Abstract: Drag is produced in a gas stream by a bluff body (47), and is converted to low pressure stable and continuous vortices by a restriction (56). The difference in gas pressure is sensed (14) between a point (15) outside the flow passage in communication therewith and a point (16) inside the flow passage between the restriction and the bluff body. The resultant flowmeter may be connected in line or as a bypass in a gas system.