ABSTRACT
The application of custom-made instrumented particles, equipped with high precision and temporal resolution micro-electromechanical sensors, is demonstrated here for obtaining a better understanding of sediment transport dynamical processes, for low mobility flow conditions. Experiments in a laboratory flume at well-controlled and a range of above threshold flow conditions, are conducted using distinct combinations of 2-bed surface roughnesses, 5 target mean flow rates and 4 densities for the instrumented particle. Results from these experiments can be used to offer information about the effect of changing flow rates and particle densities on its transport dynamics e.g. assessed using indicators such as the number of particle hops per second (as derived from processing raw recordings of the sensor data). Specific focus is given here to the analysis of the data in the frequency domain, to derive the average number of particle hops per second. It is found that the particle hop frequency decreases with lower particle density, while it increases with lower mean flow rate. The frequency analysis helps identifying the dominant (most frequently occurring) frequencies of inter-particle collisions, which are found to decrease with lower particle density, while they increase with lower flow rate.
