Velocity and Position Measurement of Oil Droplets Based on Frequency Modulated Ultrasonic Doppler and Pulse Compression

Oil-water two-phase flow existing in many industries has complex flow characteristics. The accumulation of oil droplets may cause blockage or even damage of the equipment, which affects the quality and safety of the production process. Therefore, the accurate measurement of oil droplets' velocity and position in oil-water two-phase flow plays an important role. A method for measuring the velocity and position of oil droplets in oil-water two-phase flow by frequency-modulated ultrasonic Doppler (FMUD) is proposed. To solve the problem of signal superposition caused by multiple oil droplets, the time delay of oil droplets at different positions are obtained by pulse compression method. The two-dimensional fast Fourier transform (2-D FFT) is used to demodulate the velocity and position information at the same time. The accurate identification of different oil droplets' velocity and position are realized. The experiment platform was built for multiple oil droplets rising in water. The experimental results show that the pulse compression method FMUD with pulse compression method can effectively distinguish oil droplets and measure the velocity and position of multiple oil droplets.