Flow monitoring of particle-laden flows combining ultrasonic doppler and echo intensity profiling techniques

The methodology to reveal inner structures of turbidity currents are required. Their behaviors have important roles to affect the sedimentation or transportation of fine particles. We have proposed a novel monitoring methodology for flows containing fine particles, combing Doppler velocity and echo information obtained from ultrasonic velocity profiler (UVP). In this study, we captured the relationship between the echo profiles and particle number distributions. To simplify turbidity currents, stirring flows in a cylindrical container were chosen. As suspended particles, quartz particles with 13.5 um in the central diameter was examined. In a certain range of quartz volume fraction a, UVP can detect integral echo signals obeying Rayleigh scattering and Doppler-shift frequencies, although the quartz diameter is much smaller than ordinary tracer particles adopted for UVP. The echo distribution of 1% showed that the stirring flow causes the local particle number distributions. Moreover, the possibility to reconstruct particle number distributions from echo amplitude distributions was indicated.