Assessing sediment transport dynamics from energy perspective by using the instrumented particle

Abstract

Sediment transport has been extensively studied. There is still a need to learn more about the mechanisms that make bed particles move, which is caused by turbulent flow in the low transport stages (above the motion threshold and below continuous transport). This work is focused on the use of an advanced tool to obtain a better perception of sediment transport dynamical methods: an instrumented particle equipped with a micro-electromechanical systems (MEMS) sensor. Particle transport experiments were carried out in a laboratory flume under a variety of well-controlled above-the-threshold-of-motion flow conditions. By using sensor data, the kinetic energies were calculated with different flow rates and particle densities (mimicking different types of sediments sizes) to generate the probability distribution functions (PDFs) of particle transport features, like the total kinetic energy of particles, which provided information about particle interaction with the bed surface during its motion. The energy transfer efficiency was also studied, which can link the rate of energy transferred from the flow to the particle transport, so it can determine how efficiently a flow can transfer energy to the particle and how it affects the magnitude of sediment transport. In general, the instrumented particle response by a series of experiments showed consistent and satisfactory results and demonstrated its capability to record inertial dynamics because of flow turbulence at low cost. These experiments used different particle sizes and densities than those found in real-world sediments because of sensor size and lab limitations. They do, however, provide a framework and trends that others can use to do more research into bed load transport rates in built canals and natural rivers.