Numerical Study on Turbulent Dispersion of Weakly Inertial Particles under Large Temperature Differences

We study the turbulent dispersion of weakly inertial particles under large temperature differences between the particle cloud and the ambient air. The fast Eulerian method is used to describe the turbulent dispersion of inertial particles at very small Stokes numbers, the low Mach number variable density fluid model is used to simulate the large temperature differences without using the Boussinesq approximation. We simulate the dispersion process of particles under different Reynolds numbers Re, Grashof numbers Gr and Stokes numbers St respectively. The results show that the temperature gradient plays a major role in both horizontal and normal dispersions. The dispersion rate and the rising velocity of the particle cloud are faster for larger Grashof numbers. The incoming flow velocity affects the rates of particle dispersion by changing the temperature distribution. The normal and spanwise dispersion rates are slower, and the streamwise dispersion rate and the streamwise velocity of the particle cloud are faster for larger Reynolds numbers. In the final settling period, the settling velocity of the particle cloud is faster for larger Stokes numbers. Our work is expected to be applied to the dispersion of environmental pollutants and smoke screen under large temperature differences.