers.