2017 CEDA Dredging Days: Sustainable Dredging

Velocity Profiling in Hydrotransport

Date of Conference: 
November 8, 2017
A.M. van der Spek, M. Fernald and T. Bailey
Abstract / Introduction: 

An algorithm for the calculation of the rate of flow from a five sensor velocity profiler was developed. The algorithm produces flow rate values that are to within a few percent of available reference flow rate values for polydisperse sand up to the point where a stationary sand bed is laid down. An operational definition of sanding slurry flows is formulated. Based on this definition a metric, a ζ value, is developed as the ratio of the absolute value of the velocity gradient (shear rate) near the bottom of the pipe to the absolute value of the velocity gradient (shear rate) near the top of the pipe. This ζ value appears to be a useful early warning quantity in polydisperse sand slurry flow but completely fails to indicate sanding behavior in monodisperse sand slurry flow. Field experience of the five sensor array velocity profiler in a big bore hydro-transport line is presented showing the behavior of the meter under conditions representative of the flow of sand and water mixtures in practical conditions.

Reference number: 
Asset type: 
Technical Paper