Numerical Simulation Of Wind-Blown Sand Movements Based On Eulerian Model

Wind-blown sand flow is a typical air-solid two-phase flow. How to represent the interaction effect from solid particles or air-solid two phases appropriately, as has become one of key problems in relevant research. With the fast development of computer technique and numerical simulation, computational fluid dynamics method is broadly used in study of windblown sand flow. So far, most research on the structure of wind-blown sand applies Euler-Lagrange method to calculate and simulate. However, this method is restricted by the computer running speed, so it can only calculate numbered particles, which means there is a certain distance to achieve the aim of engineering use. Therefore, In order to study the complicated wind-blown sand in real world and to provide some analysis and numerical reference for experiment research, this thesis used Euler couple fluid model to simulate the development of wind-blown sand and the elements influencing it under different conditions, by FLUENT. The content include:First of all, basing on Euler model, we developed the two phases fundamental equations of wind-blown sand, in which we applied standard k-εturbulence model to compute air phase turbulence movement.Then, in given computational domain and boundary condition, under various friction velocity and different grain diameter sizes, we simulated change of the wind-blown sand field along time advancing, also, we offered the time to achieve steady state for wind-blown sand movement and the volume distribution of sand phase at chosen space point. It turns out different wind speeds and diameter sizes directly influence the volume distribution of sand phase, as is in good agreement with the repot data in literature, so it certifies that this method is beneficial to the further study of wind-blown sand motion.At last, this paper simulates sand erosion-deposit budget of two dimensional over different sand beds. The velocity distribution of air and volume fraction distribution of sand grain were obtained for various sand supplies and different surface roughness. The simulating results disclosed the sand volume fraction distribution law in changing wind velocity and sand bedforms, and can provide groundwork for further theoretical study and desertification control.