The oil flow contains $10\%$ solid particles, each being perfect spheres with an average diameter of $12mm$ and a density of $2\mathrm{.}65\frac{g}{c}{m}^3.$ This mixture is flowing horizontally through a pipe with a diameter of $80cm.$ The solid particles move along the pipe's center at an average speed of $k\frac{m}{h}.$

Consider the particles have reached their terminal velocity at the moment the flow ceases and it starts falling due to gravity and only experience horizontal movement due to inertia, analyze which movement will cease first. Consider the particle Reynolds number of horizontal movement ceases when its particle Reynolds numbers reduces to $1\%$ of its initial value.

Use Richardson & Zaki correlation to evaluate the effect of particle concentration. The oil flow has below properties:

Oil viscosity

$8\mathrm{.}26{10}^{-3}$ Pas

Oil density

:$800\mathrm{.}92k\frac{g}{m^3}$