| 3000 years ago, in ancient Egypt who barrier method to measure the flow of the Nile. In modern times, flowmeters arewidely used in various fieldsand related research, thereby promoting the development of aerospace, radar remote sensing,meteorological science.Today, the Energy is increasingly expensive, and the demandof the measurement with high precision is increasing. Small differences of measurement onOil transport-line will result in huge economic losses. Meanwhile, oil and natural gasaslo contribute to the greenhouse gas effect,limiting emissions credits under the Kyoto Protocol,emission reduction is result of many node all over the country to accurately measure.Vortex flowmeter, Coriolis flowmeter and ultrasonic flowmeter, three types have been developing in last 40 years, should bethe most important flowmeters. Measurement range of vortex flowmeter, advantages have been widely with no moving parts;Coriolis flowmeter and ultrasonic flowmeter is the non-contact Flowmeter. Content of this project is to develop a new type of ultrasonic vortex flowmeter, improved performance at low Reynolds-number flow field of fluid dynamics, extended range limits, weaknesses to improve measurement of low speed performance.This dissertationincludes the following tasks:1.Vortex study at home and abroad, combining research and analysis need to beimproved;2.When RANS model in the form of the model of acoustic attenuation;3.Design a ultrasonic measuring method and principle of vortex Street flowmeter. According to the basic laws of fluid mechanics, theoreticalanalysis shows that the advantage;4.Test study on ultrasonic attenuation and velocity, flow around downstream dependencies experimental data obtained consistent withtheoretical expectations. |
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