Study On3D Ultrasonic Tracks Design Method Of Transit-time Ultrasonic Flowmeter Considering Track Coverage Under Symmetrical&Uncompleted Cover

The accuracy of transit-time ultrasonic flowmeter(T-UFM)depends on the flowadaptability of3D ultrasonic track. This dissertation researches on study of3D ultrasonictracks design method of transit-time ultrasonic flowmeter considering track coverage undersymmetrical&uncompleted cover, which has important academic value and practicalsignificance for improving ultrasonic measurement technology and modern detectiontechnology.The research progress of related content at home and abroad, including topology of3Dultrasonic track model and performance simulation technologies for topology of3D ultrasonictrack model, is reviewed to decide research contents of this paper. Research work includesseveral aspects as follow:(1) Make a deep analysis on the flow pattern mode in the straight pipe. Study on flowadaptability of3D ultrasonic track. Presents the design philosophy of ultrasonic trackmodel(DPUTM), including rotation invariance around the central axis of pipe and trackcoverage.2D ultrasonic track cover modes were studied, including overlapped cover、completed cover and uncompleted cover. The formulas for quantity of track segments wasderived. Study on2D ultrasonic track models of three tracks, under the symmetrical anduncompleted cover. The2D ultrasonic ipsilateral track model and opposite side track modelwere presented.(2) Study on the design of topology of3D ultrasonic track model. Establish the3Dcoordinate system based on the2D ultrasonic track model. The process constraints andboundary conditions were studied and the reduced3D ultrasonic track model was presented.The formulas of key node coordinates and the parametric equations of ultrasonic transducersand reflectors, were derived. Present the optimizing program and derive the formulas betweenpipe length and angles of3D ultrasonic neighboring track segments.(3) In order to improve the coverage, the isosceles triangle2D ultrasonic track modelwas presented. Study on ratio of pipe radius and track radius, under the maximum coverage.Establish the topology of3D ultrasonic track model of isosceles triangle2D ultrasonic trackmodel with maximum coverage. This topology has symmetrical structure and large coverage.(4) Study on3D ultrasonic track correction coefficient of transit-time T-UFM underCFD simulation, and set standard deviation of velocity correction coefficients as theperformance index of flow adaptability. Establish and mesh the CAD model, then setting the initial parameters and start simulation using FLUENT. The simulation results show thatisosceles triangle3D ultrasonic track model has better performance than equilateral triangle3D ultrasonic track model. CFD simulations prove that the study of this dissertation iseffective.