Research On The Ultrasonic Flowmeter For Partially Filled Pipe Flow

In the last 50 years, as one of the fastest growing technologies applied in the field of process monitoring, measurement and control, ultrasonic flowmeter can be used in liquid, gas and multiphase flow measurement, and has obvious advantages compared with other flowmeters. This paper studied on the velocity distribution and flow measurement of water flow in partially filled pipe, and designed an ultrasonic flowmeter for partially filled pipe flow.The main contents are as follows:1) Analyzed and developed the velocity distribution of partially filled pipe flow on the basis of the rectangular open channel flow, as well as the parameter determination method. Then improved the secondary currents compensation formula that using wake law at inner district instead of log law by the result of the simulation at different levels.2) Developed a partially filled pipe flow measurement model and a measurement strategy with unequal-intervals installation based on its flow velocity distribution and the characteristics of ultrasonic. The results of the simulations at level of 0.2m,0.5m and 0.8m showed that the model and strategy have a high measurement accuracy and feasibility.3) Designed a partially filled pipe ultrasonic flowmeter using STM32F103VE and TDC-GP22 according to the characteristics of partially filled pipe flow and the measurement requirement. The hardware and software tests show the prototype can work properly.