Calculating the explicit probability of entrainment based on inertial acceleration measurements

A new method for the approximation of the explicit probability of entrainment for individual coarse particles is presented. The method is based on the derivation of inertial acceleration measurements, space-state approximation of the dynamics close to entrainment, and the probabilistic approximation of the threshold inertial acceleration that causes incipient motion. Results from flume experiments with a custom-made inertial measurement unit enclosed in an idealized spherical enclosure, under varied flow conditions (achieved through slope change) and two different arrangements (saddle and grain-top positions) are presented to demonstrate the application of the method. The analysis supports the modification of the existing flow velocity-based entrainment criteria so they respect the particle-frame realization of forces during incipient motion.