Evolution of two-phase structures during the entire sandstorm process

The evolution of two-phase structures, turbulence/dust concentration structures, during an entire sandstorm process, including non-stationary flow, has been originally investigated in this study. Dust concentration structures are observed at different sandstorm stages, which are similar to the turbulence structures. These two-phase structures adhere to self-similarity in the steady stage but fail in the non-stationary stage. However, dust particle exhibits a better capability to follow eddies in flow, but the evolution of dust structures is not analogous to that of turbulence structures, exhibiting distinct trends. Dust particles, initiated from the ground, gradually form cluster structures in the rising stage. Their morphology exhibits a ridge-like evolutionary trend, reaching a peak in the steady stage. In contrast, turbulence structures are most persistent and oblique in the early stage but sequentially diminish in the subsequent steady and declining stages. The significant changes in shear due to sharply varying wind velocity and thermal stability are primarily responsible for these evolution differences.