Dispersion in pipe flow

For theoretical treatment of the results of the spatial droplet distribution in the gravitational field, details over the eddy diffusivity were still required in addition to the droplet size distribution. The eddy diffusivity is approximately equal to the eddy diffusivity in the bulk of the continuous phase, if the density ratio is about one. 

If the viscosity of droplets is ignored, the maximum droplet size is given by the Weber number  

According to Hinze and Kolmogorov, the following expression applies in the homogeneous and isotropic turbulence field  

The experimental data, which were obtained for flow velocities of continuous phases of v = 0.4 to 6 m/s, have been evaluated according to expression (8.27). An excellent agreement was found between the measured maximum droplet size and the calculated one, independently of whether a straight pipe or a helical coil was used. 

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