Turbulent structure in solid-liquid flow and the simulation model on particle motion in this flow

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Penetration depth on an ejection, which played an important role in the formation of concentration profile and generation of turbulent energy, was studied by means of a probability density distribution. The depth in a two phase flow was smaller than a single phase flow, the depth of a solid particle at the ejection was much smaller than that. These difference was supposed to be caused by the relaxation process of a solid particleand its reaction on the flow. This conjecture was made clear by the analysis of a particle motion in the flow. We had an exact solution on the integro-differential equation of motion of a neutrally buoyant particle, involved Stokes resistance and Basset term. This solution behaved <t^(-1/2)> in assymptotic expansion, in contrast to the exponential behavior in the case of Stokes resistance only.The probability density distribution of vertical velocities at ejection had two peaks near the wall. This results showed the possibility of the existence of different mechanism on the generation of ejection.The simple simulation model on the concentration profilewas constructed in the separation of ejection process from turbulent diffusion. The ejection process was treated as a periodically convective term in the diffusion equation. the results of this model were fairly in the agreement with the results of experiment, especially near the wall.