Investigation of Nonround Flow Part of Vortex Flowmeter and Determination of Deformation Influence on Frequency Response
Keywords:
vortex flowmeter, blunt body, Karman vortex street, simulation of fluid, CFDAbstract
The paper presents the results of research flow of the vortex flowmeter. Produced verification of the results of numerical simulation of the flow of the vortex flowmeter with a physical experiment. In the simulation of flow in the COSMOS FlowWorks package used “k-e” turbulence model. The calculation was carried out on a rectangular computational grid, containing up to 3.5 million cells at a flow part. The relative numerical simulation error is less than ± 10.0% for the extreme points of the flow rate and no more than ± 5% for the mid-range of flow rates. In the simulation, hydro-flow processes in the vortex of the flow-meter to produce a result with a relative error of ± 5% is sufficient to restrict the number of computational cells is not more than 3.0 million. The results of the numerical experiment with a deformed part of the flow in the form of an oval, as well as casting slopes and radii and shows the degree of influence of the deformation of the flow vortex flowmeter for compressed (air) and incompressible medium (water) on the amplitude-frequency characteristics. It was revealed that the flow part, deformed in the direction of flow of the body into an ellipse, has higher stability and permanence criterion Strouhal number compared to the estimated geometry. These findings have led to the creation of a new type of flow part for vortex flowmeter (utility model patent № 140006 “Flow part for the formation of the flow rate of liquids and gases measurement systems”). As the directions of future research should be focused on the study of the influence of the deformed geometry to stabilize the generation of vortices at low Reynolds numbers, and find the optimal geometry that can extend the range of stable vortex generation in small numbers Re.References
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