Experimental and numerical investigation of new bluff body design for vortex flow meters

摘要

In the present investigation, the task of further improvement of accuracy of determination of volumetricrnflows by employing the so-called vortex-shedding flow meter by using a novel design of the bluff body hasrnbeen studied. Based on earlier investigation, in which the focus was on signal processing, it was decidedrnby the present authors to study in more detail cylindrical bluff bodies with thread or with grooved surface,rnwith ring-type ribs of various high and width arranged circumferentially. Unlike in the case of a smoothrncylinder, the ribs obviously stabilized the flow in the boundary layer und suppressed the development ofrnaxially oriented vortices. The resulting frequency variation as a function of the flow velocity and, with that,rnthe Reynolds number, was much more regular, displaying good linearity. Correspondingly, the so calledrnk-factor also showed a great improvement as compared to a simple smooth cylindrical bluff body.