Research On Frequency Characteristic Optimization And Anti-vibration Method Of Cantilever Vortex Flowmeter Sensor

By taking the advantages of fast-response, strong-signal and low cost, cantilever vortex flow sensor(CVFS) is widely used in traditional stress measurement. However, CVFS is subject to low natural frequency, in which measuring accuracy will be severely affected at low flow input. Besides, with the weakness of vibration incompatibility, output signal of CVFS degrades when flow tube encounter vibration, made possible by complex industrial environment.To improve natural frequency of CVFS, and to improve vibration compatibility, the following parts were studied:1) To study the force analysis of CVFS. The main factor of determining stress transition in triple layer structure of CVFS. Plus, the standard transfer ratio between input vortex force and deformation of piezoelectric component was established.2) To study the natural frequency of CVFS, the main factors deciding it was studied. By carefully configuring these factors, natural frequencies of all caliber were improved.2) To improve vibration compatibility, the mechanical specification of tubal vibration was first studied, in the aspect of frequency domain and vibration direction respectively. Besides, this paper studied the vibration interference of level cutting and frequency peak, in which digital frequency output is introduced. The vibration compensation method of some recent sensor designs were studied by simulation.3) Finally, two novel CVFS with two separate cantilevers were devised. Experimental results suggested that vibration compatibility of these two models were enhanced. And the simplified model has better sensitivity and vibration compatibility.