Investigation of velocity profile in rock–ice avalanche by particle image velocimetry measurement

Understanding the velocity profile of geophysical flows is essential for analyzing their dynamical characteristics. However, existing studies have predominantly concentrated on the velocity profile of debris flows and rock avalanches, neglecting the investigation of rock–ice avalanches. Thus, this work investigates the velocity profile of rock–ice avalanches in the vertically rotating drum using particle image velocimetry. In this work, findings indicate that higher ice content leads to a shift from shear flow to sliding, thereby improving the overall mobility of the avalanche. As the particle size increases, there is a transition in flow patterns from parallel to chaotic, leading to heightened turbulence and collision interactions. The rotational speed of the drum affects the overall movement speed but does not significantly affect the internal shear behavior. These findings offer theoretical and experimental insights into the dynamics of rock–ice avalanches, enhancing our comprehension of multiphase flows and their characteristics.