Statistical particle stress in aeolian sand movement-derivation and validation

The statistical particle stress (SPS) is a result of group particle movement, which is not referred directly from E-L (Euler-Lagrange) calculations. This paper derives SPS in Eulerian regime and proves that in aeolian sand movement, as the height increases the gas stress also increases while the SPS decreases; however, the sum of gas stress and SPS keeps to be a constant value, which equals to the gas stress in particle absent region. This paper also suggests that SPS predominates in the momentum transportation of particle phase.