A Fluidic Flow Meter for Downhole and Other Flow Measurements

摘要

The use of the Blown Venturi flowmeter has been investigated for use in petroleum and nuclear industrial applications. It is based on the Coanda switched venturi device, which is a no moving part fluidic device. This novel device produces self-induced oscillations in the fluid whose pulse frequency is proportional to the flowrate. These pressure waves are transmitted via the flowing fluid and can be detected far downstream of the device. Experimental work has been conducted to ascertain how much pressure waves are attenuated of in air flow in a pipeline. This was done by using a 28.5 m long, 0.05 m diameter pipe installed downstream of the flowmeter. Predictions of pressure pulse strength, pressure loss and frequency for the flowmeter, scaled for a real oil production string, have been produced. These showed the viability of the remote flowmetering concept. Flow rates and pressure pulse amplitude both at end of the pipe were measured, and this allowed the calculation of attenuation rates to take place. Potential applications of this meter to nuclear fuel reprocessing and other hostile environments have also been demonstrated. Finally, the accuracy and limitations of the flowmeter are considered for some engineering applications.